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1.  Cardiac MRI evaluation of hypertrophic cardiomyopathy: Left ventricular outflow tract/aortic valve diameter ratio predicts severity of LVOT obstruction 
To evaluate if left ventricular outflow tract /aortic valve (LVOT/AO) diameter ratio measured by cardiac magnetic resonance (CMR) imaging is an accurate marker for LVOT obstruction in patients with hypertrophic cardiomyopathy (HCM) compared to Doppler echocardiography.
92 patients with hypertrophic cardiomyopathy were divided into 3 groups based on their resting echocardiographic LVOT pressure gradient (PG): <30mmHg at rest (non-obstructive, n=31), <30 mmHg at rest, >30mmHg after provocation (latent, n=29) and >30mmHg at rest (obstructive, n=32).The end-systolic dimension of the LVOT on 3-chamber steady state free precession (SSFP) CMR was divided by the end diastolic aortic valve diameter to calculate the LVOT/AO diameter ratio.
There were significant differences in the LVOT/AO diameter ratio among the 3 subgroups (non-obstructive 0.60±0.13, latent 0.41±0.16, obstructive 0.24±0.09, p<0.001). There was a strong linear inverse correlation between the LVOT/AO diameter ratio and the log of the LVOT pressure gradient (r=−0.84, p<0.001). For detection of a resting gradient >30mmHg, the LVOT/AO diameter ratio the area under the ROC curve was 0.91 (95% CI 0.85-0.97). For detection of a resting and/or provoked gradient >30mmHg, the LVOT/AO diameter ratio area under the ROC curve was 0.90 (95% CI 0.84-0.96).
The LVOT/AO diameter ratio is an accurate, reproducible, noninvasive and easy to use CMR marker to assess LVOT pressure gradients in patients with HCM.
PMCID: PMC3411926  PMID: 22549972
hypertrophic cardiomyopathy; left ventricular outflow tract; MRI
2.  Molecular Cloning and Characterization of cDNA Encoding a Putative Stress-Induced Heat-Shock Protein from Camelus dromedarius 
Heat shock proteins are ubiquitous, induced under a number of environmental and metabolic stresses, with highly conserved DNA sequences among mammalian species. Camelus dromedaries (the Arabian camel) domesticated under semi-desert environments, is well adapted to tolerate and survive against severe drought and high temperatures for extended periods. This is the first report of molecular cloning and characterization of full length cDNA of encoding a putative stress-induced heat shock HSPA6 protein (also called HSP70B′) from Arabian camel. A full-length cDNA (2417 bp) was obtained by rapid amplification of cDNA ends (RACE) and cloned in pET-b expression vector. The sequence analysis of HSPA6 gene showed 1932 bp-long open reading frame encoding 643 amino acids. The complete cDNA sequence of the Arabian camel HSPA6 gene was submitted to NCBI GeneBank (accession number HQ214118.1). The BLAST analysis indicated that C. dromedaries HSPA6 gene nucleotides shared high similarity (77–91%) with heat shock gene nucleotide of other mammals. The deduced 643 amino acid sequences (accession number ADO12067.1) showed that the predicted protein has an estimated molecular weight of 70.5 kDa with a predicted isoelectric point (pI) of 6.0. The comparative analyses of camel HSPA6 protein sequences with other mammalian heat shock proteins (HSPs) showed high identity (80–94%). Predicted camel HSPA6 protein structure using Protein 3D structural analysis high similarities with human and mouse HSPs. Taken together, this study indicates that the cDNA sequences of HSPA6 gene and its amino acid and protein structure from the Arabian camel are highly conserved and have similarities with other mammalian species.
PMCID: PMC3155347  PMID: 21845074
Arabian camel; molecular cloning; HSPA6; sequence characterization; cDNA cloning; 3D structure; alignment; RACE; real-time PCR
3.  FAST (Four chamber view And Swing Technique) Echo: a Novel and Simple Algorithm to Visualize Standard Fetal Echocardiographic Planes 
To describe a novel and simple algorithm (FAST Echo: Four chamber view And Swing Technique) to visualize standard diagnostic planes of fetal echocardiography from dataset volumes obtained with spatiotemporal image correlation (STIC) and applying a new display technology (OmniView).
We developed an algorithm to image standard fetal echocardiographic planes by drawing four dissecting lines through the longitudinal view of the ductal arch contained in a STIC volume dataset. Three of the lines are locked to provide simultaneous visualization of targeted planes, and the fourth line (unlocked) “swings” through the ductal arch image (“swing technique”), providing an infinite number of cardiac planes in sequence. Each line generated the following plane(s): 1) Line 1: three-vessels and trachea view; 2) Line 2: five-chamber view and long axis view of the aorta (obtained by rotation of the five-chamber view on the y-axis); 3) Line 3: four-chamber view; and 4) “Swing” line: three-vessels and trachea view, five-chamber view and/or long axis view of the aorta, four-chamber view, and stomach. The algorithm was then tested in 50 normal hearts (15.3 – 40 weeks of gestation) and visualization rates for cardiac diagnostic planes were calculated. To determine if the algorithm could identify planes that departed from the normal images, we tested the algorithm in 5 cases with proven congenital heart defects.
In normal cases, the FAST Echo algorithm (3 locked lines and rotation of the five-chamber view on the y-axis) was able to generate the intended planes (longitudinal view of the ductal arch, pulmonary artery, three-vessels and trachea view, five-chamber view, long axis view of the aorta, four-chamber view): 1) individually in 100% of cases [except for the three-vessel and trachea view, which was seen in 98% (49/50)]; and 2) simultaneously in 98% (49/50). The “swing technique” was able to generate the three-vessels and trachea view, five-chamber view and/or long axis view of the aorta, four-chamber view, and stomach in 100% of normal cases. In the abnormal cases, the FAST Echo algorithm demonstrated the cardiac defects and displayed views that deviated from what was expected from the examination of normal hearts. The “swing technique” was useful in demonstrating the specific diagnosis due to visualization of an infinite number of cardiac planes in sequence.
