[Influence of cold-stimuli on hemodynamics and coronary diameters. Provocation of coronary artery spasm]

In 32 patients with coronary heart disease the influence of different cold-stimuli on hemodynamic parameters and coronary artery diameter was examined during left heart catheterization. The cold pressor test (CPT) and the cold air inhalation test (CAIT) were applied to 16 patients in random sequence. 16 patients served as control group. Systolic and diastolic blood pressure increased more under CPT (by 15 and 10 mm Hg respectively) than under CAIT (by 10 and 3 mm Hg). Heart rate and left ventricular enddiastolic pressure did not change. Proximal and distal coronary segment diameters showed a slight, not statistically significant increase under cold-stimuli. All 4 patients with a history of angina pectoris at rest developed coronary spasm, some with ischemic ECG changes; spasm and symptoms disappeared spontaneously when the cold-stimulus was withdrawn. Patients with a history of angina pectoris under cold conditions showed no pathological reactions. It is concluded that two different mechanisms may cause angina pectoris under cold-stimuli. First, the oxygen-consuming effect of an increase in blood pressure, and secondly, an immediate coronary vasospastic reaction. The combined use of CPT and CAIT seems to be an effective and safe means of identifying patients with a tendency to coronary artery spasms.