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1.  A Novel Method of Placing Right Ventricular Leads in Patients With Persistent Left Superior Vena Cava Using a Conventional J Stylet 
Background
Locating pacemaker electrodes can become complicated by congenital abnormalities such as persistent left superior vena cava (LSVC).
Objective
To evaluate a technique for the implanting of ventricular electrode in patients with persistent LSVC.
Materials and Methods
The study was carried out from June 2001 to June 2010 involving all patients who were admitted to the Hospital Universitario Mayor, Instituto de Corazon de Bogota and Hospital Universitario Clinica San Rafael (Bogota-Colombia) for implanting pacemakers or cardiac defibrillators. LSVC was diagnosed by fluoroscopic observation (anterior-posterior view) of the course of the stylet. Four steps were followed: 1) Move the electrode with a straight stylet to the right atrium. 2) Change the straight stylet by a conventional J stylet and push the electrode to the lateral or anterolateral wall of the right atrium. 3) Remove the guide 3-5 cm and 4) Push the electrode which crosses the tricuspid valve into the right ventricle and finally deploy the active fixation mechanism.
Results
A total of 1198 patients were admitted for pacemaker or cardiac defibrillator implant during the 9-year study period, 1114 received a left subclavian venous approach. There were 573 males and 541 females. Persistent LSVC was found in five patients (0.45%) Fluoroscopy time for implanting the ventricular electrode ranged from 60 to 250 seconds, 40 to 92 minutes being taken to complete the whole procedure.
Conclusion
We present a simple and rapid technique for electrode placement in patients with LSVC using usual J guide and active fixation electrodes with high success.
PMCID: PMC3951613  PMID: 24669104
persistent left superior vena cava; pacemaker; implantation
2.  An Alternative Way to Reach the Epicardial Focus of the Left Ventricular Tachycardia in a Patient with Non-ischemic Cardiomyopathy 
We report a case of a 69-year-old male with non-ischemic cardiomyopathy, having drug- and antitachycardia pacing-refractory ventricular tachycardia resulted in multiple ICD shocks. The sustained and intractable ventricular arrhythmia was mapped and ablated with the aid of the three-dimensional electroanatomic mapping system, initially performed but unsuccessful from the endocardial site then performed successfully from the epicardial site via the coronary sinus.
PMCID: PMC3952608  PMID: 24669109
coronary sinus; endocardial; epicardial; ventricular tachycardia
3.  Epicardial Ablation: Prevention of Phrenic Nerve Damage by Pericardial Injection of Saline and the Use of a Steerable Sheath 
Because of the close proximity of the phrenic nerve to the pericardium, phrenic nerve damage caused by epicardial ablation can easily occur. We report two cases of epicardial VT ablation where pericardial injection of saline, combined with the use of a steerable sheath, successfully prevents the phrenic nerve from being damaged.
PMCID: PMC3952609  PMID: 24669108
Ablation; epicardium; pericardium; phrenic nerve; saline; steerable sheath
4.  Diagnostic Dilemmas for Underlying Pathophysiology of Arrhythmias Originating from the Right Ventricle 
PMCID: PMC3952610  PMID: 24669110
Right Ventricular Tachycardia; Left Ventricular Non-compaction Cardiomyopathy
5.  Right Ventricular Ablation as a Therapeutic Option for Left Ventricular Hypertrabeculation / Noncompaction 
PMCID: PMC3952611  PMID: 24669111
Right Ventricular Ablation; Left Ventricular Non-compaction Cardiomyopathy
6.  Close Proximity of Left Anterior Descending Artery to the Right Ventricular Lead Apparently Implanted into the Mid-septum 
Right ventricular (RV) mid-septal pacing should have fewer negative effects on left ventricular function compared to apical pacing. However, targeting the mid-septum may be technically challenging since it is usually done with two-dimensional fluoroscopy. The rotation of the heart and various shapes of the RV make it difficult to assess, whether the lead is really anchored in the septum. Many leads, apparently anchored in the septum, are in fact anchored in the anterior wall or anteroseptal groove, and some can get anchored in close proximity to the left anterior descending artery (LAD). We report three cases from our series of 51 patients, in whom the RV lead thought to be implanted in the mid-septum was in fact anchored in close proximity of LAD when assessed using computed tomography.
