Genetic Characterization of Patients With Arrhythmia-Induced Cardiomyopathy

Inclusion criteria

• Presence of atrial fibrillation or atrial flutter not self-limited.
• Performance of a cardiac imaging test with systolic function analysis (echocardiogram, magnetic resonance, CT scan) during the clinical course of the arrhythmia, exhibiting a left ventricular ejection fraction (LVEF) \<50%. In order for the test to be representative, the maximum time between the performance of the imaging test and the rhythm control procedure will be 3 months, in the absence of intervening cardiovascular events that may have caused a variation in LVEF. In the event that the patient had a previously known LVEF \<50%, the change with respect to this attributable to tachyarrhythmia has to be ≥10%.
• Signature of informed consent.
• Ability to understand and accept participation in the study.

Exclusion criteria

• Refusal of informed consent.
• Legal or juridical incapacity.
• Age \<18 years.
• Life expectancy less than 1 year.
• Impossibility of a follow-up of at least 6 months.
• Presence of a ventricular rate \>140 beats per minute, limiting the validity of imaging measurements.
• Presence of known factors causing systolic ventricular dysfunction:
• Prior cardiomyopathy diagnosis.
• Severe mitral or aortic valve disease.
• Non-revascularizable ischemic heart disease.
• Context of peri-resuscitation cardiopulmonary care.
• Abusive alcohol consumption, defined as \>80 grams of ethanol or \>7 standard alcoholic beverages per day.
• Active treatment with chemotherapeutic agents or radiation therapy to the thorax.
• Known infection with Trypanosoma cruzi, Borrellia burgdorferi or other infectious agent causing cardiomyopathy.