Background

The association of right ventricular (RV) structure and function with symptoms in individuals without cardiopulmonary disease is unknown. We hypothesized that greater RV mass and RV end-diastolic volume (RVEDV), smaller RV stroke volume (RVSV), and lower RV ejection fraction (RVEF) measured by cardiac magnetic resonance imaging (MRI) in participants free of clinical cardiovascular disease at baseline would be associated with a greater risk of self-reported dyspnea.

Methods

The Multi-Ethnic Study of Atherosclerosis (MESA) performed cardiac MRIs on participants without clinical cardiovascular disease between 2000 and 2002. We excluded subjects who reported “prevalent” dyspnea at the first assessment (24 months). The presence of dyspnea was assessed at 24 months, 42 months, and 60 months from baseline. Cox proportional hazards models were used to examine the relationship between RV measures and incident dyspnea.

Results

In the final study sample (N = 2763), there were significant interactions between RV measures and sex in terms of the risk of dyspnea (p<0.05). Among men (N = 1453), lower RV mass (p = 0.003), smaller RVEDV (p<0.001), smaller RV end-systolic volume (RVESV) (p = 0.03) and decreased RVSV (p<0.001) were associated with an increased risk of developing dyspnea after adjusting for covariates. Associations remained after adjusting for left ventricular function and lung function. However, there were no significant associations between RV measures and the risk of dyspnea in women.

Conclusions

Lower RV mass and smaller RV volumes were associated with an increased risk of dyspnea in men, but not in women.

Introduction

Imaging of the right ventricle (RV) for the diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) is commonly performed by echocardiography or magnetic resonance imaging (MRI). Angiography is an alternative modality, particularly when MRI cannot be performed. We hypothesized that RV volume and ejection fraction computed by angiography would correlate with these quantities as computed by MRI.

Methods and Results

RV volumes and ejection fraction were computed for subjects enrolled in the North American ARVC/D Registry, with both RV angiography and MRI studies. Angiography was performed in the 30° right anterior oblique (RAO) and 60° left anterior oblique (LAO) views. Angiographic volumes were computed by RAO view and two-view (RAO and LAO) formulae. 17 subjects were analyzed (11 men and 6 women), with 15 subjects classified as affected, and 2 as unaffected by modified Task Force criteria. The correlation coefficient of MRI to the two-view angiographic analysis was 0.76 for end-diastolic volume and 0.79 for ejection fraction. Angiographically derived volumes were larger than MRI derived volume (p=0.006) and with the slope in a linear relationship equal to 0.8 for end diastolic volume, and 0.9 for RV ejection fraction (p<0.001), computed by the two view formula. The RAO view formula was significantly related to the MRI derived quantities, but with lower correlation coefficients (0.36 for volume and 0.73 for ejection fraction).

Conclusion

End-diastolic volume and ejection fraction of the RV can be obtained by angiography and correlates with these quantities as obtained by MRI.

Background

Immunoreactive signal for the desmosomal protein plakoglobin (γ-catenin) is reduced at cardiac intercalated disks in patients with arrhythmogenic right ventricular cardiomyopathy (ARVC), a highly arrhythmogenic condition caused by mutations in genes encoding desmosomal proteins. Previously, we observed a “false positive” case in which plakoglobin signal was reduced in a patient initially thought to have ARVC but who actually had cardiac sarcoidosis. Sarcoidosis can masquerade clinically as ARVC, but has not previously been associated with altered desmosomal proteins.

Methods and Results

We observed marked reduction in immunoreactive signal for plakoglobin at cardiac myocyte junctions in patients with sarcoidosis and giant cell myocarditis, both highly arrhythmogenic forms of myocarditis associated with granulomatous inflammation. In contrast, plakoglobin signal was not depressed in lymphocytic (non-granulomatous) myocarditis. To determine whether cytokines might promote dislocation of plakoglobin from desmosomes, we incubated cultures of neonatal rat ventricular myocytes with selected inflammatory mediators. Brief exposure to low concentrations of IL-17, TNFα and IL-6, cytokines implicated in granulomatous myocarditis, caused translocation of plakoglobin from cell-cell junctions to intracellular sites, whereas other potent cytokines implicated in non-granulomatous myocarditis had no effect, even at much high concentrations. We also observed myocardial expression of IL-17 and TNFα, and elevated serum levels of inflammatory mediators including IL-6R, IL-8, MCP1 and MIP1β in ARVC patients (all p<0.0001 compared with controls).

