Late gadolinium enhancement of cardiac magnetic resonance imaging indicates abnormalities of time-domain T-wave alternans in hypertrophic cardiomyopathy with ventricular tachycardia

Background: The presence of myocardial scar detected by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) imaging has been described as a good independent predictor of mortality in patients with hypertrophic cardiomyopathy (HCM). Time-domain T-wave alternans (TWA) is also a potential predictor of cardiac mortality in patients with left ventricular dysfunction.

Objective: The purpose of this study was to elucidate the relationship between LGE distribution and TWA in patients with HCM.

Methods: CMR and TWA analyses using Holter monitoring were performed in 42 patients with HCM. The average transmural extent of LGE was scored as 1-4 in each segment, and the sum of the LGE scores (total LGE score) was calculated for each patient. The correlation between the maximal time-domain TWA voltage and LGE findings was analyzed, and the differences in time-domain TWA voltage, total LGE score, and cardiac function assessed by CMR imaging in the presence or absence of ventricular tachycardia (VT) were also compared.

Results: The total LGE score was significantly and positively correlated with the maximal time-domain TWA voltage (r = 0.59; P < .001). Furthermore, the total LGE score and maximal time-domain TWA voltage were significantly greater in patients who had episodes of VT (n = 21) than in those without VT (23 ± 7 vs. 10 ± 8; P < .001 and 87 ± 26 μV vs. 62 ± 12 μV; P < .001, respectively). However, the left ventricular ejection fraction did not statistically differ between patients with VT and those without VT (56% ± 14% vs. 61% ± 7%; P = .102).

Conclusion: The magnitude of the localized LGE was significantly correlated with abnormalities in ventricular repolarization as assessed by TWA and QT dispersion.