Effects of the cold pressor test on the left ventricular function of patients with coronary artery disease

We used the cold pressor test as provocative of myocardial ischemia in 23 subjects evaluated for chest pain on effort. Seven of them (group N) had normal coronary arteries, and 16 (group CAD) had critical stenoses along the main branches of the left coronary artery. In both groups exposure to cold induced increase in arterial pressure and double product. Left ventricular end-diastolic pressure increased +60% from baseline (P <0.001). Angiocardiographic parameters, unchanged in group N, showed an impairment of left ventricular function in group CAD. End-diastolic volume increased +11% (P <0.01), ejection fraction decreased -8% (P <0.0025), with a significant reduction in segmental wall motion in the area of the diseased artery (P <0.001). The mean V_cf was slightly and not significantly reduced, while early-systolic and end-diastolic stress and the constant of stiffness consistently increased in both groups. The appearance or extension of ventricular wall contraction abnormalities in group CAD, in the absence of demonstrable coronary spasm and in the presence of a remarkable increase in left ventricular end-diastolic pressure and stress, was interpreted as due to ischemia secondary to increased extravascular resistances to coronary flow. The cold pressor test is proposed as a useful tool for the diagnosis and evaluation of patients with ischemic heart disease.