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Mitral Valve Arcade With Concomitant Anomalous Left Coronary Artery From the Pulmonary Artery

2011; Elsevier BV; Volume: 92; Issue: 6 Linguagem: Inglês

10.1016/j.athoracsur.2011.06.010

1552-6259

Lowell Su, Harold M. Burkhart, Patrick O’Leary, Joseph A. Dearani,

Vascular anomalies and interventions

The presence of congenital mitral valve arcade with concomitant anomalous coronary artery arising from the pulmonary artery (ALCAPA) is exceedingly rare. We describe a case of a 5-month-old female patient with both ALCAPA and severe mitral regurgitation secondary to mitral valve arcade. The presence of congenital mitral valve arcade with concomitant anomalous coronary artery arising from the pulmonary artery (ALCAPA) is exceedingly rare. We describe a case of a 5-month-old female patient with both ALCAPA and severe mitral regurgitation secondary to mitral valve arcade. Mitral valve arcade and anomalous left coronary artery originating from the pulmonary artery (ALCAPA) are two rare congenital abnormalities. Layman and Edwards [1Layman T.E. Edwards J.E. Anomalous mitral arcade: a type of congenital mitral insufficiency.Circulation. 1967; 35: 389-395Crossref PubMed Scopus (90) Google Scholar] first described a type of congenital mitral insufficiency in 3 infants, which they termed anomalous mitral arcade in 1967. Bland and colleagues [2Bland E.F. White P.D. Garland J. Congenital anomalies of the coronary arteries: report of an unusual case associated with cardiac hypertrophy.Am Heart J. 1933; 8: 787Abstract Full Text PDF Scopus (336) Google Scholar] increased clinical interest in ALCAPA with their description of an infant dying of this condition 30 years earlier. This case report is one of the rare descriptions of mitral valve arcade with concomitant ALCAPA treated with successful mitral valve repair [3Stellin G. Padalino M.A. Vida V.L. et al.Surgical repair of congenital mitral valve malformations in infancy and childhood: a single-center 36-year experience.J Thorac Cardiovasc Surg. 2010; 140: 1238-1244Abstract Full Text Full Text PDF PubMed Scopus (55) Google Scholar]. A 5.3 kg, 4-month-old female infant presented with a murmur, mild tachypnea, and poor growth. A physical examination revealed a laterally displaced apical impulse and slightly increased right ventricular impulse along the left sternal border. In addition, a 2/6 holosystolic murmur radiating to the axilla and a low-pitched, diastolic rumble were noted near the apex of the heart. Two-dimensional color flow Doppler echocardiography revealed the presence of an abnormal mitral valve arcade with leaflet dysplasia and short thickened chords (Fig 1). The mitral annulus was significantly dilated (24 mm). There was a central coaptation gap and severe mitral valve regurgitation (regurgitant fraction >75%). There was left ventricular enlargement with an ejection fraction of 69% and left atrial enlargement. Elevated late-diastolic pulmonary regurgitant velocity (2.7 m/second) and diastolic pulmonic valve pressure (34 mm Hg) confirmed the presence of significant pulmonary artery (PA) hypertension. A diagnosis of mitral arcade with severe regurgitation was made. The patient was given digoxin, enalapril, and furosemide. The patient returned at 5 months old with persistent slow weight gain. A subsequent echocardiogram revealed the presence of a previously undetected ALCAPA (Fig 2) and persistent severe mitral regurgitation. However, there had been a decrease in the regurgitant fraction to 50%, a decrease in pulmonary pressure (diastolic pulmonic valve pressure = 10 mm Hg; pulmonic regurgitant velocity = 1.1 m/second), and a decrease in left ventricular ejection fraction from 69% to 58%. Cardiac catheterization confirmed the presence of ALCAPA (Fig 2). Surgical repair of the mitral valve and the ALCAPA was recommended. Intraoperatively, the chest was entered via median sternotomy. Cardiopulmonary bypass and antegrade cardioplegia were initiated. Direct observation of the mitral valve via transeptal incision revealed that the true annulus was severely dilated to 20 mm. The anterolateral papillary muscle had no chords, connecting directly into both the anterior and posterior mitral valve leaflets. The posterior medial papillary muscle had a few thick chords forming the fibrous arcade, in addition to areas of direct muscular connection to the mitral leaflets. The valve leaflets were thickened and dysplastic. An anterolateral annuloplasty with an edge-to-edge repair was performed at the noncoapting portion of the leaflet at the area of the anterolateral commissure. An Alfieri stitch was placed near the noncoapting central dysplastic