Insights into Electrocardiographic Parameters and Findings: A Potential Tool for Characterizing Cardiomyopathy

Introduction: Electrocardiographic abnormalities are common in cardiomyopathies and pose a diagnostic challenge. Our aim is to examine whether electrocardiographic findings can help characterize the type of cardiomyopathy, and the gene involved.

Methods: A rigorous clinical protocol included ECG, exercise test (ET), 12 lead Holter (12LH), echocardiography, and a broad genetic analysis in patients with cardiomyopathy, referred to the clinic from 2012-2024.

Results: Among 275 patients (180 males, age 48±16), 107 (39%) had Hypertrophic Cardiomyopathy (HCM), 19 (7%) had Arrhythmic Cardiomyopathy (ACM) and had 149 (54%) Dilated Cardiomyopathy (DCM). On ECG, T-wave inversions were the most common findings: HCM (72%), ACM (78%) and DCM (40%) (p<0.01). ST changes were more common in HCM (55%), less in DCM (21%) and not detected in ACM (p = 0.00001). Ventricular premature complex (VPC) burden> 1000/24h in12LH was highest in ACM (52%), less in DCM (36%) and rare in HCM (8.4%, p< 0.01). ACM exhibited the highest prevalence of three or more VPC morphologies (63% vs 40% in DCM and 13% in HCM, p<0.001). The major VPC morphology in ACM was LBBB (83%) and in DCM RBBB (61%, p= 0.001). During ET ACM patients were more likely to have at least one VPC (73% vs 46% DCM and 26% HCM, p=0.0004) and three or more VPC morphologies (42% ACM vs 12% DCM and 0.9% in HCM, p<0.01).
Patients with desmosomal mutation had the highest VPC burden (mean 3161 /24 h 12LH and mean 18.6/ET). Their major VPC morphology was LBBB (72%). Cytoskeletal genes had lower VPC burden (mean 1705/24 h 12LH and mean 14.6 / ET) with RBBB being the major VPC morphology (71%). Sarcomeric genes had the lowest VPC burden in 12LH and ET.

Conclusions: Electrocardiographic findings in ECG, 12LH and ET can help characterize the type of cardiomyopathy and involved gene.