Electrocardiographic abnormalities attributable to infiltrative cardiomyopathies: review and prevalence in patients with congestive heart failure

The electrocardiogram (ECG) is routinely used in patients with suspected infiltrative cardiomyopathies; heart diseases characterized by the abnormal deposition of pathological substances in the myocardium. This study presents a review of ECG features attributable to various infiltrative cardiomyopathies and analyzes the prevalence and overlap of electrocardiographic abnormalities in patients with adjudicated CHF. The study included 573 consecutive CHF patients without severe aortic stenosis, further stratified by LV hypertrophy (LVH) and preserved or decreased LV ejection fraction. Comprehensive ECG analysis revealed at least one ECG abnormality typically associated with infiltrative cardiomyopathies in 95% of patients, and more than one ECG abnormality in 70%. An average number of ECG abnormalities was 2.2 ± 1.2 per patient. There was substantial overlap in ECG abnormalities in individual patients, particularly those attributable to Fabry's disease and hemochromatosis (51.5%) or cardiac amyloidosis (46.1%), and hemochromatosis and cardiac amyloidosis (44.2%). Prevalence of various ECG abnormalities was similar across various patient demographics and co-morbidities, including LVH status and/or history of CAD which did not increase the number of ECG abnormalities (2.155 ± 1.238 vs. 2.228 ± 1.192 in patients without CAD history, p = 0.969). Patients with reduced LV ejection fraction had a higher prevalence of widened QRS and premature ventricular complexes. ECG abnormalities attributable to infiltrative cardiomyopathies are common in heart failure patients, with a significant overlap in findings classically attributed to various infiltrative cardiomyopathies. The presence of LVH and decreased LV ejection fraction do not significantly affect the prevalence of ECG abnormalities.