Turkish Society of Cardiology consensus paper on management of arrhythmia-induced cardiomyopathy

Background Heart failure (HF) is one of the major causes of mortality and morbidity. The identification of causes of left ventricular (LV) systolic dysfunction is important in terms of initiating causal treatment and improving prognosis. Arrhythmia-induced cardiomyopathy (AIC) is a potentially reversible form of cardiomyopathy (CMP) in which LV dysfunction results from atrial or ventricular arrhythmias (1). It can be resolved by eliminating or effectively treating responsible arrhythmia (2). Aim of the document Early recognition of the relationship between responsible arrhythmia and CMP is of great importance in terms of the improvement of symptoms, LV systolic dysfunction, and functional status with effective treatment. However, in the clinical practice, AIC is often overlooked, and arrhythmias are generally seen as the result of HF. Again, there is a lack of information about the pathophysiology of AIC and the course of the disease after effective treatment of the responsible arrhythmia. This document is written to give clear messages for further recognition and treatment of AIC based on the current literature. Definition AIC is defined as LV systolic dysfunction due to supraventricular or ventricular arrhythmia that can be either sustained or paroxysmal or is characterized by highly frequent ectopic activity (3). AIC can be divided into two categories. Type 1 AIC (arrhythmia-induced): arrhythmia is accepted as the absolute reason of ventricular dysfunction that returns to normal after successful treatment of arrhythmia. Type 2 AIC (arrhythmia-mediated): arrhythmia exacerbates the LV dysfunction in patients with concomitant heart disease, and treatment of the arrhythmia provides partial improvement (4). Epidemiology The prevalence of HF is increasing worldwide due to better treatment of acute cardiac events, improvements in medical and surgical treatment methods, and aging of the population. Approximately 1%–2% of the general population, and >10% of over 70 years old are affected with HF (5). Cardiac arrhythmias generally occur during the natural course of HF, but sometimes they are the sole etiology of the unexplained systolic HF or dilated CMP. Reliable epidemiological data regarding the AIC are lacking, and the prevalence in general is underestimated, given that arrhythmia is often considered to be a result of rather than a possible cause of CMP. Although age is the major determinant of incidence and prevalence of overall HF, AIC appears to occur at any age. However, the common types of arrhythmias causing AIC differ among age groups. Focal atrial tachycardia (FAT) (59%) and permanent