Review Question - QID 100559

Digoxin is used for symptomatic treatment of heart failure. Toxicity can manifest as changes in color perception, anorexia, nausea, vomiting, and diarrhea. The most serious and potentially fatal side effect is ventricular tachyarrhythmia.

This patient with signs and symptoms of severe systolic heart failure has overdosed on digoxin, an inhibitor of the Na/K ATPase that acts as a positive inotrope and also decreases AV nodal conduction. His complaints of gastrointestinal disturbances raise concern for digoxin toxicity, while the presence of atrial tachycardia with variable block is the classic EKG finding associated with this condition.

Morris et al. discuss the evidence surrounding the question of whether or not to prescribe digitalis to patients with congestive heart failure. They note that digitalis therapy has no effect on mortality in heart failure patients, but that it may decrease hospitalizations and improve quality of life.

Osmonov et al. discuss the management of patients with drug-induced AV block. They note that despite the common perception that drug-induced AV block is easily managed by discontinuing the offending drug, in this case series, half of the 108 patients with this condition also required permanent pacemaker implantation.

Figure A and Illustration A shows characteristic EKG findings seen in digitalis toxicity.

The video demonstrates an S3 gallop.

Incorrect Answer:
Answer 2: Signs and symptoms of propranolol toxicity include bradycardia, hypothermia, hypotension, shock, and hypoglycemia.

Answer 3: Signs and symptoms of verapamil toxicity include bradyarrhythmias and hyperglycemia.

Answer 4: Signs and symptoms of amiodarone toxicity include interstitial lung disease and thyroid disease.

Answer 5: Signs and symptoms of lidocaine toxicity include tongue numbness, lightheadedness, muscle twitches, syncope, seizure, coma, and cardiorespiratory arrest.