Anderson-Fabry disease patients with anatomical heart hypertrophy express a higher degree of electrocardiographic hypertrophy compared to hypertrophic cardiomyopathy patients

Abstract Background Anderson-Fabry disease (AFD) is an X-linked lysosomal storage disease that has progressively gained attention due to the availability of specific therapeutic options. Heart involvement is of critical prognostic significance and differential diagnosis with Hypertrophic Cardiomyopathy (HCM) is as challenging as it is crucial to provide the patient with the appropiate treatment. Purpose To describe ECG features in AFD patients according to the presence of anatomical hypertrophy and compare them with matched HCM patients. Methods One-hundred-sixty-two AFD patients were recruited in the present multicentre study cohort and divided into 2 groups according to the presence (Group A, n=111) or the absence (Group B, n=51) of anatomical hypertrophy. Group A patients were then compared with a matched cohort of HCM patients (n=111) with the use of Propensity Score Martching relatively to sex, age and maximal wall thickness. Results AFD patients with cardiac hypertrophy, compared with matched HCM patients with the same indexed cardiac mass at echocardiography [151 (124-211) vs 145 (123-182) g/m2; p=0.1675], showed on the surface electrocardiogram a higher degree of electrical hypertrophy expressed as increased total QRS score [204 (158-271) vs 177 (138-221) mm; p=0.0004] and R wave amplitude in aVL ≥ 11 mm [51 (45.9%) vs 25 (22.5%); p<0.0001], whereas they did not differ with respect to Sokolow-Lyon index [31 (18-44) vs 32 (22-40) mm; p=0.518] and Cornell index [19 (12-25) vs 17 (12-24) mm; p=0.5]. Furthermore, AFD patients featured wider QRS complexes [110 (100-134) vs 100 (90-106) ms; p<0.0001] and a higher prevalence of Right Bundle Branch Block (RBBB), both complete [25 (22.5%) vs 3 (2.7%); p<0.0001] and incomplete [17 (15.4%) vs 2 (1.8); p<0.0001], as well as non specific intraventricular block [14 (12.6%) vs 4 (3.6%); p<0.0001]. Conclusions Our cohort of Anderson-Fabry patients, compared with HCM patients with the same indexed cardiac mass at echocardiography matched by age, sex and wall thickness, featured a higher degree of electrocardiographic hypertrophy expressed as increased total QRS score and R wave amplitude in aVL, whereas it did not differ with respect to Sokolow-Lyon and Cornell indexes. These findings may prove beneficial in achieving earlier the diagnosis of AFD, enabling clinicians to initiate swiftly and without delay the specific disease modifying therapies available.Electrocardiographic differencesTotal QRS Score AFD vs HCM