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PubMed1986

Heart and heart-lung transplantation: the Canadian and world experience from December 1967 to September 1985.

By Sept. 1, 1985, 62 centres around the world were identified as having participated in heart transplantation; of these 14 had also performed combined heart-lung transplantation. Between December 1967 and December 1984, 1599 recipients had undergone 1644 transplant procedures. By September 1985, 112 heart-lung transplant procedures had been performed in 110 patients. Overall survival at 1 and 3 years respectively, excluding perioperative mortality, averaged 80% and 65%; for heart transplantation alone survival rates were 85% and 75%, respectively. In Canada, of 81 heart and 5 heart-lung transplant procedures that were performed in nine centres between April 1981 and September 1985, 38 heart and 2 heart-lung transplants were carried out in the first 9 months of 1985. Sixty-four of the heart and 2 of the heart-lung transplant recipient were alive from 20 days to 4.42 years postoperatively.

Adolescent↗
PubMedDate not supplied

Storage and transport of heart and heart-lung donor organs with inflatable cushions and eutectoid cooling.

A system that uses a chemical method of cooling has been developed for the storage and transport of heart and heart-lung donor organs. This provides a precisely controlled environmental temperature without the use of ice, with its attendant problems of availability and potential contamination with pathogens. Storage and preservation solutions are transported to the donor hospital within the temperature-controlled polyurethane container, and the organs are returned in the same container, within an inflatable cushion. We have used this method for the distant procurement of over 260 hearts and for the most recent 30 heart-lung organ blocks. The mean ischemic time for hearts is 2.5 hours (1.5 to 4.2 hours) and for heart-lung blocks 2.2 hours (1.2 to 4.1 hours). Most donors give multiple organs such as kidney, liver, and pancreas. One patient received heart and kidney grafts from the same donor, and another received combined heart-lung and liver grafts. In relation to primary donor organ failure, there have been four deaths of patients who have had heart transplantations and no deaths of patients who received heart-lung organ blocks. We believe that the method offers advantages over the more conventional methods of organ storage with regard to convenience, temperature control, and sterility.

Cardioplegic Solutions↗
PubMed1998

Catecholamines and heart function in heart transplant patients: effects of beta1- versus nonselective beta-blockade.

OBJECTIVES: To evaluate cardiac responses to norepinephrine and epinephrine in heart transplant patients compared with patients with mild essential hypertension and to evaluate the contribution of beta2-receptors versus beta1-receptors to the cardiac responses by assessing the effects of the 2 agonists after treatment with placebo compared with the beta1-selective blocker atenolol and the nonselective blocker nadolol. METHODS: A double-blind, randomized crossover design was used to study patients after administration of placebo, atenolol, or nadolol for 2 weeks. Infusion of norepinephrine was performed at incremental rates of 12.5, 25, 50, and 100 ng/kg/min and of epinephrine at rates of 20, 40, 80, and 120 ng/kg/min. Blood pressure, heart rate, left ventricular function (by echocardiogram), and venous plasma concentrations were assessed at rest and at the end of each infusion rate. RESULTS: Infusion of epinephrine and norepinephrine was associated with 3-fold and 2-fold higher increases, respectively, in plasma concentrations in the transplant patients versus patients with hypertension. Enhanced blood pressure responses to either agonist were found in the transplant patients, but not when venous plasma concentrations were considered. Norepinephrine decreased heart rate and cardiac index in patients with hypertension receiving placebo and more markedly when receiving atenolol and nadolol. In contrast, heart transplant patients showed increases in heart rate, ejection fraction, and cardiac index, which largely were blocked (but not reversed into decreases) by atenolol and nadolol. In patients with hypertension receiving placebo, epinephrine increased heart rate, ejection fraction, and cardiac index. These responses were enhanced in transplant patients, also relative to plasma concentrations. Atenolol had only minor effects on these cardiac responses. On nadolol epinephrine decreased heart rate, stroke volume, and cardiac index in the patients with hypertension, whereas the transplant patients receiving nadolol showed no longer increases in cardiac function by epinephrine. CONCLUSIONS: Both absence of parasympathetic buffering and diminished systemic clearance contributed to the enhanced cardiac responses to infusion of norepinephrine and epinephrine in heart transplant patients compared with patients with essential hypertension. Cardiac beta2-receptors mediate most of the chronotropic and inotropic responses to epinephrine in both patients with hypertension and heart transplant patients.

