Diagnosis of myocardial infarction during long-standing coronary artery spasm and uptitration of nitroglycerin

Excerpt

A 57-year-old man presented to our emergency service with typical angina pectoris of 5-h duration. Electrocardiography (ECG) revealed normal sinus rhythm without any ischemic signs and a heart rate of 74 bpm (Fig. 1). His blood pressure was 120/70 mmHg. The rest of the physical examination was unremarkable. The patient described having intermittent chest pain attacks at rest with a short duration of 3 or 5 min. To determine the etiology, transthoracic echocardiography (TTE) was performed after complete blood tests and cardiac biomarker measurements. TTE revealed hypokinesis in the anterior, anterior septal, and anterolateral segments of the left ventricle with an ejection fraction of 45–50 %. Without waiting for the results of the cardiac biomarkers, we performed coronary angiography because of the hypokinesis in the anterior segments and ongoing ischemia. Coronary angiography revealed about 95 % stenosis in the proximal part of left anterior descending artery (LAD) followed by a relatively normal coronary artery segment and diffuse, very thin mid and distal portions (Fig. 2 a, Video 1) with 70 % stenosis of the circumflex (Cx) coronary artery between the second and third obtuse marginal coronary artery (Fig. 3 a, Video 2). The right coronary artery was found to be normal. Before percutaneous coronary intervention (PCI) for the LAD, intracoronary nitroglycerin (200 μg) was injected to exclude the vasospasm of the coronary arteries. Control angiography showed dilatation of the LAD (Fig. 2 b, Video3). After doubling the dose of nitroglycerin, there was a great dilatation of the LAD (Fig. 2 c, Video 4) and Cx artery (Fig. 3 b, Video 5) without any stenotic lesion. Cardiac biomarkers disclosed high values of creatine kinase myocardial band and troponin I: 68 U/l (normal range: 0–24) and 16.6 ng/ml (normal range: 0–0.1), respectively. The diagnosis of non-ST-segment elevation myocardial infarction as a result of variant angina was proposed. The patient did not complain of angina pectoris with the medication of oral diltiazem and nitroglycerin. A check-up TTE showed normal systolic function of the left ventricle. He was discharged from our hospital in stable condition. …