The alkalinization test in the diagnosis of spontaneous angina

: The induction of alkalosis has been proposed as provocative test of coronary spasm in patients affected by vasospastic angina. We submitted to the test 43 patients, affected by angina with a previous documentation of spontaneous ischemia (19 patients with ST elevation and 24 patients with ST depression at the EKG registered during pain). Twelve patients had normal coronary arteries; in 14 patients a significant stenosis of a single vessel was present; in 15 patients 2 vessels were involved and in 2 a 3-vessel disease was demonstrated. The test induced ischemia in 17 patients (39.6%). The positivity of the test was strictly dependent on the period of time elapsed between the last documented crisis of angina and the provocative test: it induced ischemia in 75% of the patients who underwent the test in the acute phase: on the other hand it was constantly negative in patients who had not complained of anginal pain for more than 6 months. In the screening of patients with chest pain at rest, the test of alkalosis does not seem, therefore, useful as a diagnostic tool.