[Induction of coronary artery spasm by combined cold pressor and hyperventilation test in patients with variant angina].

To examine whether or not a combination of nonpharmacologic provocative tests potentiated the occurrence of coronary spasm, the cold pressor test combined with hyperventilation was studied in 22 consecutive patients with variant angina admitted to our hospital. After a 12-lead electrocardiogram and blood pressure were recorded, the patient was asked to hyperventilate vigorously at a rate of 30 respirations per min for 6 min under continuous electrocardiographic monitoring. Immediately after hyperventilation, the cold pressor test was performed with the patient's right hand submerged in ice water for 2 min. In some patients who showed a positive response to the combined test, a hyperventilation and cold pressor test was performed on another day. Positive response (ST segment elevation > or = 0.1 mV) to the combination test was seen in 18 of 22 patients (82%). Positive response to the hyperventilation test was seen in seven of 11 patients (64%). The response to cold pressor test was all negative in seven patients. The onset of electrocardiographic changes by the combined test occurred an average of 120 sec (30-240 sec) after the end of hyperventilation, whereas the onset by hyperventilation test occurred an average of 210 sec later (60-370 sec). These results suggest the combination of the cold pressor test and hyperventilation test potentiated the occurrence of coronary spasm. The combined cold pressor and hyperventilation test is a powerful and useful nonpharmacologic provocative test for coronary artery spasm in patients with variant angina.