Dual Chamber Epicardial Pacing for the Failing Atriopulmonary Fontan Patient

Dual Chamber Epicardial Pacing for the Failing Atriopulmonary Fontan Patient Ali Dodge-Khatami, MD, PhD, Mariette Rahn, MD, René Prêtre, MD, and Urs Bauersfeld, MD Divisions of Cardiovascular Surgery and Cardiology, University Children s Hospital Zürich, and Division of Cardiovascular Surgery, University Hospital, Zürich, Switzerland Background. The atriopulmonary Fontan circulation leads to arrhythmias, heart failure, or protein-losing enteropathy, eventually requiring conversion. In hesitant patients, we evaluated the effect of dual chamber pacing as a time-buying measure. Methods. Between 1997 and 2004, 9 patients (aged, 6 to 18 years) with an atriopulmonary Fontan connection and sinus node dysfunction received dual chamber epicardial pacemaker systems. Indications included refractory arrhythmias (n 5), protein-losing enteropathy (n 2), heart failure with effusions (n 1), and exercise intolerance (n 2). Data were compared between hospital discharge after pacemaker implantation and last follow-up. Results. There was no mortality or morbidity. At a follow-up of 3.3 1.0 years, lead survival was 100%. Both atrial (impedance 683 40 Ohm; threshold 0.8 0.1 V at 0.5 ms; sensing P waves 3.3 0.8 mv) and ventricular (impedance 630 68 Ohm; threshold 1.3 0.3 V at 0.5 ms; sensing R waves 8.7 2.5 mv) leads retained satisfactory pacing characteristics at last control, better than those at discharge. Arrhythmias subsided in all instances and no longer required medication in 3 patients. Protein-losing enteropathy improved temporarily in 1 patient and disappeared in another. Exercise intolerance diminished, and heart failure was controlled. Conclusions. Although most atriopulmonary Fontan circulations will need conversion with arrhythmia surgery, patients may delay out of fear. Dual chamber pacing improves single ventricle hemodynamics and can help decompensated Fontan patients. In a multiple-redo setting, a left lateral thoracotomy provides safe access and allows for quantitatively reliable and durable epicardial pacing. (Ann Thorac Surg 2005;80:1440 4) 2005 by The Society of Thoracic Surgeons Accepted for publication March 30, 2005. Address reprint requests to Dr Dodge-Khatami, University Children s Hospital, University of Zürich, Steinwiesstrasse 75, CH-8032 Zürich, Switzerland; e-mail: ali.dodge-khatami@kispi.unizh.ch. Palliative surgery for a functional single ventricle culminates in one of the variations of the Fontan operation. Although numerous surgical modifications have improved the hemodynamic efficiency of the Fontan circulation, sinus node dysfunction still occurs in as much as 44% of patients [1, 2], not only in the immediate postoperative period, but for years after the surgery [3]. The older atriopulmonary Fontan connections lead to additional complications, namely atrial distension and atrial flutter or fibrillation, atrioventricular valve regurgitation, ventricular failure, cyanosis from pulmonary arteriovenous malformations, and protein-losing enteropathy (PLE). Patients with palliated single ventricles are subsequently at risk for thromboembolic events relating to dilatation of the heart chambers, arrhythmias, coagulopathy inherent to a suboptimal Fontan circulation, or the complications of anticoagulation therapy, not to mention the risks of hypoproteinemia and lymphopenia when PLE is present. A failing Fontan circulation will eventually need surgical revision to improve venous blood hemodynamics and cardiac output. This can be achieved by atriopulmonary Fontan takedown, atrial reduction-plasty, and total cavopulmonary connection (TCPC). Concomitantly, antiarrhythmic procedures such as isthmus ablation, a rightsided Maze procedure, a left-sided Cox-Maze procedure, or pacemaker insertion may be added, according to the type of arrhythmia present [4]. Although extensive and difficult, these surgical procedures clearly improve functional status, exercise tolerance, and control arrhythmia, although their effect on PLE is less evident [4]. When end-stage ventricular dysfunction is present, Fontan conversion is no longer relevant, and heart transplantation may represent the only option for prolonged survival [5]. Although both Fontan conversion and transplantation can be achieved with good to excellent results in centers experienced with these procedures [4, 5], they represent a major undertaking with substantial surgical risk, and counseling patients and families to proceed with these pathways can be met with fear and resistance. As a compromise, an initial step would aim to improve cardiac output through pacing [6, 7]. In patients with single ventricle physiology and sinus node dysfunction, atrial pacing has been beneficial, as has dual chamber pacing in patients with atrioventricular block, through better synchronization of atrial and ventricular contraction [6, 7]. We analyze our results in a subgroup of patients with a failing atriopulmonary Fontan circulation and sinus 2005 by The Society of Thoracic Surgeons 0003-4975/05/$30.00 Published by Elsevier Inc doi:10.1016/j.athoracsur.2005.03.128

