Acute Mitral Incompetence Research Articles

Extracardiac Adjustment of Mitral Chordae Replacement

This study was designed to determine the feasibility of completing mitral chord repair externally when the heart was weaned from bypass. Ten anesthetized dogs (22.9 ± 4.6 kg) were placed on cardiopulmonary bypass through a left thoracotomy. The left atrium was opened and one or two marginal chords of the anterior mitral leaflet were divided. A double-armed 2-O polypropylene suture was placed in the margin of the mitral leaflet, and both suture ends were brought outside of the ventricle through the anterior papillary muscle, but were not anchored. Production of mitral incompetence was verified when the animals were weaned from bypass. Mean left atrial pressure (LAPm), the v wave of the left atrial pressure (LAPv), systolic billowing of the anterior leaflet into the left atrium above the mitral closure line (two-dimensional echocardiography, long axis), and function curves (left atrial–aortic systolic pressure, LAPv–AoSP) were used to determine valve competence and functionality of the repair. All values are expressed as means ± SE. Acute mitral incompetence in this model was associated with severe left atrial bulging, left atrial billowing of the anterior leaflet (7–12 mm, 9.6 ± 1.6 mm), significantly increased left atrial pressure [LAPv, 30.5 ± 5.8; LAPm, 23.6 ± 4.3 mm Hg; bothP< 0.01 vs control (10.5 ± 2.5 and 7.5 ± 2.7 mm Hg, respectively)], and decreased systemic pressure development (AoSP, 84 ± 8.8 vs 108 ± 12.3 mm Hg;P< 0.01). The slope of the atrial–systemic pressure curve was decreased significantly, shifted to the right and reduced by more than half (2.1069 vs 0.9190;P< 0.05). External adjustment of the pledgeted suture ends returned all values to within control limits (LAPv, 12.7 ± 4.1; LAPm, 9.8 ± 4.3; AoSP, 104 ± 10.5; LAP–AoSP slope, 2.0909; allP= n.s.), atrial bulging was not evident, and atrial displacement of the valve leaflet could no longer be visualized. These data suggest that mitral chord repair is feasible through a thoracotomy and, more importantly, final adjustments to obtain optimal chord length can be completed externally, guided by changes in dynamic, physiologic parameters.

Acute Mitral Regurgitation After Blunt Chest Trauma

We treated a case of isolated acute mitral incompetence due to complete transection of the anterior papillary muscle produced by blunt chest trauma. The excellent results obtained with conservative therapy suggest that this approach be used in other similar cases. The pertinent medical literature is reviewed.

Surgical and mechanical support of the failing heart

The surgical treatment of acute heart failure is limited to cases of pressure or volume overload. Acute valvular regurgitation due to active endocarditis or to prosthetic dysfunction is a classic example of failure which can be cured by restoring valvular competence. Acute pressure load is mostly caused by prosthetic dysfunction or pulmonary embolism; therapy is aimed at removal of the causative agent. Coronary heart disease can cause heart failure by volume overload: acute mitral incompetence or ventricular septal defect lend themselves to surgical correction. In the surgical treatment of acute heart failure maximal attention is devoted to optimal timing of surgery, anesthetic management and postoperative care. Careful attention to the function of the right and left ventricle and combination of catecholamines, afterload reducing agents and volume loading together with respirator support have considerably improved the surgical results. Acute pump failure due to coronary insufficiency and infarction is less amenable to surgical treatment, with rare exceptions of emergencies during coronary angiography and percutaneous dilatation. The intra-aortic balloon pump is the only method of mechanical circulatory assistance which has reached widespread clinical acceptance. The best results are achieved in conjunction with surgery: either as cardiac support in inherently reversible postoperative heart failure or as the means of circulatory stabilization prior to surgery. Ventricular assist devices are still in the experimental stage: their use has been sharply curtailed by the virtual disappearance of the postoperative low output syndrome. In selected cases of end-stage cardiomyopathy cardiac transplantation is nowadays performed with acceptable survival (70% at one year after surgery). Both orthotopic and heterotopic transplantation (transplanted heart in parallel with the natural one) give comparable results, but the procedure is still very restricted due to the lack of donors, multiple contraindications and lack of suitable heart preservation techniques.

Patch Enlargement of the Aortic and the Mitral Valve Rings with Aortic-Mitral Double-Valve Replacement

In 1 patient, patch enlargement of the aortic valve ring was accomplished by extending the aortic incision into the anterior mitral leaflet. The pericardial patch broke from the aortic leaflet of the mitral valve on the fourth postoperative day. The resultant acute mitral incompetence necessitated mitral valve replacement also. An aortic-mitral double-valve replacement with attendent enlargement of both the aortic and mitral valve rings ensued. To our knowledge, enlargement of the aortic and mitral valve rings with aortic-mitral double-valve replacement has not been described in the literature.