Adrenergic beta-1 Receptor Antagonists↗
PubMed1961

Immunologic studies of heart tissue. IV. Serologic reactions with human heart tissue as revealed by immunofluorescent methods: isoimmune, Wassermann, and autoimmune reactions.

Reactions of normal and pathologic sera with heart tissue have been investigated by the immunofluorescent method, with particular reference to presumptive autoantibodies to heart and their differentiation from blood group isoantibodies and Wassermann antibody. In the heart, blood group substances A and B were found distributed in capillary walls, vascular endothelium, and interstitial connective tissue. In surveys of randomly selected sera, isoimmune reactions against tissue blood group substances A and B were noted infrequently. This finding was considered related to the limited sensitivity of fluorescent antibody methods. Heart tissue from blood group O individuals was used for screening of pathologic sera for presence of tissue-reactive factors. Wassermann antibody was found reactive with constituents of myocardial sarcoplasm, of which the major reactant was cardiolipin. Wassermann-positive sera absorbed with beef cardiolipin gave evidence of reaction with other constituents of myofiber sarcoplasm. Sera of patients with rheumatic fever, rheumatic heart disease, rheumatoid arthritis, disseminated lupus, and liver disease frequently showed a marked reactivity with constituents of myofiber sarcoplasm. These serum factors were differentiated from Wassermann antibody. At least three patterns of immunofluorescent staining could be differentiated by the distribution of reactants in the myofiber sarcoplasm. These reactants were extractable with ethanol and methanol but not by acetone. Sera found reactive by immunofluorescence frequently gave positive flocculation and complement-fixation tests with alcohol extracts of human heart. Immunofluorescent tests were best correlated with flocculation reactions. Sarcoplasmic-reactive factors were associated in some sera with 19S gamma globulin as demonstrated by the use of fluorescent anti-19S gamma globulin. Serologic reactions with homologous or autologous heart were observed particularly frequently with sera from rheumatic patients approximately 2 weeks following cardiac surgery, as well as in some non-rheumatic patients following cardiac or thoracic surgery or acute myocardial infarction. The pathogenetic significance of these presumptive autoantibodies to heart is unknown. As yet, no definite conclusions may be drawn regarding their relationship to bound gamma globulin in rheumatic hearts or to the postcardiotomy and post-infarction syndromes.

Antibodies↗
PubMed1985

[The heart in the elderly. Pathology: macroscopic and light microscopy findings in the heart].

The average heart weight increases up to the 9th decade. An existence of senile atrophy is not confirmed. Various morphological abnormalities of the heart in the elderly can be found during the course of life--polypathy of the heart. The number of these changes increases on average in each heart linearly with age. In polypathy of the heart the abnormalities which have functional consequences, such as stenosing coronary sclerosis, small vessel disease, heart hypertrophy, calcification of mitral ring and/or the aortic valves, as well as a cardiac amyloidosis are of the utmost importance. The polypathy of the heart in the elderly increases its vulnerability and may lead to a latent or manifest heart insufficiency. The law of polypathy is not only valid for the heart, but also for the whole organism.

Age Factors↗
PubMed2000

Effects of controlled-release metoprolol on total mortality, hospitalizations, and well-being in patients with heart failure: the Metoprolol CR/XL Randomized Intervention Trial in congestive heart failure (MERIT-HF). MERIT-HF Study Group.

