Pure Mitral Incompetence Research Articles

Qualitätsparameter in der Mitralklappenchirurgie

Quality criteria comprise indication, perioperative results and complications as well as long-term stability Indication for surgery on asymptomatic mitral incompetence is still debated. The higher the probability within an institution to repair the valve by surgery with minimal complications, the more asymptomatic patients could be considered for early surgery. A thorough quality criterion is the percentage of valve repair in pure mitral incompetence. In Germany the rate is about 60%, but may be increased to about 90%. One prerequisite is the exact interpretation of the preoperative echocardiogram by the surgeon to be able to plan the optimal strategy for the individual patient. Recognition of even discrete subaortic hypertrophy as well as the consideration that any ring implant causes some degree of restriction of both leaflets may improve the technical results. Mortality for isolated mitral valve repair should not exceed 3%, neurologic complication should range between 1% and 1.5%. Reoperation rate within 10 year follow-up should not be higher than 4 - 6%. Surgical results after mitral valve replacement are inferior as this therapy is usually restricted to patients with more complex valve disease for primarily increased perioperative risk. Preservation of the subvalvular apparatus and the optimal orientation of implanted valve prosthesis are relevant intraoperative surgical quality criteria. Mitral valve surgery can be performed with a high rate of valve preservation. A relevant reduction of mortality and perioperative morbidity and improved long term stability could be achieved during the last years.

Differences in left ventricular response between rheumatic and myxomatous mitral valve disease following mitral valve replacement.

We studied whether differences exist between hearts having rheumatic mitral valves and those having myxomatous mitral valves, in functional, geometrical, and mass changes in the left ventricle after mitral valve replacement. Patients who underwent mitral valve replacement without preservation of annular-papillary continuity for pure mitral incompetence were classified into rheumatic and myxomatous based on valvular histopathology. Echographic data measured before surgery was compared to that about 3 weeks after surgery. In the rheumatic group, ejection fraction decreased from 57.5 +/- 10.8 to 47.7 +/- 12.0, indexed left ventricular internal dimension in systole (mm/m2) from 24.7 +/- 6.8 to 20.7 +/- 6.2 (P = 0.0001), and left ventricular mass index (g/m2) from 205 +/- 55 to 138 +/- 54 (P = 0.0002). In the myxomatous group, ejection fraction decreased from 60.4 +/- 11.6 to 39.7 +/- 14.5 (P = 0.0001), indexed left ventricular internal dimension in systole from 24.2 +/- 5.6 to 23.1 +/- 5.5, and left ventricular mass index from 195 +/- 83 to 111 +/- 72 (P = 0.0004). Mean wall thickness index and relative wall thickness showed significant differences between the two groups postoperatively but no significant difference preoperatively. Hearts dilated due to chronic mitral incompetence respond differently after valvular replacement with total chordal excision depending on whether a rheumatic or myxomatous mitral valve is involved.

Pattern of Rheumatic Heart Disease in Adults in Maiduguri — North East Nigeria

The pattern of rheumatic heart disease in 84 adolescent and adult patients seen over a 9 year period (1982-1990) at the University of Maiduguri Teaching Hospital (UMTH) is presented. Over 70% were in second and third decades of life. Pure mitral incompetence and mixed mitral valve disease were the commonest valvular lesions. This pattern appears similar to those in other developing countries. Congestive cardiac failure was the commonest complication. Declining economic fortunes of the developing countries, over crowding, malnutrition and inadequate medical facilities may further perpetuate the condition. Early recognition and the management of rheumatic carditis and early valvular lesions will reduce the morbidity and mortality.

Valve-related events and valve-related mortality in 340 mitral valve repairs *1A late phase follow-up study

To assess the early and late valve-related events, 340 consecutive patients undergoing mitral valve repair from 1969 to 1988 were evaluated. Follow-up was complete, with a mean of 7.5% years and range from 2 to 22 years (cumulative 2456 patient-years). There were 221 (65%) female patients. Rheumatic valvular disease was present in 246 (68%) patients. The remaining patients had ischemic or congenital valve disease, floppy valve or infective endocarditis. At surgery, 47% of the patients had pure mitral incompetence, 43% had mixed mitral stenosis and incompetence and 10% had predominant mitral stenosis. Seventy-three percent of the patients were in functional class III or IV. Twelve percent had had prior heart surgery. Concomitant valve procedures including coronary revascularization were performed in 62.3%. There were 23 hospital deaths (6.8%) but only 3 of these (0.8%) were valve-related in patients who died at reoperation for valve repair failure. There were 4 other early repair failures who survived early reoperation. Of the 317 hospital survivors, there were 127 late deaths, and an actuarial survival of 44 +/- 3.7% (70% CL) at 14 years. Of these, 13 were valve-related or 0.5% patient-year. Late events included thromboembolism (TE) 1% patient-year, anticoagulant bleeding 0.4% patient-year, infective endocarditis (IE) 0.2% patient-year and late reoperation for mitral valve repair failure in 63 patients or 2.8% patient-year. At the late follow-up, 88% of the hospital survivors were in functional class I or II.(ABSTRACT TRUNCATED AT 250 WORDS)