Conclusions

These results suggest novel disease mechanisms involving desmosomal proteins in granulomatous myocarditis and implicate cytokines, perhaps derived in part from the myocardium, in disruption of desmosomal proteins and arrhythmogenesis in ARVC.

Background

Right ventricular (RV) morphology is an important predictor of outcomes in heart and lung disease, however determinants of RV anatomy have not been well-studied. We examined the demographic factors associated with RV morphology and function in a population-based multiethnic sample free of clinical cardiovascular disease.

Methods and Results

The Multi-Ethnic Study of Atherosclerosis (MESA) performed cardiac magnetic resonance imaging (MRI) on 5098 participants. RV volumes and mass were available for 4204 participants. Normative equations for RV parameters were derived using an allometric approach. The study sample (N = 4123) was 61.5 ± 10.1 years old and 47.5% male. Older age was associated with lower RV mass (~5% lower mass per decade) with larger age-related decrements in men than in women (p for interaction < 0.05). Older age was also associated with higher RV ejection fraction (RVEF), an association which differed between races/ethnicities (p for interaction ≤ 0.01). Overall, men had greater RV mass (~8%) and larger RV volumes than women, but had lower RVEF (4% in absolute terms) (p < 0.001). African Americans had lower RV mass than Caucasians (p ≤ 0.002), whereas Hispanics had higher RV mass (p ≤ 0.02). Using the derived normative equations, 7.3% (95%CI, 6.5–8.1%) met criteria for RV hypertrophy and 5.9% (95%CI, 5.2–6.6%) had RV dysfunction.

Conclusions

In conclusion, age, sex, and race are associated with significant differences in RV mass, RV volumes and RVEF, potentially explaining distinct responses of the RV to cardiopulmonary disease.

Electrical impulse propagation is an essential function in cardiac, skeletal muscle, and nervous tissue. Abnormalities in cardiac impulse propagation underlie lethal reentrant arrhythmias, including ventricular fibrillation. Temporary propagation block throughout the ventricular myocardium could possibly terminate these arrhythmias. Electrical stimulation has been applied to nervous tissue to cause reversible conduction block, but has not been explored sufficiently in cardiac tissue. We show that reversible propagation block can be achieved in cardiac tissue by holding myocardial cells in a refractory state for a designated period of time by applying a sustained sinusoidal high-frequency alternating current (HFAC); in doing so, reentrant arrhythmias are terminated. We demonstrate proof of concept using several models, including optically mapped monolayers of neonatal rat ventricular cardiomyocytes, Langendorff-perfused guinea pig and rabbit hearts, intact anesthetized adult rabbits, and computer simulations of whole-heart impulse propagation. HFAC may be an effective and potentially safer alternative to direct current application, currently used to treat ventricular fibrillation.

Rationale: Sex hormones have effects on the left ventricle, but hormonal influences on the right ventricle (RV) are unknown.

Objectives: We hypothesized that sex hormones would be associated with RV morphology in a large cohort free of cardiovascular disease.

Methods: Sex hormones were measured by immunoassay and RV ejection fraction (RVEF), stroke volume (RVSV), mass, end-diastolic volume, and end-systolic volume (RVESV) were measured by cardiac magnetic resonance imaging in 1,957 men and 1,738 postmenopausal women. The relationship between each hormone and RV parameter was assessed by multivariate linear regression.

Measurements and Main Results: Higher estradiol levels were associated with higher RVEF (β per 1 ln[nmol/L], 0.88; 95% confidence interval [CI], 0.32 to 1.43; P = 0.002) and lower RVESV (β per 1 ln[nmol/L], −0.87; 95% CI, −1.67 to −0.08; P = 0.03) in women using hormone therapy. In men, higher bioavailable testosterone levels were associated with higher RVSV (β per 1 ln[nmol/L], 1.97; 95% CI, 0.20 to 3.73; P = 0.03) and greater RV mass and volumes (P ≤ 0.01). Higher dehydroepiandrosterone levels were associated with higher RVSV (β per 1 ln[nmol/L], 1.37; 95% CI, 0.15 to 2.59; P = 0.03) and greater RV mass (β per 1 ln[nmol/L], 0.25; 95% CI, 0.00 to 0.49; P = 0.05) and volumes (P ≤ 0.001) in women.

