The effect of sotalol on dynamic cardiac function and prevention of supraventricular tachycardias after coronary artery bypass graft surgery

Low-dose sotalol has been reported to reduce the occurrence of early supraventricular tachyarrhythmias (SVT) after coronary artery bypass grafting (CABG) with few clinical complications. This study aimed to quantify the haemodynamic effects of low-dose sotalol when used for this purpose and to determine the incidence of supraventricular tachyarrhythmias within the same patient group. A group of 31 consecutive patients, who had preoperatively taken beta-blocker agents and possessed no contraindications, were commenced on 40 mg sotalol taken orally 3 times a day 15–20 hours postoperatively. Haemodynamic parameters were recorded over the subsequent 2 hours at set intervals as plasma levels of sotalol rose. Dysrhythmias occurring during the subsequent 7 days were documented including significant symptoms suggesting haemodynamic abnormalities. The study had no control group to detect time-dependent effects. Sotalol significantly reduced heart rate (HR) and cardiac index (CI), whilst systemic vascular resistance index (SVRI) increased. Heart rate decreased progressively, CI decreased late, and SVRI increased early after initial administration (p<0.05). Blood pressure (BP) and pulmonary artery wedge pressure (PAWP) did not change significantly in the same period. Five of 31 patients had profound reduction in CI and HR, requiring temporary atrial pacing to improve haemodynamic parameters, whilst 1 patient had significant fall in BP and HR after sotalol. Six (19%) patients developed an SVT within 4 days despite prophylactic sotalol therapy. None was clinically compromised by the arrhythmia. Utilising sotalol as prophylaxis against SVT is controversial when considering its efficacy and the potential adverse haemodynamic effects in patients after CABG.