Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0011570 (depression)
 172,036 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Few models of heart failure (HF) are available for physiological and pharmacological studies. We report here a model of pressure plus volume overload induced in rabbits in which left ventricular (LV) function was studied in the conscious state after instrumentation of the animals with LV pressure catheter and ultrasonic crystals measuring LV diameter. Beta-Adrenoceptors were studied on crude membranes obtained from control (C) and HF rabbits using [3H]CGP 12177. LV weights and end-diastolic diameters were significantly increased in the HF group compared with the C group (by 79 and 38%, respectively). The percentage of diameter systolic shortening was decreased, in the control state, in rabbits with HF (15.3 +/- 1.6%) as compared with C rabbits (29.6 +/- 2.5%) and remained lower in the HF group when end-systolic pressures were matched. Chronotropic response to isoproterenol injection was significantly decreased in rabbits with HF compared with that of C rabbits. Beta-Adrenergic receptor density was decreased in rabbits with HF (39.3 +/- 3.7 fmol/mg) compared with C rabbits (56.7 +/- 4.2 fmol/mg) without affinity changes. This model of chronic HF thus produces a marked hypertrophy with ventricular dilatation and a depression of LV function within 2 mo, factors that are associated with a reduced cardiac responsiveness to catecholamines and a decreased ventricular beta-adrenergic receptor density.
 ...
PMID:Left ventricular function and beta-adrenoceptors in rabbit failing heart. 215 52

Congestive heart failure is a complex clinical syndrome that has its basis in an abnormality of myocardial cell function resulting in impaired ventricular performance, exercise intolerance, and ventricular arrhythmias. The functional defect in myocardial performance may be related to alterations in receptor function, in regulatory proteins, or in biochemical mechanisms. Remodeling of the left ventricle has been observed to play an important role in the natural course of heart failure. The complex interplay between cellular elongation, reactive hypertrophy, and the influence of the change from ellipsoid to spheroidal shape of the left ventricle after acute myocardial infarction are just beginning to be understood. Prevention of this remodeling effect by pharmacologic intervention is being widely explored, although the mechanisms are poorly defined. Impedance to left ventricular ejection is also an important determinant of cardiac performance in heart failure. Constriction of arteriolar resistance vessels and reduction in compliance of arterial conductance vessels is a common manifestation of heart failure and may be under the influence of neural, hormonal, endothelial, and local regulatory factors. Increased tone of venous capacitance vessels contributes to a shift of blood centrally and to an increase in ventricular preload. Vasodilator drugs by relaxing the arterial, arteriolar, and venous vasculature result in a reduction in impedance and left ventricular afterload and a decrease in cardiac filling pressure and preload. Structural changes of hypertrophy and remodeling apparently contribute to the changes in resistance, compliance, and capacitance in the vasculature. Treatment of heart failure is aimed at relieving symptoms and prolonging life. Interventions to improve left ventricular function are critical to symptom relief. Vasodilators have been most effective for this purpose, and new positive inotropic drugs are being tested for efficacy. Long-term benefit may require interference with the myocardial and peripheral vascular remodeling processes that lead to progressive depression of ventricular performance. New insights into the cellular and subcellular mechanisms of this progression are critical to the development of innovative therapeutic strategies.
 ...
PMID:Heart failure: mechanisms of cardiac and vascular dysfunction and the rationale for pharmacologic intervention. 221 Jan 53

This study tested the hypothesis that membrane transport is the major biochemical system of the myocardium altered in furazolidone-induced cardiomyopathy (round heart disease), before the development of myocardial failure, and that metabolic enzymes and contractile proteins are less affected. Compared with controls, maximal percentage depression of activities of myocardium from furazolidone-treated birds were 40 for creatine kinase, 30 for glycolysis, 30 for glycogen, 20 for myofibrils, 20 for Krebs's cycle enzymes, 15 for fatty acid oxidation and 10 for total soluble protein. Sodium and potassium transport, antioxidant system activity, myosin, myosin isoenzyme patterns and amino acid aminotransferases were unaffected. In marked contrast, the calcium-transport ATPase activity of the sarcoplasmic reticulum had undergone a 60 per cent compensatory increase in activity. The pattern of biochemical changes observed is consistent with a role of ischaemia in the pathogenesis of round heart disease and indicates that calcium transport by the sarcoplasmic reticulum is the major biochemical system affected.
 ...
PMID:Myocardial biochemical changes in furazolidone-induced cardiomyopathy of turkeys. 232 37

