Chest pain associated with rate-related left bundle branch block and cardiac memory mimicking ischemia.

BACKGROUND: Intermittent left bundle branch block (LBBB) has been linked to chest pain, and causes cardiac memory electrocardiographic (ECG) changes mimicking ischemia. PURPOSE: To present a case of chest pain with ECG abnormalities suggestive of ischemia, both likely caused by LBBB. CASE: A 33-year-old hypertensive female evaluated for chest pain and LBBB by ECG was treated with lisinopril and metoprolol, and scheduled for stress testing. A 12-lead ECG performed prior to the stress test, due to recurrence of the chest pain the preceding night, showed resolution of the LBBB with a lower heart rate, and T-wave inversions in the precordial leads suggestive of ischemia. She developed chest pains with reappearance of LBBB during stress testing, which prompted cardiac catheterization. This revealed normal coronaries and left ventricular systolic function. The ECG abnormalities were in retrospect likely due to cardiac memory. Her chest pains may have been caused by the intermittent, rate-related LBBB, as control of her heart rate and blood pressure with metoprolol and lisinopril improved her symptoms on follow-up. CONCLUSION: Intermittent LBBB causes chest pain and electrocardiographic abnormalities suggestive of ischemia in the absence of obstructive coronary disease. Certain clinical and electrocardiographic features may provide clues to a non-ischemic etiology..

Persistent right superior vena cava in a patient with dextrocardia: Case report and review of the literature.

INTRODUCTION: Systemic venous circulation anomalies are uncommon; they are often incidental findings during echocardiography. CASE: A 56-year-old man, with dextrocardia, was evaluated for dyspnea. The patient's medical history included diabetes mellitus requiring insulin treatment, hypertension, and tobacco use. Physical examination revealed normal jugular venous pulsations and clear lungs. Cardiac examination revealed normal heart sounds, and grade II/VI systolic ejection murmur over the right precordium. Echocardiography revealed normal chamber size and systolic function, without significant valvular lesions. The coronary sinus was dilated. It was evaluated using intravenous agitated saline contrast to rule out anomalous venous drainage or shunting. When injected into the left antecubital vein, contrast appeared initially in the right atrium followed by the right ventricle. However, when injected into the right antecubital vein, contrast appeared initially in the dilated coronary sinus followed by the right atrium and right ventricle. There was no evidence of intracardiac shunting. These findings were consistent with persistent right superior vena cava in the setting of situs inversus dextrocardia, with normally draining left superior vena cava. CONCLUSION: Persistent superior vena cava connection to the coronary sinus is often incidental but an important finding which helps in planning safe invasive procedures..

ST-elevation myocardial infarction in the presence of biventricular paced rhythm.

BACKGROUND: In the diagnosis of acute myocardial infarction (AMI), the presence of baseline left bundle branch block or a permanent pacemaker rhythm poses a challenge. OBJECTIVE: We present a case report highlighting this challenge, along with a review of pertinent literature. CASE REPORT: A 70-year-old female with known severe idiopathic dilated cardiomyopathy and moderate coronary artery disease who was status post-biventricular pacemaker/implantable cardioverter defibrillator insertion was brought to our institution via Emergency Medical Services with recurrent firing of her implantable cardioverter defibrillator and syncope. After stabilization in the Emergency Department and treatment with intravenous amiodarone, the patient admitted to having ongoing chest pains. The electrocardiogram revealed evidence of biventricular pacing with superimposed ST-segment elevations in the anterolateral leads indicative of myocardial injury. She underwent prompt angiography, thrombectomy, and bare-metal stent insertion to a totally occluded proximal left anterior descending coronary artery, with resolution of her chest pain and improvement in the ST-segment changes. CONCLUSIONS: Despite proposed criteria that aid in the recognition of AMI with underlying left bundle branch block and paced rhythm; the advent of new pacing modalities and the potential variability of pacing sites impose additional diagnostic challenges requiring higher level of suspicion and better physician awareness.