Ann Thorac Surg 2005;80:1922-1924
© 2005 The Society of Thoracic Surgeons
Case report
Annuloplasty of the Regurgitant Mitral Valve After Myocarditis in Children
Muthukumaran C. Sivaprakasam, MRCP,
James P. Gnanapragasam, MRCP,
Anthony P. Salmon, MD,
James L. Monro, FRCS,
Steve Livesey, FRCS,
Barry R. Keeton, MD,
Joseph J. Vettukattil, MD
*
Department of Paediatric Cardiology, Wessex Cardiothoracic Unit, Southampton General Hospital, Southampton, United Kingdom
Accepted for publication June 7, 2004.
* Address correspondence to Dr Vettukattil, Department of Pediatric Cardiology, Southampton General Hospital, Tremona Rd, Southampton, SO16 6 YD, UK (Email: joseph.vettukattil{at}lycos.com).
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Abstract
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Acute myocarditis is characterized by the development of rapid life-threatening congestive heart failure and arrhythmias. In many cases with hemodynamic compromise, medical therapy and mechanical support alone are not sufficient. Various surgical procedures have been tried to bridge patients with myocarditis to both transplant and recovery. Mitral regurgitation is a frequent association with end stage cardiomyopathy and predicts poor outcome. Mitral annuloplasty is well-established in adults with ischemic and dilated cardiomyopathy and the results are superior to medical therapy alone and are comparable to cardiac transplantation. However, its effectiveness and use is not well-established in children with cardiomyopathy. We report our experience in two children.
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Introduction
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Myocarditis is defined as inflammation of the myocardium accompanied by myocellular necrosis. The etiology of myocarditis has been associated with various infections, systemic diseases, drugs, and toxins. In the United States and Europe, viruses are probably the most important cause of myocarditis, Coxsackie virus being the most common pathogen. Nevertheless, the exact cause remains unknown in the majority of patients with presumed myocarditis. The treatment of myocarditis has improved significantly over the last decade and supportive care is still the mainstay of initial therapy. Conventional heart failure medications include angiotensin converting enzyme [ACE] inhibitors, digitalis, diuretics, and, after stabilization, ß-blockers. Mechanical cardiac support with a left ventricular assist device, biventricular assist device, or extracorporeal membrane oxygenation may benefit children with rapidly progressive severe heart failure. In many cases of acute myocarditis with compromised hemodynamics, medical therapy and mechanical support are a bridge towards cardiac transplantation. It is the only option for symptomatic children with severe left ventricular [LV] dysfunction refractory to medical treatment but donor availability significantly limits this option. We report our experience with nontransplant surgery in children with end-stage cardiomyopathy.
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Case Reports
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Patient 1
A fourteen-month-old child was admitted with a history of grunting. She had been unwell three days before admission with vomiting and being irritable. She was tachypnoeic with weak pulses, had a loud second heart sound, and pedal edema. There were fine crepitations bilaterally. The liver was enlarged and electrocardiogram showed left atrial enlargement and flat T waves in the anterior chest leads. The echocardiogram showed poor posterior wall motion with moderate mitral regurgitation [MR] and severe LV dysfunction (LVDD = 4.6 cm fractional shortening [FS] of 22%). The coronary arteries appeared normal. With a provisional diagnosis of myocarditis, she was started on antifailure measures including diuretics and ACE inhibitors. A full cardiomyopathy screen failed to show any specific etiology. In spite of vigorous antifailure treatment, her general condition did not improve and she developed severe MR. She was referred for transplant assessment. Because of the delay in finding a donor, mitral annuloplasty was planned and a cardiac catheter examination was done to rule out coronary anomalies. Annuloplasty was performed using 4–0 Prolene (Ethicon, Somerville, NJ) on pledgets of Teflon felt. The stitch was taken across the back of the mitral valve (MV) ring in a double fashion with the felt pledgets at each end. A size 16 Hagar dilator was able to pass through the MV. The MV was tested and there was very little leakage. The patient made a remarkable recovery after surgery. Although the LV function remained the same there was only mild MR. The patient was discharged eight days after surgery. She was maintained on antifailure medications and her LV function improved gradually. She is now four-years old and the LV function is back to normal (FS-31%) and the antifailure medications were stopped. She has mild restriction to mitral flow.
Patient 2
An eleven-day-old baby boy was referred from the peripheral hospital for cardiac failure. On examination his pulses were weak. He had moderate recession and there was wide spread crackles in his chest. The liver was enlarged. The electrocardiogram showed inverted T waves in anterior chest leads. The FS was 18%. Coronary anatomy was normal. He required inotropic support and mechanical ventilation for 3 days followed by antifailure treatment. A full cardiomyopathy screen showed a high titer of immunoglobulin M (IgM) against Coxsackie B virus. He made a remarkable clinical recovery initially, but on subsequent visits he had severe MR. His LV function remained unchanged. He was also admitted on two occasions requiring intensive antifailure measures. A cardiac catheter done when he was seven years of age showed severe LV dysfunction, severe MR with pulmonary hypertension [PHT] with mean pulmonary artery pressure of 25 mm Hg.
