Electrocardiographic and morphometric features in patients with ventricular tachycardia of right ventricular origin

Abstract

Objective-To study diVerences between repetitive monomorphic ventricular tachycardia (RMVT) of right ventricular origin, and ventricular tachycardia in arrhythmogenic right ventricular dysplasia (ARVD). Patients-Consecutive groups with RMVT (n = 15) or ARVD (n = 12), comparable for age and function. Methods-Analysis of baseline, tachycardia, and signal averaged ECGs, clinical data, and right endomyocardial biopsies. Pathological findings were related to regional depolarisation (QRS width) and repolarisation (QT interval, QT dispersion). Results-There was no diVerence in age, ejection fraction, QRS width in leads I, V1, and V6, and QT indices. During ventricular tachycardia, more patients with ARVD had a QS wave in V1 (p < 0.05). There were significant diVerences for unfiltered QRS, filtered QRS, low amplitude signal duration, and the root mean square voltage content. In the absence of bundle branch block, diVerences became nonsignificant for unfiltered and filtered QRS duration. Mean (SD) percentage of biopsy surface diVered between RMVT and ARVD: normal myocytes (74(3.4)% v 64.5(9.3)%; p < 0.05); fibrosis (3(1.7)% v 8.9(5.2)%; p < 0.05). When all patients were included, there were significant correlations between fibrosis and age (r = 0.6761), and fibrosis and QRS width (r = 0.5524 for lead I; r = 0.5254 for lead V1; and r = 0.6017 for lead V6). Conclusions-The ECG during tachycardia and signal averaging are helpful in discriminating between ARVD and RMVT patients. There are diVerences in the proportions of normal myocytes and fibrosis. The QRS duration is correlated with the amount of fibrous tissue in patients with ventricular tachycardia of right ventricular origin. (Heart 1998;79:388-393) Keywords: arrhythmogenic right ventricular dysplasia; electrocardiography; endomyocardial biopsy; ventricular arrhythmias It is not always easy to diVerentiate idiopathic or repetitive monomorphic ventricular tachycardia (RMVT) of right ventricular origin from tachycardia in early stages of arrhythmogenic right ventricular dysplasia (ARVD).1 From a clinical point of view, the major points helpful in the recognition of RMVT remain the absence of overt cardiomyopathy and myocardial dysfunction.2 A good tolerance of the arrhythmia (which does not exclude symptoms) is also suggestive of RMVT.3 RMVT is thought to have a good long term prognosis. Unfortunately, patients aVected by ARVD in the early stages often also have a normal heart at routine examination and even after full noninvasive and invasive investigations the diagnosis is not always definite. This is embarrassing, as some patients with ARVD may experience palpitations due to minor ventricular arrhythmias, while others may die suddenly. 4 Furthermore, ARVD can progress to left ventricular disease, making confusion with other pathology possible (for example, dilated cardiomyopathy). 5To improve our understanding of the two diseases, we analysed clinical data, routine ECG data, ECG data during ventricular tachycardia, QT measurements, and signal averaged elec...

Electrocardiographic Features of Arrhythmogenic Right Ventricular Dysplasia/Cardiomyopathy According to Disease Severity

“…11,12 However, some studies have demonstrated the presence of T-wave inversion in V 1 through V 3 in 6% to 20% of patients with RVOT. 10,13 Further studies are needed to ascertain the diagnostic value of T-wave inversion in right precordial leads in distinguishing ARVD/C from RVOT. In a landmark study, Turrini et al 4 identified QRS dispersion Ն40 ms on the 12-lead ECG as an independent predictor of sudden cardiac death in patients with ARVD/C.…”

Electrocardiographic Comparison of Ventricular Arrhythmias in Patients With Arrhythmogenic Right Ventricular Cardiomyopathy and Right Ventricular Outflow Tract Tachycardia

“…VTs from this region also share a left bundle branch block (LBBB) QRS morphology/inferior axis pattern, and differentiation between these 2 distinct disease states is paramount. The presence of T-wave inversion in V 1 to V 3 in normal sinus rhythm may aid the diagnosis of ARVD/C, but recent data showed that these changes may be present in only 32% of ARVD/C patients as well as 1% to 3% of normal young patients (7)(8)(9)(10). Similarly, other popular noninvasive studies show a 50% to 60% false-negative rate (echocardiography), and a 70% false-positive rate (magnetic resonance imaging [MRI]) for the diagnosis of ARVD/C (10,11).…”

Arrhythmogenic Right Ventricular Dysplasia: MRI Findings

“…The electrocardiogram in patients with ARVD usually shows a regular sinus rhythm, with a QRS duration of > 110 ms in lead V 1 an epsilon wave just beyond QRS complex in lead V 1 (in 30% of patients), and an inversion of T waves in precordial leads V 1 -V 3 (in 50% of cases) [33]. Also the signal-averaged electrocardiogram is abnormal in patients with diffuse form of ARVD [71].…”