Cardiac response of Nigerian hypertensives to anaesthesia and surgery.

This study was undertaken to determine the cardiac response of Nigerian hypertensives to anaesthesia and surgery, using systolic time intervals as an indication of ventricular function. Nine hypertensive and eight normotensive patients who were admitted for various operations had carotidogram, phonocardiogram and electrocardiogram recorded simultaneously before induction of anaesthesia, after induction and during operation. The pre-ejection phase, (PEP) and the left ventricular ejection time (LVET) were measured from the tracings and the ratio PEP/LVET was calculated. The results showed that for both normotensive patients and hypertensive patients there was a mean increase of the PEP/LVET ratio under anaesthesia and surgery, indicating deterioration of ventricular function. Hypertensive patients showed a much greater deviation from normal, approaching heart failure values. It is concluded that hypertensive patients seemed to be at greater risk during anaesthesia and surgery. The implication is that hypertensive patients should be adequately treated before operation.