HAEMODYNAMIC CHANGES DURING METHOHEXITONE ANAESTHESIA IN PATIENTS WITH SUPRAVENTRICULAR ARRHYTHMIAS

Abstract

The haemodynamic effects of methohexitone injection were studied in twelve patients who were anaesthetized prior to cardioversion. All had supraventricular arrhythmias, eight had rheumatic mitral valve disease and four had ischaemic heart disease. In the majority of cases there was an increase in heart rate and a fall in cardiac output and stroke volume. The systemic blood pressure fell roughly in parallel with the cardiac output, so that changes in calculated peripheral resistance were slight and variable. Since cardiac output fell in the presence of a raised right atrial pressure it is suggested that methohexitone has a depressant effect on myocardial contractility. Other factors which may have played a part in producing these circulatory changes are considered.