Patient History
The patient is a 37 year-old man who was born with double inlet left ventricle, right ventricular hypoplasia, and left transposition of the great arteries with the aorta arising from the outlet chamber. At the age of 2 months old, he underwent a staged single ventricle repair that included initial pulmonary arterial banding. At age 6.5 years an atriopulmonary Fontan palliation with patch closure of the right-sided atrioventricular valve and suture closure of the atrial septum was performed. The right atrium was directly anastomosed to the main pulmonary artery (classic Fontan). At age 21 he developed recurrent and symptomatic episodes of atrial tachycardia. He failed several catheter ablation attempts and, despite multiple cardioversions, maintenance of sinus rhythm was not feasible. Other than the aforementioned well-tolerated atrial tachycardias, he did remarkably well after his Fontan procedure until age 28 when he developed decreasing exercise tolerance, recurrent atrial dysrhythmias, and ascites: all findings concerning for failing Fontan physiology.  At age 30 he underwent cavo-pulmonary Fontan revision using a non-fenestrated, intracardiac, 20 mm Gore-Tex conduit connecting the inferior vena cava to the pulmonary artery. During this operation he also underwent a surgical maze procedure with radiofrequency lesions placed from the free right atriotomy across the atrial septum to the coronary sinus, and from the atrial pulmonary connection to approximately the 10 o’clock location of the tricuspid valve patch. Additionally, surgical cavo-tricuspid isthmus ablation with lesions placed from the right atrioventricular valve patch at 4 o’clock to the inferior vena cava orifice was performed. His rhythm in the months preceding his Fontan revision was alternating between atrial tachycardia and sinus bradycardia with junctional escape consistent with sinus node dysfunction. To manage his bradycardia, a dual chamber epicardial pacemaker system was implanted at the time of the Fontan revision. Two sew-on coaxial bipolar epicardial atrial leads (Medtronic, 35 cm, 4968 CapSure Epi) were placed along the right border of the right atrium and two epicardial screw-in bipolar leads were placed on the inferior wall of the right ventricle. The leads were tunneled to the right upper quadrant of the abdomen and placed in a subcutaneous pocket where the best of each of these two leads was chosen and connected to a dual-chamber pacemaker. The unused leads were capped and left in the pocket. Unfortunately, two months after implantation he developed a pacemaker pocket infection with methicillin-sensitiveStaphylococcus aureus for which the pacemaker was extracted. The epicardial leads were unable to be removed with counterclockwise rotation and thus were pulled gently and then cut flush to the wound edges allowing the lead remnants to retract to the depth of the wound. A vacuum-assisted drainage system was inserted into the wound and he was placed on the appropriate antibiotic regimen. His heart rate alternated between normal sinus with rates of 60-70 with junctional rhythm 40-50 and thus a decision was made not to pursue re-implantation of a pacemaker.
He continued to experience recurrent atrial tachycardias, as well as atrial fibrillation, and was managed medically with verapamil and therapeutic anti-coagulation. His atrial fibrillation burden increased, but due to sinus node dysfunction his antiarrhythmic regimen was unable to be escalated. The lack of organized atrial contraction and atrioventricular synchrony resulted in a significant deterioration of his functional status and recurrent exacerbations of failing Fontan physiology as evidenced by right heart failure and worsening of protein losing enteropathy. The patient required 6 hospitalizations over the course of 4 months for diuresis and management of his worsening protein-losing enteropathy. There was an immediate need to establish adequate atrial pacing support that would allow for cardioversion, restoration of AV synchrony and escalation of anti-arrhythmic medications. The clinical challenge was that the patient was too sick (from failing Fontan physiology) to undergo a fifth re-do sternotomy for placement of a new epicardial pacemaker system or percutaneous transvenous lead implantation. Transvenous access to his atria would require a complex procedure involving puncture of the Fontan conduit to access atrial tissue or puncture of the left pulmonary artery floor with placement of a lead into the right atrium, and the patient was deemed a high-risk candidate for the prolonged duration of anesthesia that would be required for such a procedure. As a result, an attempt was made to salvage the existing atrial leads. The endpoint of the procedure was to establish atrial pacing and AV synchrony in the short term in order to stabilize the patient enough to improve his clinical status and candidacy for a more invasive lead implantation procedure. The team worked together with the atrial lead manufacturer engineers to assure the feasibility of lead salvage. A shared-decision was made between the clinical team and the patient to attempt to salvage the existing epicardial atrial leads by using an IS-1 to IS-1 lead extender.