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KEY POINTS
Between 12% and 19% of patients in intensive care unit (ICU) settings have sustained arrhythmias.
In the ICU, the most common causes of arrhythmias are infection, electrolyte abnormalities, medications, ischemia, anemia, hypoxia, and changes in volume status and hemodynamics.
Tachycardias are more common than bradycardias and atrial arrhythmias are more common than ventricular arrhythmias.
Common causes of bradycardia include beta-blockers, calcium channel blockers, digoxin, narcotics, and antiemetics.
Patients are less likely to remain hemodynamically stable with higher degrees of atrioventricular (AV) block and usually require temporary pacing (transthoracic or transvenous), and ultimately permanent pacing if the heart block persists.
AV dissociation occurs when there is loss of the usual pattern of atrial and ventricular synchrony and there is no association between P waves and the QRS complexes.
The majority of atrial tachyarrhythmias in the critically ill patient are due to atrial fibrillation, atrial flutter, AV nodal reentry tachycardia, ectopic atrial tachycardia with rapid ventricular rates, and underlying preexcitation with an atrial arrhythmia.
For the hemodynamically unstable or symptomatic patient with AV nodal reentrant tachycardia, initial choices include adenosine or direct current cardioversion to restore sinus rhythm and hemodynamic stability.
Multifocal atrial tachycardia is usually associated with underlying pulmonary disease especially severe chronic obstructive lung disease or respiratory failure in older, acutely ill individuals.
Atrial fibrillation is the most common dysrhythmia in the critically ill. Recent clinical trials have demonstrated similar outcomes with rate and rhythm control strategies for atrial fibrillation.
Indications for urgent cardioversion in atrial fibrillation include hypotension/shock, acute or ongoing myocardial ischemia, congestive heart failure and/or acute pulmonary edema, and underlying preexcitation with rapid ventricular rates and/or hemodynamic instability.
Torsade de pointes and other forms of polymorphic tachycardia are rapid ventricular rhythms associated with hemodynamic instability and a predisposition to degenerate into ventricular fibrillation.
Patients with nonsustained ventricular tachycardias and ischemic heart disease in ICU settings should be given beta-blockers to control heart rate, blood pressure and rhythm disturbances, electrolyte replacement, and control of stimulatory factors, such as anemia, pain, and fever.
Ventricular fibrillation requires emergency defibrillation.
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Acutely ill patients frequently have significant arrhythmias. By some estimates between 12% and 19% of patients in critical care unit settings have sustained arrhythmias.1,2 Patients following cardiac and thoracic surgery have a significant incidence of postoperative arrhythmias, specifically atrial fibrillation. Tachycardias are more common than bradycardias and atrial arrhythmias are more common than ventricular arrhythmias. Patients with underlying heart disease are more likely to have clinically significant arrhythmias. In the intensive care unit (ICU), multiple stimuli and associated elevated catecholamine levels contribute to arrhythmias. These include infection, electrolyte abnormalities, medications, ischemia, anemia, hypoxia, and changes in volume status and hemodynamics. Majority of these arrhythmias are secondary to at least one of these factors and usually respond to treatment of the primary medical or surgical processes.
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Cardiac arrhythmias prolong the ICU length of stay of patients even ...