PMCID: PMC3952612  PMID: 24669107
pacing; septal; fluoroscopy; implantation
7.  Normal Heart Ventricular Tachycardia Associated with Pregnancy: Successful Treatment with Catheter Ablation 
Background
Normal heart ventricular arrhythmia occurring during pregnancy has been previously described. Whilst there are established reports of catheter ablation to treat supraventricular arrhythmia during pregnancy, there are no reports of ablation to treat ventricular tachycardia.
Case
We present the case of a 36 year old women, 31 weeks into an otherwise uncomplicated pregnancy, experiencing significant, troublesome and drug refractory tachycardia emanating from the right ventricular outflow tract.
Conclusion
We describe a successful radio frequency ablation in the third trimester of pregnancy.
PMCID: PMC3952613  PMID: 24669106
Ventricular tachycardia; Right ventricular outflow tract; Pregnancy; Catheter ablation; Verapamil
9.  Septal Pacing of Right Ventricle: Has The Last Word Been Said? 
PMCID: PMC3952615  PMID: 24669103
Right Ventricule; Septal Pacing
10.  An Approach to the Stepwise Management of Severe Mitral Regurgitation with Optimal Cardiac Pacemaker Function 
Right ventricular apical pacing may cause or worsen mitral regurgitation (MR). Potential mechanisms for this adverse sequelae include intraventricular dyssynchrony, altered papillary muscle function, pacing-induced cardiomyopathy with left ventricular dilation, and annular dilation. In contrast, biventricular (BiV) pacing may improve MR presumably by opposing the negative effects. Whether or not left ventricular lead location is important in treating mitral regurgitation in patients with pacemakers is unknown.
We report a case of severe MR and left ventricular (LV) systolic failure in a patient with right ventricular pacing. Multiple potential etiologies for the worsening valve function were noted, and a stepwise iterative optimizing scheme that included basal lateral LV pacing improved mitral valve function and ameliorated heart failure symptoms.
PMCID: PMC3952616  PMID: 24669105
mitral regurgitation; cardiac pacemaker
12.  Parahisian Atrial Tachycardia: Cryoablation from the Aortic Cusp 
PMCID: PMC3878588  PMID: 24493917
Parahisian Atrial Tachycardia; Cryoablation from the Aortic Cusp
13.  QRS as a Risk Stratification Tool: Putting the Fragments Together 
PMCID: PMC3878582  PMID: 24493910
Fragmented QRS; risk stratification
14.  Fragmented QRS as a Predictor of Appropriate Implantable Cardioverter-defibrillator Therapy 
Background
Fragmented QRS (fQRS) has been shown to be a marker of local myocardial conduction abnormalities and a predictor of cardiac events in selected populations. We hypothesized that the presence of a fQRS might predict arrhythmic events in patients who received an implantable cardioverter-defibrillator (ICD), regardless of the indications for implantation.
Methods and Results
A cohort of 107 consecutive patients (mean age, 53 years; 82% male) who underwent an ICD implantation was studied. We defined fQRS, on a routine 12-lead ECG, as the presence of an additional R wave or notching in the nadir of the S wave in 2 consecutive leads corresponding to a major coronary artery territory. In the presence of bundle branch block, more than 2 notches in the R or S waves in 2 consecutive leads were required to characterize fQRS. Patients were followed for 21.3±23 months for appropriate ICD therapy (antitachycardia pacing and/or shock). ICDs were implanted predominantly in patients with ischemic cardiomyopathy (N=45, 42.1%), followed by Brugada syndrome (N=26, 24.3%). fQRS presented in 42 patients (39.3%). During follow-up, patients with fQRS received more appropriate ICD therapy than those without fQRS (45.2% vs. 10.8%, P<0.0001). After adjustment for covariates, fQRS remained an independent predictor for appropriate ICD therapy (hazard ratio=5.32, 95% confidence interval=2.11-13.37, P<0.0001).
