RESISTANT HYPERTENSION AND PREOPERATIVE SILENT-MYOCARDIAL-ISCHEMIA INSURGICAL PATIENTS

We studied 325 patients undergoing elective noncardiac surgery who had preoperative ambulatory ECG monitoring performed for a duration of 51 30 h (range 8-24 h; mean 15.8 h). Sixty-four subjects (20%) had one or more episodes of ST segment depression consistent with myocardial isc haemia. Of all preoperative cardiovascular variables measured, the pre sence of elevated arterial pressure, despite patients being maintained on long term antihypertensive therapy, was the only factor associated significantly with the presence of preoperative silent myocardial isc haemia (P < 0.002). This correlation was confirmed when arterial hyper tension was defined in four separate ways. The incidence of silent isc haemia in these patients was 33-55%. We suggest that admission arteria l pressure may therefore be a useful screening test to identify patien ts at risk of preoperative myocardial ischaemia.