This novel and simple algorithm can be used to visualize standard fetal echocardiographic planes in normal fetal hearts. The FAST Echo algorithm may simplify examination of the fetal heart and could reduce operator dependency. Using this algorithm, the inability to obtain expected views or the appearance of abnormal views in the generated planes should raise the index of suspicion for congenital heart disease.
PMCID: PMC3037435  PMID: 20878671
STIC; prenatal diagnosis; congenital heart disease; ultrasound; four-dimensional; fetal heart
4.  Ultrasonography of the liver and kidneys of healthy camels (Camelus dromedarius) 
The Canadian Veterinary Journal  2012;53(12):1273-1278.
This study describes the ultrasonography of the liver and kidneys of healthy camels (Camelus dromedarius). Images of the liver were obtained from the 11th to 5th intercostal spaces (ICSs). The distance between the dorsal liver margin and the midline of the back was shortest (39.1 ± 7.4 cm) at the 11th ICS and increased cranially to 5th ICS. The size of the liver was largest at the 9th ICS and smallest at the 5th ICS. In 6 camels the right kidney was visualized from the 10th and 11th ICSs and upper right flank and in the 10th and 11th ICSs in the remaining 16 camels. In all camels, the left kidney was imaged from the caudal left flank. In 21 camels, the differentiation between the renal cortex and medulla was clearly visible in the ultrasonograms. Ultrasonographic description of the liver and kidneys provides a basic reference for diagnosing hepatic and renal disorders in camels.
PMCID: PMC3500117  PMID: 23729824
5.  STAR (Simple Targeted Arterial Rendering) Technique: a Novel and Simple Method to Visualize the Fetal Cardiac Outflow Tracts 
To describe a novel and simple technique (STAR: Simple Targeted Arterial Rendering) to visualize the fetal cardiac outflow tracts from dataset volumes obtained with spatiotemporal image correlation (STIC) and applying a new display technology (OmniView).
We developed a technique to image the outflow tracts by drawing three dissecting lines through the four-chamber view of the heart contained in a STIC volume dataset. Each line generated the following plane: 1) Line 1: ventricular septum “en face” with both great vessels (pulmonary artery anterior to the aorta); 2) Line 2: pulmonary artery with continuation into the longitudinal view of the ductal arch; and 3) Line 3: long axis view of the aorta arising from the left ventricle. The pattern formed by all 3 lines intersecting approximately through the crux of the heart resembles a “star”. The technique was then tested in 50 normal hearts (15.3 – 40.4 weeks of gestation). To determine if the technique could identify planes that departed from the normal images, we tested the technique in 4 cases with proven congenital heart defects (ventricular septal defect, transposition of great vessels, tetralogy of Fallot, and pulmonary atresia with intact ventricular septum).
The STAR technique was able to generate the intended planes in all 50 normal cases. In the abnormal cases, the STAR technique allowed identification of the ventricular septal defect, demonstrated great vessel anomalies, and displayed views that deviated from what was expected from the examination of normal hearts.
This novel and simple technique can be used to visualize the outflow tracts and ventricular septum “en face” in normal fetal hearts. The inability to obtain expected views or the appearance of abnormal views in the generated planes should raise the index of suspicion for congenital heart disease involving the great vessels and/or the ventricular septum. The STAR technique may simplify examination of the fetal heart and could reduce operator dependency.
PMCID: PMC3037449  PMID: 20878672
STIC; aorta; pulmonary artery; prenatal diagnosis; ventricular septum; fetal echocardiography; congenital heart disease; ultrasound
6.  Echocardiographic assessment of pulmonary vascular resistance in pulmonary arterial hypertension 
Echocardiographic ratio of peak tricuspid regurgitant velocity to the right ventricular outflow tract time-velocity integral (TRV/TVI rvot) was presented as a reliable non-invasive method of estimating pulmonary vascular resistance (PVR). Studies using this technique in patients with moderate to high PVR are scarce. Left ventricular outflow tract time-velocity integral (TVI lvot) can be easier to measure than TVI rvot, especially in patients with severe pulmonary hypertension (PH) with significant anatomical modifications of the right structures.
We wanted to determine whether the TRV/TVI rvot and TRV/TVI lvot ratios would form a reliable non-invasive tool to estimate PVR in a cohort of patients with moderate to severe pulmonary vascular disease.
Doppler echocardiographic examination and right heart catheterisation were performed in 37 patients. Invasive PVR was compared with TRV/TVI rvot and TRV/TVI lvot ratios using regression analysis. Two equations were modelled and the results compared with invasive measurements using the Bland-Altman analysis. Using receiver-operating characteristics curve analysis, a cut-off value for the two ratios was generated.
Correlation coefficients between invasive PVR and TRV/TVI rvot then TRV/TVI lvot were respectively 0.76 and 0.74. Two new equations were found but the Bland-Altman analysis showed wide standard deviations (respectively 3.8 and 3.9 Wood units). A TRV/TVI rvot then TRV/TVI lvot ratio cut-off value of 0.14 had a sensitivity of 93% and a specificity of 57% for the first and a sensitivity of 87% and a specificity of 57% for the second to determine PVR > 2 Wood units.
Echocardiography is useful for the screening of patients with pulmonary hypertension and PVR > 2 WU. It remains disappointing for accurate assessment of high PVR. TVI lvot may be an alternative to TVI rvot for patients for whom accurate TVI rvot measurement is not possible.
PMCID: PMC2898679  PMID: 20529278
7.  Assessing aortic valve area in aortic stenosis by continuity equation: a novel approach using real-time three-dimensional echocardiography 
European Heart Journal  2008;29(20):2526-2535.
Two-dimensional echocardiographic (2DE) continuity-equation derived aortic valve area (AVA) in aortic stenosis (AS) relies on non-simultaneous measurement of left ventricular outflow tract (LVOT) velocity and geometric assumptions of LVOT area, which can amplify error, especially in upper septal hypertrophy (USH). We hypothesized that real-time three-dimensional echocardiography (RT3DE) can improve accuracy of AVA by directly measuring LVOT stroke volume (SV) in one window.
