Catheter Ablation of Multiple Accessory Pathways in Duchenne Muscular Dystrophy
In a 23-year-old male, DMD was diagnosed at age 7 years upon typical clinical and instrumental findings. He learned speaking at 18 months, walking at 24 months, became continent at age 3 years, and climbed stairs and became able to get up from the floor at age 4 years. Blood chemical investigations showed elevated creatinekinase (3523 U/L, n>170 U/L). Needle electromyography was myogenic and muscle biopsy showed dystrophic features and absence of dystrophin. At age 8 years tip-toe walking developed. Since age 11 years he was permanently using a wheel-chair. Since age 16 years he was no longer able to eat independently. At, age 19 years he required a long-term oxygen therapy via an Oracle mouth mask, followed by a non-invasive positive pressure ventilation by means of a VS Ultra device (ST-mode, IPAP 18 mm Hg, EPAP 12 mm Hg, respiratory frequency 12, Tmin 1.1 seconds, Tmax 1.4 seconds, with 3 L of oxygen). Initially, he required the respirator only during the night, but later also, during the day, except when mobilized to an upright position. At age 23 years he presented with severe scoliosis and thoracic asymmetry, macroglossia, which has been only rarely described as a phenotypic feature of DMD, and severe quadriparesis with residual distal motor functions, and club feet. The family history was negative for DMD, as well as WPW-syndrome.\nCardiac involvement initially manifested as palpitations at age 19 years. Electrocardiography (ECG) at that time was normal and did not show a delta-wave. At age 23 years palpitations recurred after awaking due to a narrow complex tachycardia, which could be successfully terminated with adenosine intravenously. Blood pressure was 110/55 mm Hg. Echocardiography was normal. After resolution of the acute rhythm abnormality, ECG showed a delta-wave over all precordial recordings (), leading to the diagnosis of WPW-syndrome. Ajmaline was started and catheter ablation was scheduled. Ablation of three accessory pathways (right anterior-septal with anterograde and retrograde conduction, right posterior-septal with exclusively retrograde conduction, and right posterior-lateral with exclusively retrograde conduction) ( and ) was successfully carried out one week after starting ajmaline without complications (). One day after ablation, however, a relapse of the supraventricular tachycardia occurred, which could be again relieved with ajmaline intravenously. Six days after ablation, a re-entry tachycardia recurred, which responded favorably to adenosine intravenously, but could be finally stopped only with ajmaline intravenously. On ECG, 12 days after ablation, delta-waves had disappeared, but small Q-waves over V 2-6 were recorded (). To prevent tachycardia, verapamil (240 mg/d) was additionally given with success. Unfortunately, the delta-wave and re-entry tachycardias recurred four months after the ablation. After switching to propafenone, neither the delta-wave nor re-entry tachycardia recurred.