Surgical pathology of the mitral valve: gross and histological study of 1288 surgically excised valves

A consecutive series of 1288 mitral valves surgically excised from 1981 through 1989 were studied macroscopically and histologically. The explanted valves were affected by: chronic rheumatic disease (1179, 91.5%), floppy mitral valve (84, 6.5%), bacterial endocarditis (19, 1.5%), and post-ischemic mitral incompetence (6, 0.5%). Among 1179 post-rheumatic cases, mixed mitral stenosis and incompetence was the most frequent malfunction (747, 58%). Isolated mitral incompetence was diagnosed in 72 (6.11%) cases only, and isolated stenosis in 360 cases. In 52 valves, excised because of chronic rheumatic disease, the histology showed unexpected signs of acute rheumatism of the leaflets and the papillary muscles. In these patients clinical symptoms and blood tests were negative for rheumatic disease. Mitral incompetence, possibly due to papillary muscle dysfunction, was the prevalent lesion (61.5%). A total of 181 patients (14.05%) with pure mitral incompetence underwent surgery. In 84 patients (46.4%), the floppy mitral valve was the most frequent cause of valve dysfunction, 72 (39.8%) had rheumatic disease, 19 (10.5%) infective endocarditis, and 6 (3.4%) ischemic heart disease. In the group with floppy mitral valve, males were more prevalent than females (51:33). The mean age of the 4 patients with Marfan's syndrome and non-Marfan patients was noticeably different (17 vs 49 yr). Moreover leaflet deformation, tendinous cord elongation and annulus dilatation were the most common causes of valve incompetence. Floppy mitral valve and infective endocarditis were the cause of cordal rupture in 43.5% of the cases. This was a severe complication which always required emergency surgery.

Surgical pathology of disease of the mitral valve, with special reference to lesions promoting valvar incompetence

A consecutive series of 459 mitral valves, which had been surgically excised over a 6-year period, were evaluated by means of macroscopic and histologic study. Of the valves, 379 specimens showed evidence of rheumatic disease (82.6%), 51 were floppy (11.1%), while 29 (6.3%) belonged to a heterogeneous group. The last included cases of ischemic disease (2.4%), infective endocarditis (2.4%), congenital dysplasia (0.9%), rheumatoid arthritis (0.4%), and primary dystrophic calcification (0.2%). Eighty-seven patients had had pure mitral incompetence. Among these, floppiness of the leaflets was the major indication for valvar replacement (58.6%), followed by rheumatic disease (12.7%), ischaemic incompetence (12.7%), and infective endocarditis (11.5%). Particular attention was paid to the clinical-pathological profile of patients with floppy valves as the cause of severe incompetence. This confirmed the prevalence of male patients and the frequent incidence of complications, particularly rupture of tendinous cords (54.9%). A striking difference was also found between the mean age of those patients with and without Marfan's disease (15.3 vs. 53.9 years, P < 0.001). Although mitral incompetence in the presence of a floppy valve could simply be due to deformity of the leaflets, elongation of the cords and dilatation of the atrioventricular junction, in over half of the cases the precipitating event leading to surgery was rupture of tendinous cords.

Rheumatic heart disease in the young

Pattern of rheumatic heart disease below the age of 18 in 144 autopsies was studied. Mitral valve was affected in 100% of cases. Involvement of aortic, tricuspid and pulmonary valves was seen in 63.89%, 54.86% and 12.5% respectively. Mitral stenosis was present in 80.23% cases and was of severe degree in 45%. Pure mitral incompetence was noted in 12.79% of cases. Severe degree of subvalvular disease was present in 83%. Isolated aortic incompetence was observed only in 3.17%. Tricuspid lesions were minor in most of the cases with significant stenosis only in 7.50%. Multivalvular disease was noted in 75.69% cases; but double valve and triple valve disease which possibly would have required surgery was present in only 8.33% and 3.5% cases respectively. Pulmonary vasculature was affected in 75% cases with severe changes in 25%. Calcification of valves was uncommon and was present in 6% of mitral valves and 2% of aortic valves.

Pulmonary vein flow pattern in mitral incompetence, combined mitral stenosis/incompetence and after prosthetic valve replacement.

Pulmonary vein flow (PVF) pattern was studied with an electromagnetic flowmeter in 11 patients with combined mitral stenosis/incompetence (MS/MI), in 6 patients with pure mitral incompetence (MI) and in 24 patients after mitral valve replacement (MVR). ECG, left atrial and left ventricular pressures were recorded simultaneously. The anomalous flow patterns, which were recorded, reflected the left atrial events and mitral valve function. Before MVR, the major forward flow occurred in ventricular diastole. In patients with predominating MS and small/moderate MI, a small retrograde PVF (RF) occurred in early ventricular systole, while pure or combined severe MI produced a holosystolic reversal of PVF.

