Clinical profile of arrhythmogenic right ventricular cardiomyopathy in Chinese patients

Long-term follow-up of arrhythmogenic right ventricular cardiomyopathy patients with an implantable cardioverter-defibrillator for prevention of sudden cardiac death

BACKGROUND

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a rare inherited cardiomyopathy with a high burden of ventricular arrhythmia, which is an important cause of sudden cardiac death (SCD). Implantable cardioverter-defibrillator (ICD) is believed to be the most reliable management against SCD.

HYPOTHESIS

Ventricular arrhythmia does not necessarily confer a poor prognosis in ARVC patients with an ICD.

METHODS

A total of 39 ARVC patients (34 male) implanted with an ICD at our electrophysiology center and followed up continuously were included in this study. The mean age at diagnosis was 42.1 ± 14.8 years.

RESULTS

Thirty-three patients (84.6%) had suffered ventricular arrhythmia with hemodynamic compromise before ICD implantation. During a median follow-up of 48.6 months (interquartile range, 32.3-73.3), 3 patients (7.7%) died, 1 of sudden death, 1 of heart failure, and 1 of cerebral infarction. Twenty-eight patients (71.8%) experienced 540 appropriate ICD interventions. The first appropriate ICD intervention occurred more than 2 years after initial ICD implantation in 5 patients (12.8%). Twelve patients (30.8%) suffered from electrical storm. The event-free period was significantly shorter in patients who did not have broad precordial T wave inversion ≥V1-V3 (hazard ratio = 0.39, 95% confidence interval: 0.16-0.96). No significant difference was shown in antiarrhythmic drugs and radiofrequency catheter ablation before ICD implantation between patients with and without appropriate ICD therapies (P > 0.05).

CONCLUSIONS

Recurrence of sustained ventricular tachycardia/ventricular fibrillation is frequent in high-risk patients with ARVC. The prognosis is favorable for ARVC patients treated with an ICD for prevention of SCD.

Sudden death due to arrhythmogenic right ventricular cardiomyopathy: Two case reports

Arrhythmogenic right ventricular cardiomyopathy (ARVC) is a kind of primary myocardial disease characterized by the regional or global replacement of right ventricular myocardium by fatty and fibrolipomatous tissues. The ARVC, usually presenting with different clinical manifestations and pathological changes, were mainly seen in young men and is one of the main causes of sudden death in the young. Here two autopsied cases of Chinese men aged 30 and 23 years old who appeared healthy but died suddenly while at work are reported respectively. One of the victims had extensive and severe pathological changes in his heart involving the left ventricular wall as well as the ventricular septum and the right atrium. Not only was there a global fatty and fibrolipomatous tissue replacement of the right ventricular myocardia, but also mild sarcoplasmic coagulation in the myocardium and focal lymphocytic infiltration in the myocardial interstitium of the right ventricular wall. In addition, slight atherosclerosis of the coronary artery and intimal thickening of the sino-atrial node were observed. It is believed that there are no marked differences in the pathological changes of ARVC between Chinese patients and patients from western countries. The etiology and pathogenesis of ARVC could not be explained by a single cause or factor and they are probably related to various congenital and acquired causes or factors.

Clinical manifestations of arrhythmogenic right ventricular cardiomyopathy in Korean patients

BACKGROUND

The clinical manifestations of the Korean patients with arrhythmogenic right ventricular cardiomyopathy (ARVC) are not well known.

METHODS

The clinical data of Korean patients who met the Task Force Criteria for ARVC were analyzed.

RESULTS

Thirty-seven patients (41.2+/-14.8 years old, 19 males) were diagnosed with ARVC. The commonest presenting symptoms were palpitations (30%), syncope/presyncope (30%) and no symptoms (30%). Four patients had a family history of premature sudden death or ARVC. Most patients with no symptoms were evaluated due to ECG abnormalities or asymptomatic ventricular arrhythmias. Ventricular tachycardia, ventricular fibrillation and frequent premature ventricular contractions only were observed in 35%, 5% and 24%, respectively. Wall motion abnormalities of the right and left ventricles were detected in 92% and 41%, respectively. Fatty or fibrofatty infiltration was observed in 26 of the 32 (81%) patients who underwent an endomyocardial biopsy. Two patients had signs of heart failure. Two patients with syncope/presyncope were diagnosed with vasovagal syncope and another was due to side effects from a medication. Most of the patients with ventricular arrhythmias were treated with beta-blockers and/or amiodarone. Implantable cardioverter-defibrillators (ICDs) were implanted in 3 patients. During a mean follow-up of 27.4+/-26.5 months no syncope or sudden death developed except for in one patient with an ICD who suffered from recurrent shocks due to ventricular fibrillation.

CONCLUSIONS

ARVC may be an important cause of syncope, ventricular arrhythmias, and ECG and wall motion abnormalities of the ventricles in Koreans. The Korean patients with ARVC exhibited various clinical manifestations.

Primary Prophylaxis of Sudden Death in Hypertrophic Cardiomyopathy, Arrhythmogenic Right Ventricular Cardiomyopathy, and Dilated Cardiomyopathy

We present an evidence-based overview of primary prevention of sudden cardiac death. Several recent studies have provided important data regarding pharmacologic and device-based therapy for patients with conditions that confer high risk for sudden death. A rational approach to these therapies, with emphasis on implanted cardiovertor defibrillators, is discussed.

Genetics of arrhythmogenic right ventricular cardiomyopathy

Recent advances in molecular genetics of arrhythmogenic right ventricular cardiomyopathy (ARVD) are reviewed. In particular, the finding of mutations in the gene coding for cardiac ryanodine receptor (hRYR2), both in patients affected with ARVD2 and in patients affected with catecholaminergic ventricular arrhythmias or with familial ventricular tachyarrhythmia, is discussed. Novel data support the hypothesis that apoptosis may be a key step in molecular pathogenesis of ARVDs. A series of studies on drugs with apparent protective effect against apoptosis in myocardial cells might open new perspectives in the therapeutic approach.