CONTEXT: Results from recent studies on the effects of beta1-blockade in patients with heart failure demonstrated a 34% reduction in total mortality. However, the effect of beta1-blockade on the frequency of hospitalizations, symptoms, and quality of life in patients with heart failure has not been fully explored. OBJECTIVE: To examine the effects of the beta1-blocker controlled-release/extended-release metoprolol succinate (metoprolol CR/XL) on mortality, hospitalization, symptoms, and quality of life in patients with heart failure. DESIGN: Randomized, double-blind controlled trial, preceded by a 2-week single-blind placebo run-in period, conducted from February 14, 1997, to October 31, 1998, with a mean follow-up of 1 year. SETTING: Three hundred thirteen sites in 14 countries. PARTICIPANTS: Patients (n = 3991) with chronic heart failure, New York Heart Association (NYHA) functional class II to IV, and ejection fraction of 0.40 or less who were stabilized with optimum standard therapy. INTERVENTIONS: Patients were randomized to metoprolol CR/XL, 25 mg once per day (NYHA class II), or 12.5 mg once per day (NYHA class III or IV), titrated for 6 to 8 weeks up to a target dosage of 200 mg once per day (n = 1990); or matching placebo (n = 2001). MAIN OUTCOME MEASURES: Total mortality or any hospitalization (time to first event), number of hospitalizations for worsening heart failure, and change in NYHA class, by intervention group; quality of life was assessed in a substudy of 741 patients. RESULTS: The incidence of all predefined end points was lower in the metoprolol CR/XL group than in the placebo group, including total mortality or all-cause hospitalizations (the prespecified second primary end point; 641 vs 767 events; risk reduction, 19%; 95% confidence interval [CI], 10%-27%; P<.001); total mortality or hospitalizations due to worsening heart failure (311 vs 439 events; risk reduction, 31%; 95% CI, 20%-40%; P<.001), number of hospitalizations due to worsening heart failure (317 vs 451; P<.001); and number of days in hospital due to worsening heart failure (3401 vs 5303 days; P<.001). NYHA functional class, assessed by physicians, and McMaster Overall Treatment Evaluation score, assessed by patients, both improved in the metoprolol CR/XL group compared with the placebo group (P = .003 and P = .009, respectively). CONCLUSIONS: In this study of patients with symptomatic heartfailure, metoprolol CR/XL improved survival, reduced the need for hospitalizations due to worsening heart failure, improved NYHA functional class, and had beneficial effects on patient well-being.

Adrenergic beta-Antagonists↗
PubMed1999

Morphology of the pupal heart, adult heart, and associated tissues in the fruit fly, Drosophila melanogaster.

The early pupal heart of the fruit fly Drosophila melanogaster has recently been the subject of intense physiological and molecular work, yet it has not been well described, nor has it been compared with the heart of the adult fly. In the work reported here, the hearts of adults and early pupae of D. melanogaster were studied by scanning and transmission electron microscopy and by light microscopy. The hearts of adults and early pupae both consist of a tube of circular striated muscle one cell in thickness. The alary muscles, which suspend the heart, are more delicate in the adult compared to the early pupa. The pericardial cells in both early pupae and adults are connected to the heart by connective tissue radiating from the alary muscles or dorsal diaphragm. We confirm that four major changes occur in the heart during metamorphosis: 1) a conical chamber is formed de novo in the first and second abdominal segments; 2) the adult heart curves to conform to the contour of the abdomen; 3) a layer of longitudinal striated muscle appears on the ventral surface of the heart; 4) a fourth pair of ostia is added to the three already present in the early pupa; and note additionally that 5) the ostia appear as simple openings in the heart of the early pupa but are valve-like in the adult.

Age Factors↗
PubMed1996

Heart-focused anxiety, illness beliefs, and behavioral impairment: comparing healthy heart-anxious patients with cardiac and surgical inpatients.

Psychological features and complaints of persons presenting to medical settings with heart-focused anxiety and noncardiac chest pain are poorly understood. Comparing 20 healthy heart-anxious patients to cardiac and surgical inpatients and nonpatient controls, we found that healthy heart-anxious patients (a) were as afraid of chest pain and heart palpitations as inpatients with heart disease, (b) were as incapacitated by symptoms and using medical services as much as both inpatient groups; and (c) reported higher levels of cardiac disease conviction, heart awareness, and behaviors designed to protect their heart than surgical patients and nonpatients. Compared to all other groups, healthy heart-anxious patients reported more panic and other anxiety disorders, hypochondriacal beliefs, physical symptoms, obsessive-compulsive concerns, and negative affect. Following a hyperventilation test, heart-anxious patients also indicated more distressing symptoms and thoughts, and felt less safe and in control than surgical patients and nonpatients. Results support efforts for a timely recognition, diagnosis, and behavioral treatment of persons with heart-focused anxiety.

Adult↗
PubMed1992

Correlation of contractile dysfunction and abnormal tissue energy metabolism during hypoperfusion with norepinephrine in isolated rat hearts: differences between normal and diabetic hearts.

