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At least 577 records · Page 32Linked to original sources
PubMed1990

[The effect of chemical ablation with lugol solution for ventricular tachyarrhythmia on cardiac function].

Among various methods to treat ventricular tachyarrhythmia (VT) in the presence of acute myocardial infraction, the surgical approach is a somewhat unsatisfactory method in case of preoperative acute hemodynamic deterioration. The transatrial approach with the "topical" application of Lugol solution on left ventricular (LV) endocardium, without left ventriculotomy, i.e. a transatrial chemical ablation method; has been reported in our department as suggestive to being efficacious. The objective of the present study is to investigate the occurrence of left bundle branch block (LBBB) and the like, as well as to examine the impact on heart function, particularly LV function, by employing the just-above mentioned approach. 15 mongrel dogs were being experimented on. Through a left transatrial approach toward LV endocardium and the application of Lugol solution, with pulmonary artery flow being as constant; we measured pre- and post-operative left atrial (LA) pressure, LV pressure, aortic pressure, LV functional shortening, and stroke volume. In addition, the same protocol was also employed in another group, with the application of physiologic normal saline solution, instead. A comparative study was made between the two groups. In the Lugol solution group, postoperative LA pressure and LVEDP showed a tendency toward exhibiting higher values, when compared to preoperative readings. However, no significant difference was observed in this setting. Furthermore, in comparison with postoperative readings in the saline group, the mean LA pressure in the Lugol solution group exhibited a tendency toward somewhat higher values. Nonetheless, no significant difference was observed in LV functional shortening between the two groups; though it is known a LBB pattern could be noticed on ECG in the Lugol solution group.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1989

Physical and mechanical effects of cardioplegic injection on flow distribution and myocardial damage in hearts with normal coronary arteries.

The physical and mechanical effects of injecting crystalloid cardioplegic solution under various pressures and flows was studied (in canine hearts) to establish a safe method for administering it in the presence of normal coronary arteries. A constant pressure system (300 mm Hg = 15 psi) was maintained in the solution reservoir, and flows and pressures were varied with the use of cannulas of different inner diameters: 0.8, 1.35, 1.6, 2.3, 2.58, and 2.80 mm. Cardioplegia distribution was measured by 15 microns radioactive microspheres. Peak flow rate, total flow, and mean flow rate per infusion were measured by an inline electromagnetic flowmeter probe. Direct aortic root pressure, time to standstill, and myocardial temperatures were recorded by continuous monitoring. Cardiac isoenzymes were measured in the coronary sinus, peripheral blood, and directly in the myocardial tissue. Histologic changes in the left ventricle were examined by light microscopy. The results showed that the higher the flow and pressure, the shorter the prearrest period, the better the flow distribution, and the faster the myocardial temperature drop. Mean aortic root pressures higher than 110 mm Hg and peak flow rates greater than 1500 ml/min caused a higher incidence of mechanical-physical trauma to the vascular endothelium and the endocardium, but cellular protection was good. Low pressure (less than 30 mm Hg) and peak flows (less than 125 ml/min) showed a higher incidence of cellular (myocardial) ischemia, focal necrosis, and uneven flow distribution. An aortic root pressure of 61 +/- 5 mm Hg, a mean peak flow rate of 622 +/- 52 ml/min, and a total flow of 600 ml for the first injection seem to offer the best cellular protection with minimal physical injury to the endothelium and endocardium for a mean canine heart weight of 236 gm.

Animals↗
PubMed1987

Reconstruction of the mitral anulus.

The mitral anulus was reconstructed with autologous pericardium in nine patients. Six patients had infective endocarditis with one or more abscesses in the anulus, and three had an iatrogenically damaged anulus. In patients with disruption of the mitral anulus limited to its posterior portion, a semicircular patch of pericardium was sutured directly to the endocardium of the left ventricle. In patients with multiple defects in the anulus, circumferential reconstruction of the mitral ring with pericardium was performed. In cases in which abscesses involved the central fibrous body, pericardium was used to reconstruct both the mitral anulus and the aortic root. Eight patients survived and have remained well for a mean of 8 months. There has been no prosthetic or patch dehiscence. All patients experienced substantial functional improvement. This experience indicates that the disrupted mitral anulus can be successfully reconstructed with autologous pericardium that is sutured directly to the endocardium of the left ventricle.