Methods and results
RT3DE colour Doppler and 2DE were acquired in 68 AS patients (74 ± 12 yrs) prospectively. SV was derived from flow obtained from a sampling curve placed orthogonal to LVOT (Tomtec Imaging). Agreement between continuity-equation derived AVA by RT3DE (AVA3D-SV) and 2DE (AVA2D) and predictors of discrepancies were analysed. Validation of LVOT SV was performed by aortic flow probe in a sheep model with balloon inflation of septum to mimic USH. There was only modest correlation between AVA2D and AVA3D-SV (r = 0.71, difference 0.11 ± 0.23 cm2). The degree of USH was significantly associated with difference in AVA calculation (r = 0.4, P = 0.005). In experimentally distorted LVOT geometry in sheep, RT3DE correlated better with flow probe assessment (r = 0.96, P < 0.001) than 2DE (r = 0.71, P = 0.006).
RT3DE colour Doppler-derived LVOT SV in the calculation of AVA by continuity equation is more accurate than 2D, including in situations such as USH, common in the elderly, which modify LVOT geometry.
PMCID: PMC2721715  PMID: 18263866
Aortic stenosis; Real-time three-dimensional echocardiography; Colour Doppler; Valvular heart disease; Continuity equation
8.  Assessment of left atrial dimensions by cross sectional echocardiography in patients with mitral valve disease. 
British Heart Journal  1983;50(6):570-578.
Left atrial dimensions were measured using cross sectional echocardiography in 37 patients with mitral valve disease and 30 normal subjects of similar ages. The anteroposterior (AP), superior-inferior (SI), and medial-lateral (ML) left atrial dimensions were determined at the end of ventricular systole using parasternal long and short axis and apical four chamber views (for SIa and MLa). To assess the reliability of these measurements cross sectional echocardiographic and angiographic left atrial volumes were compared in 19 patients with mitral valve disease, giving an excellent correlation. A moderate correlation was found between the anteroposterior dimension of the left atrium obtained using M mode echocardiography and that obtained using the parasternal short axis and long axis projections. In normal subjects a good correlation was found between SI and ML dimensions, while a lower correlation was found between SI and AP, and ML and AP dimensions. The SI dimension was the major axis of the left atrium and AP dimension the minor axis. In patients with mitral valve disease a good correlation was found between SI and ML dimensions, while SI and ML dimensions had a low correlation with AP dimensions. The AP dimension was the minor axis of the left atrium, while the SI and ML dimensions were not significantly different. All left atrial dimensions were significantly greater in patients with mitral valve disease than in normal subjects. Of 30 patients with at least one dimension increased, all three dimensions were abnormal in 16, two dimensions were increased in 10, and only one dimension was increased in four. AP, SI, and ML dimensions were abnormal in 25, 20, and 27 patients, respectively. Cross sectional echocardiography may provide a reliable estimate of left atrial dimensions. In patients with mitral valve disease a thorough examination of the left atrium using multiple cross sectional views is necessary to detect asymmetric left atrial enlargement and to measure the degree of left atrial dilatation.
PMCID: PMC481461  PMID: 6228242
9.  Contrast-enhanced MRI of right ventricular abnormalities in Cx43 mutant mouse embryos† 
NMR in biomedicine  2007;20(3):366-374.
Imaging of the mammalian cardiac right ventricle (RV) is particularly challenging, especially when a two-dimensional method such as conventional histology is used to evaluate the morphology of this asymmetric, crescent-shaped chamber. MRI may improve the characterization of mutants with RV phenotypes by allowing analysis of the samples in any plane and by facilitating three-dimensional image reconstruction. MRI was used to examine the conditional knockout Cx43-PCKO mouse line known to have RV malformations. To help delineate the cardiovascular system and facilitate identification of the right ventricular outflow tract (RVOT), embryonic day (E) 17.5 embryos were perfusion fixed through the umbilical vein followed by a gadolinium-based contrast agent mixed in 7% gelatin. Micro-MRI experiments were performed at 7 T and followed by paraffin embedding of specimens, histological sectioning and hematoxylin and eosin (H&E) staining. Imaging of up to four embryos simultaneously allowed for higher throughput than traditional individual imaging techniques, while intravascular contrast afforded excellent signal-to-noise characteristics. All control embryos (n=4) and heterozygous Cx43 knockout embryos (n=4) had normal-appearing right ventricular outflow tract contours by MRI. Obvious abnormalities in the RVOT, including abnormal bulging and infiltration of contrast into the wall of the RV, were seen in three out of four Cx43-PCKO mutants with MRI. Furthermore, three-dimensional reconstruction of MR images with orthogonal projections as well as maximum-intensity projection allowed for visualization of the relationship of infundibular bulging segments to the pulmonary trunk in Cx43-PCKO mutant hearts. The addition of MRI to standard histology in the characterization of RV malformations in mutant mouse embryos aids in the assessment and understanding of morphologic abnormalities. Flexibility in the viewing of MR images, which can be retrospectively sectioned in any desired orientation, is particularly useful in the investigation of the RV, an asymmetric chamber that is difficult to analyze with two-dimensional techniques.
PMCID: PMC2732351  PMID: 17451172
embryo; transgenic; cardiac; development; phenotype; mouse; micro-MRI; ex vivo
10.  A Novel Algorithm for Comprehensive Fetal Echocardiography using 4D Ultrasound and Tomographic Imaging 
Tomographic ultrasound imaging (TUI) is a new display modality that allows simultaneous visualization of up to eight parallel anatomical planes. This study was designed to determine the role of a novel algorithm combining spatiotemporal image correlation (STIC) and TUI to visualize standard fetal echocardiography planes.
Volume datasets from fetuses with and without congenital heart defects (CHD) were examined with a novel algorithm that allows simultaneous visualization of the three-vessel and trachea view, the four-chamber view, and outflow tracts. Visualization rates for these planes as well as ductal arch and five-chamber view were calculated.
1) 227 volume datasets from fetuses without (n=138) and with (n=14) CHD were reviewed; 2) among normal fetuses, the four-chamber view, five-chamber view, ductal arch, three-vessel and trachea view, left outflow tract and short axis of the aorta were visualized in 99% (193/195), 96.9% (189/195), 98.5 % (192/195), 88.2% (172/195), 93.3% (182/195), and 87.2% (170/195) of the volume datasets, respectively; 3) these views were visualized in 85% (17/20), 80% (16/20), 65% (13/20), 55% (11/20), 55% (11/20), and 70% (14/20) of the volume datasets, respectively, from fetuses with CHD; and 4) simultaneous visualization of the short axis of the aorta, three-vessel and trachea view, left outflow tract and four-chamber view was obtained in 78% (152/195) of the volume datasets from fetuses without CHD and in 40% (8/20) of those with CHD.