Conclusions: Higher estradiol levels were associated with better RV systolic function in women using hormone therapy. Higher levels of androgens were associated with greater RV mass and volumes in both sexes.

Rationale: Intense exercise in elite athletes is associated with increased left ventricular (LV) and right ventricular (RV) mass and volumes. However, the effect of physical activity on the RV in an older community-based population is unknown.

Objectives: We studied the association between levels of physical activity in adults and RV mass and volumes.

Methods: The Multi-Ethnic Study of Atherosclerosis (MESA) performed cardiac magnetic resonance imaging on community-based participants without clinical cardiovascular disease. RV volumes were determined from manually contoured endocardial margins. RV mass was determined from the difference between epicardial and endocardial volumes multiplied by the specific gravity of myocardium. Metabolic equivalent–minutes/day were calculated from the self-reported frequency, duration, and intensity of physical activity.

Measurements and Main Results: The study sample (n = 1,867) was aged 61.8 ± 10 years, 48% male, 44% white, 27% African American, 20% Hispanic, and 9% Chinese. Higher levels of moderate and vigorous physical activity were linearly associated with higher RV mass (P = 0.02) after adjusting for demographics, anthropometrics, smoking, cholesterol, diabetes mellitus, hypertension, and LV mass. Higher levels of intentional exercise (physical activity done for the sole purpose of conditioning or fitness) were nonlinearly associated with RV mass independent of LV mass (P = 0.03). There were similar associations between higher levels of physical activity and larger RV volumes.

Conclusions: Higher levels of physical activity in adults were associated with greater RV mass independent of the associations with LV mass; similar results were found for RV volumes. Exercise-associated RV remodeling may have important clinical implications.

Elevated resistance and reduced compliance of the pulmonary vasculature increase right ventricular (RV) afterload. Local and systemic inflammation and haemostatic abnormalities are prominent in pulmonary vascular diseases. We hypothesized that plasma biomarker levels indicating greater inflammation and coagulability associated with pulmonary vascular disease would be associated with RV structure and function measured by cardiac magnetic resonance imaging (MRI). The Multi-Ethnic Study of Atherosclerosis (MESA) performed cardiac MRI among participants aged 45–84 years without clinical cardiovascular disease. We assessed the associations of RV mass, RV end-diastolic volume (RVEDV), RV stroke volume (RVSV) and RV ejection fraction (RVEF) with plasma measures of inflammation (matrix metalloproteinase (MMP)-3 and -9, intercellular adhesion molecule (ICAM)-1, tumour necrosis factor receptor (TNF-R1), and E-selectin) and thrombosis (plasminogen activator inhibitor (PAI)-1, tissue factor, tissue factor pathway inhibitor and CD40 ligand).The study sample included 731 subjects. Higher MMP-9 levels were associated with lower RV mass before and after adjustment for left ventricular (LV) mass (p = 0.008 and p = 0.044, respectively). Higher levels of MMP-9 and PAI-1 were also associated with smaller RVEDV (p<0.05). Higher PAI-1 levels were associated with lower RVEF even after adjustment for LV ejection fraction (p = 0.017). In conclusion, MMP-9 and PAI-1 are associated with changes in RV structure and function which could be potentially related to a subclinical increase in pulmonary vascular resistance.