Systolic Time Intervals in Mitral Incompetence

The systolic time intervals were measured in 17 patients with pure mitral incompetence (MI) in sinus rhythm. These were compared with hemodynamic and angiographic measurements of the severity of mitral regurgitation and the degree of left ventricular dysfunction. Pre-ejection phase (PEP), on an average, was normal in patients with MI, and the patients had normal left ventricular function. Left ventricular ejection time (LVET) was shortened: LVET was related to the forward stroke index (r = +0.81), and the abbreviation of LVET reflected the severity of mitral incompetence. Total electromechanical systole (Q-S₂) was shortened; this was due to the shortened LVET (r = +0.95). The ratio PEP/LVET reflected the left ventricular ejection fraction, but the ratio was increased in patients with severe mitral incompetence due to the shortening of LVET. In a second comparative group of patients with congestive cardiomyopathy (COCM) and MI there was a significant prolongation of PEP and a further reduction in forward stroke index and LVET. In these patients, Q-S₂ was normal and the PEP/LVET ratio was greatly increased.

Mitral valve replacement in childhood. A report of 51 patients

The mitral valve was replaced in 51 children under the age of 16 years. A Starr-Edwards ball valve was used in 32, a mounted inverted homograft in 16, and other lateral flow orifice valves in 3. Four had congenital mitral valve incompetence, one had a cardiomyopathy while the other had chronic rheumatic heart disease; there was pure mitral incompetence in 34, mixed mitral valve disease in 8, and dominant stenosis in 4. They were Grade 3 or 4 disable before operation. The severity of their disease was noteworthy. Six patients died in relation to the operation and there was one late death. The improvement in clinical status was dramatic. Only 5 have mild residual disability, a consequence of the progression of the rheumatic process, further deterioration of aortic-valve function, or unexplained left ventricular myopathy. Half the patients with a Starr-Edwards replacement were treated with anticoagulants for 3 months only. One embolic episode occurred. Mitral valve replacement is indicated in patients with severe symptoms from mitral valve disease and age should not be a contraindication to operation.

Physiological interpretation of the plain radiograph following mitral valvotomy, valvuloplasty, and prosthetic replacement.

Analysis of the plain chest radiograph taken before surgery can give a clinically valuable estimate of the hemodynamic status of the patient with mitral valve disease (4, 13, 15, 17–20, 23, 24, 33). It is not quite clear, however, whether the vascular changes of redistribution of flow, tortuosity, and “pruning” remain after the operation, or if there is any consistent alteration in the cardiac configuration or size following mitral valvotomy, valvuloplasty, or prosthetic replacement of the valve. Many studies have been carried out on the physiological changes following valvotomy and prosthetic replacement (1–3, 7, 8, 16, 20, 30, 31), but only a few have considered the radiological changes (11, 22) and in these satisfactory correlation with catheterization data has not been made.3 Without this correlation it is impossible for a radiologist to estimate quantitatively pulmonary-vascular pressures or improvement or deterioration in the cardiac status. We have now analyzed the pre- and postoperative films of 123 patients with mitral valve disease who have had full catheterization studies, and we have correlated these radiological findings with the catheterization data. The view is often expressed that much more improvement should be seen in the hemodynamic status following prosthetic replacement than after valvotomy, because the prosthesis is a more definitive form of treatment permitting much better correction of the mechanical abnormality of the valve. We have therefore compared the appearance of the pulmonary-vascular bed and the cardiac size following valvotomy and valvuloplasty with its appearance following prosthetic replacement of the valve. Materials and Methods We selected for study only those patients who had full catheterization studies, full pre- and postoperative x-ray studies, and a follow-up period of at least one year. Of the 123 chosen, 100 had undergone mitral valvotomy and 23, mitral valve replacements. Several had had repeated catheterizations. Twenty patients had had a second operation several years after the first, giving us an excellent opportunity to see whether changes occurring in the pulmonary-vascular bed after the first operation and reflecting improvement in the hemodynamic status could occur again after a second operation for restenosis. Several of these patients had prosthetic replacements. The exact valvular lesion present was determined by a combination of clinical examination, cardiac catheterization, angiocardiography, and operation. There were 59 cases (48 per cent) of “pure” mitral stenosis, 25 cases (20 per cent) of combined mitral stenosis and insufficiency, 27 cases (22 per cent) of combined mitral stenosis and aortic valvular disease, 5 cases (4 per cent) of mitral stenosis and tricuspid valvular disease, and only 7 (6 per cent) of pure mitral incompetence.