Abstract 17364: Abnormal Repolarizations in Electrocardiogram Correlate with Abnormal Diastolic Mechanics in Patients with Hypertrophic Cardiomyopathy
Introduction: HCM is often characterized by marked repolarization abnormalities. However the significance of repolarization changes in these patients has not been investigated.
Aim: We investigated the prevalence and significance of ECG repolarization patterns on sensitive measures of systolic and diastolic function in a cohort of 110 patients (mean age 52± 17 yrs, male 65%, Caucasian 73%) with HCM.
Method: We performed echocardiography and ECG evaluation in 110 HCM patients. ECG repolarization parameters including strain pattern, early repolarization pattern, ST elevation, ST depression and T wave inversion were measured. Conventional and longitudinal tissue Doppler- derived tissue velocity and strain were analyzed off-line.
Result: The mean left ventricular mass index was 141± 48 g/m,2 LVEF was 69± 10% and left ventricular outflow tract gradient was 27±29 mmHg. ECG analysis revealed mean QTc of 451± 34 ms; 45/110 had strain pattern, 17/110 had early repolarization pattern and 14/110 had deeply inverted T waves. Patients with strain pattern on ECG, demonstrated decreased early diastolic velocity (lateral: -3.7± 2.2 vs. -4.6± 2.3 cm/s, p= 0.044, anterior: -2.6± 1.5 vs. -3.4± 1.4 cm/s, p= 0.04 and inferior:-2.7± 1.4 vs. -3.9± 1.6 cm/s, p= 0.005 regions), and late diastolic velocity (lateral:-1.2+- 0.76 vs -2.3+- 1.6, p= 0.001, anterior: -1.6+- 0.7, -2.7+- 1.3, p= 0.0006 and inferior: -2.7+- 1.8 vs -4.1 +- 1.7, p= 0.0003) in the corresponding regional myocardium, when compared to HCM patients without strain pattern. Patients who exhibited deeply inverted T waves on ECG exhibited decrease in late diastolic strain rate in the corresponding regional myocardium (lateral: 0.44± 0.32 vs. 0.84±0.48 s-1, p= 0.001 and anterior: 0.56±0.19 vs. 1.0± 0.56 s-1, p= 0.005), when compared to HCM patients without this finding. In contrast, early diastolic strain rate was increased in the corresponding regional myocardium (lateral: 1.75± 0.6 vs. 1.1± 0.62 s-1, p= 0.015 and anterior: 1.17± 0.3 vs. 0.87± 0.5 s-1, p= 0.01) in patients with evidence of early repolarization on ECG, when compared to patients without this feature.
Conclusion: Strain pattern and deeply inverted T waves are markers for abnormal diastolic mechanics in patients with hypertrophic cardiomyopathy.
- © 2011 by American Heart Association, Inc.