The echocardiographic assessment of the right ventricle in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia compared with athletes and matched controls

Clinical and Genetic Characteristics of Arrhythmogenic Right Ventricular Cardiomyopathy Patients: A Single-Center Experience

Background

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is an inherited progressive cardiomyopathy. We aimed to define the long-term clinical outcome and genetic characteristics of patients and family members with positive genetic tests for ARVC in a single tertiary care cardiac center in Saudi Arabia.

Methods

We enrolled 46 subjects in the study, including 23 index-patients (probands) with ARVC based on the revised 2010 ARVC Task Force Criteria (TFC) and 23 family members who underwent a genetic test for the ARVC between 2016 and 2020.

Results

Of the probands, 17 (73.9%) were males with a mean age at presentation of 24.95 ± 13.9 years (7 to 55 years). Predominant symptoms were palpitations in 14 patients (60.9%), and syncope in 10 patients (43.47%). Sustained ventricular tachycardia (VT) was documented in 12 patients (52.2%). The mean left ventricular ejection fraction (LVEF) by echocardiogram was 52.81±6.311% (30-55%), and the mean right ventricular ejection fraction (RVEF) by cardiac MRI was 41.3±11.37% (23-64%). Implantable cardioverter-defibrillator (ICD) implantation was performed in 17 patients (73.9%), and over a mean follow-up of 13.65 ± 6.83 years, appropriate ICD therapy was noted in 12 patients (52.2%). Genetic variants were identified in 33 subjects (71.7%), 16 patients and 17 family members, with the most common variant of plakophilin 2 (PKP2) in 27 subjects (81.8%).

Conclusions

ARVC occurs during early adulthood in Saudi patients. It is associated with a significant arrhythmia burden in these patients. The PKP2 gene is the most common gene defect in Saudi patients, consistent with what is observed in other nations. We reported in this study two novel variants in PKP2 and desmocollin 2 (DSC2) genes. Genetic counseling is needed to include all first-degree family members for early diagnosis and management of the disease in our country.

A Novel Diagnostic Score Integrating Atrial Dimensions to Differentiate between the Athlete's Heart and Arrhythmogenic Right Ventricular Cardiomyopathy

Objective: The 2010 Task Force Criteria (TFC) have not been tested to differentiate ARVC from the athlete’s heart. Moreover, some criteria are not available (myocardial biopsy, genetic testing, morphology of ventricular tachycardia) or subject to interobserver variability (right ventricular regional wall motion abnormalities) in clinical practice. We hypothesized that atrial dimensions are useful and robust to differentiate between both entities and proposed a new diagnostic score based upon readily available parameters including echocardiographic atrial dimensions. Methods: In this observational study, 21 patients with definite ARVC were matched for age, gender and body mass index to 42 athletes. Based on ROC analysis, the following parameters were included in the score: indexed right/left atrial volumes ratio (RAVI/LAVI ratio), NT-proBNP, RVOT measurements (PLAX and PSAX BSA-corrected), tricuspid annular motion (TAM), precordial TWI and depolarization abnormalities according to TFC. Results: ARVC patients had a higher RAVI/LAVI ratio (1.76 ± 1.5 vs. 0.87 ± 0.2, p < 0.001), lower right ventricular function (fac: 29 ± 10.1 vs. 42.2 ± 5%, p < 0.001; TAM: 19.8 ± 5.4 vs. 23.8 ± 3.8 mm, p = 0.001) and higher serum NT-proBNP levels (345 ± 612 vs. 48 ± 57 ng/L, p < 0.001). Our score showed a good performance, which is comparable to the 2010 TFC using those parameters, which are available in routine clinical practice (AUC93%, p < 0.001 (95%CI 0.874–0.995) vs. AUC97%, p < 0.001 (95%CI 0.93–1.00). A score of 6/12 points yielded a specificity of 91% and an improved sensitivity of 67% for ARVC diagnosis as compared to a sensitivity of 41% for the abovementioned readily available 2010 TFC. Conclusions: ARVC patients present with significantly larger RA compared to athletes, resulting in a greater RAVI/LAVI ratio. Our novel diagnostic score includes readily available clinical parameters and has a high diagnostic accuracy to differentiate between ARVC and the athlete’s heart.

Right Ventricular Function and Region-Specific Adaptation in Athletes Engaged in High-Dynamic Sports: A Meta-Analysis

BACKGROUND

Structural remodeling of the right ventricle (RV) is widely documented in athletes. However, functional adaptation, including RV pressure generation and systolic free-wall longitudinal mechanics, remains equivocal. This meta-analysis compared RV pressure and function in athletes and controls.

METHODS

A systematic review of online databases was conducted up to June 4, 2020. Meta-analyses were performed on RV systolic pressures, at rest and during exercise, tricuspid annular plane systolic displacement, myocardial velocity (S'), and global and regional longitudinal strain. Bias was assessed using Egger regression for asymmetry. Data were analyzed using random-effects models with weighted mean difference and 95% CI.

RESULTS

Fifty-three studies were eligible for inclusion. RV systolic pressure was obtained from 21 studies at rest (n=1043:1651; controls:athletes) and 8 studies during exercise (n=240:495) and was significantly greater in athletes at rest (weighted mean difference, 2.9 mmHg [CI, 1.3-4.5 mmHg]; P=0.0005) and during exercise (11.0 [6.5-15.6 mm Hg]; P<0.0001) versus controls. Resting tricuspid annular plane systolic displacement (P<0.0001) and S' (P=0.001) were greater in athletes. In contrast, athletes had similar RV free-wall longitudinal strain (17 studies; n=450:605), compared with controls but showed greater longitudinal apical strain (16 studies; n=455:669; 0.9%, 0.1%-1.8%; P=0.03) and lower basal strain (-2.5% [-1.4 to -3.5%]; P<0.0001).

CONCLUSIONS

Functional RV adaptation, characterized by increased tricuspid annular displacement and velocity and a greater base-to-apex strain gradient, is a normal feature of the athlete's heart, together with a slightly elevated RV systolic pressure. These findings contribute to our understanding of RV in athletes and highlight the importance of considering RV function in combination with structure in the clinical interpretation of the athlete's heart.