Search

This report documents a case of ball variance in a Smeloff-Cutter aortic prosthesis occurring 24 years after implantation. After episodes of embolic complications the patient died in acute shock. The silicone rubber ball showed several alterations including discoloration, grooving, cracking, swelling and subtotal fracture of the poppet. Terminal valvular malfunction was caused by complete thrombosis of the prosthesis. In most patients ball variance occurred during the first years after valve replacement; thus, the observed case is a very rare late complication of a ball-valve prosthesis.

An unusual case of subaortic stenosis and aortic regurgitation caused by accessory mitral valve tissue in a 10 year old boy is reported. Two-dimensional and Doppler echocardiography revealed the characteristic feature of a mobile, parachute-like mass in the left ventricular outflow tract pro-lapsing into the aortic valve during systole and, thus, producing a systolic pressure gradient of 70 mm Hg between the left ventricle and aorta and causing mild aortic regurgitation. The accessory valve tissue was completely excised via an aortotomy without injury to the normal mitral and aortic valves. Two dimensional echocardiography provides excellent morphological information about the relationship between the accessory mitral valve tissue and the mitral and aortic valves, respectively. Accurate preoperative evaluation by two-dimensional echocardiography facilitates the successful surgical management of this rare condition.

We report on a 61-year-old patient with considerable insufficiency of a quadricuspid aortic valve and coronary three vessel disease. The congenital quadricuspid aortic valve has become symptomatic due to the development of (post-endocarditic) insufficiency only in the advanced stage of life. It was treated by replacement of the aortic valve and bypass myocardial revascularization. The physiopathology of quadricuspid aortic valve will be discussed.

We report on a 39-year-old man with Crohn's disease who was admitted with cardiogenic shock after a short history of progressive dyspnea. Echocardiographic examination (transthoracic echocardiography) showed severe aortic regurgitation, mild mitral regurgitation, and enlargement of the sinus of Valsalva and of the ascending aorta at the level of the right pulmonary artery. The left ventricular ejection fraction was 30%. After aortic valve replacement, histologic examination of the ascending aorta showed chronic aortitis resembling syphilitic aortitis (serology for syphilis was negative) and HLA B27 related aortitis. The aortic valve showed deformation and thickening of the cusps by fibrous tissue without evidence of endocarditis. The patient remained well after surgery and echocardiographic examination 6 months later showed normal function of the aortic valve prosthesis. The diameter of the sinus of Valsalva and of the ascending aorta was slightly bigger, possibly indicating ongoing destruction. The left ventricular ejection fraction nearly normalized. It seems possible that this type of aortitis, characterized by its proximity to the valve ring, is another extraintestinal cardiac manifestation of Crohn's disease. The possibility of ongoing destruction of the sinus of Valsalva and of the ascending aorta after valve replacement makes regular echocardiographic control necessary.

The case of a 76-year-old diabetic patient with known aortic valve sclerosis is reported. One week after implantation of a permanent pacemaker system (indication: 2nd degree AV-block type Mobitz) he developed fever. Large endocarditic vegetations were found on the aortic and mitral valve (blood cultures: were positive for Staphylococcus aureus). Also from the pacemaker bed Staphylococcus aureus was isolated and an antibiotic treatment including vancomycin was started. Nevertheless the patient developed insufficiencies of both the aortic and mitral valves and became hemodynamically unstable. Due to cerebral embolisms and further deterioration of the patient's overall clinical state the already planned operative replacement of the aortic and mitral valve could not be performed. The patient died because of left ventricular failure after pacemaker infection which was complicated by endocarditis.

Two cases of granulomatous endocarditis are reported. The patients developed aortal endocarditis refractory to antibiotics. Therefore, aortal valve replacement was performed. In both cases, Streptococcus viridans was demonstrated in culture and bacterioscopically to be the cause of infection. Histological examination of the valves showed characteristic endocarditis with fibrinoid necrosis and histiocytic granulomas. Streptococci were found in the cytoplasm of macrophages. The possible causes of this special form of infectious endocarditis are discussed.