The three-vessel and trachea view, the four-chamber view, and both outflow tracts can be simultaneously visualized using a novel algorithm combining STIC and TUI.
PMCID: PMC1800884  PMID: 16870887
Algorithm; 3D; 4D; three-dimensional; four-dimensional; STIC; spatiotemporal; congenital heart disease; spatiotemporal; prenatal diagnosis; fetal echocardiography
11.  DDDR pacing for symptomatic patients with hypertrophic obstructive cardiomyopathy 
Netherlands Heart Journal  2002;10(6):272-276.
Hypertrophic obstructive cardiomyopathy (HOCM) is a primary cardiac disorder with a heterogeneous expression. When medical therapy fails in patients with symptomatic HOCM, three additional therapeutic strategies exist: ventricular septal myectomy, alcohol-induced percutaneous transluminal septal myocardial ablation (PTSMA) of the first septal branch of the anterior descending artery and pacemaker implantation. In this paper we present the results of seven patients in whom a dual-chamber pacemaker was implanted to reduce the gradient in the left ventricular outflow tract (LVOT) and to relieve their symptoms.
In patients with drug refractory symptomatic HOCM, not eligible for surgery, pacemaker therapy was recommended. Symptomatic HOCM was defined as symptoms of angina and dyspnoea, functional class NYHA 3-4 and a resting LVOT gradient during Doppler echocardiography of more than 2.75 m/s (30 mmHg). In these patients, a dual-chamber pacemaker was implanted with a right ventricular lead positioned in the right ventricular apex and an atrial lead positioned in the right atrial appendage. In all patients the AV setting was programmed between 50 and 100 ms, using Doppler echocardiography to determine the optimal filling and to ensure ventricular capture.
A statistically significant reduction of the LVOT gradient was observed in all patients. The pre-implantation gradient in the LVOT measured by Doppler echocardiography varied from 3-5.8 m/s with a mean of 4.7±1.1 m/s. The post-implantation gradient varied from 1.4-2.6 m/s with a mean of 1.9±0.4 m/s (p<0.001). Symptomatic improvement was present in all patients. NYHA functional class went from 3-4 (mean 3.1±0.5) pre-implantation to 1-2 mean (1.3±0.4) after implantation (p<0.001). During a mean follow-up of 2.3±1.1 years, the improvement in functional class was maintained.
Our preliminary results demonstrate that dual-chamber pacing is an effective and safe treatment for symptomatic patients with HOCM.
PMCID: PMC2499779
DDDR pacing; hypertrophic obstructive cardiomyopathy
12.  Electrocardiogram features of premature ventricular contractions/ventricular tachycardia originating from the left ventricular outflow tract and the treatment outcome of radiofrequency catheter ablation 
Radiofrequency catheter ablation (RFCA) has been used for the ablation of premature ventricular contractions (PVCs) or ventricular tachycardia (VT). To date, the mapping and catheter ablation of the arrhythmias originating from the left ventricular outflow tract (LVOT) has not been specified. This study investigates the electrocardiogram (ECG) feature of PVCs or VT originating from the LVOT. Moreover, the treatment outcome of RFCA is analyzed.
Mapping and ablation were performed on the supravalvular or subvalvular aorta in 52 cases with PVCs/VT originating from the LVOT. The data were compared with those from 104 patients with PVCs/VT originating from the right ventricular outflow tract (RVOT). A differential procedure was prepared based on the comparison of the ECG features of PVCs/VT originating from the RVOT, LVOT, and their different parts.
Among 52 cases with PVCs originating from the LVOT, 47 were successfully treated by RFCA, with a success rate of 90.38%. Several differences among the 12-lead ECG features were observed from the RVOT and LVOT in the left and right coronary sinus groups, as well as under the left coronary sinus group (left fibrous trigone): (1) If the precordial leads transition 0 are considered as the diagnostic parameters of PVCs/VT originating from the LVOT, then the sensitivity, specificity, as well as positive and negative predictive values are 94.12%, 93.00%, 87.27%, and 96.88%, respectively; (2) The analysis of different subgroups of the LVOT are as follows: (a) A mainly positive wave of r or m pattern was recorded in the lead I in 72.73% of patients in the right coronary sinus group, versus 12.90% of patients in the left coronary sinus group, and 0% in the under left coronary sinus group. (b) All patients in the right coronary sinus group presented waves of RII>RIII and QSaVR>QSaVL, whereas most patients in the other two groups showed waves of RIII>RII and QSaVL>QSaVR. (c) Most patients in the under left coronary sinus group in lead V1 had a mainly positive wave (R) (77.78%), whereas those in the right (81.82%) and left (62.50%) coronary sinus groups had mainly negative waves (rS).
RFCA is a safe and effective curative therapy for PVCs/VT originating from the LVOT. The 12-lead ECG features of the LVOT from different origins exhibit certain distinctions.
PMCID: PMC3571934  PMID: 23186541
Electrophysiology; Ventricular arrhythmia; Left ventricular outflow; Catheter ablation; Radiofrequency current
13.  Initial Experience of a Cohort of Patients With Hypertrophic Cardiomyopathy Undergoing Biventricular Pacing 
Dual chamber pacing improves functional status and reduces left ventricular outflow tract gradients in some, but not all patients with hypertrophic cardiomyopathy (HCM) by altering ventricular depolarisation. We investigated the use of biventricular (BIV) pacing in symptomatic patients with HCM.
8 patients aged 58±7yrs with symptomatic HCM underwent BIV pacing. 5 patients had LVOT gradients >30mmHg. Ventricular electrodes were placed in the right ventricle (RV) and a branch of the coronary sinus. An atrial electrode was inserted to achieve BIV pacing with a short AV delay. The short-term effects of different pacing modalities were assessed using 2-D and Doppler echocardiography. Symptoms and exercise tolerance were assessed after a month of each pacing mode. Long-term follow up data was available for 5 years.
