. HF and AF alone increase the morbidity and mortality. When they coincide the morbidity and mortality become even higher. AF is likely to cause worsening of HF and greatly complicates management. Similarly worsening of HF is also likely to provoke the onset of AF. AF and worsening HF constitute a classic vicious circle of deterioration in HF. . The Framingham Heart study showed that in a general population 50 years the incidence of HF among AF patients was 33 in 1 000 patient years and the incidence of AF among HF patients was 54 in 1 000 patient years. . The Euro Heart Surveys of current cardiology practice in patients with AF or with HF showed that HF is present in 34 of AF patients and AF in 42 of HF patients. . HF 8594 Atrial remodeling 8594 AF 8594 induces further electrophysiologic changes that promote AF 8594 HF. HF begets AF which begets HF. . Primary therapeutic aim is to address the two problems together. These are Restore and maintain sinus rhythm whenever possible Rhythm control reduce the heart rate Rate control minimize occurrence of HF by minimizing impact of AF on cardiac performance minimizing cardiac remodeling prevent thromboembolic events in order to reduce symptoms and improve QoL and reduce risk of stroke and thereby reducing mortality. Interestingly three common therapeutic measures digoxin anticoagulants and CRT bind the duo together.