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 Holler 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 mu V vs 62 +/- 12 mu V; 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.