Abnormal orthostatic blood pressure control among subjects with lacunar infarction

Hypertension is a recognised risk factor for lacunar stroke. However, their association has been evaluated using static blood pressure (BP) assessment in supine or sitting position alone. We hypothesised that impaired dynamic (orthostatic) BP control may associate with lacunar strokes.

Consecutive subjects with mitral regurgitation (MR) confirmed, lacunar strokes were compared with two control groups. Firstly "normal", age and sex matched, population controls (1:3 ratio) and then 'at risk' controls matched for age, sex, hypertension history and antihypertensive medication (1:2 ratio). Orthostatic BP control was assessed by active stand tests with continuous, phasic, beat-to-beat BP measurement.

Thirty-six subjects (mean 69.9 years) were compared with 108 controls in group 1 and 72 in group 2. Prevalence of syncope was higher among those with lacunar stroke (cases: 44.4%, group 1: 17.6%, p = 0.003, group 2: 12.5%, p = 0.0004, Fisher's exact). Mean baseline systolic BP (SBP) was significantly higher in cases (cases: 150 mm Hg, group 1: 140 mm Hg, p = 0.03, group 2: 143 mm Hg, p = 0.1). Ten seconds after standing, SBP dropped significantly less in cases (cases: -14.1 mm Hg, group 1: -31.4 mm Hg, p < 0.0005, group 2: -27.3 mm Hg, p = 0.001, t test). Diastolic BP also fell significantly less in cases. Cases' SBP and DBP recovered to, then persistently overshot baseline levels.

Subjects with MR-defined lacunar stroke, of likely small vessel aetiology, exhibit orthostatic hypertension compared with population norms.