Subaortic stenosis produced by an accessory mitral valve: the role of echocardiography

Subaortic stenosis caused by an accessory mitral valve is an exceedingly rare finding. We report the case of an asymptomatic 14-year-old patient, in whom transthoracic echocardiography revealed an accessory mitral valve in the left ventricular outflow tract, producing mild subaortic stenosis. Except for an aneurysm of the interventricular septum, with no shunt, there were no other anomalies. Transesophageal echocardiography provided details about the morphology and location of the accessory valve. Being asymptomatic and having only a mild gradient, antibiotic prophylaxis for infective endocarditis and follow-up were recommended. After 2 years the patient is asymptomatic, with a similar echocardiographic gradient.     

Functional assessment of mitral stenosis

The following parameters must be taken into account when assessing the severity of mitral stenosis: symptoms, objective examination, electrocardiogram, chest X-ray, a simple exercise test with or without cardiopulmonary test, echocardiography and lastly a hemodynamic test. Differences are often observed between the clinical and instrumental findings. In these cases a major contribution is made by the use of physical effort in response to both ECG and heart catheterization in order to quantify the patient's functional deficiency and valve response. The latter aspect must be validated using a simultaneous comparison between echocardiography and the hemodynamic test and longitudinal clinical studies.     

Natural and post-surgical history of mitral stenosis and mitral stenosis and insufficiency: an observational study

Natural and post-surgical history has been investigated in 410 pts with mitral stenosis and 209 pts with mixed mitral stenosis and regurgitation. They had undergone cardiac catheterization in the years 1968-1980. Hemodynamic data and clinical status (NYHA class) have been statistically analyzed in order to obtain prognostically useful parameters. In mitral stenosis peak pulmonary artery pressure is the most important parameter for natural history, whereas cardiac index is the leading parameter in the operated patients. Commissurotomy has a very low surgical mortality, largely due to the better conditions of the patients undergoing this type of conservative surgery. Results are similar in mixed mitral stenosis and regurgitation. Surgery markedly improves survival in comparable patients. Therefore, intervention seems to be indicated especially in patients with elevated pulmonary artery pressure, because they can get the maximum advantage at a minimal risk.     

Percutaneous mitral valvuloplasty in an adult patient with calcific rheumatic mitral stenosis

A 75 year old man with long-standing rheumatic mitral stenosis who refused surgical intervention was treated with percutaneous balloon valvuloplasty. Prevalvuloplasty evaluation revealed a heavily calcified mitral valve, a mean transvalvular gradient of 18 mm Hg, a Fick cardiac index of 1.7 liters/min per m2, a mitral valve area of 0.6 cm2 and 1 + mitral regurgitation. After transeptal catheterization and balloon dilation of the interatrial septum with an 8 mm angioplasty balloon, a 25 mm valvuloplasty balloon was advanced over a guide wire across the interatrial septum and positioned across the mitral anulus. Subsequent balloon inflation at 3 atm pressure resulted in a reduction of the mean mitral valve gradient to 12 mm Hg, an increase in cardiac index to 2.5 liters/min per m2, an increase in mitral valve area in 1.4 cm2 and an increase in mitral regurgitation from 1 + to 2 +. Valvuloplasty was well tolerated without embolization of clot or valvular debris, and resulted in marked clinical improvement with decreased dyspnea and increased exercise tolerance. Repeat catheterization 2 months after valvuloplasty showed further resolution of pulmonary hypertension and no evidence of valvular restenosis or worsening mitral regurgitation, but detected a small atrial septal defect with a pulmonary to systemic blood flow ratio of 1.8. It is concluded that percutaneous valvuloplasty is possible in the adult patient with calcific rheumatic mitral stenosis, and may result in a significant improvement in valvular function without producing life-threatening complications.     