Advances in cardiovascular imaging increasingly afford unique insights into heritable myocardial disease. As clinical presentation of genetic cardiomyopathies may range from nonspecific symptoms to sudden cardiac death, accurate diagnosis has implications for individual patients as well as related family members. The initial consideration of genetic cardiomyopathy may occur in the imaging laboratory, where one must recognize the patient with arrhythmogenic right ventricular cardiomyopathy (ARVC) among the many with ventricular arrhythmia referred to define myocardial substrate. Accurate diagnosis of the patient presenting with dyspnea and palpitations whose first-degree relatives have lamin A/C cardiomyopathy may warrant genetic testing1, 2 plus imaging of diastolic function and myocardial fibrosis3. As advances in cardiac imaging afford detection of subclinical structural and functional changes, the imaging specialist must be attuned to signatures of specific genetic disorders. With increased availability of both advanced imaging as well as genotyping techniques, this review seeks to provide cardiovascular imaging specialists and clinicians with the contemporary information needed for more precise diagnosis and treatment of heritable myocardial disease. A companion paper in this series covers imaging phenotype and genotype considerations in hypertrophic cardiomyopathy (HCM). This review details clinical features, imaging phenotype and current genetic understanding for two of the most common non-HCM conditions that prompt myocardial imaging - dilated cardiomyopathy (DCM) and arrhythmogenic right ventricular cardiomyopathy (ARVC). While all modalities are considered herein, considerable focus is given to CMR with its unique capabilities for myocardial tissue characterization.

Arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C) is an inherited form of cardiomyopathy with low penetrance and variable expressivity. Dominant mutations and rare polymorphisms in desmosome genes are frequently identified. We reasoned that individuals with earlier onset disease would have more frequent desmosome gene mutations and rare polymorphisms. Three groups were compared: Young with symptoms attributable to ARVD/C or a diagnosis of ARVD/C at age of 21 years or earlier, Middle with first symptoms or diagnosis age of 22–49 years, and Late with first symptoms or diagnosis at age of 50 or more years. deoxyribonucleic acid (DNA) sequence analysis was performed on five cardiac desmosome genes, and the presence of mutations and rare missense polymorphisms was compared among the three groups. In the entire Young cohort, 20 (67%) had one or more cardiac desmosome gene mutations. The prevalence of cardiac desmosome gene mutations was similar in the Middle (48%) and Late (53%) cohorts (P=0.23). Similar numbers of individuals in each cohort had more than one desmosome gene mutation, although the numbers are too small for statistical comparisons. The prevalence of certain rare missense DNA variants was not different among the cohorts (P=0.71), yet these rare missense alleles were more prevalent in the overall study cohort of 112 ARVD/C participants compared to 100 race-matched controls (P=0.027). The presence of these variants did not associate with the age of onset of ARVD/C or ventricular tachycardia. These findings highlight the complex interplay of environmental and genetic factors contributing to this condition.

Background

Sudden cardiac death (SCD) is a common initial presentation of coronary artery disease (CAD). Despite the growing epidemic of CAD in India, the epidemiology of SCD is largely unknown.

Objective

The objective of the study was to define the prevalence and determinants of sudden cardiac deaths in rural South India.

Methods

Prospective mortality surveillance was conducted in 45 villages (180,162 subjects) in rural South India between January 2006 and October 2007. Trained multipurpose health workers sought to do verbal autopsies within 4 weeks of any death. Detailed questionnaires including comorbidities and circumstances surrounding death were recorded. SCD was adjudicated using the modified Hinkle-Thaler classification.

Results

A total of 1916 deaths occurred in the study population over the 22 month time period and verbal autopsy was obtained in 1827 (95%) subjects. Overall mean age of the deceased was 62 ± 20 years and 1007 (55%) were men. Cardiovascular and cerebrovascular diseases together accounted for 559 deaths (31%), followed by infectious disease (163 deaths, 9%), cancer (126 deaths, 7%) and suicide (93 deaths, 5%).

Of the 1827 deaths, after excluding accidental deaths (89 deaths), 309 deaths (17%) met criteria for SCD. Cardiovascular disease was the underlying causes in the majority of the SCD events (231/309 (75%)). On multivariate analyses, previous MI/CAD (p < 0.001, OR 14.25), hypertension (p < 0.001, OR 1.84), and age groups between 40-60 yrs (p=0.029) were significantly associated with SCD.

Conclusion

Sudden cardiac death accounted for up to half of the cardiovascular deaths in rural Southern India. Traditional cardiovascular risk factors were strongly associated with SCD.

