european heart rhythm association score of atrial fibrillation european heart rhythm association score of atrial fibrillation the european heart rhythm association score of atrial fibrillation (or ehra score) is a classification system for the extent of atrial fibrillation. it places patients in one of four categories based on how much they are limited during physical activity; the limitations/symptoms are in regard to normal breathing and varying degrees in shortness of breath and/or angina. ehra class symptoms i no symptoms. ii mild symptoms; normal daily activity not affected. iii severe symptoms; normal daily activity affected. iv disabling symptoms; normal daily activity discontinued. the classification system is named after the european heart rhythm association.