Late gadolinium enhancement on cardiac magnetic resonance represents the depolarizing and repolarizing electrically damaged foci causing malignant ventricular arrhythmia in hypertrophic cardiomyopathy

Naka Sakamoto; Yuichiro Kawamura; Nobuyuki Sato; Asami Nimura; Motoki Matsuki; Atsushi Yamauchi; Takayasu Kanno; Yasuko Tanabe; Toshiharu Takeuchi; Shunsuke Natori; Yasuaki Saijo; Tamio Aburano; Naoyuki Hasebe

doi:10.1016/j.hrthm.2015.02.004

Late gadolinium enhancement on cardiac magnetic resonance represents the depolarizing and repolarizing electrically damaged foci causing malignant ventricular arrhythmia in hypertrophic cardiomyopathy

Heart Rhythm. 2015 Jun;12(6):1276-84. doi: 10.1016/j.hrthm.2015.02.004. Epub 2015 Feb 12.

Affiliations

¹ Department of Cardiology, Asahikawa Medical University, Asahikawa, Japan.
² Department of Cardiology, Asahikawa Medical University, Asahikawa, Japan. Electronic address: nsato@asahikawa-med.ac.jp.
³ Department of Cardiology, Furano Hospital, Furano, Japan.
⁴ Division of Community Medicine and Epidemiology, Department of Health Science.
⁵ Department of Radiology, Asahikawa Medical University, Asahikawa, Japan.

PMID: 25684235
DOI: 10.1016/j.hrthm.2015.02.004

Abstract

Background: The presence of a myocardial scar detected by late gadolinium enhancement (LGE) on cardiac magnetic resonance (CMR) has been described as a predictor of all-cause mortality in hypertrophic cardiomyopathy (HCM). However, the detailed spatial relationship between LGE site and electrical abnormality is unclear in high-risk HCM with malignant arrhythmia.

Objective: The purpose of this study was to elucidate the detailed relationship between the site on CMR imaging and the electrically damaged site, a potential origin of ventricular arrhythmias in patients with HCM.

Methods: Fifty consecutive HCM patients underwent contrast-enhanced CMR. Of those patients, 18 patients with ventricular tachycardia underwent electrophysiology study including endocardial mapping of the left ventricle (LV). The LGE area was calculated at 12 different LV sites: anterior, lateral, posterior, and septal segments of the basal, middle, and apical portions. At each LV site, the bipolar electrogram, effective refractory period (ERP), and monophasic action potential were recorded.

Results: LGE-positive segments demonstrated a significantly lower amplitude (4.0 ± 2.8 mV vs 7.3 ± 3.6 mV; P < .001), longer duration (54.7 ± 17.8 vs 40.6 ± 7.8 ms; P < .001), longer ERP (320 ± 42 ms vs 284 ± 37 ms; P = .001), and longer monophasic action potential duration measured at 90% repolarization (321 ± 19 ms vs 283 ± 25 ms; P < .001) than did LGE-negative segments. The LGE area negatively correlated with the amplitude (r = -0.59; P < .001) and positively correlated with the duration (r = 0.64; P < .001), ERP (r = 0.44; P < .001), and action potential duration measured at 90% repolarization (r = 0.63; P < .001). All the observed VTs originated from LGE-positive segments.

Conclusion: The spatial distribution of LGE significantly correlates with depolarizing and repolarizing electrical damage in high-risk HCM with malignant ventricular arrhythmia.

Keywords: Cardiac magnetic resonance; Hypertrophic cardiomyopathy; Late gadolinium enhancement; Ventricular tachycardia.

MeSH terms

Arrhythmias, Cardiac / etiology*
Cardiomyopathy, Hypertrophic / complications*
Female
Gadolinium / pharmacology
Heart Ventricles
Humans
Magnetic Resonance Imaging*
Male
Middle Aged
Tachycardia, Ventricular / physiopathology

Substances

Gadolinium