Value of Electrocardiography to Distinguish Fabry Disease from Sarcomeric Hypertrophic Cardiomyopathy

Abstract

Fabry disease (FD) is a rare genetic disorder that leads to left ventricular hypertrophy (LVH), frequently misdiagnosed as hypertrophic cardiomyopathy (HCM). We sought to assess the value of electrocardiography for distinguishing FD from HCM. We retrospectively reviewed and compared standard electrocardiograms and echocardiograms from 26 patients with FD and LVH and 33 sarcomeric patients with HCM, matched for gender, age, and degree of LVH. The mean age of patients with FD was 46years (interquartile range) (28 to 53) and of HCM 50 (30 to 61) years (p=0.27). Of them, 16 (61%) and 25 (76%) were male, respectively (p=0.26). Indexed left ventricular mass was 166g/m² in FD versus 181g/m² in HCM (p=0.88). All patients with FD and 30 (91%) with HCM were in sinus rhythm (p=0.25). A higher prevalence of right bundle branch block (RBBB) was observed in FD (27%) versus HCM (6%) (p=0.03). The PR interval was shorter in FD, 140ms (120-160) versus 160ms (140 to 180) (p=0.004). P-wave duration was longer in patients with FD, 100ms (80 to 120) versus 80ms (80 to 100) (p=0.01). The PQ interval (PR interval minus P-wave duration) was shorter in patients with FD, 40ms (20 to 45) versus 80ms (40 to 80) (p=0.001). There were no differences regarding P-wave amplitude, QRS complex duration, corrected QT length, conduction or repolarization abnormalities, Sokolow-Lyon index, and Cornell index. After multivariate adjustments for RBBB, PR interval, P-wave duration, and PQ interval, a PQ interval ≤40ms and RBBB were significantly associated with FD. In conclusion, there are electrocardiogram characteristics, such as the presence of RBBB or a PQ interval ≤40ms, that may be helpful for screening and reducing the delay in FD diagnosis.