leaflet portion. The main PA was circumferentially transected proximal to the PA branches. Direct observation of the left coronary artery confirmed an origin from the anterolateral aspect of the PA. A Takeuchi repair could not be performed. The left coronary artery button was mobilized, and a 4-mm Gore-Tex graft was spatulated and sutured to the coronary button. The left coronary artery graft was brought anterior to the PA and attached to the aorta. Bovine pericardium was used to repair the PA sinus of Valsalva. Aortic cross-clamp time was 45 minutes and cardiopulmonary bypass time was 141 minutes. An intraoperative echocardiogram demonstrated marked improvement with only mild mitral regurgitation and no stenosis. Antegrade flow through the left coronary artery graft was confirmed. The patient was extubated on postoperative day 1, had an uneventful recovery, and was discharged on postoperative day 7. At 1 year follow-up, the patient was thriving and the mitral valve was stable with only mild regurgitation. Stellin and colleagues [4Stellin G. Padalino M.A. Milanesi O. et al.Repair of congenital mitral valve dysplasia in infants and children: is it always possible?.Eur J Cardiothorac Surg. 2000; 18: 74Crossref PubMed Scopus (41) Google Scholar] described their experience with surgical treatment of congenital mitral valve dysplasia. Included in their experience was treatment of mitral valve arcade and hammock mitral valve. Hammock mitral valve is defined either by an absence of tendinous cords or by chords that are inappropriately joined across the mitral valve orifice. The fusion of both papillary muscle apices with the leaflet tissue at the commissures produces a hammock appearance from the atrial side. Mitral valve arcade is characterized by direct attachment of the papillary muscles into the mitral valve leaflets. The result is a fibrous or muscular arcade formed by the papillary muscles, the short tendinous chords, and the edge of the anterior leaflet. These abnormalities can inhibit mitral closure and leaflet coaptation, leading to regurgitation and stenosis. A significant difference reported by Stellin and colleagues [4Stellin G. Padalino M.A. Milanesi O. et al.Repair of congenital mitral valve dysplasia in infants and children: is it always possible?.Eur J Cardiothorac Surg. 2000; 18: 74Crossref PubMed Scopus (41) Google Scholar] between mitral valve arcade and hammock repair was that hammock repair resulted in eventual replacement in two of the six patients at 4 and 27 months after initial repair, respectively. This repair is challenging because of the amount of papillary muscle beneath the mitral leaflets, which may contribute to the eventual valve replacement. Currently, there are no data showing that arcade repair has led to valve replacement, and consequently we treated our patient with repair. In our case, a successful repair was performed after direct visualization of the pathologic arcade valve, demonstrating that mitral valve repair is preferred over valve replacement because it allows the child to grow and potentially accommodate a bigger prosthetic valve. The presence of ALCAPA with mitral arcade was unique in this case. ALCAPA usually results in global myocardial ischemia and dysfunction, because the myocardium is perfused by a coronary artery that carries low oxygen blood under low perfusion pressure and the presence of collateral circulation from a normal arising coronary artery results in a coronary shunt of blood flow from the myocardium to the pulmonary artery [5Wright N.L. Baue A.E. Baum S. Blakemore W.S. Zinsser H.F. Coronary artery steal due to an anomalous left coronary artery originating from the pulmonary artery.J Thorac Cardiovasc Surg. 1970; 59: 461PubMed Google Scholar]. The imaging study of choice for mitral valve arcade diagnosis is an echocardiogram that incorporates both a two-dimensional and color-flow Doppler modality [6Espinola-Zavaleta N. Vargas-Barron J. Keirns C. et al.Three-dimensional echocardiography in congenital malformations of the mitral valve.J Am Soc Echocardiogr. 2002; 15: 468-472Abstract Full Text Full Text PDF PubMed Scopus (38) Google Scholar]. The elevated PA pressures seen at presentation in our patient may have enhanced forward flow through the anomalous left coronary artery. Once anticongestive medications were provided and the PA pressure decreased, the shunting into the main PA became evident by Doppler echocardiography (Fig 2), providing an important clue leading the recognition of ALCAPA as a second anomaly in this patient. The presence of ALCAPA did not alter our approach to repair of the mitral valve arcade, but it remained an impressive concomitant finding.