Baseline EF was 67±14% and mean QRS duration was 132±26msecs. BIV pacing reduced QRS duration compared to RV pacing (129±46 vs. 205±54msecs, p<0.005). Five of the seven patients had baseline LVOT gradients (mean 67±25mmHg) that decreased to 41±15mm Hg with RV pacing (p<0.01) and 25±15mmHg with BIV pacing (p<0.005). Improvements in exercise time with active pacing occurred in six out of eight patients (75%), three (37.5%) had optimal exercise times with RV pacing and three with BIV pacing. Of the three patients with short term improvements with BIV pacing, one died 4 years post implant, one deteriorated with LV dilatation and one had the system explanted for infection.
BIV pacing showed short-term beneficial effects in some patients over and above RV pacing alone.
PMCID: PMC3065748  PMID: 21468273
pacemakers; hypertrophic cardiomyopathy; conduction; biventricular
14.  Reduced fractional shortening of right ventricular outflow tract is associated with adverse outcomes in patients with left ventricular dysfunction 
Recent studies suggest the significance of right ventricular (RV) function in the outcome in patients with left ventricular dysfunction (LVSD); however, global assessment of RV remains to be determined by echocardiogram because of its complex geometry. This study aimed to validate RV outflow tract fractional shortening (RVOT-FS) in the evaluation of RV function and its prognostic value in patients with LVSD.
This study included eighty-one patients (62 ± 17 years, mean ± SD, male 79%) with reduced LV ejection fraction (LVEF) (≤40%). Two-dimensional echocardiogram of the parasternal short axis view was obtained at the level of the aortic root, and RVOT-FS was calculated as the ratio of end-diastole minus end-systole dimension to end-diastole dimension.
RVOT-FS ranged from 0.04 to 0.8 (0.3 ± 0.2, mean ± SD), and correlated with LVEF (r = 0.33, p = 0.0028), RV fractional area change (r = 0.37, p = 0.0008) and brain natriuretic peptide level (r = -0.38, p = 0.0005). In Cox multivariate regression analysis, RVOT-FS [hazard ratio (HR) 0.028, 95% confidence interval (CI): 0.002-0.397]; p = 0.008] and New York Heart Association functional class III-IV [HR 2.233, 95% CI: 1.048-4.761]; p = 0.037] were independent factors to predict the events. During a median follow-up period of 319 days (1 to 1862 days), patients with RVOT-FS ≥ 0.2 showed a higher event-free rate than those < 0.2 by Kaplan-Meier analysis (log-rank test, p = 0.0016).
Our data suggest that RVOT-FS is a simple parameter reflecting the severity of both ventricular function in patients with LVSD. In addition, RVOT-FS might be useful to predict adverse outcomes in such a patient population.
PMCID: PMC3681625  PMID: 23731725
Heart failure; Right ventricle; Brain natriuretic peptide
15.  In Vivo Measurement of Mitral Leaflet Surface Area and Subvalvular Geometry in Patients With Asymmetrical Septal Hypertrophy 
Circulation  2010;122(13):1298-1307.
Analyzing the determinants of systolic anterior motion of the mitral valve and consequent left ventricular outflow tract (LVOT) obstruction in patients with asymmetrical septal hypertrophy requires a comprehensive 3-dimensional analysis of mitral leaflet (ML) area, papillary muscle (PM) geometry, and the distribution of left ventricular hypertrophy.
Methods and Results
Real-time 3-dimensional echocardiography was performed in 47 patients with asymmetrical septal hypertrophy and 32 normal controls. Patients included 20 with resting LVOT obstruction (group I) and 27 without (group II). Customized software (Omni 4D) provided a validated measure of ML surface area, LVOT area, mitral annular area and nonplanarity, LVOT hypertrophy index by topography (percent area with wall thickness >16 mm), and 3-dimensional PM positions relative to annulus. ML area was more than twice as large in group I than normal and 1.4 times normal in group II (P<0.001). Group I patients were also characterized by higher LVOT hypertrophy index and medial and anterior displacements of both PMs, resulting in a shorter inter-PM distance. Independent determinants of LVOT obstruction were indexed total ML area (adjusted odds ratio, 5.651; 95% confidence interval, 1.573 to 20.304; P=0.008) and inter-PM distance (adjusted odds ratio, 0.416; 95% confidence interval, 0.203 to 0.854; P=0.0169). Minimal LVOT area during systole correlated well with peak LVOT pressure gradient (R2=0.83, P<0.001); its independent determinants were left ventricular end-systolic volume (P=0.0183), indexed total ML area (P=0.0108), inter-PM distance (P=0.0378), annular height (P=0.0047), and LVOT hypertrophy index (P=0.0098).
Myocardium is not the only tissue affected in patients with asymmetrical septal hypertrophy, and primary changes of the mitral apparatus, including ML area increase and PM displacement, are independent determinants of LVOT obstruction and provide a comprehensive mechanism that determines leaflet slack and anteriorly directed motion. Abnormal PM–mitral valve geometry assessed by real-time 3-dimensional echocardiography can provide reasonable new targets for individualized intervention.
PMCID: PMC3027224  PMID: 20837895
echocardiography; cardiomyopathy, hypertrophic; left ventricle; mitral valve
16.  Right atrial area and right ventricular outflow tract akinetic length predict sustained tachyarrhythmia in repaired tetralogy of Fallot 
International Journal of Cardiology  2013;168(4):3280-3286.
Repaired tetralogy of Fallot (rtoF) patients are at risk of atrial or ventricular tachyarrhythmia and sudden cardiac death. Risk stratification for arrhythmia remains difficult.
We investigated whether cardiac anatomy and function predict arrhythmia.
One-hundred-and-fifty-four adults with rtoF, median age 30.8 (21.9–40.2) years, were studied with a standardised protocol including cardiovascular magnetic resonance (CMR) and prospectively followed up over median 5.6 (4.6–7.0) years for the pre-specified endpoints of new-onset atrial or ventricular tachyarrhythmia (sustained ventricular tachycardia/ventricular fibrillation).
