RESUMO
INTRODUCTION: Coronary spasm can cause myocardial ischemia and angina in both patients with and without obstructive coronary artery disease. However, provocation tests using intracoronary acetylcholine (ACh) have been rarely performed in the Western world. CASE REPORT: We report a case of a 75-year-old woman with a history of hypertension and a mechanical aortic prosthesis who presented in the emergency room with acute-onset chest pain, widespread ST-segment depression and severe left ventricular systolic dysfunction, with no signs of prosthesis dysfunction. Emergent coronary angiography excluded obstructive coronary artery disease. Pain relief and normalization of ST segment and systolic function occurred within six hours. The patient was treated for a possible thromboembolic myocardial infarction and was discharged home asymptomatic. Two weeks later, cardiac magnetic resonance was performed showing inferoseptal transmural infarct scar, inferior and inferolateral subendocardial infarct and mid-basal ischemia in the anterior and anterolateral walls. She was readmitted with recurrence of chest pain and it was decided to perform a provocation test with ACh. After injection of ACh into the left anterior descending artery, chest pain, ST-segment depression, blood flow impairment (TIMI 1) and transient grade 3 atrioventricular (AV) block occurred. Intracoronary administration of nitrates reversed the coronary spasm and AV conduction disturbances. Twenty minutes later, chest pain and ischemic ST changes recurred; there was no response to vasodilators and the patient developed cardiac arrest with pulseless electrical activity. Advanced life support was maintained for 32 minutes without return of spontaneous circulation. CONCLUSIONS: Provocation tests have a high sensitivity and specificity for the diagnosis of vasospastic angina. Although it is rare, these tests have the potential risk of irreversible spasm leading to arrhythmia and death.