Prinzmetal's Variant Angina Treatments

Verapamil is indicated for the treatment of supraventricular tachyarrhythmias, including: Rapid conversion to sinus rhythm of paroxysmal supraventricular tachycardias, including those associated with accessory bypass tracts (Wolff-Parkinson-White and Lown-Ganong-Levine syndromes). When clinically advisable, appropriate vagal maneuvers should be attempted prior to Verapamil administration., Temporary control of rapid ventricular rate in atrial flutter or atrial fibrillation, except when the atrial flutter and/or atrial fibrillation are associated with accessory bypass tracts (Wolff-Parkinson-White and Lown-Ganong-Levine syndromes). In controlled studies in the U.S., about 60% of patients with supraventricular tachycardia converted to normal sinus rhythm within 10 minutes after intravenous Verapamil hydrochloride. Uncontrolled studies reported in the world literature describe a conversion rate of about 80%. About 70% of patients with atrial flutter and/or fibrillation with a fast ventricular rate respond with a decrease in heart rate of at least 20%. Conversion of atrial flutter or fibrillation to sinus rhythm is uncommon after Verapamil hydrochloride and may reflect the spontaneous conversion rate, since the conversion rate after placebo was similar. The effect of a single injection lasts for 30–60 minutes when conversion to sinus rhythm does not occur. Because a small fraction of patients treated with Verapamil hydrochloride respond with life-threatening adverse responses , the initial use of intravenous Verapamil hydrochloride should, if possible, be in a treatment setting with monitoring and resuscitation facilities, including DC-cardioversion capability. As familiarity with the patient’s response is gained, an office setting may be acceptable. Cardioversion has been used safely and effectively after intravenous Verapamil.