The relationship of myocardial high-energy phosphate depletion and lactate accumulation with contractile dysfunctions was investigated in streptozotocin-diabetic (DM) and normal rat hearts. The isolated hearts were perfused with 10(-6) M norepinephrine (NE) at various low-flow rates (0.4-6 ml/min/g heart wt) for 1 h. Left ventricular pressure (LVP) and contractile force (CF) were monitored, through a water-filled balloon in LV and through a hook attached to the apex, respectively. In DM hearts resting CF (diastolic tension) increased, when the perfusion flow rate was reduced below 6 ml and reached a maximum at a flow rate of less than 3 ml. The large increase in LV stiffness correlated with an elevation in diastolic LVP. In normal hearts these parameters were elevated at a flow rate below 1 ml. A flow-dependent decrease in developed CF was more prominent in DM than in normal hearts, while developed LVP and perfusion pressure were slightly higher in DM hearts with a marked increase in the LV stiffness. A flow-dependent decrease in high-energy phosphates and increases in inorganic phosphate and lactate were more prominent in the inner than in the outer layer of LV free wall in both groups. The change of ATP in the inner layer was greater, while increases of lactate in both layers were smaller in DM hearts. Changes in mechanical parameters correlated well with the ATP decrease and lactate increase in the inner layer in both groups. The correlation curves, however, were not coincidental: at the same low ATP and high lactate level, the LV stiffness was higher in DM hearts. Results indicate that DM hearts are more susceptible to flow-reduction with NE and depletion of total ATP in their tissue, and easily suffer from increased LV stiffness. This cannot be explained by the rate of decrease in total ATP and lactate accumulation alone.

Adenosine Triphosphate↗
PubMed2006

Higher New York Heart Association classes and increased mortality and hospitalization in patients with heart failure and preserved left ventricular function.

BACKGROUND: The association between higher New York Heart Association (NYHA) class and outcomes in patients with heart failure and preserved systolic function is not well known. METHODS: We performed a retrospective follow-up study of 988 patients with heart failure with ejection fraction > 45% who participated in the DIG trial. Using Cox proportional hazard models, we estimated risks and all-cause mortality, heart failure mortality, all-cause hospitalization, and hospitalization due to worsening heart failure during a median follow-up of 38.5 months. RESULTS: Patients had a median age of 68 years; 41.2% were women and 13.9%, nonwhites. Overall, 23.4% of patients died, and 19.9% were hospitalized because of worsening heart failure. Proportion of patients with NYHA classes I, II, III, and IV were 19.9%, 58.0%, 20.9%, and 1.2%, respectively, and 14.7%, 21.1%, 35.9%, and 58.3%, respectively, died of all causes (P < .001 for trend). Respective rates for heart failure-related hospitalizations were 14.2%, 17.1%, 32.5%, and 33.3% (P < .001 for trend). Compared with NYHA class I patients, adjusted hazard ratios (HRs) for all-cause mortality for class II, III, and IV patients were 1.54 (95% CI 1.02-2.32, P = .042), 2.56 (95% CI 1.64-24.01, P < .001), and 8.46 (95% CI 3.57-20.03, P < .001), respectively. Respective adjusted HRs (95% CI) for hospitalization due to heart failure for class II, III, and IV patients were 1.16 (0.76-1.77) (P = .502), 2.27 (1.45-3.56) (P < .001), and 3.71 (1.25-11.02) (P = 018). New York Heart Association classes II through IV were also associated with higher risk of all-cause hospitalization. CONCLUSION: Higher NYHA classes were associated with poorer outcomes in patients with heart failure and preserved systolic function.

Aged↗
PubMed2006

Impact of the history of congestive heart failure on the utility of B-type natriuretic peptide in the emergency diagnosis of heart failure: results from the Breathing Not Properly Multinational Study.

