Successful elimination of a Mahaim pathway using an 8 mm tip cryoablation catheter in a child

Mahaim fibers typically demonstrate decremental conduction properties and constitute approximately 3% of preexcitation syndromes (1). Mahaim pathways are usually right-sided, however several leftsided cases have been reported (2). Conventionally Mahaim pathway ablation is performed with radiofrequency ablation (RFA). We report a patient who presented with a wide QRS tachycardia with left bundle branch block (LBBB) pattern. The electrophysiology study demonstrated Mahaim tachycardia and the patient was successfully treated with cryoablation following a failed attempt with RFA.