The impact of cardiovascular risk factors on the left ventricle is well known but their impact on right ventricle has not been studied using advanced imaging techniques. The purpose of this study was to determine the relation between cardiovascular risk factors and right ventricular (RV) structure and function and its interaction with the left ventricle. Cardiac magnetic resonance images were analyzed in 4204 participants free of clinical cardiovascular disease in the Multi-Ethnic Study of Atherosclerosis. Multivariable linear regression models were used to study the cross sectional association between individual RV parameters and risk factors. All RV parameters except ejection fraction decreased with age (p<0.0001). RV mass was positively associated with systolic blood pressure (+0.4g, p<0.0001) and high density lipoprotein (HDL) cholesterol (+0.2g, p<0.0001); inversely with diastolic blood pressure (−0.3g, p<0.0001) and total cholesterol (−0.2g, p<0.01). RV end diastolic volume was positively associated with systolic blood pressure (+1.6ml, p<0.01) and HDL cholesterol (+1.8ml, p<0.0001); and inversely with diastolic blood pressure (−2.2 ml, p<0.0001), total cholesterol (−1.4ml, p<0.0001), current smoking (−2.7ml, p<0.05) and diabetes mellitus (−3.1ml, p<0.01). RV ejection fraction was positively related with systolic blood pressure (+1.0%, p<0.0001), HDL cholesterol (+0.4%, p<0.0001) and inversely with diastolic blood pressure (−0.7%, p<0.0001). In conclusion, the mass and volumes of the right ventricle decrease with age. Cardiovascular risk factors, especially blood pressure and HDL cholesterol are associated with subclinical changes in RV mass and volumes.

Background

Although arrhythmogenic right ventricular dysplasia (ARVD) is characterized by predominantly right sided morphologic changes, genetic/histological and molecular changes are biventricular. Alterations in regional left ventricular (LV) strain in patients referred for suspicion of ARVD have not previously been determined.

Methods and Results

The study population included 21 patients with suspected ARVD who underwent evaluation with MRI including tagging. Eleven healthy volunteers served as controls. Global RV and LV function were studied by MRI and peak regional systolic circumferential strain (Ecc, %) was calculated by harmonic phase from tagged MRI based on a 16-segment model. Patients who met ARVD Task Force criteria were classified as definite ARVD, whereas patients with a positive family history who had one additional minor criterion and patients without a family history with at least 1 major or 2 minor criteria were classified as probable ARVD.

Of the 21 ARVD subjects, 11 had definite ARVD (63.6% males, mean age 41.2 ± 14.2 years) and, 10 had probable ARVD (30% males, 34.9 ± 12.1 years). Compared with controls (58.9 ± 6.2%), probable ARVD patients (53.6 ± 7.6%) had similar global RV ejection fraction (RVEF) (p> 0.05), but definite ARVD patients (45.2 ± 6.0%) had significantly reduced RVEF (p< 0.0001). Global LVEF was normal in all three groups (p>0.05). Compared to controls, mean LV circumferential strain (Ecc) was significantly reduced in 7/16 (44%) segments in definite ARVD, and 3/16 segments (19%) in probable ARVD (p< 0.05 for all).

Conclusions

There was a high prevalence of regional LV dysfunction in patients with definite ARVD, with less dysfunction in those with probable ARVD. Further, the extent of regional LV dysfunction appeared to parallel RV dysfunction, whereas global LV function was normal. Similar to the RV abnormalities, our findings suggest ARVD results in regional alterations of LV dysfunction prior to global abnormalities.

Background

In 1994, an International Task Force proposed criteria for the clinical diagnosis of ARVC/D which facilitated recognition and interpretation of the frequently non-specific clinical features of ARVC/D. This enabled confirmatory clinical diagnosis in index cases through exclusion of phenocopies, and provided a standard upon which clinical research and genetic studies could be based. Structural, histological, electrocardiographic, arrhythmic, and familial features of the disease were incorporated into the criteria, subdivided into major and minor according to the specificity of their association with ARVC/D. At that time, clinical experience with ARVC/D was dominated by symptomatic index cases and sudden cardiac death victims: the overt and/or severe end of the disease spectrum. Consequently, the 1994 criteria were highly specific but lacked sensitivity for early and familial disease.