PURPOSE: B-type natriuretic peptide is known to correlate with hemodynamic state, presence and severity of congestive heart failure, and prognosis. Although low-range B-type natriuretic peptide less than 100 pg/mL has a high negative predictive value (90%), and high-range B-type natriuretic peptide greater than 500 pg/mL has a high positive predictive value (87%), there remains some ambiguity in the interpretation of results in the medium range (100-500 pg/mL). We hypothesized that taking into account the history of congestive heart failure along with other clinical variables would be helpful in this range of B-type natriuretic peptide levels. METHOD: The Breathing Not Properly Multicenter Study was an international, 7-center, prospective study including 1475 patients with a mean age of 63 years (57% were male, and 54% were female); 35% of patients with a history of congestive heart failure were enrolled, and a final diagnosis of congestive heart failure was made in 46%. The index criteria was defined as positive if any 2 index findings (ie, history of coronary artery disease, lower extremity edema, pulmonary edema, cephalization of the pulmonary arteries, and cardiomegaly) were present. RESULTS: The interval likelihood ratios (LR) for low, medium, and high B-type natriuretic peptide ranges are 0.13, 1.85, and 8.1, respectively. For medium B-type natriuretic peptide levels a positive history of congestive heart failure makes the diagnosis of congestive heart failure more probable with a cumulative LR of 4.3. Also in this range a positive index criterion was strongly indicative of congestive heart failure even in the absence of a history of congestive heart failure (LR 3.3). Where there are both a positive history of congestive heart failure and a positive index criteria for the medium B-type natriuretic peptide group, the cumulative LR (10.2) is similar to that of a high B-type natriuretic peptide level (8.1). CONCLUSION: Even in the medium range (100-500 pg/mL), when using the history of congestive heart failure and index criteria, B-type natriuretic peptide can be a powerful diagnostic tool in the hands of clinicians in the emergency department.

Aged↗
PubMed2005

Risk stratification in a Brazilian hospital-based cohort of 1220 outpatients with heart failure: role of Chagas' heart disease.

BACKGROUND: Few studies evaluated prognostic factors of outpatients with heart failure of different etiologies including Chagas' heart disease. METHODS: We studied 1220 outpatients with heart failure in functional classes III and IV (NYHA) to evaluate prognostic factors. Patients aged 13-72 years (mean 45.5, standard deviation 11); 952 men (78%) and 268 women (22%) were followed up for 25.6+/-26 months from 1991 to 2000. Heart failure was attributed to idiopathic dilated cardiomyopathy in 454 (37%) patients. Etiologies were Chagas' heart disease in 242 (20%) patients, ischemic cardiomyopathy in 212 (17%), hypertensive cardiomyopathy in 170 (14%) and others in 142 (12%). Statistical analyses were performed with Kaplan-Meier and Cox proportional hazards methods, following a strategy of noninvasive model as well as in an invasive model to identify the risk of death. RESULTS: Four hundred fifteen (34%) patients died in the follow-up period, 71 (6%) patients underwent heart transplantation and 28 (2%) underwent other surgical interventions. In the noninvasive model, Chagas' heart disease (relative risk compared with other etiologies 2.26 to 2.97), left ventricular end diastolic diameter on echocardiography (relative risk 1.13) and left ventricular ejection fraction on radionuclide angiography (relative risk 0.96) were associated with higher mortality. In the invasive model, Chagas' heart disease (relative risk compared with other etiologies 2.66 to 9.13) was the most important determinant of mortality in association with the cardiac index (relative risk 0.40). CONCLUSIONS: In this cohort of patients with heart failure of different etiologies, Chagas' heart disease was the main prognostic factor for mortality.

Adolescent↗
PubMedDate not supplied

From left ventricular hypertrophy to congestive heart failure: management of hypertensive heart disease.

Other than age, left ventricular hypertrophy (LVH) is the most potent predictor of adverse cardiovascular outcomes in the hypertensive population, and is an independent risk factor for coronary heart disease, sudden death, heart failure and stroke. Although directly related to systolic blood pressure, other factors including age, sex, race, body mass index and stimulation of the renin-angiotensin-aldosterone and sympathetic nervous systems play an important role in the pathogenesis of LVH. LVH involves changes in myocardial tissue architecture consisting of perivascular and myocardial fibrosis and medial thickening of intramyocardial coronary arteries, in addition to myocyte hypertrophy. The physiologic alterations which occur as a result of these anatomical changes include disturbances of myocardial blood flow, the development of an arrhythmogenic myocardial substrate and diastolic dysfunction. The latter is directly related to the degree of myocardial fibrosis and is the hemodynamic hallmark of hypertensive heart disease. When diastolic dysfunction is present, left ventricular end-diastolic pressure increases out-of-proportion to volume and may be elevated at rest or with exertion leading to clinical heart failure. At least one third of heart failure patients in the United States can be considered to have heart failure related to diastolic dysfunction. Compared to heart failure patients with systolic dysfunction, diastolic heart failure patients are more likely to be older, female, and to be hypertensive at the time of presentation. Although it has been assumed that LVH may lead to systolic dysfunction, evidence is lacking that LVH resulting from hypertension is a major risk factor for systolic heart failure independent of coronary artery disease. Treatment of hypertension greatly attenuates the development of LVH and significantly decreases the incidence of heart failure. In patients with established LVH, regression is both possible and desirable and results in a significant reduction in adverse clinical endpoints.

