Pathological features of hypertrophic obstructive cardiomyopathy (HOCM) in the elderly.
(1/45)
The pathological findings and available clinical data in 15 necropsy cases of HOCM, aged over 61 years, are reported. Three patients were in the eighth decade and 4 in the ninth; 8 were women. Five presented as sudden death, 2 died in congestive cardiac failure, and 7 died of unrelated conditions and HOCM was an apparently incidental postmortem finding. Compared with cases under 60 years, the hearts of the elderly patients were heavier and less likely to show typical asymmetrical hypertrophy, the free wall of the left ventricle also being thickened in two-thirds of the cases over 60 years. Most of the elderly cases showed a distinctive band of fibrous thickening over the upper part of the interventricular septum. This lesion had a "mirror image" relation to the lower part of the aortic surface of the anterior mitral cusp, with the histological features of a friction lesion. It appears to be a morphological expression of the systolic contact of anterior mitral cusp and interventricular septum seen on cineangiography and thus diagnostic of HOCM. Once formed, the fibrous band appears to persist even if the obstructive element disappears. It is, therefore, a valuable diagnostic feature indicating a diagnosis of HOCM in an age group where the morphology is usually not the classical asymmetrical form and in which this diagnosis is usually not considered. (+info)
Subaortic stenosis diagnosed in the course of a twins pregnancy: a controversial management.
(2/45)
Fixed subaortic stenosis, commonly associated with other congenital cardiac defects, is the cause of 10 per cent of cases of congenital obstruction of the left ventricular outflow. Corrective surgery is frequently a successful treatment, recommendations being based on the transaortic gradient in Europe while in the USA the most prevalent opinion is surgical repair independently of the gradient. We present a case of adult clinical onset of a fixed subaortic stenosis during pregnancy, in which hemodynamic changes are significant, that was medically treated and followed in the outpatient clinic of our hospital, and review the state of the art of the management and surgical indications of this condition. (+info)
Ultrastructural features of degenerated cardiac muscle cells in patients with cardiac hypertrophy.
(3/45)
Degenerated cardiac muscle cells were present in hypertrophied ventricular muscle obtained at operation from 12 (38%) of 32 patients with asymmetric septal hypertrophy (hypertrophic cardiomyopathy) or aortic valvular disease. Degenerated cells demonstrated a wide variety of ultrastructural alterations. Mildly altered cells were normal-sized or hypertrophied and showed focal changes, including preferential loss of thick (myosin) filaments, streaming and clumping of Z band material, and proliferation of the tubules of sarcoplasmic reticulum. Moderately and severely degenerated cells were normal-sized or atrophic and showed additional changes, including extensive myofibrillar lysis and loss of T tubules. The appearance of the most severely degenerated cells usually reflected the cytoplasmic organelle (sarcoplasmic reticulum, glycogen, or mitochondria) which underwent proliferation and filled the myofibril-free areas of these cells. Moderately and severely degenerated cells were present in areas of fibrosis, had thickened basement membranes, and had lost their intercellular connections. These observations suggest that degenerated cardiac muscle cells have poor contractile function and may be responsible for impaired cardiac performance in some patients with chronic ventricular hypertrophy. (+info)
Neurally-mediated increase in calcineurin activity regulates cardiac contractile function in absence of hypertrophy.
(4/45)
OBJECTIVE: The calcineurin pathway has been involved in the development of cardiac hypertrophy, yet it remains unknown whether calcineurin activity can be regulated in myocardium independently from hypertrophy and cardiac load. METHODS: To test that hypothesis, we measured calcineurin activity in a rat model of infrarenal aortic constriction (IR), which affects neurohormonal pathways without increasing cardiac afterload. RESULTS: In this model, there was no change in arterial pressure over the 4-week experimental period, and the left ventricle/body weight ratio did not increase. At 2 weeks after IR, calcineurin activity was increased 1.8-fold (P<0.05) and remained elevated at 4 weeks (1.7-fold, P<0.05). Similarly, the cardiac activity of calcium calmodulin kinase II (CaMKII) was increased significantly after IR, which confirms a regulation of Ca(2+)-dependent enzymes in this model. In cardiac myocytes, the increased activity of calcineurin was accompanied by a significant decrease in L-type Ca(2+) channel activity (I(Ca)) and contraction velocity (-dL/dt). Cardiac denervation prevented the activation of calcineurin after IR, which demonstrates that a neurohormonal mechanism is responsible for the changes in enzymatic activity. In addition, cardiac denervation suppressed the effects of IR on I(Ca) and -dL/dt, which shows that calcineurin activation is related to altered contractility. However, action potential duration, the densities of inward rectifier K(+) currents (I(K1)), and outward K(+) currents (I(to) and I(K)) were not altered in IR myocytes. CONCLUSIONS: Calcineurin can be activated in the heart through a neural stimulus, which induces alterations in Ca(2+) currents and contractility. These effects occur in the absence of myocyte hypertrophy, electrophysiological changes in action potential, and K(+) channel currents. (+info)
Rheologic genesis of discrete subvalvular aortic stenosis: a Doppler echocardiographic study.
