Carvedilol for Prevention of Paroxysmal Atrial Fibrillation

Atrial fibrillation (AF) is the most common sustained heart rhythm disorder and is associated with significant symptoms and health problems including an increased risk of stroke and death. Current drug therapies are often ineffective and associated with significant side effects. Abnormalities of calcium regulation in cells may lead to triggers for AF. Emerging data suggest that abnormal intracellular calcium regulation mediated through the ryanodine receptor in heart cells may contribute to AF. Recently the investigators have shown that the I2-blocker carvedilol which is most commonly used to treat patients with heart failure, modifies calcium regulation mediated through the ryanodine receptor. At present this drug is not frequently used to treat AF. Therefore the investigators will conduct a randomized trial comparing carvedilol to metoprolol for prevention of paroxysmal AF. This may result in improved health and quality of life for people who suffer AF.