Early repolarization pattern in patients with provocable Brugada phenocopy: A marker of additional arrhythmogenic cardiomyopathy?

Abstract

In 2003 in a published manuscript QRS prolongation in inferior leads was described in 22% of cases with arrhythmogenic right ventricular cardiomyopathy [1], meanwhile named arrhythmogenic cardiomyopathy. In a further look at these ECGs it seems that these belong to early repolarization pattern with slurring of the QRS complex. We have recently described a few patients with a definitive diagnosis of arrhythmogenic cardiomyopathy and provocable Brugada pattern by ajmaline testing [2,3]. The extent to which ERP and BrS may overlap remains unclear. ERP could be confirmed in 11–31% in typical BrS cases according to recent publications [4–7]. The question is whether patients with provocable coved-type ST-segment elevation in right precordial leads have ERP when arrhythmogenic right ventricular cardiomyopathy is an additional feature. In 19 patients with provocable coved-type ST-segment elevation in right precordial leads ERP in inferior and lateral leads were analyzed before ajmaline challenge. 17 patients had epsilon potentials and right ventricular conduction abnormalities and echocardiographic, angiographic and magnetic resonance hints of additional arrhythmogenic right ventricular cardiomyopathy (ARVC/D). Magnetic resonance technique and electrocardiographic results of a female patient are shown in Fig. 1a and b. In 17 patients with provocable Brugada pattern and additional ARVC/D ERP was found in 11/17 cases (64%). In 5 cases ERP could be found in lateral leads and in 6 cases in inferior leads. In all patients localized right precordial QRS prolongation with a difference of right to left precordial QRS complexes of more than 1.2 was present. Epsilon potentials were found in 11 cases. Right precordial T wave inversions beyond V1 were present in 6 patients. In 2 patients without additional ARVC/D ERP could be excluded. The number of patients was too small to draw any conclusions. In a large collective of patients with arrhythmogenic cardiomyopathy (ARVC/D) QRS prolongation in inferior leads and slurring of the QRS complex could be found in 22% of the cases [1]. In almost all cases left ventricular function showed inferior and posterolateral hypokinesia beside right ventricular contraction abnormalities. ECG abnormalities are shown in Fig. 2. In typical Brugada syndrome (BrS) early repolarization pattern (ERP) in larger trials are described in 11 up to 31% of the cases [4–7]. The combination of provocable BrS and ERP was more often found in patients with additional hints of ARVC/D (64%). The number of cases without additional ARVC/D was too small to draw any conclusions. The hypothesis is that in patients with provocable BrS and additional ARVC/D the rate of ERP is more pronounced. If ERP and provocable BrS exist in the same patient, screening of additional features of ARVC/D should be performed. The indication in these patients exist for right ventricular angiography, echocardiography and magnetic resonance imaging as listed in the modified diagnostic criteria of ARVC/D published in 2010 [8]. In summary, in all patients with provocable Brugada pattern and early repolarization pattern attempts should be made to diagnose additional arrhythmogenic right ventricular cardiomyopathy by simple ECG analysis and by cardiac imaging techniques. Up to now the risk for ventricular arrhythmias is not clear but theoretically higher as in isolated arrhythmogenic cardiomyopathy.