ABSTRACT
As first reported in a study completed in 1947, electrocardiographic (ECG) changes may occur in up to 90" of patients with cerebrovascular disease. Serious arrhythmias may occur in approximately 5" of patients with subarachnoid hemorrhage - most commonly atrial fibrillation or atrial flutter. A P wave represents atrial depolarization and contraction. A QRS complex represents depolarization of ventricular myocardium/beginning of ventricular contraction. Sinus rhythm is characterized by normal P waves and a normal QRS. The rate is between 60 and 100 beats per minute. Sinus bradycardia is characterized by a rate of less than 60 beats per minute, although in certain individuals, such as extreme athletes, a rate less than 60 may be normal. ECG characteristics will be similar to sinus rhythm but at a slower rate. Sinus bradycardia is usually asymptomatic. However, symptoms such as hypotension, altered mental status, dizziness, blurred vision, chest pain, or syncope may occur.