Between January, 1982, and December, 1987, 14 patients failed to approximate sternum after open-heart surgery in infants and children. The indications for keeping sternum open were enlarged heart, myocardial edema, severe depression of myocardial contractility and reduced lung compliance due to pulmonary edema. Of the 14 patients, 9 underwent delayed sternal closure between 2nd and 13th postoperative day, and 4 were long-term survivals. All the rest of five patients who were left their sternum open, died of intractable cardiac failure within 16th postoperative day. During the sternum open, three patients suffered from complications-myocardial bleeding in one, and mediastinitis in two. But none of them directly related to the death, and one patient with mediastinitis successfully healed with closed mediastinal irrigation. Although the employment of the delayed sternal closure is rare and limited to the patient with severe heart failure, its judicious use adds advantages in the management of low cardiac output state in infants and children immediately postoperative period.
 ...
PMID:[Delayed sternal closure following open-heart surgery in infants and children]. 234 25

Lack of donor availability has heightened our awareness of the need for suitable long-term management of heart failure in patients awaiting heart transplantation. Frequently patients become dependent on intravenous inotropic agents despite attempts to discontinue these agents. This can lead to prolonged hospitalizations, separation anxiety and depression in families, high hospitalization costs, and poor quality of life. Between June 1987 and April 1988 three patients awaiting heart transplantation at the University of Cincinnati Hospital were sent home while receiving constant intravenous infusion of dobutamine. All three patients had had prolonged hospitalizations and were unable to be weaned from dobutamine without clinical compromise. The patients were New York Heart Association functional class III to IV, had cardiac indices between 1.5 to 2.13 L/min/m2, cardiac output less than 4.0 L/min, pulmonary capillary wedge pressures 17 to 27 mm Hg, and left ventricular ejection fraction less than 20% in two of the patients (idiopathic cardiomyopathy), and 30% in the third patient who was awaiting retransplantation (refractory repeated acute rejections). Dobutamine was infused by means of a constant-rate portable cassette pump at 3.17 micrograms/kg/min in patient 1, 10 micrograms/kg/min in patient 2, and 5 micrograms/kg/min in patient 3. A critical care home health nursing agency was used for follow-up home care. All three patients had central lines placed before discharge from the hospital. Each patient was instructed in proper care of the central line and infusion pump and was able to demonstrate accurate technique before being discharged home. Complications were minimal and were related to central line placement. No patient required rehospitalization for complications. No wound infections were reported.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Home intravenous dobutamine therapy in patients awaiting heart transplantation. 235 73

Beta-adrenergic blocking agents may have negative inotropic effects that are particularly worrisome in patients with depressed cardiac function. Their membrane-stabilizing properties may be a contributing factor. Sotalol is currently thought not to cause significant myocardial depression. Intravenous sotalol administration has minimal effects on resting stroke volume, although heart rate and consequently cardiac output are significantly decreased. Systolic blood pressure decreases, with a minimal change in diastolic or mean pressure. Hemodynamic effects are usually seen within 15 to 20 minutes of administration. Hemodynamic indexes are maintained even in patients with mildly depressed ejection fractions (mean ejection fraction of 43 +/- 15%) after oral sotalol administration. Although heart rate decreases, cardiac index is unchanged because of a significant increase in stroke volume index. The latter results from an increase in preload (secondary to bradycardia) and a decrease in afterload. Sotalol is well tolerated, although occasionally it may cause worsening heart failure. This is seen in patients with markedly depressed left ventricular function and inadequate cardiac reserve characterized by an inability to increase stroke volume and cardiac output with exercise. Long-term (1-year) patient follow-up reveals no significant hemodynamic deterioration from initial values obtained after oral administration.
 ...
PMID:Hemodynamic effects of intravenous and oral sotalol. 240 32

Corwin is a new, long-acting beta 1-adrenergic partial agonist for oral and intravenous (i.v.) use. The effects of corwin were compared with those of dobutamine in acute ischemic left ventricular failure in dogs. Failure was produced by embolization of the left main coronary artery with 50 micron plastic microspheres. This induced severe depression in left ventricular function, as evidenced by a marked increase in left ventricular end-diastolic pressure, reduction in left ventricular dP/dtmax, and cardiac output. After 45 min was allowed for stabilization, the 27 dogs were randomly assigned to three groups: control (n = 9), dobutamine-treated (5-10 micrograms/kg/min i.v., n = 9), and corwin-treated (0.025-0.10 mg/kg i.v., n = 9). The doses of dobutamine and corwin were adjusted to give an increase in left ventricular dP/dtmax of 50%. Both drugs similarly increased cardiac output (p less than 0.01), lowered left ventricular end-diastolic pressure (p less than 0.01) and total peripheral vascular resistance (p less than 0.01), but did not affect the heart rate. Only dobutamine increased the mean arterial pressure (p less than 0.01). Both drugs also increased the arterial concentrations and myocardial uptake of fatty acids (p less than 0.05) but caused only a small and nonsignificant increase in myocardial oxygen consumption. Our findings indicate that the hemodynamic and metabolic profiles of corwin and dobutamine are similar, and both drugs should be of special value in the treatment of congestive heart failure. Since corwin can be given orally and has a longer duration of action, it is potentially useful in the long-term treatment of heart failure.
 ...
PMID:Comparative effects of dobutamine and corwin, a beta 1-adrenergic partial agonist, in experimental left ventricular failure. 241 Jul 22

