A 14-year-old boy was referred to our institution for evaluation of heart failure potentially related to a tachycardia-induced cardiomyopathy. The condition was first diagnosed at the age of 7 years, because of frequent palpitations. Echocardiography excluded a congenital heart disease and the ejection fraction (EF) was 68% at this time, whereas Holter-electrocardiographic monitoring demonstrated incessant paroxysmal focal atrial tachycardia (FAT) ( Fig. 1 A). Various antiarrhythmic drugs were started, without any effect (verapamil, digoxin, propanolol, amiodarone). At the age of 13 years, the patient’s functional status had gradually worsened to reach stage 3 of the New York Heart Association. Echocardiography revealed altered left ventricular function (EF 35%) and significant dilation of the left ventricle, without any evidence for coronary disease or specific cause of cardiomyopathy.
