HYPERTENSION AND SILENT-MYOCARDIAL-ISCHEMIA - THEIR INFLUENCE ON CARDIOVASCULAR MORTALITY AND MORBIDITY

The presence of ST-segment depression during ambulatory electrocardiog raphic monitoring, in relation to blood pressure treatment and control , was monitored in a non-randomized study in 167 men (49%) from the 'M en born in 1914' Malmo study, who were considered to have hypertension (diastolic blood pressure [DBP], greater than or equal to 95 mm Hg or receiving antihypertensive therapy). Men were excluded if they had a history of ischemic heart disease. A high frequency of ST-segment depr ession (41%) and associated high cardiac event rate (14%) were found i n hypertensive elderly men who had inadequately controlled blood press ure (i.e. DBP greater than or equal to 95 mm Hg). This was associated with a relative risk of a cardiac event of 9.8 (95% confidence interva l: 2.6-36.9), even after adjustment for smoking, blood lipids and alco hol consumption. The lower frequency of ST-segment depression (21%) an d lower cardiac event rate (5%) in hypertensive men with adequate bloo d pressure control suggests that effective antihypertensive treatment leads to a reduced event rate. In conclusion, the occurrence of ST-seg ment depression during ambulatory electrocardiographic monitoring in t his group of subjects may be an expression of silent myocardial ischem ia, with or without left ventricular hypertrophy. The incidence of asy mptomatic ST-segment depression and the rate of cardiac events in hype rtensive patients may be, in part, related to the level of blood press ure control attained.