Michael R. Kaufmann

Iatrogenic Ventricular Fibrillation after Direct-Current Cardioversion of Preexcited Atrial Fibrillation Caused by Inadvertent T-Wave Synchronization

Direct-current cardioversion is an important means of managing arrhythmias. During treatment, carefully synchronizing energy delivery to the QRS complex is necessary to avoid ventricular fibrillation caused by a shock during the vulnerable period of ventricular repolarization, that is, a shock on the T wave. The presence of an accessory pathway and ventricular preexcitation can lead to difficulty in distinguishing the QRS complex from the T wave because of bizarre, wide, irregular QRS complexes and prominent repolarization. We present the cases of 2 patients who had iatrogenic ventricular fibrillation from inappropriate T-wave synchronization during direct-current cardioversion of preexcited atrial fibrillation. Our experience shows that rapidly recognizing the iatrogenic cause of VF and immediate treatment with unsynchronized defibrillation can prevent adverse clinical outcomes.

Facial palsy and atrial fibrillation: a special case of Ramsay Hunt syndrome

Ramsay Hunt syndrome (herpes zoster oticus) is a rare complication of latent Varicella Zoster virus infection. It can be complicated by permanent hearing loss, loss of taste and postherpetic neuralgia. Although Ramsay Hunt syndrome most prominently involves the facial nerve, a number of other cranial nerves can be involved such as the vestibulocochlear, glossopharyngeal and the vagus nerve. We report on a case of Ramsay Hunt syndrome with cranial polyneuritis complicated by atrial fibrillation. Vagal involvement as evidenced by physical examination and MRI findings was present in our patient. We hypothesise that viral vagal neuritis likely contributed to the development of atrial fibrillation in our patient through involvement of the autonomic components of the vagus nerve.

Impact of a Pharmacy-Cardiology Collaborative Practice on Dofetilide Safety Monitoring

Background: Limited studies have been published examining dofetilide’s postmarketing use and its recommended monitoring. Objective: To evaluate the impact of a collaborative pharmacy-cardiology antiarrhythmic drug (AAD) monitoring program on dofetilide monitoring. Methods: This retrospective cohort study was performed to assess if a novel monitoring program improved compliance with dofetilide-specific monitoring parameters based on the Food and Drug Administration’s Risk Evaluation and Mitigation Strategy. Results: A total of 30 patients were included in the analysis. The monitoring parameters evaluated included electrocardiogram, serum potassium, serum magnesium, and kidney function. The primary outcome evaluated was the composite of these dofetilide monitoring parameters obtained in each cohort. In the standard cohort, 245 of 352 (69.6%) monitoring parameters were completed versus 134 of 136 (98.5%) in the intervention group (P < 0.05). Conclusion: A collaborative pharmacy-cardiology AAD monitoring program was associated with a significant improvement in dofetilide monitoring. This improvement could potentially translate into enhanced patient safety outcomes, such as prevention of adverse drug reactions and decreased hospitalizations.

An Unusual Presentation of QT Prolongation

A 55-year-old woman with a history of chronic bronchitis, Clostridium difficile colitis, and alcohol and tobacco abuse was admitted with altered mentation, hyponatremia, and necrotizing right-upper-lobe pneumonia. She was started on cefepime and vancomycin; metronidazole was added for colitis. A resting electrocardiogram (ECG) showed sinus tachycardia with a QS pattern in the precordial leads, normal intervals, and small T-wave inversions in leads V5 and V6. Four days later, significant changes in her baseline telemetry rhythm prompted a repeat 12-lead ECG; the patients pulse rate was 75 beats/min with a QT interval of 720 ms and QTc of 746 ms (Fig. 1). Her troponin T level was <0.03 ng/mL, and she had no new symptoms. Her medications at that time were aspirin, metoprolol, lisinopril, cefepime, atorvastatin, pantoprazole, metronidazole, oral vancomycin, and subcutaneous heparin. Her potassium level was 2.9 mEq/L, and her magnesium level was 1.6 mEq/L. An echocardiogram showed severe left ventricular dysfunction with wall motion that suggested stress-induced cardiomyopathy.

Pitfalls in the Acute Management of Atrial Fibrillation

The evaluation and management of atrial fibrillation is complex, and errors can lead to patient harm. Pitfalls to avoid are numerous—incorrect diagnosis can lead to improper treatment or omission of appropriate therapies, inappropriate management of anticoagulation in atrial fibrillation (AF) places the patient at risk of debilitating stroke or bleeding complications, and injudicious use of antiarrhythmic drug (AAD) therapy can risk dangerous pro-arrhythmic side effects. Furthermore, direct current cardioversion carries its own unique procedural risks. The astute clinician will be aware of potential mistakes and, by avoiding them, will deliver safe and optimal patient care. This chapter will highlight potential errors in AF care.

MACROSCOPIC T-WAVE ALTERNANS: AN UNUSUAL COMPANION OF QT PROLONGATION

Macroscopic T-wave alternans (MTWA) is beat to beat variability in the vector or amplitude of T-waves on surface ECG. Often linked with acquired long-QT syndrome, MTWA is a sign of electrical instability and impending reentrant arrhythmias. This is a case of medication related QT-prolongation with

Subcutaneous ICD implant complicated by an intraperitoneal lead course and device infection

Introduction The subcutaneous implantable cardioverter-defibrillator (S-ICD) is a novel device that demonstrates high efficacy for treatment of ventricular tachycardia and ventricular fibrillation and is an alternative to the transvenous ICD device. The safety and efficacy of the S-ICD has been thoroughly evaluated, and pooled data from the IDE and Effortless studies show only a 0.8% incidence of suboptimal electrode placement. We present a case of extreme lead misplacement that represents how a usually simple implant procedure can result in a serious complication in the hands of an inexperienced implanter.