Left ventricular function during systole and diastole in mitral incompetence

Left ventricular function during systole and diastole was studied in 17 young patients with mitral incompetence and sinus rhythm; 13 had established chronic mitral incompetence, 3 had prolapsing posterior leaflet syndrome and 1 had ruptured chordae tendineae. In chronic mitral incompetence and prolapsing posterior leaflet syndrome, clinical disability was related to a low forward stroke index, a large regurgitant volume and tall left atrial V wave. The defect was mechanical, and the ventricle had adapted by compensatory dilatation so that overall systolic function was normal, as measured by peak rate of rise of left ventricular pressure ( dP dt ) and ejection fraction. The dilated ventricle operated at a normal or slightly increased end-diastolic pressure, a consequence of normal resting tension (O point) and a more elastic myocardium with a low rate of change of instantaneous stiffness (m) and a flattened diastolic pressure-volume curve. In acute mitral incompetence, systolic function was normal but the sudden volume overload caused the unprepared ventricle with an almost normal modulus of elasticity and slope (m) to ascend its pressure-volume curve in diastole. End-diastolic pressure was increased.

Double valve replacement after staphylococcal endocarditis

THE incidence of bacterial endocarditis and its attendant mortality have undoubtedly been reduced since the introduction of antibiotics (Williams, Viroslav and Knight, 1970). The proportion of more virulent organisms is, however, increasing. The staphylococcus aureus is the most common of these and often causes ulcerative endocarditis of previously healthy valves (Quinn, Cox and Drake, 1966; British Medical Journal, 1969; Somers et al., 1972). Acute bacterial endocarditis of the aortic and mitral valves may produce cardiac failure that is not amenable to medical management. The sudden development of aortic incompetence is poorly tolerated and carries a particularly high mortality (Wise et al., 1971). Urgent repair or replacement of one or both valves may become necessary and is often life saving. There have been several reports of valve replacement for acute aortic incompetence after bacterial endocarditis (Wallace, Young and Osterhout, 1965; Windsor and Shanahan, 1967; Wise et al., 1971) but few after acute mitral incompetence (Robicsek et al., 1967; Yacoub et al., 1972; English, Honey and Clelland, 1972). Urgent double valve replacement after acute bacterial endocarditis is, however, rare (Windsor and Shanahan, 1967; Kretschmer and Lawrence, 1969; Gonzalez-Lavin, Wise and Ross, 1971). It is thus thought worthwhile reporting the following case.

Acute mitral incompetence.

SUMMARYWe have reported the occurrence of acute mitral incompetence in 22 patients. The mitral incompetence was considered to be secondary to ruptured chordæ tendineæ in 12 patients and to papillary muscle infarction in 10 patients. In three, the mitral leak was secondary to papillary muscle rupture.The clinical manifestations have been reviewed and attention drawn to the need to differentiate the signs of acute mitral incompetence from combined aortic and mitral valve disease or from muscular subaortic stenosis. The clinical signs, radiographs and hæmodynamic studies are all helpful in this diagnosis.It is important to recognize acute mitral incompetence so that appropriate treatment can be commenced. In those not responding adequately to a medical régime, surgical correction of the mitral incompetence should be considered. The results of the surgical treatment of acute mitral incompetence are reported in seven patients, there being a good result in four. A satisfactory outcome is more likely in those patients with ruptured chordæ and a previously normal myocardium. In patients with papillary muscle infarction and severe mitral incompetence, valve replacement may be required. Because of the underlying coronary disease, the outcome in this group will be less favourable.

Acute mitral incompetence

The plain films and angiocardiograms of 23 patients with acute mitral incompetence due to sudden dysfunction of a previously normal mitral valve were analysed and the angiocardiograms of these patients were compared with those of 17 patients with chronic rheumatic mitral incompetence. The plain film analysis showed that cardiac enlargement in general was only slight and that left atrial enlargement was minimal, but in some cases there was evidence of rapid progression. The lung fields were either normal or there was evidence of acute pulmonary oedema. The contrast medium studies confirmed the plain film impressions of the relatively normal heart chambers. Gross reflux of contrast from the left ventricle into the atrium and into the pulmonary veins, together with systolic expansion of the atrium, was noted to be much more marked than in the rheumatic group. A distinctive type of regurgitant jet of contrast which spread around the atrial wall was seen in the patients with acute mitral incompetence and this differed from that seen in patients in the rheumatic group, where the jet went straight back into the atrium. An explanation for these specific and diagnostic features is suggested.

ACUTE MITRAL INCOMPETENCE AFTER ACUTE MYOCARDIAL INFARCTION, WITH SUCCESSFUL EARLY TREATMENT BY MITRAL-VALVE PROSTHESIS

ACUTE MITRAL INCOMPETENCE AFTER ACUTE MYOCARDIAL INFARCTION, WITH SUCCESSFUL EARLY TREATMENT BY MITRAL-VALVE PROSTHESIS