Miscellaneous Causes of Cardiac Electrical Disturbances
Understand basic electrophysiology and mechanisms of arrhythmias.
Understand the incidence and management of common arrhythmias post-myocardial infarction.
Understand the causes and management of bradycardia and heart block.
Understand the differential diagnosis and acute management of tachycardias.
Understand the diagnosis and management of ventricular arrhythmias.
Arrhythmias are common in the ICU setting and can be caused by a variety of reasons. The most common cause of arrhythmias in the ICU is metabolic disturbances. Tachyarrhythmias may occur in 12% to 78% of patients. Approximately 12% of patients develop sustained arrhythmias, and up to 78% have isolated premature atrial contractions or premature ventricular contractions. Both tachycardia and bradycardia may occur in the setting of acute myocardial infarction. Post-myocardial infarction tachycardias occur in 10% to 20%, with the most common being atrial fibrillation. Sustained ventricular tachycardia or ventricular fibrillation occur in <5% of patients usually in the first 4 h after ST-segment elevation myocardial infarction. The main principle in managing arrhythmias is to first evaluate the patient. This will help to determine the urgency and type of treatment based on the underlying cardiac status.