Adult↗
PubMed1985

The effects of myocardial ischemia followed by reperfusion on perfused coronary capillarity.

To determine the effects of ischemia and reperfusion on myocardial perfused capillary density, rat hearts were excised, kept ischemic for thirty minutes then reperfused with blood from a support animal. Control hearts were isolated and perfused for either 10 or 60 minutes before injection of a vascular marker (Monastral Blue-blood mixture, 30 sec at 100 mmHg). The ischemic hearts were perfused with Blue after 10 minutes of reperfusion. The perfused capillary density (theta) and capillary/fiber ratio (C/F) were measured from frozen transverse sections of the left ventricle. For 10- and 60-minute control hearts, the epicardial theta values were 2324 +/- 476 caps/mm2 and 2378 +/- 330 SD. The endo/epi theta ratio was not significantly less than unity for either control group. For the ischemic group, theta was significantly decreased both in the epicardium (707 +/- 515 caps/mm2) and endocardium (130 +/- 30 caps/mm2) (p less than 0.05). The endo/epi theta ratio was significantly less than unity for the ischemic group (P less than 0.05). The C/F ratio analysis yielded the same results. The decrease in both theta and CF ratio indicate that 30 minutes of ischemia followed by 10 minutes of reperfusion caused a marked "No-reflow" phenomena in isolated, supported hearts. The No-reflow was most pronounced in the endocardium.

Animals↗
PubMed1985

[Abnormal left ventricular endocardial structures detected by two-dimensional echocardiography in systemic lupus erythematosus].

This is a report of abnormal endocardial structures on the left ventricular wall as visualized by two-dimensional echocardiography (2-D echo) in patients with systemic lupus erythematosus. Abnormal endocardial structures, arising from the left ventricular endocardium and appearing to proliferate into the cavity, were found in 11 (20%) of 54 patients. The most frequently involved site was posterobasal left ventricular wall in the parasternal long-axis view, and the posterolateral segment of the left ventricle including the anterior and posterior papillary muscles in the parasternal short-axis view. M-mode echocardiograms, simultaneously recorded with 2-D echo, revealed abnormal structures of increased intensity adjacent to the endocardium with thicknesses of 4 approximately 7 mm. Most of the abnormal endocardial structures were observed in patients in the active phase by 2-D echo, and they appeared to regress with steroid therapy. In one autopsy case, fibrous endocardial thickening suggesting healed endocarditis was present in the anterior papillary muscle as observed by 2-D echo. Their location and response to steroid therapy suggests that these abnormal echoes could represent Libman-Sacks endocarditis.

Adult↗
PubMed1979

The porous-surfaced electrode: a new concept in pacemaker lead design.

Three major problems which may be encountered with endocardial pacemaker electrodes are a lack of stable position, a chronic increase in stimulation threshold, and a diminishing magnitude of the sensed endocardial signal. These problems are particularly manifest in the atrium. Having previously shown that porous metal surfaces can support stable tissue ingrowth in both bloodstream and soft tissue environments, we set out todetermine the performance of porous-surfaced endocardial pacing electrodes in the atrial position. In two groups of six dogs each, J-shaped atrial leads with Elgiloy electrode tips (2.3 mm. in diameter, 2.3 mm. in length), having either conventional smooth surfaces (control) or porous surfaces (20 to 50 micron particle size) produced by powder metallurgy techniques, were positioned in the right atrial a-pendage. Stimulation thresholds and P-wave amplitude were repeatedly measured until the dogs were put to death 30 w-eks following implantation. The presence or absence of electrode fixation was observed and the atrial tissue reaction was examined grossly and by both light and scanning electron microscopy (SEM). The porous-surfaced electrodes demonstrated superior long-term stimulation thresholds which, at 30 weeks, averaged less then one third of those in the control group. In addition, the porous group showed a small but significant improvement in the amplitude of the sensed P wave. None of the smooth-surfaced electrodes showed fixation, and the tissue reaction consisted of a thick layer of granulation and fibrous tissue on the underlying endocardium, widely separating the electrode from the myocardium. In contrast, all of the porous-surfaced electrodes were fexed to the endocardium by fibrous tissue ingrowth into the surface pores. This tissue fixation of the electrode tip in close proximity to underlying myocytes explains their superior performance.

Animals↗
PubMed1984

Reperfusion of the human myocardium by saphenous vein bypass grafts. Biochemical considerations.