Atrial tachyarrhythmia (n = 11) was predicted by maximal right atrial area indexed to body surface area (RAAi) on four-chamber cine-CMR (Hazard ratio 1.17, 95% Confidence Interval 1.07–1.28 per cm2/m2; p = 0.0005, survival receiver operating curve; ROC analysis, area under curve; AUC 0.74 [0.66–0.81]; cut-off value 16 cm2/m2). Atrial arrhythmia-free survival was reduced in patients with RAAi ≥ 16 cm2/m2 (logrank p = 0.0001). Right ventricular (RV) restrictive physiology on echocardiography (n = 38) related to higher RAAi (p = 0.02) and had similar RV dilatation compared with remaining patients.
Ventricular arrhythmia (n = 9) was predicted by CMR RV outflow tract (RVOT) akinetic area length (Hazard ratio 1.05, 95% Confidence Interval 1.01–1.09 per mm; p = 0.003, survival ROC analysis, AUC 0.77 [0.83–0.61]; cut-off value 30 mm) and decreased RV ejection fraction (Hazard ratio 0.93, 95% Confidence Interval 0.87–0.99 per %; p = 0.03). Ventricular arrhythmia-free survival was reduced in patients with RVOT akinetic region length > 30 mm (logrank p = 0.02).
RAAi predicts atrial arrhythmia and RVOT akinetic region length predicts ventricular arrhythmia in late follow-up of rtoF. These are simple, feasible measurements for inclusion in serial surveillance and risk stratification of rtoF patients.
PMCID: PMC3819622  PMID: 23643427
Tetralogy of Fallot; Tachyarrhythmias; Congenital heart defects; Cardiovascular magnetic resonance imaging
17.  Functional Organization of hsp70 Cluster in Camel (Camelus dromedarius) and Other Mammals 
PLoS ONE  2011;6(11):e27205.
Heat shock protein 70 (Hsp70) is a molecular chaperone providing tolerance to heat and other challenges at the cellular and organismal levels. We sequenced a genomic cluster containing three hsp70 family genes linked with major histocompatibility complex (MHC) class III region from an extremely heat tolerant animal, camel (Camelus dromedarius). Two hsp70 family genes comprising the cluster contain heat shock elements (HSEs), while the third gene lacks HSEs and should not be induced by heat shock. Comparison of the camel hsp70 cluster with the corresponding regions from several mammalian species revealed similar organization of genes forming the cluster. Specifically, the two heat inducible hsp70 genes are arranged in tandem, while the third constitutively expressed hsp70 family member is present in inverted orientation. Comparison of regulatory regions of hsp70 genes from camel and other mammals demonstrates that transcription factor matches with highest significance are located in the highly conserved 250-bp upstream region and correspond to HSEs followed by NF-Y and Sp1 binding sites. The high degree of sequence conservation leaves little room for putative camel-specific regulatory elements. Surprisingly, RT-PCR and 5′/3′-RACE analysis demonstrated that all three hsp70 genes are expressed in camel's muscle and blood cells not only after heat shock, but under normal physiological conditions as well, and may account for tolerance of camel cells to extreme environmental conditions. A high degree of evolutionary conservation observed for the hsp70 cluster always linked with MHC locus in mammals suggests an important role of such organization for coordinated functioning of these vital genes.
PMCID: PMC3212538  PMID: 22096537
18.  Systolic Anterior Motion of the Mitral Valve after Mitral Valve Repair 
Texas Heart Institute Journal  2005;32(1):47-49.
Factors predisposing patients to systolic anterior motion of the mitral valve (SAM) with left ventricular outflow tract (LVOT) obstruction after mitral valve repair are the presence of a myxomatous mitral valve with redundant leaflets, a nondilated hyperdynamic left ventricle, and a short distance between the mitral valve coaptation point and the ventricular septum after repair.
From December 1999 through March 2000, we used our surgical method in 6 patients with severely myxomatous regurgitant mitral valves who were at risk of developing SAM. Leaflets were markedly redundant in all 6. Left ventricular function was hyperdynamic in 4 patients and normal in 2. Triangular or quadrangular resection of the midportion of the posterior leaflet and posterior band annuloplasty were performed. To prevent SAM and LVOT obstruction, extra, posteriorly directed, mid-posterior-leaflet secondary chordae tendineae, which would otherwise have been resected, were transferred to the underside of the middle of the mid-anterior leaflet with a small piece of associated valve as an anchoring pledget. This kept the redundant anterior leaflet edge, which extended below the coaptation point, away from the LVOT.
No post-repair SAM or LVOT obstruction was observed on intraoperative or discharge echocardiography. All patients had no or trivial residual mitral regurgitation.
We conclude that extra chordae tendineae, when available, can be used in mitral valve repair to tether the redundant anterior leaflet and thus prevent it from flipping into the LVOT. This will theoretically prevent SAM and LVOT obstruction in patients with risk factors for SAM.
PMCID: PMC555821  PMID: 15902821
Cardiac surgical procedures/adverse effects; chordal transposition; mitral valve/surgery; postoperative complications/prevention & control; systole/physiology; ventricular outflow obstruction/etiology/prevention & control
19.  Confocal fluorescence assessment of bioenergy/redox status of dromedary camel (Camelus dromedarius) oocytes before and after in vitro maturation 
Reproductive biotechnologies in dromedary camel (Camelus dromedarius) are less developed than in other livestock species. The in vitro maturation (IVM) technology is a fundamental step for in vitro embryo production (IVP), and its optimization could represent a way to increase the success rate of IVP. The aim of the present study was to investigate the bioenergy/oxidative status of dromedary camel oocytes before and after IVM by confocal microscopy 3D imaging.
Oocytes were retrieved by slicing ovaries collected at local slaughterhouses. Recovered oocytes were examined before and after IVM culture for nuclear chromatin configuration and bioenergy/oxidative status, expressed as mitochondria (mt) distribution and activity, intracellular Reactive Oxygen Species (ROS) levels and distribution and mt/ROS colocalization.
