Inotropic function of myocardium in patients with persistent form of atrial fibrillation receiving antiarrhythmic drugs class Ic

The aim of our study was to evaluate structural changes in the myocardium in patients with persistent AF receiving class I c antiarrhythmic drugs and to determine whether they are hyperdiagnosed and associated with an adverse treatment prognosis. This prospective study included 62 patients undergoing ECV (electrical cardioversion) for persistent form of AF in the Latvian Centre of Cardiology, Pauls Stradins Clinical University Hospital from September 2019 to June 2020. The inclusion criteria were as follows: atrial fibrillation recurrence , patient have not received any antiarrhythmic drugs before (except amiodarone and beta blockers). All patients received beta blockers bisoprolol 5 mg daily, amiodarone 200 mg daily, propaphenone 300 mg daily or aethacizinum 100 mg daily for 6 months from the day of admission to the hospital. Symptoms and safety were evaluated by brain natriuretic peptide (BNP) level, rest electrocardiogram (ECG), exercise test, echocardiography, complete blood count, clinical biochemistry, Holter monitoring and transthoracic electrocardiography. The total number of patients finished study per protocol – n=57. Between AF group and SR group echocardiographic data no significant changes were found. Early diastolic atrial myocardial velocity and strain showed no significant difference between groups. No safety parameters changed significantly in patients completed the study. Recurrence rate of AF in aethacizinum group showed close to statistically significant superiority compared to propafenone (55,6% vs 72,5%) (p=0.05). Patients with higher atrial strain have better opportunity to maintain sinus rhythm. Antiarrhythmic medications of Ic class may be safe in patients with persistent form of atrial fibrillation and have no negative impact on inotropic function of myocardium. The most commonly used drug from Ic class is aethacizinum.