SUBJECTS AND METHODS

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1 Acquired Mitral Stenosis in Children under Fifteen Boonchob PONGPANICH, M.D. and Sahas LIAMSUWAN, M.D. SUMMARY The clinical and hemodynamic studies of acquired MS in 30 children under the age of 15 are reviewed. There are 13 male and 17 female patients with an age range from 9 to 14 (mean 12.6) years. The majority of the patients (78%) are in New York Heart Association functional class 3 or 4. Only 55% of the patients had a history suggestive of previous rheumatic fever. All patients had pulmonary hypertension and 41% had severe pulmonary hypertension. A closed mitral commissurotomy was performed in all patients. There were 3 deaths and 2 patients required reoperation because of restenosis. The early onset of mitral stenosis in our population was suggestive of a very early onset of valvulitis with subsequent fibrosis and narrowing of the mitral valve. This is in contrast to the acute fulminating form of rheumatic fever with valvulitis manifested by severe mitral and or aortic insufficiency. Additional Indexing Words: Juvenile mitral stenosis Rheumatic carditis CQUIRED mitral stenosis (MS) is a disease of adults in most western countries. Juvenile mitral stenosis is found in many developing countries.1)-5) In Thailand, the most common age of patients with MS is years.6) Severe MS in children under the age of 15 is rarely reported and there have been few detailed hemodynamic studies of this population. The purpose of this report is to re-emphasize the continuing occurrence of juvenile MS in young children and to present the clinical and hemodynamic characteristics of this entity. SUBJECTS AND METHODS Children under the age of 15 years who were admitted to the Department of Pediatrics, Ramathibodi Hospital during the period from 1969 to 1985 with the diagnosis of acquired MS were evaluated. A routine chest X-ray and electrocardiography were done in all patients. Cardiac catheteri- From the Department of Pediatrics, Faculty of Medicine, Ramathibodi Hospital, Mahidol University, Bangkok, Thailand. Received for publication January 27, Accepted July 27,

2 182 PONGPANICH AND LIAMSUWAN Jpn. Heart J. M arch 1989 zation and cineangiocardiography were done in 24 patients. Recently, echocardiograms have also been performed. The diagnoses were all confirmed at cardiac surgery. The cardiac symptoms were classified according to the New York Heart Association. The severity of pulmonary hypertension was classified into mild if the mean pulmonary artery pressure was over 13mmHg but less than half of the systemic pressure, moderate if the mean pulmonary artery pressure was between 50 and 75% of the systemic pressure and severe if the mean pulmonary artery pressure was greater than 75% of systemic pressure. A closed mitral commissurotomy was done in all patients. These patients were regularly followed at our cardiac clinic. RESULTS During the period of the study there were 30 patients of whom 13 were male and 17 female. The age distribution is shown in Fig.1. The mean age was 12.6 years, with a range from 9 to 14 years. Only 27 medical records were available for complete analysis. Most of the patients were in functional class 3 or 4 at the time of the first visit to our hospital. All patients had a history of dyspnea on exertion for a period of 2 months to 3 years. Nocturnal Number of patients Age in years Fig.1. The age distribution of the patients.

3 Vol.30 No.2 ACQUIRED MITRAL STENOSIS IN CHILDREN 183 dyspnea was found in 55.6%. Other symptoms included edema, palpitations, coughing, fainting and hemoptysis. A history of joint pain was found in 55.5% (Table I). The detailed physical findings are demonstrated in Table II. All patients were in sinus rhythm. A diastolic murmur was detected at the mitral valve area in every patient. The laboratory findings are shown in Table III. Only 7.4% of the patients were anemic. Seventy eight percent had an ASO titer of less than Table I. Symptoms of Patients with Juvenile MS Table II. Physical Findings in Juvenile MS Table III. Laboratory Findings

4 184 PONGPANICH AND LIAMSTTWAN Jpn. Heart J. M arch Todd units. All patients had cardiomegaly on chest X-ray. Fifty eight percent had pulmonary congestion. The electrocardiogram showed left atrial enlargement in 96%, right ventricular hypertrophy in 69%, right atrial enlargement in 46% and left ventricular hypertrophy in 7%. Almost all patients who had moderate to severe pulmonary hypertension had right axis deviation on the electrocardiogram. The results of cardiac catheterization are demonstrated in Table IV. Most patients had a mean pulmonary artery wedge pressure over 20mmHg with moderate to severe pulmonary hypertension. Table V demonstrates the correlation of mitral valve diameter measured during surgery with functional classification and the severity of pulmonary hypertension. Thirteen of 15 patients who had a mitral valve diameter of less than 0.5cm were in functional class 3 or 4, while 10 of 13 patients with a mitral valve diameter of less than 0.5cm had moderate to severe pulmonary hypertension. Mitral valve calcification was found in 7 patients. None of the patients had clots in the left atrium. There were 3 postoperative deaths, 2 from pneumonia and I from congestive heart failure. The histological findings of the left atrial appendage in 7 patients showed chronic epicarditis or endocarditis. Only one specimen Table IV. Cardiac Catheterization Data Table V. The Correlation between Mitral Valve Diameter and Functional Classification and Degree of Pulmonary Hypertension

