[Effects of antiarrhythmic drugs on some echocardiographic parameters of left ventricular function in patients with...

This study was performed to evaluate the effects of antiarrhythmic drugs on left ventricular function in 843 patients with ischaemic heart disease and ventricular arrhythmias (Lown classes 2-5). Rhythm abnormalities were observed by ambulatory electrocardiographic monitoring before and after 2-weeks of antiarrhythmic therapy. Haemodynamic variables such as cardiac output (CO), ejection fraction (EF), stroke volume (SV), and ratio of myocardial contractility (RMC) were derived from the cross sectional echocardiography. Efficacy of the applied drugs was 42-71%. Of these antiarrhythmic agents only propranolol caused the deterioration of left ventricular performance, measured by CO; in mono-therapy propranolol produced significant changes (p less than 0.05), in combination with amiodarone--at point of significance. Mexiletine produced significant improvement in EF and SV (p less than 0.05). There were no significant changes in haemodynamic parameters after treatment with the other drugs.