Exercise capacity and cardiac hemodynamic response in female ApoE/LDLR(-/-) mice: a paradox of preserved V'O2max and exercise capacity despite coronary atherosclerosis.

We assessed exercise performance, coronary blood flow and cardiac reserve of female ApoE/LDLR(-/-) mice with advanced atherosclerosis compared with age-matched, wild-type C57BL6/J mice. Exercise capacity was assessed as whole body maximal oxygen consumption (V'O2max), maximum running velocity (vmax) and maximum distance (DISTmax) during treadmill exercise. Cardiac systolic and diastolic function in basal conditions and in response to dobutamine (mimicking exercise-induced cardiac stress) were assessed by Magnetic Resonance Imaging (MRI) in vivo. Function of coronary circulation was assessed in isolated perfused hearts. In female ApoE/LDLR(-/-) mice V'O2max, vmax and DISTmax were not impaired as compared with C57BL6/J mice. Cardiac function at rest and systolic and diastolic cardiac reserve were also preserved in female ApoE/LDLR(-/-) mice as evidenced by preserved fractional area change and similar fall in systolic and end diastolic area after dobutamine. Moreover, endothelium-dependent responses of coronary circulation induced by bradykinin (Bk) and acetylcholine (ACh) were preserved, while endothelium-independent responses induced by NO-donors were augmented in female ApoE/LDLR(-/-) mice. Basal COX-2-dependent production of 6-keto-PGF1α was increased. Concluding, we suggest that robust compensatory mechanisms in coronary circulation involving PGI2- and NO-pathways may efficiently counterbalance coronary atherosclerosis-induced impairment in V'O2max and exercise capacity.

[Diagnostic effectiveness of Rtg-TV, echocardiography and computerized tomography in mitral valve calcinosis]. / Skutecznosc diagnostyczna Rtg-TV, echokardiografii i tomografii komputerowej w wykrywaniu zwapnien zastawki dwudzielnej.

The aim of the study was a comparative evaluation of the three diagnostic procedures: fluoroscopy (Rtg-TV), echocardiography (ECHO) and computer assisted tomography (CT) in detection of mitral valve calcifications. These methods were applied to the 46 patients with mitral valve disease (24 males and 22 females which age was 24-56 years). The results were compared with radiograms of isolated valves after surgery. We found that the most efficient diagnostic method is CT which provided following results: sensitivity--100%, specificity-- 89% efficiency--95%, false positives and false negatives rates 11% and 0% respectively. The same diagnostic indices in the other methods were: ECHO--92%, 77%, 85%, 22%, 7%; Rtg-TV--50%, 100%, 75%, 0%, 50%. The last method can not be used as a routine examination in detecting of the mitral valve calcifications because of its low sensitivity+ and high grade of false-negatives rate.

[Intensity of tone and opening snap, and morphology of the bicuspid valve in patients with mitral valve disease]. / Intensywnosc I tonu I stuku otwarcia, a morfologia zastawki dwudzielnej u chorych z wada mitralna.

The purpose of this study was to investigate the correlation between mitral valve morphology and amplitude of the first heart sound and the opening snap. The material consisted of 21 women and 19 men with mitral valve disease. They ranged in age from 24 to 56 years. 36 patients had pure or dominant mitral stenosis and 4 patients had combined mitral valve disease with dominant regurgitation. Phonocardiograms were recorded in all patients before mitral valve replacement. We analyzed the presence and the amplitude of opening snap and the amplitude of the first heart sound at the apex. The amplitude of the opening snap was expressed in mm and as a ratio to the maximal vibration of the second sound in the same cycle. The amplitude of the first sound was expressed in mm and as a ratio of the maximal vibration of the first sound to the maximal vibration of the first sound to the maximal vibration of the second sound in the same cycle. All amplitude measurements were made in 10 consecutive cardiac cycles and were then averaged. Then we studied all mitral valves removed in a uniform manner by one surgeon. Excised valves were fixed in 5% solution of formaline. The extent of calcification was determined by radiographs (fig. 1). The mitral valve area and calcification area were estimated by planimetry of radiographs. Then we analyzed the localization of calcification and we calculated the ratio of calcification area to valve area. Valves were divided into three groups according to the degree of the fusion of subvalvular structures ("a funnel") (fig. 2).(ABSTRACT TRUNCATED AT 250 WORDS)

[The mitral valve in mitral valve defect. Histological and clinical correlations]. / Zastawka dwudzielna w wadzie mitralnej. Korelacja histologczno-kliniczna.

The purpose of this study was to investigate the correlation between the histologic changes in the excised mitral valves and the clinical findings in patients with mitral stenosis (with or without regurgitation). The Study group consists of 26 men and 23 women ranged in age from 24 to 56 years. The mitral valves were removed in a uniform manner by one surgeon during mitral valve replacement. The controls were 13 mitral valves removed at necropsy from patients who died of extracardiac causes. Excised valves were fixed in 5% solution of formaline. The extent of calcification was determined by radiographs. Tissue from the center of the anterior and posterior leaflet were selected as the samples. The blocks were paraffin embedded and processed in the conventional manner. For histological examination 11.5 um thick sections were stained with haematoxylin and eosin, Alcian blue, Van Gieson and Von Koss stain. Then the sections were examined under light microscope. We estimated the degree of fibrotic disorganization of architecture, vascularization, acid mucopolysaccharide content, number of fibroblasts, and the presence of calcific deposits and lymphoid infiltrates. The control valves had normal architecture with thick "fibrosa". In all stenotic mitral valves we found complete or partial disorganization of architecture. The most common change was hyalinization present in 94% valves, vascularization in 84% and calcification present in 66% of valves. In 33% of stenotic valves were present infiltrations by lymphocytes. We found a significant correlation (p less than 0.05) between the presence of lymphoid infiltrates and the duration of disease prior to surgery.(ABSTRACT TRUNCATED AT 250 WORDS)

[Comparative evaluation of coronary arteriosclerosis in arterial hypertension and ischemic heart disease. Morphometric analysis of 4062 coronary artery specimens]. / Porównawcza ocena miazdzycy tetnic wiencowych w nadcisnieniu tetniczym i w chorobie niedokrwiennej serca. Morfometryczna ocena 4062 preparatów tetnic wiencowych.

We performed a postmortem study on 61 hearts from patients who died of acute ischemic heart disease (IA). Chronic ischemic heart disease (IB) and from hypertensive patients who died of heart infarction (IIA) and other hypertensive complications (IIB). Control group consisted of 16 pts. who died of non cardiac diseases. 4062 coronary artery specimens were estimated. Irrespective of the clinical course of ischemic heart disease the mean percent of coronary artery stenosis was similar in both ischemic groups and significantly higher than in control group. In hypertensive pts. who died of heart infarction it was also significantly higher and similar to ischemic pts. We found the highest percent of segments with critical stenosis in the left anterior descending coronary artery in group IA, IB, IIA. It was also significantly higher in the left main coronary artery in the group of ischemic pts. (IA, IB).