CV Response to Mental Stress:Mechanistic Considerations

Yale University, New Haven CT

Investigators

Linked publications & trials

Abstract

[unreadable] DESCRIPTION (provided by applicant): It is presumed that mental stress induced regional wall motion abnormalities and/or a decrement in left ventricular performance as measured by LVEF are a result of ischemia. Mental stress induced ischemia (MSI) is presumed to be a result of reduced regional coronary blood flow to the extent that myocardial demand is not adequately addressed. However there are several physiologic factors, which are specific to psychological stress, that confound a single measurement as a suitable gold standard and/or physiologic signature for MSI. Most notably, recent studies from the PIMI trial and our group have demonstrated a decrement in LV performance in normal subjects in response to MS. Furthermore, these studies and others have demonstrated a concomitant increase in peripheral vascular resistance (PVR). This increase in PVR differs from stress exercise and may reflect differences in the peripheral sympathetic response. This may alter the cardiac response and the attendant specificity of a given measurement as a marker of ischemia. Our group and others have demonstrated, that a reduced blood flow response to mental stress may occur in epicardial vessels which do not demonstrate significant coronary artery disease. The importance of identifying the factors that are specific to the myocardial response to MSI is central to ongoing and future studies that pursue the prognostic and clinical factors of psychologically mediated mental stress. The overall aim of this investigation is to identify the relationship between myocardial flow, function and peripheral hemodynamics that is most specific for ischemia during mental stress. We hypothesize that those subjects with a decrement in myocardial flow and/or function during mental stress that is not attributable to the associated hemodynamic response alone, will have a prognosis worse than predicted by their standard exercise/dipyridamole perfusion study. We will study 200 patients with chronic CAD who have had a recent abnormal myocardial perfusion study. These patients will undergo simultaneous echocardiography, myocardial perfusion SPECT and assessment of peripheral arterial tone at rest and during a mentally stressful task (anger recall, which is robust and reproducible). Regional and global LV function data, myocardial perfusion and hemodynamics in these subjects during rest and stress will be assessed and subjects will be categorized according to their degree of functional coronary perfusion, and hemodynamic response. These data will be compared to their predicted cardiovascular outcome as based upon the widely accepted criteria by their initial exercise/dipyridamole myocardial perfusion studies. [unreadable] [unreadable]