Ann Thorac Surg DODGE-KHATAMI ET AL 2005;80:1440 4 EPICARDIAL PACING IN FAILING FONTAN PATIENTS 1441 node dysfunction. They all would have been candidates for a Fontan conversion to TCPC with or without arrhythmia surgery, but were reluctant to undergo these procedures, and consented to implantation of an epicardial pacing system. Patients and Methods This nonconsecutive series includes a subgroup of 9 severely symptomatic patients (New York Heart Association functional class IV) with a failing atriopulmonary Fontan connection and sinus node dysfunction, followed at our institution on an outpatient basis. The Institutional Review Board approved retrospective chart review, and informed consent was obtained from the patients or from the families of minors. Age range was from 6 to 18 years. Baseline cardiac diagnoses included tricuspid atresia (n 5), double inlet left ventricle (n 1), double outlet right ventricle with transposition and mitral atresia (n 1), unbalanced congenitally corrected transposition (n 1), and dextrocardia with criss-cross heart (n 1). Additional patient demographic data is given in Table 1. Between 1997 and 2004, bipolar steroid-eluting epicardial pacing leads (Medtronic Capsure Epi 10366, [Medtronic, Minneapolis, MN]) and dual chamber systems were inserted through a left thoracotomy in 8 patients and through a median sternotomy in 1. Mean age at pacemaker implantation was 13.0 4.5 years. The mean time from Fontan-Kreutzer operation to pacemaker insertion was 9.7 4.0 years. The reasons for implanting a dual chamber system rather than an AAI system were twofold. These included (1) the uncertainty regarding a potentially jeopardized atrioventricular node function with anti-arrhythmic medication, and (2) an increased safety net in case of atrial lead dysfunction. We did not opt for VVI pacing in any patient, conform with the results of Fishberger and colleagues, who demonstrated improved hemodynamics and survival with dual chamber pacing compared with single chamber VVI pacing in patients after a Fontan operation [6]. When adequate atrioventricular node function was present, devices were programmed to an AAI pacing mode to allow intrinsic conduction and prevent potential ventricular sensing dysfunction. Indications for pacemaker implantation included refractory arrhythmias (n 5), PLE (n 2), intractable heart failure with pleural effusions (n 1), and severe exercise intolerance (n 2) (1 patient had both PLE and bradycardia). Patient and lead data (mean standard deviation) were compared between hospital discharge after implantation of the pacemaker and last follow-up (mean, 3.3 1.0 years). During follow-up, all patients underwent serial transthoracic echocardiography, stress electrocardiograms, and pacemaker system interrogation at 6-month intervals. Results There was no surgical mortality or morbidity. Lead implantation and DDD pacing with good values was possible at each attempt, despite a heavily scarred epicardium and adhesions in a multiple redo surgery setting. Values are given in mean standard deviation. Lead survival was 100%. After implantation, atrial lead characteristics at discharge from hospital were satisfactory (impedance 825 88 Ohm; threshold 1.5 0.3 V at 0.5 ms; sensing P waves 3.7 0.5 mv), as were ventricular lead characteristics (impedance 839 111 Ohm; threshold 1.7 0.2 V at 0.5 ms; R wave sensing 7.9 1.4 mv). At a follow-up of 3.3 1.0 years, both atrial (impedance 683 40 Ohm; threshold 0.8 0.1 V at 0.5 ms; sensing P waves 3.3 0.8 mv) and ventricular leads (impedance 630 68 Ohm; threshold 1.3 0.3Vat 0.5 ms; sensing R waves 8.7 2.5 mv) retained satisfactory pacing characteristics, even better than values obtained at implantation or discharge from the hospital. During follow-up, three pacing systems were converted to the AAI mode, not for lead failure, but electively. This was performed after echocardiographic documentation of stable and satisfactory ventricular function and laminary flow in the pulmonary artery, as during dual chamber pacing. Arrhythmias subsided in all instances and no longer required medication in 3 patients. Two patients are still on anti-arrhythmic medication without further breakthrough of atrial flutter or fibrillation. Protein-losing enteropathy was temporarily controlled in 1 patient for 4 months before reappearing in a milder form, and disappeared completely in another patient. In both patients undergoing pacemaker