ventricular tachycardia
"Doc prescribed this medication to control my high heart rate after a 3 day hospitalization due to supra ventricular tachycardia. I had horrible side effects. Terrible insomnia, sometimes awake for 24 hours. Palpitations. Heavy congested feeling in chest. Anxiety. I was only on it for 10 days! Switched to metoprolol and after 2 days started to feel tons better!!!"