5 Vol.30 No.2 ACQUIRED MITRAL STENOSIS IN CHILDREN 185 had an Aschoff body. Twenty patients were adequately followed postoperatively. Most patients improved in exercise tolerance. The mean follow up time was 32 months. It ranged from 1 month to 12 years. Two patients were reoperated on due to restenosis at 3 and 9 years after the first operation. DISCUSSION Although rheumatic fever and rheumatic heart disease are decreasing in developed countries, it is still commonly seen in the Thai population.5)-7) There was very little evidence of rheumatic activity and certainly no fulminant rheumatic state in the past history of our cases of juvenile MS. Only half of our patients had a history of joint pain and only one atrial specimen had an Aschoff body suggestive of rheumatic fever in the past. It is therefore very difficult to date the onset of the rheumatic process and even more so its duration leading to a stenosed mitral valve. Could it be that a high prevalence of a characteristically mild, subdued form of rheumatic fever among children in our area leads to this high incidence of juvenile MS, since it has been suggested that a mild original rheumatic attack favors the later development of pure mitral stenosis without loss of valve substance? In contrast, the more florid the original attack the more likely that insufficiency with destruction of valve substance will occur.8) This is supported by our long term follow up of patients with acute rheumatic carditis and mitral valve insufficiency, who rarely develop mitral valve stenosis. All patients in this report had pure mitral stenosis without significant mitral or aortic insufficiency. The clinical picture, electrocardiogram and hemodynamic data in our patients are similar to previous reports.2),5) The differences from adults with MS are the absence of atrial fibrillation and thromboembolism. The high incidence of congestive heart failure and high pulmonary artery pressure and pulmonary edema are consistent with the severe narrowing of the mitral valve found at surgery. The standard closed mitral valvotomy has proved to be a very satisfactory operation. The results of mitral valvotomy in our patients have in general been excellent. The true incidence of restenosis in our patients will not be known for many years. It has been shown that the risk of restenosis depends to a large extent on the adequacy of the initial valvulotomy.9) Inspite of the fact that most of these young children came from families of poor socioeconomic and educational background in which children ordinarily do not receive adequate medical treatment and secondary prophylaxis

6 186 PONGPANICH AND LIAMSUWAN Jpn. Heart J. M arch 1989 for recurrence of streptococcal infection, the incidence of recurrent rheumatic activity is relatively low and the long term results are fairly satisfactory. REFERENCES 1. Bhayana JN, Khanna SK, Gupta BK, Sharma SR, Gupta MP, Padmavati S: Mitral stenosis in the young in developing countries. J Thorac Cardiovasc Surg 68: 126, Ozcan R, Danopuless D, Dorken N, Ozsaruhan O, Alhan MA, Camli N: Severe mitral stenosis under the age of 15. Proceeding 4th APCC, Tel Aviv, p177, Mori C: Clinical observation on mitral stenosis in children and adolescents. Proceeding 4th APCC, Tel Aviv, p181, Vytiligam KI, Cherian G, Sukuman IP: A study of juvenile mitral stenosis during a 10 year period ( ). Proceeding 4th APCC, Tel Aviv, p187, Jumbala B, Sukumalchantra Y, Vichitpan P, Tongmita V, Prachuabmoh K, Chatikavanij K: Juvenile mitral stenosis in Thailand. Proceeding 4th APCC, Tel Aviv, p184, Sukumalchantra Y, Tongmitr V, Vongtongsri W, Haraphong M, Kochaseni S: Rheumatic mitral stenosis at Siriraj Hospital. Siriraj Hosp Gaz 21: 7, Sindhavananda K, Jumbala B, Siriwan C, Kchachiva C, Dhamasakdi D, Vathanakasetr S: Incidence, etiology and mortality of 4370 heart patients admitted to 4 hospitals in Bangkok and Thonburi, Thailand. Proceeding 4th APCC, Tel Aviv, p41, Walsh B, Bland EF, Jones TD: Pure mitral stenosis in young persons. Arch Intern Med 65: 321, Wilcken DEL: Mitral valvotomy and restenosis. Br Med J 1: 681, 1960