Case #17 — Tachycardia in the Presence of Ventricular Pacing

by Toug Tanavin, MD, Mark Pollet, MD, and Yochai Birnbaum, MD, FACC

A 61-year-old man with coronary artery disease presented with volume overload caused by medication noncompliance. His medical history included percutaneous coronary intervention; ischemic cardiomyopathy (left ventricular [LV] ejection fraction, <0.15); and placement of a biventricular implantable cardioverter-defibrillator (ICD), model and programming unknown. Chest radiographs showed properly positioned ventricular and right atrial leads. Figure 1 shows the patient’s electrocardiogram (ECG) on presentation.

Case #16 — Cocaine-Induced Electrocardiographic Phenomenon

by Sundeep Kumar, MD, Luis Sanchez, MD, Ruthvik Srinivasamurthy, MD, and Patrick F. Mathias, MD, FACC

A 27-year-old white man presented at the hospital after recent cocaine use, reporting intermittent left-sided chest pain, diaphoresis, and dizziness. His vital signs were normal; results of physical examination were not noteworthy. Chest radiographic and cardiac enzyme test results were normal. His urine was positive for cocaine. An electrocardiogram (ECG) during a pain-free state revealed findings not present one month earlier: a prolonged QTc interval, new T-wave inversions, and biphasic T waves in leads V₂ and V₃ (Fig. 1, arrows).

Case # 15 — Chest Radiograph Clarifies an Electrocardiographic Abnormality

by Alexander Postalian, MD, Yochai Birnbaum, MD, FACC, and Mohammad Saeed, MD, FACC

A 69-year-old man with severe aortic stenosis underwent transcatheter aortic valve replacement with a 29-mm Edwards Sapien 3 Transcatheter Heart Valve (Edwards Lifesciences LLC). During the procedure, he had transient 3rd-degree atrioventricular block, followed by sinus rhythm with PR prolongation, right bundle branch block, and left anterior fascicular block. Our electrophysiology team was consulted.

We decided to implant a dual chamber pacemaker (Medtronic) in DDDR mode. The day after implantation, the following surface electrocardiogram (ECG) was obtained (programmed atrioventricular [AV] delay, 160 ms).

Case #14 — Slow, But Dangerous

by Kelvin N.V. Bush, MD, and Gregg G. Gerasimon MD

A 70-year-old man with ischemic heart disease, chronic heart failure, and a left ventricular ejection fraction of 0.25 presented with recurrent palpitations and diaphoresis. His single-chamber implantable cardioverter-defibrillator had recently been upgraded to a Dynagen™ X4 Cardiac Resynchronization Therapy Defibrillator (Boston Scientific Corporation), and he had been taking β-blockers and amiodarone. Physical examination results were notable for hemodynamic stability, jugular venous distention, a jugular venous pressure of 12 cm H₂O, and no evidence of pulmonary or hepatic congestion. The patient’s resting electrocardiogram (ECG) revealed a wide-complex rhythm (Fig. 1).

Case #13 — Confusion, Ataxia, and Wide-Complex Tachycardia: What Caused This Arrhythmia?

by Justin Price, MD, Jinesh Shah, MD, Michael Q. Bui, MD, and Christopher D. Chiles, MD, FACC

A previously healthy 36-year-old woman presented at the emergency department with gradual-onset confusion, ataxia, and aphasia. Her vital signs were normal. On physical examination, she reacted to painful stimuli but was nonverbal and unable to follow commands. Initial laboratory results revealed no abnormalities. Computed tomograms of the head and results of a lumbar puncture were nondiagnostic. During hospitalization, the patient decompensated and needed emergency intubation and vasopressor support. An electrocardiogram (ECG) was obtained (Fig. 1). An echocardiogram revealed an acute reduction of left ventricular ejection fraction (range, 0.35–0.40) and anterior wall-motion abnormalities. Notable laboratory results included troponin I, 17.1 ng/mL; normal thyroid values; and negative toxicology screening.

Case #12 — Varying Morphology of QRS Complexes: A Possible Explanation

by Rida Laeeq, MD, Mark Pollet, MD, Nadeen Faza, MD, and Yochai Birnbaum, MD

A 62-year-old man with nonischemic cardiomyopathy (left ventricular [LV] ejection fraction, 0.30–0.34) presented for evaluation of weakness. In 2011, he had undergone placement of a D224TRK Consulta® CRT-D (Medtronic, Inc.; Minneapolis, Minn) biventricular implantable cardioverter-defibrillator. The pacemaker, programmed in DDD mode, had a lower rate limit of 60 beats/min (cycle length, 1,000 ms) and an upper limit of 130 beats/min (cycle length, 430 ms), a paced atrioventricular (AV)-delay period of 130 ms, and a sensed AV-delay period of 100 ms. The LV lead threshold was 1.25 V at 0.6 ms and was programmed to deliver 1.75 V at 0.6 ms. The right atrial and right ventricular leads were in standard positions. The electrocardiogram appeared as follows (Fig. 1).

Case #11 — Is the Pacemaker Functioning Properly?

Alexander Postalian, MD, Mohammad Saeed, MD, J. Alberto Lopez, MD, and Yochai Birnbaum, MD

A 93-year-old woman with no symptoms was admitted to the hospital for a pacemaker generator exchange. She had a history of ischemic cardiomyopathy and was taking optimal medical therapy. She had also experienced paroxysmal atrial arrhythmia, which had been treated with atrioventricular node ablation and dual-chamber permanent pacemaker implantation. Upon her arrival, a 12-lead electrocardiogram was obtained (Fig. 1).