Methods and Results

Revision of the diagnostic criteria provides guidance on the role of emerging diagnostic modalities and advances in the genetics of ARVC/D. The criteria have been modified to incorporate new knowledge and technology to improve diagnostic sensitivity, but with the important requisite of maintaining diagnostic specificity. The approach classifying structural, histological, electrocardiographic, arrhythmic, and genetic features of the disease as major and minor criteria has been maintained. In this modification of the Task Force Criteria, quantitative criteria are proposed and abnormalities are defined based on comparison with normal subject data.

Conclusions

The diagnosis of ARVC/D based on modification of the original Task Force criteria is a working framework to improve the diagnosis and management of this condition.

Background

In 1994, an International Task Force proposed criteria for the clinical diagnosis of arrhythmogenic right ventricular cardiomyopathy/dysplasia (ARVC/D) that facilitated recognition and interpretation of the frequently nonspecific clinical features of ARVC/D. This enabled confirmatory clinical diagnosis in index cases through exclusion of phenocopies and provided a standard on which clinical research and genetic studies could be based. Structural, histological, electrocardiographic, arrhythmic, and familial features of the disease were incorporated into the criteria, subdivided into major and minor categories according to the specificity of their association with ARVC/D. At that time, clinical experience with ARVC/D was dominated by symptomatic index cases and sudden cardiac death victims–the overt or severe end of the disease spectrum. Consequently, the 1994 criteria were highly specific but lacked sensitivity for early and familial disease.

Methods and Results

Revision of the diagnostic criteria provides guidance on the role of emerging diagnostic modalities and advances in the genetics of ARVC/D. The criteria have been modified to incorporate new knowledge and technology to improve diagnostic sensitivity, but with the important requisite of maintaining diagnostic specificity. The approach of classifying structural, histological, electrocardiographic, arrhythmic, and genetic features of the disease as major and minor criteria has been maintained. In this modification of the Task Force criteria, quantitative criteria are proposed and abnormalities are defined on the basis of comparison with normal subject data.

Conclusions

The present modifications of the Task Force Criteria represent a working framework to improve the diagnosis and management of this condition.

Clinical Trial Registration

clinicaltrials.gov Identifier: NCT00024505.

Background

Left ventricular (LV) mass is a strong predictor of cardiovascular disease (CVD), and magnetic resonance imaging (MRI) of the heart is a standard of reference for LV mass measurement. Ethnicity is believed to affect ECG performance. We evaluated the diagnostic and prognostic performance of ECG for left ventricular hypertrophy (LVH) as defined by MRI in relationship to ethnicity.

Methods and Results

Data were analyzed from 4967 participants (48% males, mean age 62 ± 10 years; 39% Caucasian, 13% Chinese, 26% African American, 22% Hispanic) enrolled in the Multi-Ethic Study of Atherosclerosis (MESA) who were followed for a median of 4.8 yearsfor incident CVD. Thirteen traditional ECG-LVH criteria were assessed and showed overall and ethnicity-specific low sensitivity (10–26%) and high specificity (88–99%) in diagnosing MRI-defined LVH. 10 out of 13 ECG-LVH criteria showed superior sensitivity and diagnostic performance in African Americans as compared to Caucasians (p=0.02–0.001). The sum of amplitudes of S wave in V1, S wave in V2 and R wave in V5 (a MESA specific ECG-LVH criterion) offered higher sensitivity (40.4%) compared to prior ECG-LVH criteria while maintaining good specificity (90%) and diagnostic performance (ROC area=0.65). In fully adjusted models, only the MESA-specific ECG-LVH criterion, Romhilt-Estes score, Framingham score, Cornell voltage, Cornell duration product and Framingham-adjusted Cornell voltage predicted increased CVD risk (p<0.05).

Conclusions

ECG has low sensitivity but high specificity for detecting MRI-defined LVH. The performance of ECG for LVH detection varies by ethnicity, with African Americans showing higher sensitivity and overall performance compared to other ethnic groups.

