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).


CONCLUSIONS
The magnitude of the localized LGE was significantly correlated with abnormalities in ventricular repolarization as assessed by TWA and QT dispersion.
Department of Cardiology.
Naka
N
Sakamoto
Department of Cardiology. Electronic address: nsato@asahikawa-med.ac.jp.
Nobuyuki
N
Sato
Department of Pathology.
Kensuke
K
Oikawa
Department of Cardiology.
Ahmed
A
Karim Talib
Department of Cardiology.
Eitaro
E
Sugiyama
Department of Cardiology.
Akiho
A
Minoshima
Department of Cardiology.
Yasuko
Y
Tanabe
Department of Cardiology.
Toshiharu
T
Takeuchi
Department of Cardiology; Department of Pathology.
Kazumi
K
Akasaka
Division of Community Medicine and Epidemiology, Department of Health Science, Asahikawa Medical University, Asahikawa, Japan.
Yasuaki
Y
Saijo
Department of Cardiology.
Yuichiro
Y
Kawamura
Department of Cardiology.
Naoyuki
N
Hasebe
D000368:Aged; D002312:Cardiomyopathy, Hypertrophic / Q000150:complications / Q000401:mortality / Q000473:pathology*; D003287:Contrast Media; D004562:Electrocardiography; D015716:Electrocardiography, Ambulatory; D005260:Female; D019786:Gadolinium DTPA; D006801:Humans; D019028:Magnetic Resonance Imaging, Cine; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D017180:Tachycardia, Ventricular / Q000209:etiology / Q000401:mortality / Q000503:physiopathology*; D013997:Time Factors
D003287:Contrast Media; D019786:Gadolinium DTPA
Cardiac magnetic resonance imaging; Hypertrophic cardiomyopathy; Late gadolinium enhancement; T-wave alternans; Ventricular fibrillation; Ventricular tachycardia