Open AccessFibrosis and wall thickness affect ventricular repolarization dynamics in hypertrophic cardiomyopathy
Author(s) -
Jalanko Mikko,
Väänänen Heikki,
Tarkiainen Mika,
Sipola Petri,
Jääskeläinen Pertti,
Lauerma Kirsi,
Laitinen Tiina,
Laitinen Tomi,
Laine Mika,
Heliö Tiina,
Kuusisto Johanna,
Viitasalo Matti
Publication year - 2018
Publication title -
annals of noninvasive electrocardiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.494
H-Index - 48
eISSN - 1542-474X
pISSN - 1082-720X
DOI - 10.1111/anec.12582
Subject(s) - medicine , hypertrophic cardiomyopathy , cardiology , qt interval , left ventricular hypertrophy , muscle hypertrophy , repolarization , heart rate , cardiomyopathy , heart failure , blood pressure , electrophysiology
Background Hypertrophic cardiomyopathy ( HCM ) is characterized by ventricular repolarization abnormalities and risk of ventricular arrhythmias. Our aim was to study the association between the phenotype and ventricular repolarization dynamics in HCM patients. Methods HCM patients with either the MYBPC 3 ‐Q1061X or TPM 1 ‐D175N mutation ( n = 46) and control subjects without mutation and hypertrophy ( n = 35) were studied with 24‐hr ambulatory ECG recordings by measuring time intervals of rate‐adapted QT ( QT e), maximal QT , and T‐wave apex to wave end ( TPE ) intervals and the QT e/ RR slope. Findings were correlated to specified echocardiographic and cardiac magnetic resonance imaging ( CMRI ) findings. Results Rate‐adapted QT e interval was progressively longer in HCM patients with decreasing heart rates compared to control subjects ( p = 0.020). The degree of hypertrophy correlated with measured QT e values. HCM patients with maximal wall thickness higher than the mean (20.6 mm) had longer maximum QT e and median TPE intervals compared to control subjects and HCM patients with milder hypertrophy ( p < 0.001 and p = 0.014, respectively). HCM patients with late gadolinium enhancement ( LGE ) on CMRI had steeper QT e/ RR slopes compared to HCM patients without LGE and control subjects ( p = 0.044 and p = 0.001, respectively). LGE was an independent predictor of QT e/ RR slope ( p = 0.023, B = 0.043). Conclusion Dynamics of ventricular repolarization in HCM are affected by hypertrophy and fibrosis. LGE may confer an independent effect on QT dynamics which may increase the arrhythmogenic potential in HCM .