Abstract 1. 1. Auricular flutter is a common result of quinidine therapy given for conversion of auricular fibrillation to normal sinus rhythm. 2. 2. The appearance of auricular flutter is in itself not a contraindication to continue quinidine therapy. In most instances if the dosage of quinidine is maintained or increased, conversion to a regular sinus rhythm will result. 3. 3. Cardiac enlargement and congestive heart failure in themselves are not contraindications to quinidine therapy. The danger of embolic phenomena remains a possibility, but since this occurs even more commonly if the auricular fibrillation persists, it cannot be considered a definite contraindication.