Arrhytmogenic right ventricle - Prognostic signifi cance of exercise test

Abstract

The authors summarize the present knowledge on arrhythmogenic right ventricular cardiomyopathy/dysplasia. Limited data are available about natural history of asymptomatic patients with arrhythmogenic right ventricle cardiomyopathy/dysplasia, who have a ventricular tachycardia during exercise test. A 25-year old female patient was treated with osteosynthesis because of ankle injury. Cardiology consultation was performed because of an abnormal ECG. Physical examination was normal. ECG showed a normal sinus rhythm, left axis deviation, negative T waves in leads II, III, aVF and V2-V6. Chest X-ray and laboratory findings were normal. Echocardiography showed normal left ventricular ejection fraction along with inferior akinesis and dilated right ventricle. Bicycle exercise test revealed a good exercise tolerability (9 MET), and after sporadic ventricular extra systoles ventricular tachycardia developed lasting for 3 minutes, which spontaneously stopped after aborting the test and performed abdominal strain. MRI was performed which has shown normal left ventricular size, wall motion and ejection fraction and depressed right ventricle function (ejection fraction 31.6%) enlarged right ventricular end-systolic and diastolic volumes, hypo-akinetic regions without aneurysm and bulging. No contrast enhancement was seen in the thin right ventricular wall. According to abnormal ECG and MRI findings arrhythmogenic right ventricle cardiomyopathy/dysplasia was diagnosed. No ICD implantation was indicated because the patient was asymptomatic, and no sudden cardiac death occurred in the family. Three month later the patient was found dead. At autopsy the right ventricular chamber was markedly enlarged, with multiple translucent areas of fatty accumulation accompanied with extended myocytes loss. There was a characteristic triangle dysplasia: the inflow, outflow tracts and apical areas. The coronaries were free of atherosclerosis. Mallory's phosphotungstic acid-hematoxilin stain demonstrated the presence of fibrosis within the scattered myocardium. Conclusion: malignant ventricular arrhythmia provoked by exercise test in an asymptomatic arrhythmogenic right ventricle cardiomyopathy/dysplasia patient with negative family history should be an indication for ICD implantation.