Association Between Left Ventricular Diastolic Dysfunction and Subsequent Detection of Sick Sinus Syndrome and Atrial Fibrillation in Patients With Unexplained Syncope

ABSTRACT Background Atrial fibrillation (AF) and sick sinus syndrome (SSS) frequently coexist and may share common atrial structural and electrophysiological remodeling substrates. Left ventricular (LV) diastolic dysfunction frequently coexists with AF; however, its association with subsequent detection of SSS and AF remains incompletely understood. This study investigated whether LV diastolic dysfunction is associated with the detection of SSS and AF. Methods This study included patients who underwent insertable cardiac monitor implantation for recurrent unexplained syncope. Patients with prior AF, LV ejection fraction < 50%, or without remote monitoring were excluded. LV diastolic dysfunction was assessed using the HFA‐PEFF score. The primary endpoints were SSS requiring pacemaker implantation and AF during follow‐up. Results Among 164 patients (median age 71 years; 34.1% women; median follow‐up 35 months), SSS was detected in 31 patients (18.9%), and AF episodes lasting ≥ 6 min were detected in 48 patients (29.3%). Patients with high HFA‐PEFF scores (5, 6) had a significantly higher risk of detection of SSS and AF. The HFA‐PEFF score remained independently associated with SSS (hazard ratio HR, 1.51; 95% confidence interval CI, 1.07–2.13; p = 0.021) and AF lasting ≥ 6 min (HR, 1.94; 95% CI, 1.40–2.67; p < 0.001) after multivariable adjustment. Conclusion LV diastolic dysfunction, as quantified by the HFA‐PEFF score, is independently associated with the detection of SSS and AF, suggesting a potential association between LV diastolic dysfunction and arrhythmogenic atrial remodeling substrates.