Fibrosis and wall thickness affect ventricular repolarization dynamics in hypertrophic cardiomyopathy

Research output: Contribution to journalArticleScientificpeer-review

Researchers

  • Mikko Jalanko
  • Heikki Väänänen

  • Mika Tarkiainen
  • Petri Sipola
  • Pertti Jääskeläinen
  • Kirsi Lauerma
  • Tiina Laitinen
  • Tomi Laitinen
  • Mika Laine
  • Tiina Heliö
  • Johanna Kuusisto
  • Matti Viitasalo

Research units

  • University of Helsinki
  • University of Eastern Finland
  • Kuopio University Hospital

Abstract

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 MYBPC3-Q1061X or TPM1-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 (QTe), maximal QT, and T-wave apex to wave end (TPE) intervals and the QTe/RR slope. Findings were correlated to specified echocardiographic and cardiac magnetic resonance imaging (CMRI) findings. Results: Rate-adapted QTe 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 QTe values. HCM patients with maximal wall thickness higher than the mean (20.6 mm) had longer maximum QTe 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 QTe/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 QTe/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.

Details

Original languageEnglish
Article numbere12582
Pages (from-to)1-10
JournalAnnals of Noninvasive Electrocardiology
Volume23
Issue number6
Publication statusPublished - Nov 2018
MoE publication typeA1 Journal article-refereed

ID: 27183212