Conclusion
The presence of fQRS appeared to be directly associated with appropriate ICD therapy.
PMCID: PMC3878583  PMID: 24493911
Fragmented QRS; Implantable cardioverter-defibrillator; tachyarrhythmia; electrocardiography
15.  Successful Non-fluoroscopic Radiofrequency Ablation of Incessant Atrial Tachycardia in a High Risk Twin Pregnancy 
We describe a patient presenting with incessant ectopic atrial tachycardia during a high risk twin pregnancy. Tachycardia was resistant to escalating doses of beta-blockade with digoxin. Because of increasing left ventricular dysfunction early in the third trimester, catheter ablation was performed successfully at 30 weeks gestation. Electro-anatomic mapping permitted the entire procedure to be conducted without the use of ionizing radiation. The pregnancy proceeded to successful delivery near term and after three years the patient remains recurrence free with normal left ventricular function, off all medication.
PMCID: PMC3878584  PMID: 24493913
Ectopic atrial tachycardia; Tachycardia-cardiomyopathy; Twin pregnancy
16.  Evaluation of Left Ventricular Endocardial Cardiac Resynchronization Therapy in a Non-responder with Ventricular Arrhythmias 
Approximately one third of patients treated with cardiac resynchronization therapy do not derive any detectable benefit. In these patients, acute invasive hemodynamic evaluation can be used for therapy optimization. This report describes the use of systematic invasive hemodynamic measurements for clinical decision making in a patient who experienced severe ventricular arrhythmias and clinical deterioration following a biventricular upgrade.
PMCID: PMC3878585  PMID: 24493914
Cardiac resynchronization therapy; Ventricular arrhythmia; Acute invasive hemodynamic measurements
17.  Complex Biventricular Pacing - A Case Series 
It is established that cardiac resynchronisation therapy (CRT) reduces mortality and hospitalisation and improves functional class in patients with NYHA class 3-4 heart failure, an ejection fraction of ≤ 35% and a QRS duration of ≥ 120ms. Recent updates in the American guidelines have expanded the demographic of patients in whom CRT may be appropriate. Here we present two cases of complex CRT; one with a conventional indication but occluded central veins and the second with a novel indication for CRT post cardiac transplant.
PMCID: PMC3878586  PMID: 24493915
Biventricular Pacing
18.  Dual AV Nodal Nonreentrant Tachycardia Resulting in Inappropriate ICD Therapy in a Patient with Cardiac Sarcoidosis 
Dual atrioventricular nodal nonreentrant tachycardia (DAVNNT) occurs due to concurrent antegrade conduction over fast and slow atrioventricular nodal pathways and is treated by slow pathway modification. We describe a unique case of a patient with cardiac sarcoidosis who received inappropriate ICD shocks for DAVNNT. Atrial and ventricular device electrograms satisfied both rate and V>A criteria for ventricular tachycardia. We postulate that alterations in refractoriness and conduction as is seen in cardiac sarcoidosis (CS) may have contributed to occurrence of DAVNNT.
PMCID: PMC3878587  PMID: 24493916
supraventricular tachycardia; dual atrioventricular nodal nonreentrant tachycardia; DAVNNT; sarcoidosis
19.  Dual Atrioventricular Nodal Pathways Physiology: A Review of Relevant Anatomy, Electrophysiology, and Electrocardiographic Manifestations 
More than half a century has passed since the concept of dual atrioventricular (AV) nodal pathways physiology was conceived. Dual AV nodal pathways have been shown to be responsible for many clinical arrhythmia syndromes, most notably AV nodal reentrant tachycardia. Although there has been a considerable amount of research on this topic, the subject of dual AV nodal pathways physiology remains heavily debated and discussed. Despite advances in understanding arrhythmia mechanisms and the widespread use of invasive electrophysiologic studies, there is still disagreement on the anatomy and physiology of the AV node that is the basis of discontinuous antegrade AV conduction. The purpose of this paper is to review the concept of dual AV nodal pathways physiology and its varied electrocardiographic manifestations.