implantation for exercise intolerance, New York Heart Association functional class improved from IV to II. Heart failure was better controlled with disappearance of chronic pleural effusions in the last patient, although she still remained in New York Heart Association functional class III. During follow-up, we could demonstrate objective hemodynamic improvement in only 3 patients, as assessed by transthoracic echocardiography. One to 2 months after pacemaker implantation, systemic ventricular ejection fraction increased, end-diastolic ventricular volume decreased, and atrioventricular valve regurgitation improved compared with preoperative values. Comment The atriopulmonary Fontan operation [8], later modified by Kreutzer and colleagues [9], uses the patient s own pulmonary valve and artery, which are detached from the right ventricle and anastomosed to the right atrial appendage. In Fontan s original description, a concomitant uni-directional cavopulmonary anastomosis provides the right lung with non-pulsatile flow. These operations universally result in suboptimal hemodynamics owing to dilated cardiac chambers that lead to atrial arrhythmias and reduced cardiac output. Although the newer TCPC modification is more energy-efficient and provides the functional single ventricle with superior flow characteristics, early or late sinus node dysfunction, or both, remains a major postoperative concern. The pioneering work of Mavroudis and colleagues [4] has clearly demonstrated the benefits of total cavopulmonary conversion

Table 1. Patient Data (n 9) Patient Initials Date of Birth Diagnosis Palliation Fontan Findings Symptoms Pre-Implant Pacemaker Symptoms Post-Implant FS 23/3/1990 CCTGA ASD closure, B-T 11/11/1992 MI II IART, sotalol 2.4.1997 No arrhythmia shunt PE 28/3/1991 TA 28/10/1992 RPA Ex intolerance IV 22.4.1997 Ex intolerance II stenosis AB 16/2/1991 DILV,TGA PA banding 2/11/1992 RPA PLE 20.2.2001 Relief 4 months stenosis DM 12/8/1989 TA B-T shunt 3/9/1990 Ex intolerance IV 3.7.2002 Ex intolerance II TF 1/7/1981 TA RA/RV conduit, B-T shunt, conduit change 25/5/1992 Ventricular dysfunction SND, Afib, amiodarone Arrhythmia Medication at Follow-Up 19.5.1998 No arrhythmia Amiodarone DH 2/4/1985 TA 13/6/1988 IART, sotalol 27.8.2002 No arrhythmia Sotalol SA 27/12/1988 DORV-TGA, 14/6/1991 PLE, digitalis, 19.8.2004 No PLE MA Bradycardia TE 12/9/1989 Criss-cross, small RV 28/8/1992 IART, sotalol 8.10.2003 No arrhythmia NH 22/7/1985 TA ASD closure, B-T shunt 17/1/1990 MI II CHF, effusions 3.11.2003 No effusions Afib atrial fibrillation; ASD atrial septal defect; B-T Blalock-Taussig; CCTGA congenitally corrected transposition; CHF congestive heart failure; DILV double inlet left ventricle; DORV double outlet right ventricle; Ex exercise; IART intraatrial reentry tachycardia; MA mitral atresia; MI mitral insufficiency; PA pulmonary artery; PLE protein-losing enteropathy; RA right atrium; RPA right pulmonary artery; RV right ventricle; SND sinus node dysfunction; TA tricuspid atresia; TGA d-transposition of the great arteries. 1442 DODGE-KHATAMI ET AL Ann Thorac Surg EPICARDIAL PACING IN FAILING FONTAN PATIENTS 2005;80:1440 4

Ann Thorac Surg DODGE-KHATAMI ET AL 2005;80:1440 4 EPICARDIAL PACING IN FAILING FONTAN PATIENTS 1443 with arrhythmia surgery and pacemaker implantation in patients with a failing Fontan circulation [4]. He and others [4, 10, 11] advocate routine prophylactic insertion of an epicardial pacing system in order to avoid redo sternotomy for ulterior pacemaker implantation. The rare patients with a failing Fontan circulation and irreversible ventricular dysfunction are not candidates for conversion therapy, and heart transplantation may be the only alternative to allow prolonged survival [5]. Protein-losing enteropathy is one of the most serious and poorly understood complications in patients with single ventricle physiology, occurring in 3% to 15% of survivors of a Fontan operation [12, 13]. The onset may be insidious, appearing years after a successful surgical result, despite documented unobstructed pathways and low Fontan pressures. Medical therapy for this condition has met with partial and temporary success, and 5-year survival after diagnosis of PLE is a dismal 46% [12]. After conversion of an atriopulmonary Fontan-Kreutzer connection to a TCPC circulation alone, anecdotal control of PLE has been reported. More favorable venous hemodynamics and cardiac output may account for the clinical improvement, which also occurs after dual chamber pacing through restored atrioventricular synchrony [4, 10, 14]. The same improvement in hemodynamics may explain the therapeutic success of pacing in patients with plastic bronchitis, which is another long-term complication of obscure origin from which Fontan patients suffer [15]. In our study, 2 patients underwent pacemaker insertion in an attempt to treat PLE with only temporary resolution (4 months) in 1 patient, albeit improved clinical status at last follow-up, and disappearance of PLE in the other patient. Other groups have reported successful treatment of PLE by pacemaker insertion, although in 6 of 7 patients, prior or simultaneous TCPC circulations were present, making it difficult to distinguish if the TCPC circulation or pacing contributed to clinical improvement [4, 10, 14]. Atrial pacing per se did treat PLE in 2 patients [14]. Further prospective, randomized studies are required to assess the impact of pacing versus TCPC alone in patients with single ventricle physiology and PLE. In summary, we reviewed a subgroup of 9 patients, followed on an outpatient basis, who were clear candidates for a TCPC conversion, but were reluctant to proceed with our recommendation. As an intermediate measure, insertion of a dual-chamber epicardial pacemaker system resulted in improved clinical status in all 9 patients, for a mean follow-up of as many as 3.3 1.0 years. Adepts of endocardial pacing have voiced concerns with epicardial lead insertion, both with regards to the need for an additional surgical approach and implantation in scarring myocardium with adhesions [6, 16]. Our current and past results would speak against this concern [17]. We and others believe that an experienced surgical group accustomed to redo surgery in children with congenital heart disease can offer safe and reproducible pacemaker implantation and performance, and should not resort to endocardial lead insertion through extra-anatomic venous pathways [10]. Single-ventricle patients with transvenous pacing leads require anticoagulation, exposing them to the risks of iatrogenic bleeding or thromboembolism [6, 16]. Furthermore, by definition, these patients still have intracardiac shunts, and their single functional ventricle is a systemic one. There have been documents of paradoxical air embolism during endovenous lead insertion, as well as thrombosis of endovenous leads with embolization [18, 19]. In light of these findings, we find endovenous leads to be contraindicated in patients with single ventricle physiology or with intracardiac shunts. The limitations of the study are inherent to the retrospective nature of the review and the lack of controls, although it seems unlikely that a similar subgroup of patients would have improved spontaneously without some sort of therapy. The patient group is small and heterogenous with regard to intracardiac anatomy. Although all patients underwent echocardiography at regular intervals, objective hemodynamic improvement was documented in only 3 patients after pacemaker therapy. In a recent study by Bacha and colleagues [7], real time 3-dimensional echocardiography demonstrated improved cardiac performance in patients with single-ventricle palliation by multi-site pacing, presumably through better synchrony of ventricular contraction. Additional valuable studies with objective data would help better to understand the beneficial effects of pacing in these patients. Post-script Remark Since the completion of this article, 1 patient accepted and underwent Fontan conversion with arrhythmia surgery. She had been paced for heart failure and chronic pleural effusions that required repetitive chest tube drainage. Although the effusions subsided shortly during the hospital stay after pacemaker insertion, her New York Heart Association functional class only improved from IV to III. After a 10-month interval with anti-congestive heart failure therapy, she underwent an uneventful elective conversion to an extracardiac TCPC with a right-sided Maze procedure using radio-frequency ablation. References 1. Cohen MI, Bridges ND, Gaynor JW, et al. Modifications to the cavopulmonary anastomosis do not eliminate early sinus node dysfunction. J Thorac Cardiovasc Surg 2000;120:891 901. 2. Bae E-J, Lee J-Y, Noh C-I, Kim W-H, Kim Y-J. Sinus node dysfunction after Fontan modifications influence of surgical method. Int J Cardiol 2003;88:285 91. 3. Cohen MI, Wernovsky G, Vetter VL, et al. Sinus node dysfunction after a systematically staged Fontan procedure. Circulation 1998;98(19S):352II 8II. 4. Mavroudis C, Deal BJ, Backer CL. The beneficial effects of total cavopulmonary conversion and arrhythmia surgery for the failed Fontan. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2002;5:12 24 (review). 5. Mitchell MB, Campbell DN, Boucek MM. Heart transplantation for the failing Fontan circulation. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2004;7:56 64. 6. Fishberger SB, Wernovsky G, Gentles TL, et al. Long-term outcome in patients with pacemakers following the Fontan operation. Am J Cardiol 1996;77:887 9.

