Influence of Left Ventricular Morphology and Functions in The Accuracy of Non- Invasive Blood Pressure NIBP Recording Compared to Intra-Arterial Pressure IAP - A Correlative Study

Abstract

Non-invasive blood pressure measurement with a brachial cuff sphygmomanometer is an important assessment tool in the diagnosis and management of hypertension and disturbed hemodynamic status. However, when compared to intra-arterial BP, the accuracy of BP measured by non-invasive methods remains questionable. The study attempted to estimate the difference in blood pressure measured by the two methods, as well as analyse the impact of left ventricular morphology and functions on the magnitude of the BP difference recorded by invasive and non-invasive methods. Methods: The subjects were patients undergoing diagnostic coronary angiography for the evaluation of chest pain. The morphology and functions of the left ventricle were determined as part of the routine pre procedural screening. NIBP and IAP were measured twice during the CAG at the radial and aortic levels. Noninvasive BP was measured using a brachial cuff of mercury sphygmomanometer by the auscultatory method. Results of our study revealed that in non-invasive BP both the systolic and the diastolic pressures were higher than their corresponding recordings obtained by invasive methods. The ECHO-derived left ventricular hypertrophy and left ventricular diastolic function correlated positively with the systolic and diastolic pressure differences respectively. Conclusion: Hence we suggest evaluation of the above parameters by echocardiography after obtaining a high BP by non-invasive methods can be done before the commencement of antihypertensive drugs A pre-treatment echo will give a clue on the differences.