Time Of Valve Replacement Research Articles

Observations on the timing of operative intervention for aortic regurgitation.

We examined the application and timing of valve replacement in 105 cases of aortic regurgitation, from the aspect of etiology, clinical findings and prognosis. The mortality for patients after aortic valve replacement was 12.9%. This was lower than that for the patients not operated up on, which was 35.0%. The mortality after valve replacement for patients having acute aortic regurgitation due to active endocarditis was as high as 80%, which showed the limitations of medical and surgical therapy. In cases of chronic aortic regurgitation, if valve replacement is performed within 3 years of the appearance of heart failure symptoms, the mortality is 0. Even after three years, valve replacement is applicable if there are no ventricular premature contractions. CTR 65%, %FS 21%, R/Th 2.9 and EF 38% were considered to be the critical factors for postoperative prognosis.

Present Status of Prosthetic Cardiac Valves

Cardiac prosthetic valves have not yet reached the point of reliability and durability to be used for other than remedial purposes. In mitral valve disease, the prime targets are patients in whom medical treatment could not successfully reverse progressive clinical disability, or in whom less drastic mitral valve operations have failed. In aortic stenosis, the prime targets are patients with substantial cardiac symptoms. In aortic regurgitation, earliest indications of disability provide the timing for valve replacement. In this lesion, prophylactic operations in the absence of symptoms are often proposed. Such operations should be given the most cautious considerations.

Chest film diagnosis of disc embolization in patients with Beall mitral valve prostheses

This report presents the chest film findings in three patients with Beall mitral valve prostheses in whom severe disc wear resulted in disc embolization. In all three cases the worn disc embolized to the thoracic aorta with catastrophic decompensation, and all three patients were salvaged with emergency operation. Detection of the embolized disc was possible with plain chest radiography in each case and may permit removal of the embolized disc at the time of valve replacement. Early detection of disc wear and replacement of worn Beall mitral valve prostheses are advocated to avoid this left-threatening complication.

Timing of valve replacement in patients with chronic aortic regurgitation.

Timing of valve replacement in patients with chronic aortic regurgitation.

Behaviour of ATP and lactate in human papillary muscle during profound hypothermia and injection cardioplegia with magnesium-asparatate-procaine (author's transl)

In 53 patients with mitral- or aortic-mitral valve disease, the content of ATP and lactate of the papillary muscles resected at the time of valve replacement was investigated at the beginning of ischemic arrest and at the time of reperfusion. Profound body hypothermia (25 degrees C) and injection cardioplegia using magnesium-aspartate-procaine were applied for myocardial protection. In hypertrophic papillary muscles the myocardial ATP content decreased at a slower rate (ATP decay 12% of the initial value after 60 minutes of ischemia) than in normal papillary muscles obtained from patients with isolated mitral stenosis (ATP decay 33% of the initial value after 40 minutes of ischemia). 20% of the patients required temporary inotropic circulatory support postoperatively for 12 to 88 hours. The ATP content of the papillary muscles of these patients differed only little from those, in who no myocardial failure occurred. However the myocardial lactate levels were higher in patients in whom a low cardiac output state evolved.

Valve replacement for rheumatic aortic incompetence in adolescents.

The timing of valve replacement in patients with rheumatic aortic regurgitation is assessed by balancing the mortality and complications associated with the operation and the prosthetic valves against the natural history of the lesion. The time course without surgery is determined by the severity of the volume overload and the gradual deterioration of myocardial function. We wished to obtain information both on the haemodynamic recovery achieved after aortic valve replacement in young patients and also on the risks of operation in this group. Twenty patients, in whom the aortic valve was replaced at a mean age of 15 years, were reviewed. An improvement in symptoms and in the cardiothoracic ratio on the chest radiograph occurred in every case, and the voltage measurements suggestive of left ventricular hypertrophy on electrocardiogram diminished in all but two. The left ventricular end-diastolic pressure decreased in the 11 patients who were recatheterised after operation. The ejection fraction improved in three patients and stayed the same in three others. While there were no operative deaths in our series the incidence of serious morbidity, in terms of myocardial damage at or after operation, was disappointingly high. Early valve replacement to preserve myocardial function is especially attractive in young patients but cannot be advised if the insertion of the prosthetic valve is associated with appreciable myocardial damage.

Acute coronary embolism complicating bacterial endocarditis: Operative treatment

A patient with bacterial endocarditis and no previous history of angina sustained an acute anterolateral myocardial infarction while awaiting surgery. Selective coronary arteriography revealed a filling defect in the left anterior descending coronary artery with limited flow beyond the area of occlusion. A calcific embolus from the infected aortic valve was removed at the time of valve replacement, and the patient had an uneventful immediate postoperative course. Late postoperatively paravalvular aortic regurgitation recurred before and after a second repair.

Accuracy of echocardiography for assessing aortic root diameter.

The normal range for aortic root diameters employing the echocardiographic continuous recording technique was determined in 159 adult subjects without aortic valve disease or hypertension. In order to evaluate the accuracy of this noninvasive technique, the aortic root diameters as measured by ultrasound before operation in 31 patients with aortic valve disease were compared with their respective aortic annulus diameters as determined at the time of valve replacement. The 159 normal subjects consisted of 78 men and 81 women whose ages ranged from 18 to 74 pears (average 38). The normal range of aortic root diameters in this group was 17 to 33 mm (mean 23.7). A significant difference (P is smaller than 0.001) in aortic root diameters existed between men and women which could not be explained by differences in body surface area. The mean diameter among the 81 women was 22.4 plus or minus 3.3 mm(I SD) compared to the mean diameter in the 78 men of 25 plus or minus 3.5 mm. These results indicate a normal range for aortic root diameters which is significantly lower than previously reported. The aortic root diameter which was measured reoperatively by ultrasound in the 31 patients with aortic valve disease averaged 25.1 plus or minus 1.9 mm and did not differ significantly from the actual aortic annulus diameter of 25.5 plus or minus 2.6 mm measured at the time of surgery. The aortic root measurements by echo were within 2 mm of the corresponding annulus diameter in 25 of the 31 operated patients (80%).