The adenine nucleotide content of the human myocardium in the distribution of the left anterior descending coronary artery (LAD) was measured before and after saphenous vein bypass grafting. The purpose of the study were twofold: (1) to relate the level of adenosine triphosphate (ATP) before bypass grafting to the percent stenoses of the LAD and (2) to determine the benefit or lack of benefit of bypass grafting on ATP content. Eighteen patients with angiographically determined LAD lesions of 40% to 100% underwent bypass grafting with standard cardiopulmonary bypass and cardioplegia. Transmural needle biopsy specimens were obtained from the center of the area perfused by the LAD immediately before cross-clamping of the aorta and 30 minutes after reperfusion of the myocardium via the native LAD and the graft. The tissue was divided into thirds: The endocardial and epicardial thirds were analyzed for ATP by high-pressure liquid chromatography and the middle third was viewed by light microscopy. The percent narrowing of the LAD correlated well (r = -0.71) with the ratio of ATP to total adenine nucleotides (TAN) in the endocardium. Epicardial ATP did not correlate with the percent stenoses of the LAD. The endocardial ATP/TAN ratio increased in the group as a whole from 0.51 +/- 0.27 (mean +/- SD) to 0.64 +/- 0.26 (p less than 0.01) after bypass grafting, and this was most impressive in those eight patients with LAD lesions greater than 90% (0.32 +/- 0.20 before grafting to 0.60 +/- 0.29 after grafting, p less than 0.005). However, the epicardial ATP/TAN ratio decreased from 0.75 +/- 0.15 before grafting to 0.64 +/- 0.17 after grafting (p less than 0.05), and this decrease occurred regardless of the percent narrowing of the LAD. There was no difference in vacuolization between the pre-grafting and post-grafting biopsy specimens, and intramyocardial hemorrhage was not observed. This study has demonstrated a close relationship between the degree of LAD stenosis and endocardial ATP content. Also, the endocardium supplied by arteries with greater than 90% lesions had significantly increased ATP while the epicardium had decreased ATP content after bypass grafting.

Adenine Nucleotides↗
PubMed1984

[Endomyocardial fibrosis or fibroplastic endocarditis. Indications and results of surgical treatment].

Endocardial fibrosis is most common in tropical regions where it affects young subjects. Fibroplastic endocarditis appears to be the same condition, seen in temperate countries. Fibrosis of the endocardium is the common lesion which initially involves the endocardium and not the myocardium. These lesions result in a restrictive and a valvular syndrome. The author recalls the signs of the right-sided, left-sided and bilateral forms of the disease. The signs in common to all forms are early diastolic endocardial vibration, arrhythmias and conduction disturbances and the possibility of endocardial calcifications. The disease progresses towards death within 3, 4 or 5 years after the discovery of the condition. Medical treatment is effective initially. Surgical treatment improves the prognosis, as demonstrated by the comparative study conducted in Abidjan between 30 operated patients and 31 non-operated patients. The most favourable forms are the isolated left-sided forms. However, surgery is indicated in all forms whenever there are signs of a restrictive syndrome or a moderate to severe mitral incompetence. The only definitive contra-indication at the present time is the presence of recurrent ascites with hepatic fibrosis.

Adolescent↗
PubMed1984

Ectopic mineralization and nutritional hyperparathyroidism in boars.

The influence of a high phosphorus (1.5%) and high calcium (2.2%) diet on ectopic mineralization in boars was examined over a four month period. The high phosphorus diet caused metastatic mineralization in the left atrial endocardium in 84% of animals and in the pulmonary and diaphragmatic pleura in 21 and 58% of animals, respectively. Mineralization, that apparently commenced as deposits of extraneous calcium and progressed by metastatic deposition, occurred also in the lamina propria mucosae of the respiratory airways and in the lamina muscularis mucosae of fundic stomach. Hyperplasia of osteoclasts and microfractures in costochondral junction, morphological features of activated parathyroid cells and a significant drop in serum phosphorus during the fourth month in boars fed high phosphorus, suggest that nutritional hyperparathyroidism was experimentally induced. No systemic bone disease developed. Feeding a high calcium diet resulted in 20% incidence of discrete lesions in the left atrial endocardium and no pleural involvement. Also, lesions in respiratory airways and fundic stomach were mild. The fact that high phosphorus but not high calcium increased the incidence and extent of ectopic mineralization suggests that hyperparathyroidism under normocalcemic conditions might be involved in the pathogenesis of these lesions.

