Surface Recording of Aortic Pressure Wave from Aortic Area of Auscultation in Women with Hypertension: A New Idea to Indirectly Monitor Aortic Pressure

Abstract

Blood pressure recording from the peripheral artery is subject to variations. While blood pressure is said to a modifiable risk factor for many cardiovascular and neurological diseases, the diagnosis of hypertension using Sphygmomanometry must be complemented with other tests to find central blood pressures. A newer, non-invasive method to indirectly record the aortic pressures is required. Aim of the study is to record surface aortic pressure waves (SAP) from aortic area of auscultation during breath holding and to compare the wave characteristics in hypertensive and normotensive women at rest and after mild exercise. 128 women were recruited in the study. Piezoelectric sensor placed in the aortic area was used for getting the SAP waves during breath holding for 30 seconds. ECG was taken to show temporal association of these waves to R waves. Mean arterial pressures from arm (map-a) and from SAP waves (map-s) were calculated. Powerlab 8/35 and Labchart Pro software by AD Instruments were used in the study. R waves were followed by the SAP waves by about 31±2.2 ms at rest and 11±2.4 ms after mild exercise in all subjects. In hypertensive women, the map-s values were significantly (p < 0.05) lower in magnitude than in normotensive women both at rest and after exercise. There was no significant correlation between the map-a and map-s in any of the groups at rest or after exercise. This new method, with some refinement could prove as a better alternative to blood pressure recording.