(5/45)
To determine whether morphologic structures or abnormal flow patterns predispose to pathologic proliferation of subvalvular tissue, 26 patients (mean age 19.8 +/- 10.3 years) were studied greater than or equal to 6 months after operation for isolated discrete subvalvular aortic stenosis. The aortic root diameter and the mitral-aortic separation were measured with sector echocardiography. Flow patterns in the left ventricular outflow tract of these patients and control subjects were evaluated with a color flow mapping system optimized for the detection of turbulence. All control subjects had laminar flow throughout systole in the left ventricular outflow tract. By contrast, turbulence originating well below the site where the shelf had previously been resected was observed in 20 (77%) of the 26 patients. In 16 of these 20 patients turbulence was caused by a ridge, which in 13 patients could be identified as the offshoot of a ventricular band. In four patients the turbulence was caused by malalignment of the muscular and membranous septum, resulting in protrusion of the muscular septum into the outflow tract. Except for the latter four patients, the aortic root diameter was 84 +/- 10% of values predicted by body surface area, with values in six patients falling below the third percentile (p less than 0.01). The mitral-aortic separation was 9.7 +/- 3.5 mm, values in 21 patients falling above the 97th percentile (p less than 0.001). These data support the theory that discrete subvalvular aortic stenosis may be caused by a chronic flow disturbance, preferably in a small and long outflow tract. Left ventricular bands, if reaching the outflow tract, may be a factor.(ABSTRACT TRUNCATED AT 250 WORDS) (+info)
Echocardiographic assessment of subvalvular aortic stenosis before and after operation.
(6/45)
The development of two-dimensional and Doppler echocardiography has provided a noninvasive technique for the diagnosis and serial assessment of patients with subvalvular aortic stenosis. The clinical records and echocardiographic data were reviewed of all patients with subaortic stenosis diagnosed between 1983 and 1991. Of the 77 patients identified (45 male and 32 female), 28 had isolated subaortic stenosis and 49 had associated cardiac lesions. The most frequently encountered associated lesions were ventricular septal defect (n = 19) and coarctation of the aorta/interrupted aortic arch (n = 14). Serial echocardiographic studies, performed in 38 of the 77 patients, documented significant progression of the left ventricular outflow tract gradient in 25 patients (66%) and development of aortic regurgitation in 25 patients (66%). Surgical resection was performed in 36 patients. The preoperative outflow tract peak gradient was 62.9 +/- 31 mm Hg (range 0 to 153), whereas the immediate postoperative gradient was 14.4 +/- 14 mm Hg (range 0 to 67). The two patients with a significant residual gradient (37 and 67 mm Hg, respectively) in the immediate postoperative period had severe subaortic stenosis preoperatively with marked left ventricular hypertrophy and intracavitary gradient. The immediate postoperative echocardiograms demonstrated no worsening of aortic regurgitation in any patient and regression of regurgitation in one patient from mild to none. Intermediate-term follow-up studies were available for review in 13 postoperative patients at a mean of 4 years postoperatively. In 2(15%) of these 13 patients, subaortic stenosis recurred; however, the degree of aortic regurgitation did not increase in any patient.(ABSTRACT TRUNCATED AT 250 WORDS) (+info)
Left subclavian artery to descending aorta bypass for coarctation physiology after descending aortic repair.
(7/45)
Stenosis of the aorta observed after descending aorta replacement for traumatic aortic injury was managed by a placement of a bypass between the left subclavian artery and the distal descending aorta with success. (+info)
Subaortic stenosis caused by an unusual fibrous blood-filled cyst of the left ventricle with outflow tract obstruction associated with a ventricular septal defect.
(8/45)
A large blood-filled cyst formed from a fibrous tissue tag of a right ventricular septal aneurysm was successfully resected. This cyst, which was causing subaortic stenosis, was attached to the margin of the closed ventricular septal defect and not to the mitral valve itself nor the papillary muscle of the left ventricle. (+info)