The mean recovery rate was 6 oocytes/ovary. After IVM, 61% of oocytes resumed meiosis and 36% reached the Metaphase II stage (MII). Oocyte bioenergy/redox confocal characterization revealed changes upon meiosis progression. Immature oocytes at the germinal vesicle (GV) stage were characterised by prevailing homogeneous mt distribution in small aggregates while MI and MII oocytes showed significantly higher rates of pericortical mt distribution organized in tubular networks (P < 0.05). Increased mt activity in MI (P < 0.001) and MII (P < 0.01) oocytes compared to GV stage oocytes was also observed. At any meiotic stage, homogeneous distribution of intracellular ROS was observed. Intracellular ROS levels also increased in MI (P < 0.01) and MII (P < 0.05) oocytes compared to GV stage oocytes. The mt/ROS colocalization signal increased in MI oocytes (P < 0.05).
This study provides indications that qualitative and quantitative indicators of bioenergy and oxidative status in dromedary camel oocytes are modified in relation with oocyte meiotic stage. These data may increase the knowledge of camel oocyte physiology, in order to enhance the efficiency of IVP procedures.
PMCID: PMC3931272  PMID: 24548378
Dromedary camel oocyte; in vitro maturation (IVM); Mitochondrial distribution pattern; Mitochondrial activity; Intracellular reactive oxygen species (ROS) levels; Mitochondria/ROS colocalization
20.  Localization of premature ventricular contraction foci in normal individuals based on multichannel electrocardiogram signals processing 
SpringerPlus  2013;2:486.
A premature ventricular contraction (PVC) is relatively a common event where the heartbeat is initiated by the other pathway rather than by the Sinoatrial node, the normal heartbeat initiator. Determining PVC foci is important for ablation procedure and it can help in pre-procedural planning and potentially may improve ablation outcome.
In this study, 12-lead Electrocardiogram (ECG) of 87 patients without structural cardiac diseases, who had experienced PVC, were obtained. Initially, PVC foci were labeled based on Electrophysiology study (EPS) reports. PVC beats were detected by wavelet method and their foci were classified using Mahalanobis distance and One-way ANOVA. Using morphological, frequency and spectrogram features, these foci in the heart were classified into five groups: Left Ventricular Outflow Tract (LVOT), Right Ventricular Outflow Tract (RVOT) septum, basal Right Ventricular (RV), RVOT free-wall, and Aortic Cusp (AC).
The results showed that 88.4% of patients are classified correctly.
PMCID: PMC3790125  PMID: 24098858
Electrocardiogram; Premature ventricular beats; PVC foci (focuses)
21.  Sequencing, Analysis, and Annotation of Expressed Sequence Tags for Camelus dromedarius 
PLoS ONE  2010;5(5):e10720.
Despite its economical, cultural, and biological importance, there has not been a large scale sequencing project to date for Camelus dromedarius. With the goal of sequencing complete DNA of the organism, we first established and sequenced camel EST libraries, generating 70,272 reads. Following trimming, chimera check, repeat masking, cluster and assembly, we obtained 23,602 putative gene sequences, out of which over 4,500 potentially novel or fast evolving gene sequences do not carry any homology to other available genomes. Functional annotation of sequences with similarities in nucleotide and protein databases has been obtained using Gene Ontology classification. Comparison to available full length cDNA sequences and Open Reading Frame (ORF) analysis of camel sequences that exhibit homology to known genes show more than 80% of the contigs with an ORF>300 bp and ∼40% hits extending to the start codons of full length cDNAs suggesting successful characterization of camel genes. Similarity analyses are done separately for different organisms including human, mouse, bovine, and rat. Accompanying web portal, CAGBASE (, hosts a relational database containing annotated EST sequences and analysis tools with possibility to add sequences from public domain. We anticipate our results to provide a home base for genomic studies of camel and other comparative studies enabling a starting point for whole genome sequencing of the organism.
PMCID: PMC2873428  PMID: 20502665
22.  Proteomics of old world camelid (Camelus dromedarius): Better understanding the interplay between homeostasis and desert environment 
Journal of Advanced Research  2013;5(2):219-242.
Life is the interplay between structural–functional integrity of biological systems and the influence of the external environment. To understand this interplay, it is useful to examine an animal model that competes with harsh environment. The dromedary camel is the best model that thrives under severe environment with considerable durability. The current proteomic study on dromedary organs explains a number of cellular mysteries providing functional correlates to arid living. Proteome profiling of camel organs suggests a marked increased expression of various cytoskeleton proteins that promote intracellular trafficking and communication. The comparative overexpression of α-actinin of dromedary heart when compared with rat heart suggests an adaptive peculiarity to sustain hemoconcentration–hemodilution episodes associated with alternative drought-rehydration periods. Moreover, increased expression of the small heat shock protein, α B-crystallin facilitates protein folding and cellular regenerative capacity in dromedary heart. The observed unbalanced expression of different energy related dependent mitochondrial enzymes suggests the possibility of mitochondrial uncoupling in the heart in this species. The evidence of increased expression of H+-ATPase subunit in camel brain guarantees a rapidly usable energy supply. Interestingly, the guanidinoacetate methyltransferase in camel liver has a renovation effect on high energy phosphate with possible concomitant intercession of ion homeostasis. Surprisingly, both hump fat tissue and kidney proteomes share the altered physical distribution of proteins that favor cellular acidosis. Furthermore, the study suggests a vibrant nature for adipose tissue of camel hump by the up-regulation of vimentin in adipocytes, augmenting lipoprotein translocation, blood glucose trapping, and challenging external physical extra-stress. The results obtained provide new evidence of homeostasis in the arid habitat suitable for this mammal.
