[Incidental high blood pressure in family practice: due to hypertension and/or left ventricular hypertrophy in more than half of the patients]

OBJECTIVE: To determine if patients with incidentally high blood pressure actually have hypertension and if these patients have an increased left ventricular mass. DESIGN: Cross-sectional study. SETTING: Two family practices with 8 general practitioners in Leiden and Noordwijk, the Netherlands. METHODS: From the Family Practice Network in the Leiden area 133 (67{\%}) out of 200 patients with incidental high blood pressure, who did not receive antihypertensive medication, participated in the study. Their blood pressure was measured 6 times with a mercury manometer, an automatic, non-invasive ambulatory blood pressure monitoring during 24 hours was performed once and their left ventricular mass was measured by means of echocardiography. RESULTS: Of the 133 selected patients 46{\%} had a mean diastolic blood pressure > 95 mmHg measured with the mercury manometer and 64{\%} had a mean 24-hr diastolic blood pressure > 90 mmHg measured with the ambulatory blood pressure monitor. The correlation between both blood pressure measurements was moderate (correlation coefficient 0.73). Left ventricular hypertrophy was found in 53{\%} of the patients, irrespective of their blood pressures. CONCLUSION: In this investigation 45-65{\%} of patients with an incidentally high blood pressure had a mean diastolic pressure > 95 mmHg as measured with a mercury manometer and (or) a mean 24-hr diastolic blood pressure > 90 mmHg as measured with the ambulatory blood pressure monitor; 53{\%} had left ventricular hypertrophy