Significance of arrhythmias in acute respiratory failure.

Arrhythmias are as likely to strike patients with acute respiratory failure as patients with acute myocardial infarction. Both supraventricular and ventricular types were detected in half or more of the patients in two recent studies. Ventricular arrhythmias have a particularly bleak prognosis, since they often deteriorate into ventricular fibrillation or cardiac arrest. The exact causes of these arrhythmias are still a mystery, but metabolic abnormalities associated with respiratory failure are highly suspect. These disturbances can disrupt the transmembrane action potential of cardiac conducting tissue, causing electrophysiologic phenomena known to trigger arrhythmias. Until a specific etiology is confirmed, treatment should focus on identifying and correcting possible metabolic causes. Congestive heart failure--itself a cause of arrhythmias--also should be treated. Cardioversion and antiarrhythmic drugs should be used only in life-threatening situations.