PMCID: PMC4294715
2D, two-dimensional; MS, mass spectrometry; CHAPS, 3-(3-cholamidopropyl)-dimethylammoniopropane sulfonate; pI, isoelectric point; IPG, immobilized pH gradient; DTT, dithiothreitol; SDS, sodium dodecylsulfate; PAGE, polyacrylamide gel electrophoresis; TFA, trifluoracetic acid; MALDI, matrix assisted laser desorption ionization; CHCA, α-cyano-4-signal-to-noise; ACTH, adrenocorticotropic hormone; PMF, peptide mass finger printing; PDB, protein database; TOF, time of flight; hsp, heat shock protein; MAPK, map kinase; Dvl, dishevelled: scaffold protein involved in the regulation of the Wnt signaling pathway; DAPLE, Dvl-associating protein with a high frequency of leucine residues; Camel; Proteome; Metabolism; Crystallin; Actin; Vimentin
23.  Prevalence of Cryptosporidium-like infection in one-humped camels (Camelus dromedarius) of northwestern Iran 
Cryptosporidium is a ubiquitous enteropathogen protozoan infection affecting livestock worldwide. The present study was carried out to determine the prevalence of Cryptosporidium infection in different age groups of dromedary camels in northwestern Iran from November 2009 to July 2010. A total number of 170 fecal samples were collected and examined using modified Ziehl-Neelsen (MZN) staining under light microscope. Examination of stained fecal smears revealed that 17 camels (10%) were positive for Cryptosporidium-like. The prevalence of Cryptosporidium-like was significantly higher in camel calves (< 1 years old) (20%) than other age groups, in which the diarrhoeic calves had the prevalence of 16%. In adult camels the prevalence was 6.5%. There was no significant difference in the prevalence of Cryptosporidium-like between male and female camels. It is concluded that Cryptosporidium infection is a problem in camel husbandry and could be of public health concern in the region.
PMCID: PMC3671425  PMID: 22314242
Cryptosporidium; protozoan; prevalence; livestock; camel; Iran; Cryptosporidium; protozoaire; prévalence; bétail; dromadaire; Iran
24.  Monophyletic origin of domestic bactrian camel (Camelus bactrianus) and its evolutionary relationship with the extant wild camel (Camelus bactrianus ferus) 
Ji, R | Cui, P | Ding, F | Geng, J | Gao, H | Zhang, H | Yu, J | Hu, S | Meng, H
Animal Genetics  2009;40(4):377-382.
The evolutionary relationship between the domestic bactrian camel and the extant wild two-humped camel and the factual origin of the domestic bactrian camel remain elusive. We determined the sequence of mitochondrial cytb gene from 21 camel samples, including 18 domestic camels (three Camelus bactrianus xinjiang, three Camelus bactrianus sunite, three Camelus bactrianus alashan, three Camelus bactrianus red, three Camelus bactrianus brown and three Camelus bactrianus normal) and three wild camels (Camelus bactrianus ferus). Our phylogenetic analyses revealed that the extant wild two-humped camel may not share a common ancestor with the domestic bactrian camel and they are not the same subspecies at least in their maternal origins. Molecular clock analysis based on complete mitochondrial genome sequences indicated that the sub-speciation of the two lineages had begun in the early Pleistocene, about 0.7 million years ago. According to the archaeological dating of the earliest known two-humped camel domestication (5000–6000 years ago), we could conclude that the extant wild camel is a separate lineage but not the direct progenitor of the domestic bactrian camel. Further phylogenetic analysis suggested that the bactrian camel appeared monophyletic in evolutionary origin and that the domestic bactrian camel could originate from a single wild population. The data presented here show how conservation strategies should be implemented to protect the critically endangered wild camel, as it is the last extant form of the wild tribe Camelina.
PMCID: PMC2721964  PMID: 19292708
bactrian camel; domestication; mitochondrial genome; phylogeny
25.  Right ventricular filling in dilated cardiomyopathy. 
British Heart Journal  1995;74(3):287-292.
PURPOSE--To assess right ventricular filling in dilated cardiomyopathy. PATIENTS--32 patients with dilated cardiomyopathy and 24 healthy controls. METHODS--Stroke distances were measured by pulsed Doppler echocardiography at left ventricular outflow and left and right ventricular inflow. The inflow tract dimensions of both ventricles and the outflow tract dimension of the left ventricle were measured from two dimensional images. Right and left sided atrioventricular (AV) ring excursions were measured by M mode echocardiography at the tricuspid and mitral rings. Stroke volume was derived as stroke distance multiplied by left ventricular outflow tract area. Total stroke distances were calculated as the sum of AV valve Doppler stroke distances and ring excursion. The effective orifice areas of the two AV valves were thus defined as stroke volumes divided by total stroke distance. RESULTS--Total tricuspid stroke distance was normally less than mitral (6.0 (1.7) v 7.6 (1.7) cm, P < 0.05), implying that effective orifice area of the tricuspid valve was consistently greater (6.6 (1.6) v 4.5 (0.8) cm2, P < 0.01). Total tricuspid ring excursion was normally more than mitral (2.30 (0.30) v 1.62 (0.22) cm, P < 0.01). Total tricuspid stroke distance in dilated cardiomyopathy was also less than mitral (7.8 (2.4) v 9.7 (2.8) cm, P < 0.05). Tricuspid stroke distance was significantly increased in patients with dilated cardiomyopathy compared with that in healthy controls (P < 0.05 v controls), though stroke volume was much smaller (26 (10) v 63 (11) ml, P < 0.01) so that tricuspid effective orifice area was reduced to less than half normal (2.7 (1.2) cm2, P < 0.01). Total tricuspid ring long axis excursion was more than mitral (1.37 (0.6) v 0.74 (0.21) cm, P < 0.01). Right ventricular end diastolic inflow dimension was increased compared with that in healthy controls (3.9 (0.7) v 2.8 (0.5) cm, P < 0.01), correlating inversely with tricuspid effective orifice area (r = -0.71, P < 0.01). Total tricuspid ring excursion was bimodally distributed as a low amplitude group (less than 1.6 cm, n = 23) and a high amplitude group (more than 1.6 cm, n = 9), in which the interval P2 to onset of tricuspid flow was much longer (100 (35) v 50 (14) ms, P < 0.01). CONCLUSIONS--Enlargement of the right ventricular inflow tract in dilated cardiomyopathy, especially to more than 5 cm, is accompanied by a progressive decrease in effective tricuspid orifice area, sometimes to less than 1 cm2 and increased inflow velocities. Right ventricular relaxation was incoordinate in 28% of the patients studied. These disturbances of right ventricular filling are likely to compromise overall cardiac function independently of left ventricular disease.
PMCID: PMC484020  PMID: 7547024

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