A 42-year-old man is admitted to the hospital due to fever and shortness of breath. He has chronic hepatitis C, HIV, and alcohol-induced cardiomyopathy. Temperature is 38.6 C (101.5 F). Thrush is present in the oropharynx. Chest x-ray reveals right lower lobe consolidation. He is started on fluconazole and moxifloxacin. The patient's pneumonia and thrush improve over the next 2 days. However, he develops palpitations on the third day of hospitalization. His ECG strip is shown in the exhibit. Which of the following is the most appropriate next step in the management of this patient?

Question

A 42-year-old man is admitted to the hospital due to fever and shortness of breath.  He has chronic hepatitis C, HIV, and alcohol-induced cardiomyopathy.  Temperature is 38.6 C (101.5 F).  Thrush is present in the oropharynx.  Chest x-ray reveals right lower lobe consolidation.  He is started on fluconazole and moxifloxacin.  The patient's pneumonia and thrush improve over the next 2 days.  However, he develops palpitations on the third day of hospitalization.  His ECG strip is shown in the exhibit.  Which of the following is the most appropriate next step in the management of this patient?

Quizplus · Accepted Answer

The ECG strip shows torsades de pointes (TdP), which is a form of polymorphic ventricular tachycardia with a cyclic or sinusoidal alteration of QRS axis and/or morphology ("twisting of the points"). It occurs in the setting of congenital or acquired QT interval prolongation. This patient likely has medication-induced prolongation of QT interval (due to fluconazole and moxifloxacin), which along with a history of alcohol use (electrolyte imbalances), cardiomyopathy and HIV, predisposes him to develop TdP. acquired QT interval prolongation Arrhythmic episodes can present with palpitations, presyncope or syncope, and may resolve spontaneously or degenerate into ventricular fibrillation and result in sudden cardiac death. Immediate defibrillation is indicated in hemodynamically unstable patients with TdP. Intravenous magnesium is the first-line therapy in conscious and stable patients with episodes of TdP; this is followed by identification and removal/correction of the offending causes. Intravenous magnesium is effective even in patients with normal serum magnesium concentrations. (Choice A) Adenosine is primarily used for the acute termination of paroxysmal supraventricular tachycardia (PSVT). It is not recommended for the treatment of ventricular tachycardia. (Choice B) Amiodarone is a class III antiarrhythmic, and is used both for atrial and ventricular tachycardia (VT). It is used occasionally in patients with polymorphic VT (and normal baseline QT interval) due to myocardial ischemia or infarction. It has no role in the management of patients with TdP. (Choice C) Atropine is used in the treatment of symptomatic sinus bradycardia or atrioventricular nodal block. It has no role in the management of patients with TdP and may even be deleterious. (Choice D) Calcium gluconate is useful for patients with cardiotoxicity due to hyperkalemia. It is occasionally used in patients with beta-blocker and/or calcium channel blocker overdose. ECG of patients with hyperkalemia shows peaked T waves, followed by lengthening of the PR and QRS intervals, eventually resulting in a sine wave. ECG (Choice F) Sodium bicarbonate is useful in the management of patients with TdP due to quinidine use. It is also beneficial in patients with cardiac arrest due to metabolic acidosis, hyperkalemia, or tricyclic antidepressant overdose. (Choice G) Sotalol is a class III antiarrhythmic agent that causes QT prolongation and TdP; it is therefore not useful in this setting. Patients being initiated on sotalol therapy for other indications should be admitted to the hospital for serial ECG and cardiac rhythm monitoring. Educational objective: Torsades de pointes (TdP) refers to polymorphic ventricular tachycardia that occurs in the setting of a congenital or acquired prolonged QT interval. Immediate defibrillation is indicated in hemodynamically unstable patients with TdP, while intravenous magnesium is the first-line therapy for stable patients with recurrent episodes of TdP. References: Preventing torsades de pointes by careful cardiac monitoring in hospital settings. (http://www.ncbi.nlm.nih.gov/pubmed/18019519) Acquired Long QT Syndrome and Torsade de Pointes Associated with HIV Infection. (http://www.ncbi.nlm.nih.gov/pubmed/20827440)

A 42-Year-Old Man Is Admitted to the Hospital Due to Fever