Long-term transvenous AV-sequential pacing in a failing atriopulmonary Fontan patient

Current Treatment Options for the Failing Fontan Circulation

The Fontan operation was introduced in 1968. For congenital malformations, where biventricular repair is unsuitable, the Fontan procedure has provided a long-term palliation strategy with improved outcomes compared to the initially developed procedures. Despite these improvements, several complications merely due to a failing Fontan circulation, including myocardial dysfunction, arrhythmias, increased pulmonary vascular resistance, protein-losing enteropathy, hepatic dysfunction, plastic bronchitis, and thrombo-embolism, may occur, thereby limiting the life-expectancy in this patient cohort. This review provides an overview of the most common complications of Fontan circulation and the currently available treatment options.

Endocardial transvenous pacing in patients with surgically palliated univentricular hearts: A review on different techniques, problems and management

Fontan surgery and its modifications have improved survival in various forms of univentricular hearts. A regular atrial rhythm with atrioventricular synchrony is one of the most important prerequisite for the long-term effective functioning of this preload dependent circulation. A significant proportion of these survivors need various forms of pacing for bradyarrhythmias, often due to sinus nodal dysfunction and sometimes due to atrioventricular nodal block. The diversion of the venous flows away from the cardiac chambers following this surgery takes away the simpler endocardial pacing options through the superior vena cava. The added risks of thromboembolism associated with endocardial leads in systemic ventricles have made epicardial pacing as the procedure of choice. However challenges in epicardial pacing include surgical adhesions, increased pacing thresholds leading to early battery depletion and frequent lead fractures. When epicardial pacing fails, endocardial lead placement is equally challenging due to lack of access to the cardiac chambers in Fontan circulation. This review discusses the univentricular heart morphologies that may warrant pacing, issues about epicardial pacing, different techniques for endocardial pacing in patients with disconnected superior vena cava, pacing in different modifications of Fontan surgeries, issues of systemic thromboembolism with endocardial leads, atrioventricular valve regurgitation attributed to pacing leads and device infections. In a vast majority of patients following Glenn shunt and Senning surgery, an epicardial pacing and lead replacement is always feasible though technically very difficult. This article highlights the different options of transatrial and transventricular endocardial pacing.

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Fontan surgery prolongs the mean survival of patients with univentricular hearts beyond 30 years.

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9-20% of survivors need permanent pacing for bradyarrhythmias.

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Epicardial pacing is preferred as the first choice for permanent pacemaker.

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There is 20-40% failure of permanent pacing at 10 years due to high threshold, lead fractures.

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Repeated epicardial pacing with surgical revisions are difficult.

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Endocardial pacing involves special techniques.

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Manoeuvring through fenestrations,venous collaterals, hepatic veins, pulmonary valve or hybrid peratrial routes is needed.

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Systemic thromboembolism, endocarditis and systemic AV valve regurgitation should be prevented by meticulously measures.

Novel direct approach for placement of permanent transvenous pacing leads after Fontan procedure

The need for transvenous pacing (patients who have exhausted epicardial options) after a Fontan-type operation has been recognized. Many novel strategies have been proposed, but currently, all of them require additional maneuvers or rerouting of the leads to the pacemaker pocket. In this report, we describe a novel direct approach to transvenous pacing after a Fontan-type operation from a standard, prepectoral approach.

Fontan Operation: Indications, Short and Long Term Outcomes

Fontan operation, since its original description, has undergone a number of modifications so that it is now a staged, total cavo-pulmonary connection with fenestration. Stage I is palliation, depending upon the pathophysiology of the defect complex in early life, Stage II is bidirectional Glenn at about the age of 6 mo and Stage III is transfer of inferior vena caval blood to the pulmonary circuit along with fenestration between 2 to 4 y. Any patient that has only one functioning ventricle is a candidate for Fontan surgery. The morbidity and mortality have remarkably improved since the institution of staged, total cavo-pulmonary connection with fenestration. Complications during follow up continue to occur, though diminished with the newer modifications, and should be promptly addressed.