[A clinical case: coronary vasospasm induced by exercise after stopping nifedipine therapy].

A 60-year-old man with atypical chest pain not submitted to adequate diagnostic procedures was treated on an empirical basis with nifedipine 20 mg b.i.d. The patient was referred to our institution where a first symptom-limited exercise stress-test during treatment was performed; neither S-T alterations nor clinical symptoms were induced at the maximal tolerated work load. Therefore we suggested a short period of hospital stay to repeat the stress-test after a progressive tapering off of the drug with the aim of obtaining a more definite diagnosis. However the patient refused and an at-home nifedipine withdrawal was planned. Some days later a second test showed marked S-T segment elevation in leads V4 to V6; concomitant high-grade ventricular arrhythmias and anginal pain occurred. Both the ECG alterations and the clinical symptom promptly regressed interrupting the test and administering sublingual isosorbide dinitrate. A coronary angiography performed few days later showed only a single and no significant stenosis of the left anterior descending artery (60%). The clinical and electrocardiographic pictures were therefore attributed to stress-induced vasospastic ischemia. A week later a third maximal stress-test during further treatment with nifedipine was totally negative. The pathophysiological mechanisms of rest and stress-induced vasospastic angina and the usefulness of Ca-blocking agents are discussed.