Introduction: Paroxysmal supraventricular tachycardias (PSVT) are among common cardiac arrhythmias. Atrial fibrosis correlates with several cardiac dysrhythmias and while its role is well described in atrial fibrillation, its role in PSVTs is less clear. We sought to investigate the extent of left atrial (LA) and right atrial (RA) enhancement in patients with supraventricular tachycardia (SVT) without a history of atrial fibrillation.
Methods and Results: In our case-control study the information of 212 patients was collected. 30 patients with PSVT (age 48.6 ± 20.1 and 43% male) and 182 patients with no known arrhythmic disorder as the control group (age 50.3 ± 14.7 and 66% males) matched for age, LA volume, left ventricular ejection fraction (LVEF) and other comorbidities such as hypertension, hyperlipidemia, diabetes, coronary artery disease, heart failure, and smoking. LA and RA fibrosis were quantified by the Late Gadolinium Enhanced Magnetic Resonance Imaging (LGE-MRI) using signal intensity analysis. The average % LA wall enhancements were 15.2% ± 6.3% in the SVT group and 10.7% ± 6.5% in the control group (p = 0.001) while for RA enhancement they were 11.1% ± 5% and 8.1% ± 4.1% for the SVT and control groups respectively (p = 0.009). Our logistic regression analysis showed that for each 1% increase in LA and RA enhancement, there was a 19% and 16% greater chance of having PSVT (p = 0.006, p = 0.013 respectively).
Conclusions: Our study suggests that the extent of atrial fibrosis (either in the left or right atrium), quantified using LGE-MRI, is higher among patients with PSVT. The impact of increased atrial fibrosis in this patient population, could be correlated with other major adverse cardiac events.