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.