Lutembacher syndrome

To the Editor: I read with interest the case report by Shen et al1 of transcatheter treatment of Lutembacher syndrome. Lutembacher syndrome refers to a congenital atrial septal defect (ASD) complicated by acquired mitral stenosis (MS).2 The incidence of MS in patients with ASD is 4%, the incidence of ASD in patients with MS is 0.6% – 0.7%.2 Lutembacher syndrome in the past has been overdiagnosed or misdiagnosed because of the presence of a mid-diastolic murmur in patients with ASD, until it was realized that the mid-diastolic murmur was due to excessive flow through the tricuspid valve from the left-to-right interatrial shunt. In patients with MS who had undergone percutaneous balloon mitral valvuloplasty (PBMV) through the transseptal approach, the latter procedure created an ASD during the procedure: the iatrogenic Lutembacher syndrome. The incidence of atrial left-to-right shunt following PBMV is 11% – 12%.3 In most of these patients, the magnitude of the shunt was small and the defect usually diminished in size or closed over the ensuing months. In rare instances, the iatrogenic ASD might be hemodynamically significant enough to warrant surgical intervention. Mitral stenosis serves to augment the left-to-right atrial shunt through the ASD, but decompression of the obstructed left atrium by the ASD attenuates the symptoms of MS. When the ASD is sizable, it has an ameriorating effect on the clinical manifestations of MS. The ameriorating role of the ASD in MS was evident in Lutembacher's original report of 1916; the patient was a 61-year-old woman who had been pregnant seven times.4 An earlier case report in the literature in 1880 (and referred to by Perloff2) was of a 74-year-old woman who had endured 11 pregnancies. Survival to advanced age has also been reported;2 in one instance an 81-year-old woman experienced no symptoms related to her heart disease until she reached 75 years of age.5 These favorable reports, however, should not obscure the fact that the long-term natural history of ASD is unfavorably influenced by MS, which augments the left-to-right shunt and predisposes to atrial fibrillation and right ventricular failure.6 The presence of MS, especially when accompanied by mitral regurgitation, increases susceptibility to infective endocarditis, in contrast to the low incidence of infective endocarditis in uncomplicated ASD.2 Therefore, these patients in the past usually underwent corrective surgery as soon as the diagnosis was established. With the advent of percutaneous technique of transcatheter closure of ASD and PBMV, Lutembacher syndrome can now be successfully treated nonsurgically.6 Because the Inoue technique has been used in the largest number of patients around the world7 with excellent long-term results,8 it has become the procedure of choice for PBMV.9 The Amplatzer septal occluder appears to be the device of choice for transcatheter closure of ASD.10 By combining these two techniques in the same patient at the same cardiac catheterization, percutaneous management of Lutembacher syndrome can obviate the morbidity and mortality associated with cardiac surgery, the psychological trauma of a thoracotomy scar, the prolonged hospital stay followed by another prolonged period of home convalescence and the possibility of repeat thoracotomy for mitral restenosis.6 In the latter situation, PBMV may be repeated.8 Of course, the presence of the Amplatzer septal occluder makes it undesirable to use the transseptal approach. An alternative approach would be transarterial retrograde nontransseptal technique in which entry into the left atrium is achieved retrogradely via the left ventricle.6