Isolated minor non-specific ST-segment and T-wave (NSSTA), minor and major electrocardiographic (ECG) abnormalities are established, independent risk markers for incident cardiovascular events. Their association with subclinical atherosclerosis has been postulated but is not clearly defined. The aim of this study is to define the association between ECG abnormalities and measures of subclinical atherosclerosis. We studied participants from MESA, a multi-ethnic sample of men and women aged 45–84 and free of clinical cardiovascular disease at enrollment. Baseline examination included measurement of traditional risk factors, resting 12-lead electrocardiograms, coronary artery calcium (CAC) measurement and common carotid intima-media thickness (CCIMT). Electrocardiograms were coded using Novacode criteria and were defined as having either minor abnormalities (e.g., minor non-specific STTA, first degree atrioventricular block, and QRS axis deviations) or major abnormalities (e.g., pathologic Q waves, major ST-segment and T-wave abnormalities, significant dysrhythmias and conduction system delays). Multivariable logistic and linear regressions were used to determine the cross-sectional associations of ECG abnormalities with CAC and common carotid-IMT. Among 6710 participants, 52.7% were women, with a mean age of 62 years. After multivariable-adjustment, isolated minor STTA, minor and major ECG abnormalities were not associated with the presence of CAC (>0) among men (OR 1.04, 95% CI 0.81–1.33; 1.10, 0.91–1.32; and 1.03, 0.81–1.31, respectively) or women (1.01, 0.82–1.24; 1.04, 0.87–1.23; and 0.94, 0.73–1.22, respectively). Lack of association remained consistent when using both log CAC and CC-IMT as continuous variables. ECG abnormalities are not associated with markers of subclinical atherosclerosis in a large multi-ethnic cohort.

Background

Parietal block, defined as intra right ventricular (RV) conduction slowing is a major diagnostic criterion for ARVD/C.

Objective

We evaluated the utility of total RV endocardial activation duration (EAD) measured by 3D electroanatomic mapping during sinus rhythm in the diagnosis of ARVD/C.

Methods

25 consecutive patients with frequent LBBB morphology PVCs who underwent electroanatomic mapping as a part of the evaluation for ARVD/C were included in the study. All patients were evaluated using standard protocol that included, ECG, signal averaged ECG, Holter, Echocardiography, and MRI. Invasive testing was performed as indicated. Total RV EAD was measured as the time interval between the onset of RV activation to the latest activated region in the RV.

Results

Mean age of the study subjects was 38±11 and 32% were men. 14 subjects were diagnosed as ARVD/C using task force criteria and the remainder had idiopathic VT. While the surface QRS durations were similar, the total RV EAD was significantly prolonged in ARVD/C compared with idiopathic VT (83.9±10 msec vs. 50.8±7 msec, p<0.001). None of the idiopathic VT subjects had RV EAD of > 65 msec. RV EAD also showed significant negative correlation with RV ejection fraction.

Conclusions

Total RV EAD obtained by 3D electroanatomic mapping is a sensitive marker of intra RV conduction delay in ARVD/C and a total RV EAD of >65 msec accurately differentiates ARVD/C from idiopathic VT.

Arrhythmogenic right ventricular dysplasia (ARVD) is a genetic cardiomyopathy characterized clinically by ventricular arrhythmias and progressive right ventricular (RV) dysfunction. The histopathologic hallmark is fibro-fatty replacement of RV myocardium. It is inherited in an autosomal pattern with variable penetrance. ARVD is unique in that it most commonly presents in young, otherwise healthy and highly athletic individuals. The cause of ARVD is not well-known but recent evidence suggests strongly that it is a disease of desmosomal dysfunction. The disease involvement is not limited only to the RV as left ventricle (LV) has also been reportedly affected. Diagnosis of ARVD is challenging and is currently based upon a multi-disciplinary work-up of the patient as defined by the Task Force. Currently, implanted cardioverter defibrillators (ICD) are routinely used to prevent sudden death in patients with ARVD. Cardiovascular MR is an important non-invasive diagnostic modality that allows both qualitative and quantitative evaluation of RV. This article reviews the genetics of ARVD, current status and role of CMR in the diagnosis of ARVD and LV involvement in ARVD.