Unsuspected mitral stenosis

PURPOSE AND PATIENTS AND METHODS: We observed a series of patients in whom the diagnosis of mitral stenosis was first discovered in the echocardiography laboratory. Because of this experience, we examined the records of 152 patients with echocardiographic evidence of rheumatic mitral stenosis to determine the clinical characteristics and course of patients with unsuspected mitral stenosis as well as those factors that may have obscured the diagnosis. RESULTS: Of these 152 patients, 18 had mitral stenosis that was unsuspected clinically until the echocardiogram. These patients were elderly, with a median age of 72 years. They were all referred for echocardiography because of cardiac symptoms. Eight patients were referred for evaluation of congestive heart failure. Five patients were referred for evaluation of aortic valve disease. Three patients were referred because of cerebrovascular accidents and atrial fibrillation. The Doppler-determined mean diastolic mitral gradient ranged from 4 to 15 mm Hg (mean: 7 mm Hg). Mitral stenosis ranged in severity from trivial to very severe. Eight patients had moderate to severe mitral stenosis with estimated mitral valve areas less than or equal to 1.5 cm2. Seven had mild or trivial mitral stenosis with estimated mitral valve areas greater than 1.5 cm2. After further evaluation, two patients underwent mitral valve surgery with improvement of congestive failure. In three patients, warfarin therapy was begun to prevent emboli. Thus, five of 18 patients had a significant immediate change in therapy because of the discovery of mitral stenosis. CONCLUSION: The diagnosis of mitral stenosis may not be suspected in the presence of advanced age, other serious cardiac and medical conditions, or mechanical factors that complicate the physical examination. In these patients, mitral stenosis may be hemodynamically significant and may cause significant symptoms.     

Rheumatic mitral stenosis

Patients with symptomatic mitral stenosis should undergo evaluation with transthoracic and transesophageal echocardiography (Table 1). Those patients with suitable valve morphology should be treated with percutaneous transvenous mitral commissurotomy (PTMC). Randomized trials of catheter commissurotomy have shown no differences in long-term outcome compared with surgical commissurotomy; there is therefore no role for surgical commissurotomy in patients who are suitable candidates for balloon commissurotomy. Mitral valve replacement should be recommended for those patients with valve deformity too severe to undergo catheter therapy. Some older patients who are less-than-ideal candidates for catheter therapy nonetheless may benefit from it as a palliative alternative to otherwise high-risk valve surgery. Asymptomatic patients should be screened for the presence of pulmonary artery hypertension. Those who have pulmonary artery systolic pressure at rest of greater than 50 mm Hg or who develop pulmonary artery systolic pressure of greater than 60 mm Hg with exercise should be considered for PTMC.     

Congenital mitral stenosis

This study consists of a detailed analysis of the clinical, hemodynamic, surgical and pathologic findings of 23 children with congenital mitral stenosis and 99 additional cases from the literature. These cases were grouped into three major pathologic complexes: (1) the isolated form; (2) the form associated with other obstructive left-sided heart lesions (coarctation of the aorta, aortic stenosis) and a patent ductus arteriosus, or both; and (3) the type associated with a ventricular septal defect. Clinical observations indicate a high mortality rate in infancy secondary to early and refractory cardiac decompensation. In the majority of instances there is severe pulmonary hypertension which approaches systemic levels when the mean left atrial pressure reaches 20 mm. Hg. The surgical mortality is still high, and an objective assessment of the operative results is not yet available.     

Cardiogenic shock secondary to mitral stenosis treated by balloon mitral valvuloplasty

Percutaneous balloon mitral valvuloplasty is a well-established elective treatment for mitral stenosis in selected patients; it has been used to treat cardiogenic shock secondary to aortic stenosis but has not been previously used for cardiogenic shock secondary to mitral stenosis. We describe a case of cardiogenic shock secondary to severe mitral stenosis, treated by balloon mitral valvuloplasty. Cathet. Cardiovasc. Diagn. 43:195–197, 1998. © 1998 Wiley-Liss, Inc.