Arrhythmias originating from coronary sinus with multi-level conduction block as a cause of tachyarrhythmic cardiomyopathy reversed by successful RF ablation

A patient with a 6-year history of drug-resistant, recurrent arrhythmias (AT/AFL, single SVEBs, pairs and series) developed arrhythmogenic cardiomyopathy. Conduction block between coronary sinus (CS) and atria caused periodical change of tachycardia's rate. Successful RF ablation performed in the middle of CS at a place of spike potentials of a 284 ms CL. During a 6-years follow-up after ablation, ejection fraction increased from 38 to 59% and the quality of life improved significantly.