Abstract-The aim of this study was to elucidate further the precise nature of the so-called "white coat" (WC) effect. We enrolled 88 hypertensive (46 men, 42 women) and 18 normotensive (4 men, 14 women) subjects in whom beat-to-beat blood pressure (BP) and heart rate (HR) were measured with a Finapres device at rest (R period) and during conventional BP measurement (WC period). The WC effect was defined as WC period minus R period values of Finapres systolic BP. Using the same method, we also measured the BP and HR variations induced by mental stress (MS period) and by assuming the standing position (S period). Variability was estimated in the frequency domain for BP (BPV) and HR (HRV) and gave indices of the autonomic nervous system. Pulse wave velocity was taken as an index of arterial distensibility. In hypertensive subjects, the WC effect was significantly and positively correlated with the BP response to stress (0.51, PϽ.0001) and standing (0.63, PϽ.0001). An increased BPV was observed in the low-frequency band (0 to 0.150 Hz) during WC, MS, and S periods. In normotensive subjects, the WC effect was very slight and not correlated with the responses to stress and standing. In this group, the WC period was not accompanied with an increased BPV, unlike the stress and standing periods. HRV was similar in normotensives and in hypertensives: decreased, unchanged, and increased during MS, S, and WC periods, respectively. The PWV was significantly increased in the hypertensives relative to the normotensives, even in the quartile of those with the lowest BP (on average similar to that of the normotensives). This work shows that the WC effect is associated with an enhanced BP response to standing and mental stress; these three situations are characterized by an increased BPV in the low frequencies, suggesting a similar modification of the sympathovagal balance. The WC effect may entail an increased risk because it is associated with impaired arterial distensibility. (Hypertension. 1998;31:1021-1029.)Key Words: hypertension, white coat Ⅲ blood pressure monitoring Ⅲ baroreflex Ⅲ autonomic nervous system W hite coat hypertension is characterized by a difference between office and ambulatory BP. It usually implies that a subject demonstrates "normal" BP levels when measured out of the physician's office but levels in the hypertensive range when taken by a physician using arbitrary conventional criteria.
The objective of this trial was to assess the effects of 6-month daily treatment with two doses of ramipril on left ventricular mass and the dependence of this on blood pressure changes in hypertensive patients with left ventricular hypertrophy. After a selection phase of 4 to 6 weeks with patients under antihypertensive therapy with 20 mg furosemide daily, 115 patients with either controlled or uncontrolled hypertension and left ventricular hypertrophy were randomized in a double-blind manner to receive either placebo (n = 40), 1.25 mg (low dose, n = 38), or 5 mg (regular dose, n = 37) ramipril daily for 6 months. Treatment with furosemide was continued unchanged during this phase. The main outcome measured was left ventricular hypertrophy regression as assessed from central blind reading of echocardiograms recorded at randomization and after 6 months. No significant differences were observed for changes in casual or ambulatory blood pressure between the three groups. Left ventricular mass index was found to be significantly reduced in patients receiving 5 mg ramipril compared with those receiving placebo (-10.8 +/- 3.7 versus +4.1 +/- 4.0 g/m2, P = .008); in patients receiving 1.25 mg ramipril, the difference was close to borderline significance compared with placebo (-7.0 +/- 4.3 g/m2, P = .06). Similar results were observed for changes in left ventricular mass (-20.3 +/- 6.6 and -13.0 +/- 7.8 g in the 5- and 1.25-mg ramipril groups, respectively, versus +9.1 +/- 7.2 g in the placebo group; P = .004 and .04, respectively).(ABSTRACT TRUNCATED AT 250 WORDS)
The present work supports the view that the true WC effect and its estimation are not equivalent. However, the way in which the WC response is defined does not alter its effect on target organs or cardiovascular risk profile.
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