PMCID: PMC3893335  PMID: 24493912
dual AV nodal; arrhythmias; physiology; manifestations
20.  The ABC of a Simple Method for Pulmonary Vein Angiography 
Catheter-directed intervention to treat atrial fibrillation (AF) is becoming widely accepted procedure in current clinical practice. For assessment of pulmonary vein (PV) anatomy, angiography of left atrium (LA) and/or PV is often performed. We present a new, simple angiographic method for PVs and LA opacification using SL1 sheath. Total of 100 patients in our clinic underwent this procedure. In all of the cases good angiographic results were achieved. No immediate or late complications related to this procedure were observed.
PMCID: PMC3907124  PMID: 24493918
Pulmonary Vein Angiography
21.  Idiopathic Right Atrial Scar 
PMCID: PMC3907125  PMID: 24493919
Idiopathic Right Atrial Scar
23.  Randomized Prospective Comparison of Two Protocols for Head-up Tilt Testing in Patients with Normal Heart and Recurrent Unexplained Syncope 
Background
This randomized study was aimed to compare the diagnostic value of two head-up tilt testing protocols using sublingual nitroglycerin for provocation in patients with recurrent unexplained syncope and normal heart.
Methods
The patients with normal findings in physical examination, electrocardiography and echocardiography were randomly submitted to one of upright tilt test protocols. The only difference between two protocols was that nitroglycerin was administered after a five minute resting phase in supine position during protocol B. We also considered eighty normal persons as the control group.
Results
Out of 290 patients that underwent tilt testing, 132 patients were in group A versus 158 patients in group B. Both groups had an identical distribution of clinical characteristics. Tilt test was positive in 79 patients in group A (25 in passive phase, 54 in active phase) versus 96 patients in group B (43 in passive phase, 53 in active phase). There was no significant difference between results in two groups (P value= 0.127). Forty cases were tested with protocol A and forty underwent tilt testing with protocol B. Tilt test was positive in 4 cases with protocol A versus 3 cases in protocol B. The positive rates of tilt testing with protocol A was 60% while it was 61% in protocol B. The specificity of testing with protocol A was 90% and it was 92.5% in protocol B.
Conclusions
According to our data, adding a period of rest and returning to supine position before nitroglycerin administration had no additional diagnostic yield.
PMCID: PMC3876579  PMID: 24482561
Head-up tilt test; Neurally mediated syncope; Unexplained syncope
24.  Transmural "Scar-to-Scar" Reentrant Ventricular Tachycardia 
We describe a scar-related reentrant ventricular tachycardia circuit with a proximal segment in an endocardial basal septal scar and an exit in a region of slow conduction in a non-overlapping region of epicardial basal lateral scar. The 12-lead EKG demonstrates criteria for a basal lateral epicardial VT, however the same morphology could be produced with a longer stim-latency with pace mapping or VT induction from the endocardial septal region of scar. A significant segment of myocardium demonstrated no endocardial or epicardial scar on electroanatomic mapping, suggesting the presence of a mid-myocardial isthmus. Further evidence was provided by assessment of unipolar settings. The epicardial VT that initially appeared to originate from the basal lateral epicardial region, was successfully treated with radiofrequency ablation of the lateral aspect of the endocardial septal scar.
PMCID: PMC3876580  PMID: 24482562
Reentrant Ventricular Tachycardia; Transmural Scar
25.  Balloon Venoplasty of Subclavian Vein and Brachiocephalic Junction to Enable Left Ventricular Lead Placement for Cardiac Resynchronisation Therapy 
This report describes the successful implantation of a LV lead using balloon venoplasty to overcome a very tight stenosis of the right subclavian vein / brachiocephalic junction for cardiac resynchronisation therapy (CRT-P) in a patient with a right sided CRT-P system and a failed epicardial LV lead. It is important for device implanters to be familiar with interventional equipments and techniques such as balloon venoplasty to overcome difficult venous access.
PMCID: PMC3876581  PMID: 24482564
Balloon Venoplasty of Subclavian Vein; Cardiac Resynchronisation Therapy

Results 1-25 (543)