Antihypertensive Agents↗
PubMed2002

The anterior heart-forming field: voyage to the arterial pole of the heart.

Studies of vertebrate heart development have identified key genes and signalling molecules involved in the formation of a myocardial tube from paired heart-forming fields in splanchnic mesoderm. The posterior region of the paired heart-forming fields subsequently contributes myocardial precursor cells to the inflow region or venous pole of the heart. Recently, a population of myocardial precursor cells in chick and mouse embryos has been identified in pharyngeal mesoderm anterior to the early heart tube. This anterior heart-forming field gives rise to myocardium of the outflow region or arterial pole of the heart. The amniote heart is therefore derived from two myocardial precursor cell populations, which appear to be regulated by distinct genetic programmes. Discovery of the anterior heart-forming field has important implications for the interpretation of cardiac defects in mouse mutants and for the study of human congenital heart disease.

Animals↗
PubMed2002

The heart LIM protein gene (Hlp), expressed in the developing and adult heart, defines a new tissue-specific LIM-only protein family.

In a subtraction designed to identify transcripts accompanying mesodermal lineage specification in mouse ES differentiation cultures, we identified a gene encoding a two LIM-domain protein which we named heart LIM protein (Hlp). Hlp is most closely related to thymus LIM protein, and these two genes comprise a new gene family related to the cysteine-rich protein (CRP) gene family. In the embryo, Hlp expression is primarily restricted to the developing heart. In situ hybridization showed expression at E7.75 in the paired heart-forming primordia prior to linear heart-tube formation. At E8.5, strong expression is detected in the heart, with equal expression in both heart chambers. Hlp expression is detected in both myocardium and endocardium, and in vascular endothelium. Later in fetal development low levels of Hlp expression are detected outside the heart, including dorsal root ganglia and the spinal cord. In the adult, Hlp is expressed at highest levels in the heart, and at lower levels in the brain, skeletal muscle and aorta. Hlp expression is unchanged in hypertrophic hearts induced by aortic constriction. These data suggest a role for the two LIM-domain gene Hlp in the very earliest stages of heart differentiation and development.

Amino Acid Sequence↗
PubMed2001

Experimental heterotopic heart transplantation without cardiopulmonary bypass: auxiliary support for the recipient heart.

BACKGROUND: Auxiliary cardiac support using heterotopic heart transplant is of considerable interest, but the outcome is not known. To investigate technical feasibility and the possibility of using auxiliary support from heterotopic heart transplantation without cardiopulmonary bypass, we evaluated hemodynamics including the pressure-volume relationship in experimental animals. METHODS: In heterotopic heart transplantation, we tailored the donor heart by removing the pulmonary and tricuspid valves, and by wide removal of the inter-atrial septum. Next, we anastomosed the descending aorta and left atrium of the donor heart to the descending aorta and left atrium of the recipient, without using cardiopulmonary bypass. Consequently, declamping the recipient's descending aorta allowed the donor heart to fill with blood and to start beating. We performed hemodynamic assessments including the effects of adrenergic stimulation. We measured the pressure and volume relationship of the recipient heart by closing and opening inflow of the donor left atrium to change the pre-load of the donor left ventricle. RESULTS: The donor left ventricle produced a systolic blood pressure that was augmented by the recipient blood pressure and responded to adrenergic stimulation. When inflow of the donor left atrium was opened, the pressure-volume loop of the recipient heart shifted to the left and pressure-volume area decreased. Simultaneously, the mechanical efficiency and E(max) (the slope of the end-systolic pressure-volume relationship) of the recipient heart increased when inflow of the donor left atrium was opened. CONCLUSIONS: This transplant model, without cardiopulmonary bypass, is feasible and can be applied to transplant investigations as a working heart model on the basis of the response of adrenergic stimulation. The increased pre-load of the donor left atrium from the recipient left atrium resulted in a recipient leftward shift of the pressure-volume relationship, suggesting that this transplant model with adequate pre-load acts as auxiliary assistance in the recipient intrathoracic cavity.

