Effective monitoring of BP control in patients with hypertension (HTN) is essential to prevent complications. This study investigates the effectiveness of the clinical autonomic orthostatic tests for insuring well BP control.
The study included 23 age match subjects; 12 hypertensive males (mean ± SD; 45 ± 14.4 years) and 11 (3 females, 8 males) controls (35.6 ± 9.7 y). Ethical approval and informed consent were obtained. Arterial BPs (mmHg); systolic, diastolic and mean (M), heart rate (HR) (beats/min) and indices of brainstem responses; cardiac vagal tone (CVT; arbitrary units) and cardiac sensitivity to baroreflex (CSB; ms/mmHg) were continuously monitored and recorded using the Neuroscope system (Medifit instruments Ltd, UK). Baseline and two orthostatic tests: first, shifting from recline to supine position and secondly, standing up from a low sitting position were performed in each subject. Each test lasted for about 5 minutes. Data were collected and analyzed. Statistical analysis was performed using two tail student's t test in each group before and after performing orthostatic tests.
All the results during baseline, supine and standing up positions are presented in the attached table1. Hypertensive patients showed inappropriate systolic, diastolic, mean BPs responses associated with inadequate central regulatory mechanism as compared to control subjects during orthostatic tests.
This study demonstrates different but effective approach of using orthostatic tests as a mean to monitor BP control. The tests exhibit complex physiology and the various cardiovascular responses elicited during this simple and short duration study could be used as signs to monitor the efficiency of antihypertensive therapy.