Electrocardiographic differences between Anderson-Fabry and sarcomeric hypertrophic cardiomyopathy and correlation with cardiac magnetic resonance

Abstract

Abstract Background Differential diagnosis between Anderson-Fabry (AF) and sarcomeric hypertrophic cardiomyopathy (HCM) is often very challenging particularly in AF patients with late onset cardiac involvement. Purpose To gain new insights from standard electrocardiogram (ECG) in AF disease for differential diagnosis from sarcomeric HCM. Additionally, to better understand ECG features in AF patients, a correlation substudy ECG-cardiac magnetic resonance (CMR) has been performed. Methods From 162 patients with definite diagnosis of AF disease, 111 [65 males, median age 57 (51–67) years] with pathologic left ventricular hypertrophy (LVH) (Group A) were compared with 111 sarcomeric HCM patients (Group B) sex, age and maximal wall thickness matched by 1:1 propensity score. Results AF patients showed shorter PR interval [155 (140–180) vs 163 (149–184) msec; p=0.005) and wider QRS interval [110 (100–134) vs 100 (90–106) msec; p<0.0001). Additionally AF patients had a higher prevalence of complete (22% vs 3%; p<0.0001) and incomplete (13% vs 1%; p<0.0001) right bundle branch block (RBBB) and a higher percentage of ST segment depression (12% vs 1%; p=0.001) and inferior negative T waves (34% vs 19%; p=0.01). No differences in terms of Sokolow-Lyon and Cornell scores were found whereas total QRS score was higher in Group A [20 (16–27) vs 18 [14–22] mV; p=0.0004). Low QRS voltages and inferior Q waves were not present in AF patients. Among the 69 AF patients who underwent MRI, the 44 with late gadolinium enhancement (LGE) were older [59 (52–66) vs 53 (40–59) years; p=0.017] and had more frequently negative T waves on ECG, particularly in the inferior leads (64% vs 8%; p<0.0001), compared to the 25 without LGE. At multivariate analysis, age and negative T waves were independently associated to the presence of LGE on CMR. Conclusions Compared to matched sarcomeric HCM, AF patients had a shorter PR, wider QRS and a higher percentage of RBBB in relation to to the different aetiology (storage vs “pure” hypertrophy). The higher total QRS score and the absence of inferior Q waves could reflect the more frequent concentric distribution of LVH. Additionally negative T waves, especially in inferior leads, are related to the presence of LGE on CMR (often in the postero-lateral wall). Funding Acknowledgement Type of funding source: None