Animals↗
PubMed1973

Effects of dichloroacetate on the metabolism of glucose, pyruvate, acetate, 3-hydroxybutyrate and palmitate in rat diaphragm and heart muscle in vitro and on extraction of glucose, lactate, pyruvate and free fatty acids by dog heart in vivo.

1. The extractions of glucose, lactate, pyruvate and free fatty acids by dog heart in vivo were calculated from measurements of their arterial and coronary sinus blood concentration. Elevation of plasma free fatty acid concentrations by infusion of intralipid and heparin resulted in increased extraction of free fatty acids and diminished extractions of glucose, lactate and pyruvate by the heart. It is suggested that metabolism of free fatty acids by the heart in vivo, as in vitro, may impair utilization of these substrates. These effects of elevated plasma free fatty acid concentrations on extractions by the heart in vivo were reversed by injection of dichloroacetate, which also improved extraction of lactate and pyruvate by the heart in vivo in alloxan diabetes. 2. Sodium dichloroacetate increased glucose oxidation and pyruvate oxidation in hearts from fed normal or alloxan-diabetic rats perfused with glucose and insulin. Dichloroacetate inhibited oxidation of acetate and 3-hydroxybutyrate and partially reversed inhibitory effects of these substrates on the oxidation of glucose. In rat diaphragm muscle dichloroacetate inhibited oxidation of acetate, 3-hydroxybutyrate and palmitate and increased glucose oxidation and pyruvate oxidation in diaphragms from alloxan-diabetic rats. Dichloroacetate increased the rate of glycolysis in hearts perfused with glucose, insulin and acetate and evidence is given that this results from a lowering of the citrate concentration within the cell, with a consequent activation of phosphofructokinase. 3. In hearts from normal rats perfused with glucose and insulin, dichloroacetate increased cell concentrations of acetyl-CoA, acetylcarnitine and glutamate and lowered those of aspartate and malate. In perfusions with glucose, insulin and acetate, dichloroacetate lowered the cell citrate concentration without lowering the acetyl-CoA or acetylcarnitine concentrations. Measurements of specific radioactivities of acetyl-CoA, acetylcarnitine and citrate in perfusions with [1-(14)C]acetate indicated that dichloroacetate lowered the specific radio-activity of these substrates in the perfused heart. Evidence is given that dichloroacetate may not be metabolized by the heart to dichloroacetyl-CoA or dichloroacetylcarnitine or citrate or CO(2). 4. We suggest that dichloroacetate may activate pyruvate dehydrogenase, thus increasing the oxidation of pyruvate to acetyl-CoA and acetylcarnitine and the conversion of acetyl-CoA into glutamate, with consumption of aspartate and malate. Possible mechanisms for the changes in cell citrate concentration and for inhibitory effects of dichloroacetate on the oxidation of acetate, 3-hydroxybutyrate and palmitate are discussed.

Acetates↗
PubMed1997

Interfetal heart rate and size variation in first-trimester multifetal pregnancies and heart rate of surviving fetuses after fetal reduction.

The objective of this study was to determine the variation in first-trimester fetal size and fetal heart rates in multifetal pregnancies, and to study the effect of fetal reduction on the surviving fetal heart rate. Fetal crown-rump length and fetal heart rates were measured in 44 patients with multifetal pregnancies who underwent fetal reduction. The heart rates of the surviving fetuses were also measured immediately after, and 1 h following the procedure. A total of 143 fetuses were evaluated prior to reduction and 75 fetuses following the procedure. There was no significant difference in crown-rump length between fetuses of the same gestation. The interfetal fetal heart rate variation between fetuses of the same gestation, expressed as a standard deviation, was 4.78 +/- 0.51 beats/min (mean standard deviation +/- standard error of the mean) before reduction; this was a significantly greater variation than could be attributed to error in the measurement of heart rate. In the surviving fetuses, the mean heart rate did not change. However, immediately after the reduction, interfetal heart rate variation was abolished, but was observed again 1 h after the reduction. We conclude that in first-trimester multifetal pregnancies (1) there is no significant difference in fetal crown-rump length; (2) there is interfetal variation in heart rates; and (3) fetal reduction has only a limited effect on the heart rates of surviving fetuses.

Embryonic and Fetal Development↗