Abstract
BACKGROUND: Idiopathic premature ventricular contractions (PVCs) are defined as PVCs in the absence of obvious structural heart disease, which is typically excluded by electrocardiography (ECG), echocardiography. The purpose of this study was to investigate the prevalence of subclinical myocardial changes detected by cardiac magnetic resonance imaging (CMRI) in patients with idiopathic PVCs. METHODS: In this cross-sectional study, thirty-three patients (age 54 ± 17 years, 19 male) with idiopathic PVCs diagnosed using ECG and echocardiography who subsequently underwent CMRI at 3-Tesra between September 2019 and May 2024 were included in this study. CMRI, including late gadolinium enhancement (LGE), native T1 values, and extracellular volume fraction (ECV), was performed. RESULTS: PVCs most frequently originated from the right ventricular outflow tract (15 of 33 patients, 45%). CMR identified myocardial changes in 17/33 (52%). LGE was present in 11/33 (33%). Importantly, mapping-derived indices (native T1 values/ECV) revealed subclinical interstitial changes in several patients, including those without LGE (four with elevated native T1 and two with elevated ECV). Among patients with myocardial changes, the incidence of non-sustained ventricular tachycardia and the maximum consecutive number of PVCs were significantly higher than in those without myocardial changes (P < 0.05 for both). CONCLUSIONS: In this exploratory study, multiparametric CMRI frequently revealed subclinical myocardial changes in patients with idiopathic PVCs despite normal ECG and echocardiography. Given the small sample size and the heterogeneous, ECG-based estimation of PVC origin, these findings should be considered hypothesis-generating, and larger studies are warranted.