Thein Tun Aung

LONG TERM MORTALITY RATES OF U.S. VETERANS WITH BUNDLE BRANCH BLOCKS PRESENTING FOR CORONARY ANGIOGRAPHY

Background: The evidence for left bundle branch block (LBBB) or right bundle branch block (RBBB) being a better predictor of mortality is inconsistent. A retrospective analysis was conducted to determine if BBB is an independent risk factor for mortality in a cohort of U.S. Veterans with

Electromagnetic Interference from Swimming Pool Generator Current Causing Inappropriate ICD Discharges

Electromagnetic interference (EMI) includes any electromagnetic field signal that can be detected by device circuitry, with potentially serious consequences: incorrect sensing, pacing, device mode switching, and defibrillation. This is a unique case of extracardiac EMI by alternating current leakage from a submerged motor used to recycle chlorinated water, resulting in false rhythm detection and inappropriate ICD discharge. A 31-year-old female with arrhythmogenic right ventricular cardiomyopathy and Medtronic dual-chamber ICD placement presented after several inappropriate ICD shocks at the public swimming pool. Patient had never received prior shocks and device was appropriate at all regular follow-ups. Intracardiac electrograms revealed unique, high-frequency signals at exactly 120 msec suggestive of EMI from a strong external source of alternating current. Electrical artifact was incorrectly sensed as a ventricular arrhythmia which resulted in discharge. ICD parameters including sensing, pacing thresholds, and impedance were all normal suggesting against device malfunction. With device failure and intracardiac sources excluded, EMI was therefore strongly suspected. Avoidance of EMI source brought complete resolution with no further inappropriate shocks. After exclusion of intracardiac interference, device malfunction, and abnormal settings, extracardiac etiologies such as EMI must be thoughtfully considered and excluded. Elimination of inappropriate shocks is to “first, do no harm.”

Absent Left Main Coronary Artery and Separate Ostia of Left Coronary System in a Patient with Holt-Oram Syndrome and Sinus Node Dysfunction

Patient: Male, 41 Final Diagnosis: Sick Sinus Syndrome and absent left main coronary artery • separate ostia of left anterior descending and circumflex arteries in Holt-Oram Syndrome Symptoms: Conduction disturbance • seizure-like activity • upper extremity malformations Medication: — Clinical Procedure: Electro physiology study • coronary catheterization • pacemaker Specialty: Cardiology Objective: Congenital defects/diseases Background: Holt-Oram syndrome (HOS) is a rare but significant syndrome consisting of structural heart defects, conduction abnormalities, and upper extremity anomalies. It was first described in the British Heart Journal in 1960 by Mary Holt and Samuel Oram as a report of atrial septal defect, conduction disturbances, and hand malformations occurring in family members. Patients can present with heart blocks or symptoms of underlying congenital heart defects. Case Report: A 41-year-old man with Holt-Oram syndrome presented with seizure-like activity and was found to have an underlying conduction disturbance. Physical exam showed bilateral atrophic upper extremities with anatomic disfiguration, and weakness of the intrinsic hand muscles. Cardiovascular exam revealed a slow heart rate with irregular rhythm. EKG showed sinus arrest with junctional escape rhythm. Cardiac catheterization revealed coronary anomalies, including absent left main coronary artery and separate ostia of the left anterior ascending and left circumflex coronary artery. Coronary arteries were patent. Following electrophysiology study, sick sinus syndrome and AV block were diagnosed, and the patient received implantation of a permanent pacemaker. Conclusions: This patient presented with a seizure-like episode attributed to hypoxia during asystole from an underlying cardiac conduction defect associated with Holt-Oram syndrome. Arrhythmias and heart blocks are seen in these patients, and conduction defects are highly associated with congenital heart defects. Holt-Oram syndrome rarely presents with coronary artery anomalies. There is no reported case of separate coronary ostia and absent left main coronary artery. Prompt diagnosis is important since anomalies in coronary and upper extremity vasculature might be challenging for invasive procedures.

LONG TERM MORTALITY RATES IN UNITED STATES VETERANS WITH CORONARY RISK FACTORS, WITH OR WITHOUT SIGNIFICANT CORONARY ARTERY DISEASE

Coronary artery disease (CAD) is a major cause of death in United States. Mortality rate in US Veterans with coronary risk factors, with or without CAD are not well known. We did a retrospective study to compare the all-cause mortality rate in patients with obstructive CAD, nonobstructive CAD and

Not all ST-segment changes are myocardial injury: hypercalcaemia-induced ST-segment elevation.

ST-segment elevation myocardial infarction is an important, life-threatening diagnosis that requires quick diagnosis and management. We describe the case of an 83-year-old man with coronary artery disease, ischaemic cardiomyopathy with left ventricular ejection fraction of 15%, newly diagnosed multiple myeloma that had an initial ECG showing ST-segment elevation in anterior leads V1–3 and ST-segment depression in lateral leads concerning for an ST-segment elevation myocardial infarction. Troponins were negative and his calcium was 3.55 mmol/L. It was thought that the ECG changes were not indicative of cardiac ischaemia but, rather, hypercalcaemia. He was treated with fluids, diuretics and zolendronic acid, with subsequent resolution of ST-segment changes. This case demonstrates that one must consider disease other than myocardial ischaemia as the culprit of ST-segment changes if physical examination and history do not point towards myocardial injury, as unnecessary invasive revascularisation procedures have inherent risks.