Animals↗
PubMedDate not supplied

[Reliability of the ultrasonic study of the heart].

Based on a study of echograms from the heart structures the probabilities of receiving echosignals have been calculated. The probability to detect signals from the endocardium has been shown to be markedly higher than that from the pericardium. Because of great diffusive component of a scattered signal from the endocardium echosignals are reliably received during ultrasonic heart examination.

Animals↗
PubMed1982

Indwelling cardiac catheters. An autopsy study of associated endocardial lesions.

An autopsy study was carried out to assess the relationship between indwelling intracardiac catheters and hemorrhagic, thrombotic, and infective lesions of the right heart endocardium and valve. Intracardiac catheters cause such lesions frequently, with a spectrum from uncomplicated valvular hemorrhage through nonbacterial thrombotic endocarditis to infective endocarditis. Pulmonary emboli were associated with the thrombotic, infective lesions. Endocardial lesions are more commonly seen with Swan-Ganz (SG) catheters; with these, lesions are more common and severe, with longer periods of catheterization. Pulmonic-valve lesions were only seen with SG catheters. However, not all hemorrhagic lesions in the right heart endocardium were associated with catheters, because a few inpatients without catheters had small subendocardial valvular hemorrhages; the cause of these hemorrhages is obscure because they were not seen in the hearts of patients who died outside the hospital.

Autopsy↗
PubMed1981

Surgical treatment of constrictive fibrous endocarditis.

Between 1971 and 1980, 20 patients with fibrous endocarditis were treated by resection of ventricular endocardium and replacement of the atrioventricular valve. There were 13 male and seven female patients whose ages ranged between 12 and 58 years. Thirteen were white and the remaining seven were black Africans. Nine presented a right-sided form, five a left-sided one, and six presented involvement of both ventricles. The role of hypereosinophilia is discussed in the etiology of the disease. The operation was performed according to the techniques we had developed in our first operative case-excision of the atrioventricular valve. Complete resection of the endocardium, and valvular replacement. There were three operative deaths. Complete atrioventricular dissociation was observed in seven of our patients. particularly in those with right-sided endocarditis. At late follow-up, we have not observed any case of recurrence of the disease. On the basis of our experience and the results previously published in the literature, we believe that endocardiectomy is the best current treatment of this disease.

Adolescent↗
PubMed1981

Origin and migration of cushion tissue in the developing heart.

The origin of cushion tissue mesenchyme in the developing chick heart was investigated by three basic methods: use of an inert metabolic marker; time lapse recording of organ-cultured heart regions; and scanning stereo-microscopy. All three approaches support the hypothesis that the endocardium is the progenitor of cushion tissue mesenchyme. Additional observations show a cell:matrix interaction by the endocardium prior to the formation of mesenchyme. It is postulated that this activity in some manner alters the underlying matrix and helps to initiate and maintain migratory activity of the mesenchyme.

Animals↗
PubMed1980

[Pathomorphologic and ultrastructural characteristics of endocardial Cysticercus cellulosae].

A case is presented of a solitary endocardial cysticercus of cellulose discovered at a biopsy in the left auricula of the heart, got by a 36-year old patient at the operation who had a mitral and aortal defect caused by a reumatic endocarditis. The cisticercus is implanted on the surface of an intact endothelium and the fibroelastic structure of the superficial part of the endocardium is preserved. Inflammation of the endocardium and the myocardium is presented by a perivascular infiltrates eosinophile granulocytes, plasms cells and lymphocytes, suggesting an allergic nature of inflammation. In histological preparates stained by selective methods of fungus according to Gridley and Crocott on the wall of the membrane of the cyst polymorphal Yeast-like elements are discovered at a size of 2-12 mil. mic. which ultrastructurally show degenerative forms of membranous structures suspected as immature primitive proglotids. In this paper, the objective difficulties are pointed out at the microscopic diagnosis of the cisticercus in the pathological material.

Adult↗
PubMed1994

The mouse tie receptor tyrosine kinase gene: expression during embryonic angiogenesis.

