Measurement of haemodynamic parameters during dobutamine echocardiography by automated impedance cardiography

Dobutamine stress echocardiography (DSE) has become a widely used method for the evaluation of patients (PTS) with suspected coronary artery disease (CAD). However, little is known about the haemodynamic effects of such short-term, high-dose dobutamine infusions. The authors investigated 50 PTS who were referred for DSE. Heart rate (HR), stroke volume (SV), cardiac output (CO) and index of contractility (IC) measured by automated impedance cardiography. Baseline values were compared to the corresponding values at peak stress with dobutamine. All PTS underwent coronary angiography within the next 1-7 days. For interpretation of the data, PTS were subdivided into 3 groups: PTS without CAD (A), PTS with single vessel disease (B) and PTS with multivessel disease (C). At baseline, there was no significant difference between the three groups. The infusion of dobutamine resulted to an significant increase of HTI SV, CO and IC in all PTS. At peak stress, there was no significant difference between PTS of group A and B, but PTS of group C showed a significantly smaller increase of SV, CO and IC (p < 0.05). It is concluded that automated impedance cardiography allows continuous haemodynamic monitoring during DSE. In PTS with multivessel disease, the impaired systolic performance of the left ventricle during pharmacological stress could be clearly demonstrated.