Preinfarction angina entailing precordial ST segment depression with positive T wave

Abstract

A 46-year-old male, cigarette smoker with dyslipidemia was admitted because of atypical chest pain associated with nonspecific T wave abnormalities in leads III and aVF. Serial cardiac enzyme evaluation, including troponin, was negative and he was discharged home following absence of exercise-induced ischemia. Three days later, he was readmitted because of acute rest angina. His ECG recorded during pain displayed a heart rate (HR) of 68 beats/min, ST segment depression (STD) with positive and peaked T waves in leads I, II, aVL and V2-V6 and absence of ST segment elevation (STE) in the posterior leads (Fig. 1a). Medical therapy resulted in abolishment of angina and STD resolution, but inverted T waves in leads III and aVF. About 1 h later, angina recurred in association with STD and peaked positive T waves in leads V2-V6, loss of R wave in V2, a Q wave in V3, subtle STE in lead III, pseudonormalization of the T wave in aVF and STD in I and aVL (Fig. 1b). Echocardiography during this phase displayed left anterior descending artery (LADA)-related segmental akinesia. Angina continued despite maximally tolerated medical therapy and provided the acute ischemic ECG changes, we recommended urgent coronary angiography. However, the patient expressed his preference to have this examination done in a private hospital, thus immediate transfer was arranged. Unfortunately, a precatheterization ECG was not performed, but provided that the angiogram displayed a total proximal LADA occlusion (Fig. 2) without collateral flow, we presumed that the ECG showed an STE pattern. The left circumflex (LCx) artery contained an intermediate proximal stenosis, whereas the dominant right coronary artery (RCA) was free of atherosclerosis (Fig. 2). The LADA was successfully tackled with a sirolimus-eluting stent. Creatine kinase and creatine kinase-myocardial band isoenzyme peaked at 3127 IU/l (reference value: 26-171 IU/l) and 247 IU/l (reference value: 0-25 IU/l), respectively. The patient was discharged home following a 6-day uneventful hospital course and ECG evidence of a Q wave anterior myocardial infarction (MI) (Fig. 3). The dobutamine stress echocardiogram performed to assess the functional significance of the LCx artery stenosis was negative, thus this lesion was deferred. CommentThe ECG pattern of precordial STD with positive T wave is an unusual manifestation of acute ischemic heart disease. It has been ascribed to regional subendocardial ischemia of the anterior wall produced by a subtotal occlusion or total occlusion with collateral flow of the LADA, in which case it is maximally recorded in leads V2-V4. [1][2][3][4][5][6][7] In addition, such an ECG presentation has been documented along with a total occlusion of the first diagonal branch, in which case it represents subendocardial ischemia of the border zone surrounding the area of mid-anterior transmural ischemia; it is recorded in leads V4-V5 and sometimes in V3 along with STE in leads aVL and V2 and sometimes in I. [2][3][4][5]8 This ECG pattern has been presented by Pruitt e...