Occurrence and morphology of ventricular arrhythmias in apparently normal hearts in relation to late gadolinium enhancement on cardiovascular magnetic resonance

Cardiac magnetic resonance (CMR) is the gold standard for evaluating myocardial fibrosis. Few studies have explored the association between ventricular arrhythmias (VAs) and fibrosis in apparently normal hearts. We aimed to investigate the association between the occurrence and morphology of VAs and left ventricular late gadolinium enhancement (LV-LGE) in patients without known structural heart diseases. This study enrolled 78 patients with apparently normal hearts who underwent 24-h ambulatory Holter electrocardiogram (ECG) and CMR examinations simultaneously. The presence and extent of LGE was determined using CMR imaging and compared based on occurrence and morphology of VAs. The clinical characteristics were also recorded and calculated. LV-LGE was observed in 19 (37.3%) and 4 (14.8%) patients with and without VAs, respectively (P = 0.039). It was more frequently observed in patients with polymorphic VAs (P = 0.024). The polymorphic VAs had a higher tendency of LGE extent than monomorphic VAs, while the difference did not reach statistical significance (P = 0.055). In multivariable analyses, the presence of polymorphic VAs [hazard ratio (HR) 11.19, 95% CI 1.64–76.53, P = 0.014] and hypertension (HR 4.64, 95% CI 1.08–19.99, P = 0.039) were associated with greater prevalence of LV-LGE. In patients without structural heart diseases, besides hypertension, multiple VA morphologies on Holter ambulatory ECG measurements is another important marker of increased incidence of myocardial fibrosis.