Malignant arrhythmogenic right ventricular dysplasia/cardiomyopathy with a normal 12-lead electrocardiogram: a rare but underrecognized clinical entity

Abstract

Background: In Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy (ARVD/C), a normal electrocardiogram (ECG) is considered reassuring. However, some patients with ARVD/C experiencing ventricular arrhythmias have a normal ECG.

Objectives: To estimate how often patients with ARVD/C experiencing ventricular arrhythmias have a normal ECG during sinus rhythm, and to provide a clinical profile of these patients.

Methods: We included 145 patients with ARVD/C experiencing a documented sustained ventricular arrhythmia. Conventional 12-lead sinus rhythm ECGs within 6 months of the event were reviewed for diagnostic Task Force Criteria (TFC). ECGs were classified as abnormal (≥1 TFC), nonspecific (abnormal, no TFC), or normal. Cardiologic investigations within 6 months of the event were evaluated as per TFC in those with a nonspecific or normal ECG.

Results: The ECG was nonspecific or normal in 17 of 145 (12%) subjects. Mean age of these patients was 41.3 ± 12.4 years and 14 (82%) were men, comparable to those with an abnormal ECG. Most patients with a nonspecific or normal ECG showed ≥1 TFC on Holter monitoring (n = 9 of 10) and signal-averaged ECG (n = 4 of 5), and all had nonsustained ventricular tachycardia recorded. Among 15 patients who underwent structural evaluation, 11 (73%) showed structural TFC (9 major and 2 minor).

Conclusions: Although most patients with ARVD/C experiencing arrhythmias have an abnormal ECG, a nonspecific or normal ECG does not preclude ARVD/C diagnosis. All patients with a nonspecific or normal ECG had alternative evidence of disease expression. These results alert the physician not to rely exclusively on ECG in ARVD/C, but to assess arrhythmic risk by comprehensive clinical evaluation.

Keywords: ARVD/C; Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy; CMR; Cardiomyopathy; Concealed; Diagnosis; ECG; Electrocardiogram; PKP2; PVC; Plakophilin-2; RV; Risk stratification; SAECG; TAD; TFC; Task Force Criteria; VF; VT; Ventricular arrhythmias; cardiac magnetic resonance; electrocardiogram/electrocardiographic; premature ventricular complex; right ventricular; signal-averaged electrocardiogram; terminal activation duration; ventricular fibrillation; ventricular tachycardia.