Angiogenesis, the process by which new blood vessels are formed, is essential in reproduction, development, wound repair and oncogenesis. Endothelial receptor tyrosine kinases are likely to play key roles in the intercellular signalling controlling angiogenesis. We have here analysed the expression of the endothelial receptor tyrosine kinase tie during the earliest stages of vascular development. The mouse tie cDNA was isolated and sequenced and the exon structure of the coding region was determined. The part of the tie gene encoding the extracellular domain was found to be organized in exons specifying the characteristic domains of the Tie polypeptide. Early postimplantation mouse tissues were analysed for tie expression by in situ hybridization. No tie mRNA was detected in 7.5 day mouse embryos. In 8.5 day embryos, tie expression was observed in differentiating angioblasts of the head mesenchyme, in the splanchnopleure and dorsal aorta as well as in migrating endothelial cells of the developing heart. A weak tie signal was also obtained from angioblasts in the blood islands of the yolk sac. Furthermore, tie mRNA was prominent in the endocardium of the embryo and in the endothelial cells forming the lung vasculature. Expression of tie persisted in the lung capillaries of adult mice, but was decreased in the endocardium. These results suggest that the tie receptor tyrosine kinase is involved in angiogenesis and/or maintenance of endothelial cell functions.

Amino Acid Sequence↗
PubMed1993

The role of endocardial endothelium in the modulation of myocardial contraction in the isolated whole heart.

Selective damage to the endocardial endothelium in isolated papillary muscle preparations has been shown to produce an abbreviation of contraction, changes which were also observed following an increase in myocardial cyclic GMP in those preparations. In the present study we have investigated the effects of removing the endocardium and increasing myocardial cyclic GMP on contractile parameters in isolated Langendorff perfused ferret hearts, where the myocardial mass underlying the endocardium is much greater. Selective damage to left ventricular endocardial endothelium without damaging the underlying myocardium was achieved by brief exposure to a weak detergent solution (Triton X-100 0.005% v/v). This resulted in a significant abbreviation of the left ventricular pressure-time curve due to the earlier onset of relaxation, but there was little effect on early systole. The direct intraventricular infusion for 15 minutes of 10 microM sodium nitroprusside, a donor of nitric oxide, or of 1 microM substance P, to stimulate release of endothelium-derived relaxing factor, did not increase myocardial cyclic GMP levels or alter left ventricular contractile performance. Myocardial cyclic GMP levels were significantly increased by 15 minute intracoronary infusions of 10 microM nitroprusside and 1 microM substance P, approximately ten-fold and two-fold respectively. Intracoronary nitroprusside induced an abbreviation of the left ventricular pressure-time curve with an earlier onset of relaxation, but contraction was unaltered by intracoronary substance P. These results show that, in the isolated Langendorff perfused ferret heart, both selective removal of endocardial endothelium and an increase in myocardial cyclic GMP cause an abbreviation of left ventricular pressure and an earlier onset of relaxation with little change in early systole.

Animals↗
PubMed1995

Deringing procedure for congenital pulmonary vein stenosis.

We operated on a 14-year-old boy who had an echocardiographic diagnosis of ventricular septal defect. At surgery we found, in addition, an anomalous and obstructive intraventricular muscle bundle. Detection of a continuous thrill over the right pulmonary veins, prior to cardiopulmonary bypass, led to exploration of the left atrium. The ostia of the right superior and inferior pulmonary veins were impeded by circumferential membranous rings of endocardium with central stenotic openings. Excision of these annular rings relieved the obstruction. The left lung was drained by a long intrapericardial common venous channel that entered the left atrium through a stenotic ostium; excision of an annular ridge of endocardium restored normal flow. The patient remains asymptomatic after 23 months. The case is reported for the new deringing technique and the rarity of successful correction of congenital pulmonary vein stenosis.

Adolescent↗
PubMed1993

[Diagnosis and treatment of infantile endocardial fibroelastosis].

The diagnosis, treatment and etiology of primary infantile endocardial fibroelastosis were studied in 33 patients from 1989 to 1992. Two dimensional echocardiography with Doppler examination showed that the thickness of the endocardium obviously increased and systolic and diastolic functions of the left ventricles were abnormal. Endomyocardial biopsy proved that the endocardium and myocardium under went pathological changes. The virus probe examination of biopsy tissue showed negative results and the effectiveness of immunosuppressive therapy (total effective rate 96%) indicated that this disease is probably of autoimmune etiology. The facts led us to nominate this disease as infantile endomyocardial disease. Besides, the classification, diagnostic criteria, principles of treatment and prognosis of this disease were discussed.

Child, Preschool↗