enalapril and Chest-Pain

A variety of clinical syndromes can cause T-wave inversion (TWI), ranging from life-threatening events to benign conditions. One benign cause of TWI is cardiac memory, which is characterized by the transient inversion of T-waves following abnormal activation of the ventricles, commonly due to intermittent left bundle branch block (LBBB), tachydysrhythmias, electrical pacing, or ventricular pre-excitation.. A 72-year-old man presented to the emergency department with chest pain, nausea, vomiting, and headache. Upon arrival, his electrocardiogram (ECG) showed new-onset LBBB with appropriate secondary ST-T wave changes. A subsequent ECG showed disappearance of LBBB and newly inverted T-waves in precordial leads V1-V5, followed by a repeat ECG that again showed LBBB. Serial troponin testing was unremarkable. During hospitalization, echocardiogram and nuclear perfusion stress test were normal. The transient TWIs in this patient were believed to be due to cardiac memory. We performed a literature review and identified 39 published cases of cardiac memory. The most common etiology for cardiac memory was after cardiac pacemaker placement, followed by intermittent LBBB (as was seen in our patient), and post-tachydysrhythmia. Patient ages ranged from 21 to 88 years, with an equal number of cases reported in men and women. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Cardiac memory is a poorly understood, rarely observed phenomenon that can occur in the setting of intermittent LBBB. Testing for acute cardiac ischemia and underlying coronary artery disease is still recommended, as the diagnosis of cardiac memory can only be made after negative workup.

Topics: Aged; Amlodipine; Arrhythmias, Cardiac; Aspirin; Bundle-Branch Block; Chest Pain; Electrocardiography; Emergency Service, Hospital; Enalapril; Headache; Heart Ventricles; Humans; Isosorbide Dinitrate; Male; Nausea; Nitroglycerin; Platelet Aggregation Inhibitors; Vasodilator Agents; Vomiting

The goal of this study was to determine: 1) whether bradykinin (BK) directly stimulates tissue plasminogen activator (tPA) secretion in human coronary circulation, and 2) whether angiotensin-converting enzyme (ACE) inhibition favorably alters the fibrinolytic balance regulated by BK.. Bradykinin is a potent stimulator of tPA secretion in endothelial cells; however, the effect of BK on tPA release in the human coronary circulation has not been studied.. Fifty-six patients with atypical chest pain were randomly assigned to two groups: 25 patients were treated with the ACE inhibitor enalapril (ACE inhibitor group), and 31 were not treated with ACE inhibitors (non-ACE inhibitor group). Graded doses of BK (0.2, 0.6, 2.0 microg/min), acetylcholine (ACh) (30 microg/min) and papaverine (PA) (12 mg) were administered into the left coronary artery. Coronary blood flow (CBF) was evaluated by Doppler flow velocity measurement. Blood samples were taken from the aorta (Ao) and the coronary sinus (CS).. Bradykinin induced similar increases in CBF in both groups. The net tPA release induced by BK was dose-dependently increased in both groups, and the extent of that increase in the ACE inhibitor group was greater than that in the non-ACE inhibitor group. Bradykinin did not alter plasminogen activator inhibitor-1 (PAI-1) levels in the Ao or CS in either group. Neither ACh nor PA altered tPA levels or PAI-1 levels in either group.. Intracoronary infusion of BK stimulates tPA release without causing any change in PAI-1 levels in the human coronary circulation. In addition, this effect of BK is augmented by an ACE inhibitor.

Topics: Acetylcholine; Analysis of Variance; Angiotensin-Converting Enzyme Inhibitors; Blood Flow Velocity; Bradykinin; Cardiac Catheterization; Chest Pain; Coronary Angiography; Coronary Circulation; Drug Synergism; Echocardiography, Doppler; Enalapril; Female; Fibrinolysis; Hemodynamics; Humans; Male; Middle Aged; Myocardial Ischemia; Papaverine; Tissue Plasminogen Activator; Vasodilator Agents

Topics: Aspirin; Bisoprolol; Cardiomyopathies; Cardiotonic Agents; Chest Pain; Dobutamine; Echocardiography, Stress; Enalapril; Humans; Male; Middle Aged; Simvastatin