Cold Exposure and Left Ventricular Diastolic Performance In Coronary Artery Disease

Abstract

It is known that cold exposure is accompanied by coronary artery vasoconstriction and ischemia in patients with coronary artery disease (CAD). The aim of the present study was to evaluate the response of left ventricular (LV) diastolic and systolic functions, estimated by means of Doppler echocardiography, to cold pressor test (CPT) in patients with CAD. Twenty- five male patients (mean age 50.8 ±8.1 years) with documented CAD underwent CPT with Doppler echocardiographic assessment of LV diastolic and systolic functions. According to the development of ischemic response to CPT, all patients were divided into 2 groups: group 1,10 patients with ischemia and group 2, 15 patients without ischemia during CPT. Cold exposure caused significant increase in blood pressure with no changes in heart rate in all CAD patients. Patients with signs of ischemia during cold exposure had lower transmitral flow velocity during early filling (p < 0.001), prolonged isovolumic relaxation time (p < 0.04), shortened deceleration time of early transmitral flow velocity (p < 0.001), and higher values of Doppler-derived index of myocardial performance (p< 0.0001) than those without ischemic response to CPT. Cold exposure in CAD patients through stimulating of vasoconstriction and ischemia was associated with derangements in LV myocardial performance, manifested by delayed relaxation, impaired stiffness, and reduced contractility.