Quantitative ultrastructural changes of the left ventricular (LV) myocardium and contractile function were studied in 9 symptomatic patients with severe aortic insufficiency (AI). The volume fractions of myofibrils, sarcoplasm, and mitochondria in myocardial cells were determined by electron microscopic morphometry in small LV tissue samples. Interstitial fibrosis was measured by light microscopic morphometry. Transmural biopsies of the LV free wall perfused by the left anterior descending coronary artery (LAD) were obtained during aortic valve replacement. Biopsies from the LAD-perfusion area of 10 surgical patients with coronary artery disease but moderate LAD-stenosis and normal regional motion of LAD-area were taken as controls for morphometric data. LV-function was analyzed from preoperative heart catheterization. In initial reproducibility studies of biopsy samples of 17 patients a sampling error for evaluation of myocardium was defined and differences exceeding 6.2% transmural fibrosis and 6.5% myofibrils were considered biologically significant differences. Patients with AI had higher LV end-diastolic volume (180 versus 77 ml/m2, p less than 0.001), and lower LV ejection fraction (51 versus 69%, p less than 0.001) than 10 control individuals. The volume fraction of myofibrils was lower in AI than in controls (44 versus 53%, p less than 0.01), and sarcoplasm was higher (33 versus 21%, p less than 0.01). Mitochondria and interstitial fibrosis did not differ between groups (p greater than 0.05). Thus reduction in the volume fraction of myofibrils was the major ultrastructural finding in LV biopsy samples of patients with heart failure due to aortic insufficiency.

Physiological hypertrophy is present when the increase in myocardial mass resulting from chronic mechanical loading is associated with normal or enhanced myocardial function and myosin ATPase activity. Morphological alterations occurring during the formation of hypertrophy are fully reversible in physiological hypertrophy. In pathological hypertrophy myocardial function and myosin ATPase activity are depressed and morphological changes do not or only incompletely regress following the elimination of the stimulus of hypertrophy. In the experimental animal myocardial hypertrophy resulting from exercise conditioning or slight to moderate ventricular pressure overload fulfills the criteria of physiological hypertrophy. More severe sudden pressure overload is accompanied by depression of contractile function. These pressure overload models have however, little analogy to the more progressive development of pressure loading in humans. In young dogs and in cats with a gradually increasing pressure load, in vivo ventricular ejection fraction remained within normal limits 37 to 60 weeks after banding of the ventricular outflow vessel. In vitro myocardial function evaluated in the hypertrophied papillary muscle was, however, at least in part depressed, notably when hydroxyproline concentration was augmented. Following debanding in rats with aortic constriction hydroxyproline content did not regress suggesting that fibrosis once established is not reversible. In man myocardial hypertrophy from exercise conditioning is associated with normal ventricular function except in older athletes, who may show a subtle reduction in ventricular shortening. Patients with chronic pressure overload from aortic stenosis or volume overload from aortic insufficiency in whom the angiographic muscle mass is severely increased (greater than or equal to 180 g/m2) elicit a depressed left ventricular contractile function. Preserved left ventricular ejection performance in aortic valve disease is however not associated with normal myocardial structure because interstitial fibrosis evaluated from endomyocardial biopsies or biopsies obtained at surgery was found to be increased. Patients with depressed left ventricular contractility were characterized by having an abnormally high muscle fibre diameter. Normal function after surgery was not accompanied by normalization of myocardial structure: Interstitial fibrosis increased, fibrous content remained the same and cellular hypertrophy regressed incompletely regardless whether angiographic muscle mass had regressed to normal or remained still increased after surgery. In summary, the bulk of available functional and morphological data suggests that the occurrence of true physiological hypertrophy is probably limited to exercise conditioning and eventually to mild chronic mechanical overload. The more severe secondary hypertrophy such as in patients with aortic valve disease who undergo valve replacement, is not a physiological adaptation, but must be considered as a pathological process.

