ABSTRACT
Aim To investigate the effects of dagliflozin (DAPA) on atrial tachyarrhythmia (AT) in rats with right heart failure (RHF) due to pulmonary arterial hypertension (PAH) and the underlying mechanisms. Methods Sixty male SD rats were randomly divided into four groups: control group (CTL group), model group (MCT group), MCT + low-dose DAPA intervention group (MCT + LD group) and MCT + high-dose DAPA intervention group (MCT + HD group). After 35 days of continuous intervention, the model and cardiac function evaluation, atrial structural remodelling assessment, inflammatory factor detection, and in vivo cardiac electrophysiology experiments were completed. Results DAPA reduced menn pulmonaryarterial pressure (mPAP) and menn right ventricular pressure (mRVP) in the model rats (P <0.05), attenuated the inflammatory response (P < 0.05), reduced right atrial fibrosis (P <0.05), reduced AT induction rate (P < 0.05) and mean atrial tachyarrhythmia duration (MATD) (P < 0.05), the extent of which was more pronounced in the high-dose DAPA intervention group. Conclusions DAPA can reduce AT susceptibility in PAH-induced RHF rats, and the mechanisms may be related to the inhibition of systemic inflammation and anti-atrial fibrosis by DAPA.
ABSTRACT
Objective: To observe the outcomes of radiofrequency ablation in patients with atrial tachyarrhythmia (ATa) after circumferential pulmonary vein isolation (CPVI), so as to discuss the related mechanism. Methods: A total of 64 patients underwent mapping and ablation using an electroanatomic mapping system (CARTO) at a mean of (3.7±2.4) months after the first CPVA procedure. Results: A total of 78 types of ATa were mapped, including 30 (38.5%) with re-entry mechanism and 48 (61.5%) with focal mechanism. Among reentrant ATa 12 had common atrial flutter and 18 had left atrial re-entry; the reentrant circuits were related to the mitral isthmus, the anterior wall of the left atrium, and the gaps on previous encircling lines. The tachycardias were unstable in 2 patients and were not mapped. Catheter ablation was successful in 56 of the 64 patients (87.5%), and cardioversion was needed in 8 patients to achieve sinus rhythm. During a mean follow-up of 13-21(16.5±2.9) months, 60 (93.8%) cases no longer had ATa. Conclusion: ATa after CPVA can have macro-reentrant and focal mechanisms. These arrhythmias can be successfully mapped and ablated with an electroanatomic mapping system.