1444 DODGE-KHATAMI ET AL Ann Thorac Surg EPICARDIAL PACING IN FAILING FONTAN PATIENTS 2005;80:1440 4 7. Bacha EA, Zimmerman FJ, Mor-Avi V, et al. Ventricular resynchronization by multisite pacing improves myocardial performance in the postoperative single-ventricle patient. Ann Thorac Surg 2004;78:1678 83. 8. Fontan F, Baudet E. Surgical repair of tricuspid atresia. Thorax 1971;26:240 8. 9. Kreutzer G, Galindez E, Bono H, et al. An operation for the correction of tricuspid atresia. J Thorac Cardiovasc Surg 1973;66:613 21. 10. Heinemann MK, Gass M, Breuer J, Ziemer G. DDD pacemaker implantation after Fontan-type operations. PACE 2003;26[Pt II]:492 5. 11. Cohen MI, Rhodes LA, Spray TL, Gaynor JW. Efficacy of prophylactic epicardial pacing leads in children and young adults. Ann Thorac Surg 2004;78:197 203. 12. Feldt RH, Driscoll DJ, Offord KP, et al. Protein-losing enteropathy after the Fontan operation. J Thorac Cardiovasc Surg 1996;112:672 80. 13. Rychik J, Spray TL. Strategies to treat protein-losing enteropathy. Semin Thorac Cardiovasc Surg Pediatr Card Surg Annu 2002;5:3 11. 14. Cohen MI, Rhodes LA, Wernovsky G, Gaynor JW, Spray TL, Rychik J. Atrial pacing: an alternative treatment for proteinlosing enteropathy after the Fontan operation. J Thorac Cardiovasc Surg 2001;121:582 3. 15. Barber BJ, Burch GH, Tripple D, Balaji S. Resolution of plastic bronchitis with atrial pacing in a patient with Fontan physiology. Pediatr Cardiol 2004;25:73 6. 16. Shah MJ, Nehgme R, Carboni M, Murphy JD. Endocardial atrial pacing lead implantation and mid-term follow-up in young patients with sinus node dysfunction after the Fontan procedure. PACE 2004;27:949 54. 17. Valsangiacomo E, Molinari L, Rahn-Schönbeck M, Bauersfeld U. DDD pacing mode survival in children with a dual-chamber pacemaker. Ann Thorac Surg 2000;70:1931 4. 18. Silka M, Rice M. Paradoxic embolism due to altered hemodynamic sequencing following transvenous pacing. PACE 1991;14:499 503. 19. Dodge-Khatami A, Johnsrude CL, Backer CL, Deal BJ, Strasberger J, Mavroudis C. A comparison of steroid-eluting epicardial versus transvenous pacing leads in children. J Card Surg 2000;15:323 9. The Society of Thoracic Surgeons Policy Action Center The Society of Thoracic Surgeons (STS) is pleased to announce a new member benefit the STS Policy Action Center, a website that allows STS members to participate in change in Washington, DC. This easy, interactive, hassle-free site allows members to: Personally contact legislators with one s input on key issues relevant to cardiothoracic surgery Write and send an editorial opinion to one s local media E-mail senators and representatives about upcoming medical liability reform legislation Track congressional campaigns in one s district and become involved Research the proposed policies that help or hurt one s practice Take action on behalf of cardiothoracic surgery This website is now available at www.sts.org/takeaction. 2005 by The Society of Thoracic Surgeons Ann Thorac Surg 2005;80:1444 0003-4975/05/$30.00 Published by Elsevier Inc