In the experiments intact dog hearts with ligated descendents, hearts with aorta insufficiency and others with a cardiopulmonary bypass were perfused. It was demonstrated that both ischaemia and relative oxygen deficiency induce within a comparatively short time the same type of irreversible damage in the structure of the subendocardial layers of the myocardium (lysis and rupture of the myofilament, swelling of the mitochondrium, rupture and lysis of the crista, clearing of the matrix). Consequently, the aimed protection of the myocardium during cardiac surgery is of the greatest importance.

It is reported on the results of one- and two-dimensional echocardiographic investigations, which were partly supplemented by investigations in Doppler-technique, in 20 patients with an aortic insufficiency in the clinical stage II and 20 patients with an aortic insufficiency in stage III. As comparison serve the results of the examinations of 20 normal persons. The diagnosis of an aortic insufficiency was to be made in all cases by the evidence of fluttering waves on the anterior and posterior mitral valve, partly also on the ventricular septum. The diagnosis can be ascertained by the Doppler-echocardiographic proof of a regurgitation through the aortic valve. Diameter, thickness of the wall, volumes and functional parameters of the left ventricle as well as the size of the left atrium and the diameter of the aortic root proved to be suitable for the judgment of the degree of severity. Severe aortic insufficiencies are characterized by a dilatation and hypertrophy of the left ventricle, a dilatation of the left atrium, an enlarged diameter of the aortic root, clearly increased volumes restricted functional parameters of the left ventricle.

Biopsies from hypertrophied left ventricles were obtained intraoperatively from patients undergoing valve replacement for aortic valve disease. The tissue was immediately fixed in glutaraldehyde and, after appropriate preparation, examined by light and electron microscopy. Morphologic characterization was carried out with respect to 1. qualitative alterations within myocytes, mostly degenerative, 2. measurement of cell diameter and the percentage of interstitial tissue volume within the total myocardium, 3. determination of volume densities of mitochondria, myofibrils, and cytoplasm in myocardial cells by morphometric techniques. Data from hypertrophied hearts were compared with those from normal hearts (control group). Analysis of morphologic and clinical data yielded the following results: 1. The increase in the clinically determined left ventricular muscle mass due to hypertrophy in aortic valve disease is caused by an increase in cellular diameter as well as an increase in interstitial tissue; 2. The morphologic correlate of the reduction of left ventricular function (EF) with increasing degrees of hypertrophy consists of an increase in interstitial tissue, i.e. fibrosis, and a marked relative loss of myofibrillar components from hypertrophied myocardial cells which is accompanied by an increase in cytoplasm-filled areas.

Hemodynamic parameters have recently been described which are of prognostic importance for the outcome of valve replacement in patients with aortic insufficiency. It was investigated whether pathological values for the left ventricular end-systolic volume index, the ejection fraction, the end-diastolic radius/wall thickness ratio, the end-systolic diameter (DS) and shortening of the diameter (Sh), and the end-diastolic volume index are accompanied by morphological alterations evaluated from left ventricular endomyocardial biopsies. Hypertrophy of the cardiac fibers was significantly increased in patients in whom preoperative Sh was less than 25% and DS greater than 55 mm. In contrast, left ventricular interstitial fibrosis did not differ between these patients and those with Sh greater than or equal to 25% and DS less than or equal to 55 mm.

Biopsies of hypertrophied human myocardial left ventricles were investigated morphometrically. The diagnoses of the patients were stenosis of the aortic valve, aortic insufficiency or a combination of both lesions. The results were compared with those from normally loaded human left ventricles. There are no differences on light microscopical level between the volume densities of interstitial tissue and of heart muscle cells in the three groups of patients. A significant diminution of the volume density of the nuclei (P less than 0.001) and the number of nuclei per test area (P less than 0.001) when compared with normal groups suggests an increase in volume of the single heart muscle cell. The ultrastructural study shows marked increase in volume density of myofibrils (P less than 0.0001), with accompanying decrease in the volume densities of mitochondria (P less than 0.0001) and the remaining cytoplasm (P less than 0.001). A gross decrease in the surface area of mitochondria (P less than 0.001) and of cristae mitochondriales (P less than 0.0001) is found. The morphological equivalents of this result are numerous stages of mithochondrial destruction including cristolysis. All myocardial weights were beyond the "critical heart weight".