Abstract 15035: Differential Effects on Left Ventricular Contractility: A Comparison Between Dobutamine vs Exercise Stress Echocardiography
Background: Stress echocardiography is an important tool for the diagnosis, risk stratification and prognosis of patients with known or suspected coronary artery disease. Achievement of a diagnostic stress test is based on heart rate (HR) and double product (DP) criteria which are applied to both dobutamine (DSE) and exercise (ESE) stress echocardiography. However, DSE affects cardiac contractility directly whereas ESE induces physiological responses to increase myocardial workload. Thus a diagnostic stress may be achieved at a lower HR/DP goal for dobutamine versus exercise due to differential effects on myocardial workload. We hypothesized that dobutamine and exercise stress have differential effects on left ventricular (LV) workload including LV volumetric changes and the deformation of the LV myocardium. The aim of this study is to explore the effects of pharmacological vs exercise stress echocardiography to determine if similar information can be concluded from a submaximal DSE as an optimal ESE.
Methods: 125 patients with negative stress echocardiograph were enrolled LV volumes (ESV, EDV), EF and peak systolic global longitudinal strain (GLS) and circumferential strain (CS) by 2D speckle tracking were measured. The patients were divided into four groups according to if the target heart rate is achieved.
Results: At peak stress, DSE led to greater decrease in ESV and greater increase in EF and CS than ESE. Importantly, those with submaximal DSE had greater decrease in ESV(-44.6±21.5% vs -22.0±12.3%, P<0.001) and greater increase in CS(32.0±9.0% vs 22.4±13.4%, P=0.02) than optimal ESE despite achievement of greater HR and DP with ESE.
Conclusions: DSE and ESE have significantly different effects on parameters of myocardial contractility. And submaximal DSE resulted in a greater reduction in ESV and greater increase in CS compared to optimal ESE, suggesting a submaximal DSE may reveal similar information as an optimal ESE.<!--EndFragment-->
- © 2013 by American Heart Association, Inc.