[Severe tachycardiomyopathy and thrombus in the left atrial appendage--a case report].

We describe a case of severe left ventricular (LV) heart failure caused by tachycardiomyopathy with concomitant presence of unsolved thrombus in left atrial appendage despite effective oral anticoagulant treatment. Successful ablation of atrial flutter and atrioventricular nodal reentry tachycardia entailed resolution of heart failure symptoms and normalisation of LV function.