Evaluation of acute stress-induced regional myocardial ischemia: Comparison of regional contractile and metabolic indices to easily accessible global left ventricular indices

Publisher Website
Google Scholar
Abstract
In clinical studies stress-induced myocardial ischemia in patients with coronary artery disease is used to evaluate the severity of this disease. The discussion on the importance of some parameters measured during this intervention is controversial, other parameters are difficult to obtain. On the basis of an experimental model of stress-induced myocardial ischemia, we tried to find an index that reflects best this cardiac state. We therefore compared in eight anesthetized open-chest dogs control conditions with three other hemodynamic states with increasing imbalance between myocardial oxygen demand and oxygen supply: severe stenosis on circumflex coronary artery, 60 s cardiac sympathetic nerve stimulation (CSNS) with a severe stenosis on circumflex coronary artery, and 60 s complete occlusion of circumflex coronary artery. Using a one-way analysis of variance, we found two significantly changed parameters during the stressinduced ischemia: Regional lactate extraction was turned to production (32 ± 4 vs. −4 ± 1%) and the ratio ofdP/dt min todP/dt max was decreased (1.13 ± 0.05 vs. 0.67 ± 0.05; control vs. CSNS with a severe stenosis on circumflex coronary artery). We conclude that the ratio ofdP/dt min todP/dt max is an easily accessible, sensitive, and dynamic index for characterization of an stress-induced myocardial ischemia.