Because of the PHT due to severe MR leading to PHT and progressive deterioration of LV function, MV repair with a 26 mm Carpentier-Edwards classic annuloplasty ring was done. Echocardiogram on follow-up showed mild MR. A repeat cardiac catheter done after one year, showed good hemodynamic with near normal mean pulmonary pressure [18 mm Hg]. He was stabilized on ACE inhibitors and ß-blockers were added for atrial arrhythmia. He is now thirteen-years old with good LV function [FS-38%]. He has no MR now but has mild restriction to mitral flow.
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Comment
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Functional MR is a significant complication of end-stage cardiomyopathy, and may affect most heart failure patients as a preterminal or terminal event. It develops secondary to change in MV apparatus and altered ventricular geometry resulting in incomplete leaflet coaptation. The resultant regurgitation begets further annular dilatation and progressive MR, which leads to a vicious cycle where LV function deteriorates further.
Various surgical options have been in vogue in adults with progressive cardiomyopathy. This includes mitral and tricuspid valve repair [1, 2], cardiomyoplasty [3], and partial left ventriculectomy. Szalay and colleagues [1] recently reported their experience with mitral annuloplasty in end-stage cardiomyopathy in adults. One hundred and twenty-one patients with idiopathic or ischemic cardiomyopathy had posterior ring annuloplasty. The early mortality was 6.6% and actuarial survival after five years was 70%. Szalay and colleagues [1] identified a larger annuloplasty ring and larger preoperative LV dimensions as risk factors for overall mortality. All the survivors showed improvement in ejection fraction, cardiac output, and end-diastolic volumes. Other studies have shown midterm survival after two years (71%) [4] and after 5 years (78%) [2], respectively. These survival rates are comparable to heart transplantation (68%) [5]. Surgical therapies of end-stage cardiomyopathy are rapidly evolving. As a result of improvements in preoperative selection, operative techniques, and postoperative care, surgical mortality and morbidity in patients with end-stage heart disease have significantly improved. By combining operative techniques with optimal medical management, it may be possible to avoid or postpone transplantation.
Children with fulminant myocarditis who have severe heart failure may have a good long-term prognosis [6] and should be given sufficient time to demonstrate recovery and not be rushed to heart transplantation. Mitral regurgitation with severe LVDD can be a presenting feature of anomalous origin of the coronary arteries. As this is reversible with appropriate surgical intervention it has to be excluded.
Experience with nontransplant surgical intervention is very limited in children. Partial left ventriculectomy and MV repair have been reported in three children; two of whom required transplantation later [7, 8]. Moreover, the follow-up period reported is very limited. The problems encountered in the management of adults with cardiomyopathy and prognosis differs from children as adults have an increased propensity for coexistent conditions like hypertension, renal insufficiency, coronary problems, and diabetes. This may put children and young adults in a more favorable group for nontransplant surgery.
We report the long-term beneficial effects of mitral annuloplasty for cardiomyopathy associated with severe mitral regurgitation in two children. Dilatation of the MV annulus is part of the pathological process of cardiac enlargement following myocarditis, and regurgitation is inevitable. The effect of increased preload on the failing heart causes further dilation leading to a vicious cycle. This may rapidly progress to uncontrolled cardiac failure needing transplantation. There are no well-deliniated factors to differentiate children who may benefit from surgical intervention from those who do not. Careful assessment of the contractility of the underlying myocardium and reducing the preload on preserving the function is mandatory in all children with myocarditis and MV regurgitation.
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References
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- Szalay ZA, Civelek A, Hohe S, et al. Mitral annuloplasty in patients with ischemic versus dilated cardiomyopathy Eur J Cardiothorac Surg 2003;23:567-572.[Abstract/Free Full Text]
- Calafiore AM, Gallina S, Mauro MD, et al. Mitral valve procedures in dilated cardiomyopathyrepair or replacement?. Ann Thorac Surg 2001;71:1146-1152.[Abstract/Free Full Text]
- Mordeira LF, Stolf NA, Bocchi EA. Lattissimus dorsi cardiomyoplasty in the treatment of patients with dilated cardiomyopathy Circulation 1990;82:IV257-IV263.
- Hendren WG, Nemec JJ, Lytle BW, et al. Mitral valve repair for ischemic mitral insufficiency Ann Thorac Surg 1991;52:1246-1252.[Abstract]
- Robbins RC, Barlow CW, Oyer PE. Thirty years of cardiac transplantation at Stanford University J Thorac Cardiovasc Surg 1999;117:939-951.[Abstract/Free Full Text]
- McCarthy III RE, Boehmer JP, Hruban RH, et al. Long-term outcome of fulminant myocarditis as compared with acute (nonfulminant) myocarditis N Engl J Med 2000;342:690-695.[Abstract/Free Full Text]
- Hsu RB, Chein CY, Wang SS, Chu CH. Nontransplant cardiac surgery as a bridge to heart transplantation in pediatric dilated cardiomyopathy Tex Heart Inst J 2002;29:213-215.[Medline]
- Gradinac S, Jovanovic I, Dukic M, et al. Partial left ventriculectomy in a two-year-old girl with dilated cardiomyopathy J Heart Lung Transplant 1999;18:381-383.[Medline]
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Abstract
Introduction
