Haemodynamic alterations during ischaemia induced by dobutamine stress testing

Abstract

To identify the haemodynamic response to ischaemia induced by dobutamine stress testing, 15 patients with a first acute myocardial infarction underwent right-sided heart catheterization during dobutamine stress cross-sectional echocardiography. Haemodynamic variables and echocardiography were recorded at rest and during dobutamine infusion at each dose from 5 to a maximum of 40 micrograms kg-1 min-1. Ischaemia was diagnosed by cross-sectional echocardiography if asynergy appeared in at least two ventricular segments other than the area of acute myocardial infarction. Ischaemia was absent in six patients (group I) and identified in nine (group II). Response curves for each haemodynamic variable in the two groups were compared by applying Zerbe's method. The response curves were similar in the two groups for heart rate, arterial, right atrial, pulmonary arterial and pulmonary artery wedge pressures. The response curves were significantly different in groups I and II for thermodilution cardiac output, stroke volume and systemic vascular resistance (P less than 0.05). An increase in stroke volume was observed at low dosage of dobutamine in both groups. From low to maximum dose, stroke volume remained unchanged in group I and was significantly decreased in group II. Ischaemia induced by dobutamine stress testing leads to a decrease in stroke volume with no change in pulmonary artery wedge pressure.

Dobutamine-Atropine Stress Echocardiography

“…Healthy subjects exhibited the expected haemodynamic response to the DASE protocol, that is fully in accordance with previous reports [11,12] and signifi cantly different from the response to bicycle exercise [8] . A lower cardiac stress load in terms of the pressure-rate product was achieved with the DASE protocol, primarily because of an only slight increase in systolic blood pressure and to a lesser degree a smaller increase in heart rate.…”

“…At higher infusion rates (15-40 g/kg/min) the ␤ 1 -mediated positive chronotropic effect is predominant [10] . The net haemodynamic response to dobutamine infusion is therefore a substantial increase in cardiac output through an increased stroke volume and a decreased peripheral vascular resistance resulting in a virtually unchanged blood pressure at lower infusion rates and a further increase in cardiac output through an increase in heart rate with only a modest increase in blood pressure at higher infusion rates [8,11,12] . Atropine has vagolytic properties that are rapid in unset after intravenous administration, the effect duration is 2-4 h, the drug is partly metabolised in the liver and partly excreted through the kidneys.…”

Atropine reduces dobutamine‐induced side effects in ponies undergoing a pharmacological stress protocol

“…In man, dobutamine, like muscular exercise, is known to decrease vascular resistance. However, unlike exercise, during dobutamine infusion venous return is not increased (Pierard et al 1989) and left ventricular volume decreases (Olsen et al 1994). The decreases in venous return and systemic vascular resistance, as well as the shortened time for ventricular filling at high HR, may contribute to the decreases in ventricular volumes and SV observed with high doses of dobutamine (Pellikka et al 1995).…”

Intraoperative Stress Echocardiography

“…Dobutamine is a synthetic catecholamine that binds to cardiac · 1 -and ß 1 -receptors and produces a positive inotropic and chronotropic effect in a dose-dependent manner. It has a short half-life of 2 min and increases cardiac oxygen demand by increasing the heart rate and, to a lesser extent, contractility [15][16][17]. In patients on ß-blocking medication, it can be difficult to reach the required heart rate.…”