Cardiac Output Assessment by Transthoracic Electrical Bio-impedance in Patients of Acute Myocardial Infarction: Comparative Analysis with Echocardiography.

ABSTRACT

Objectives: Transthoracic electrical bio-impedance (TEB) has been proposed as a non-invasive and continuous method of cardiac output (CO) measurement, but it still has not found wide usages in clinics. The present study measured CO, using a new instrument NICOMON, and compared it with Echocardiography (ECHO) in acute myocardial infarction (AMI) patients. Methods: In the present study 100 patients of AMI were assessed by both ECHO and NICOMON for cardiac output and ECHO is considered as a reference method for comparison. TEB CO was measured by passing an alternating current and measuring the bio-impedance across the thorax. End diastolic volume (EDV), End systolic volume (ESV) & Left ventricular outflow tract (LVOT) diameter, measured by ECHO were used to calculate CO. Various statistical methods like "t"-test & correlation coefficient (r) were used where found suitable. Results: Results: Mean TEB-CO (4.03±1.11 l/min) was significantly higher (p<0.001) than mean ECHO-CO (3.80±1.28 l/min) with a mean difference of 0.25±1.02 l/min. Conclusions: NICOMON measures CO non-invasively but, it needs more elaborative studies on a larger sample to establish it as an alternative method of ECHO for cardiac output measurement on regular basis.