The discovery of insulin in 1922 aroused immediate clinical interest in its use in heart disease. In severe heart failure, insulin release is suppressed by the combined effect of poor pancreatic perfusion and by increased sympathetic activity. In these circumstances, myocardial metabolism of glucose may break down through the deficiency of insulin. Because of this, glucose, insulin and potassium solution (GIK solution) has been used in cardiopulmonary resuscitation. However, its mechanism is not yet fully known. This study was designed to determine the effect of insulin on cardiac muscle at various temperatures. The mechanical response of papillary muscle isolated from guinea pig ventricle was observed under various thermal conditions (23-37 degrees C). Twitch tension was increased by the administration of 0.2 I.U./ml insulin under each thermal condition. In all circumstances, the increase in contractile force was noted about 2 min after the administration of insulin. The effect of insulin on 20 preparations demonstrated the mean maximum contractile force was 226% ( +/- 34 S.D., n = 5) in 37 degrees C, 194% ( +/- 36 S.D., n = 5) in 30 degrees C, 190% ( +/- 30 S.D., n = 5) in 27 degrees C and 200% ( +/- 36 S.D., n = 5) in in 23 degrees C. The differences between different temperatures was not significant. The effect of insulin during depression Na-K pump by high concentration of ouabain (g-strophanthin, 10(-5) M) was also observed. Insulin (0.2 I.U./ml) was administered when the papillary muscle showed no response to electrical stimulation.(ABSTRACT TRUNCATED AT 250 WORDS)
 ...
PMID:Response of isolated guinea pig myocardium to insulin therapy during normothermia and graded hypothermia. 242 78

Twenty-four patients with single ventricle, six with single left (SLV) and 18 with single right (SRV) ventricle, who received a Blalock-Taussig (BT) shunt at an average age of 3.2 years were studied. Ventricular function was assessed angiographically by end-diastolic volume index (EDVI) and ejection fraction (EF), and attempts were made to measure ventricular mass index (VMI) and VM/EDV. In 14 patients, the preoperative and postoperative results (average 2.4 years after placement of BT shunt) were compared in SLV (n = 5) and SRV (n = 9) groups. The SLV group showed significant increases in EDVI, VMI, and VM/EDV without a significant change in EF. The SRV group showed significant increases in EDVI and VMI, while EF decreased and VM/EDV was unchanged. Late death from congestive heart failure occurred in five patients with SRV. Three patients with atrioventricular valve regurgitation suffered late death. Among the patients with SRV, the late death group had significantly lower preoperative EF and VM/EDV compared with the survivors (n = 13). All of those with a preoperative EF of less than 0.50 and a VM/EDV of less than 0.35 g/ml suffered late death. In summary, patients with SRV appear to fail to develop adaptational hypertrophy to volume loading after the BT shunt procedure, with concomitant depression in ventricular pump function. Also, late cardiac failure seems likely to develop when low EF and VM/EDV are present preoperatively.
 ...
PMID:Analysis of the effects of the Blalock-Taussig shunt on ventricular function and the prognosis in patients with single ventricle. 244 94

This study describes the effects of beta-receptor blockade on systemic hemodynamics and regional blood flows during acute ischemic heart failure in dogs. Depression of left ventricular (LV) function was induced by embolization of the left main coronary artery and was evidenced by a significant increase in LV end-diastolic pressure (LVEDP) and decrease in LV dP/dtmax and in cardiac output. Measurements of femoral, renal, mesenteric, and carotid blood flows showed a redistribution of cardiac output during failure. Femoral blood flow decreased to a greater extent than did cardiac output, carotid blood flow decreased in proportion to cardiac output, whereas mesenteric and renal blood flows were moderately reduced in relation to the decrease in cardiac output. Administration of 0.125 mg of propranolol intravenously (i.v.) significantly decreased the performance of the failing left ventricle. Reductions in cardiac output were accompanied by reductions in the peripheral circulations. The decrease in flow was evenly distributed in the femoral, mesenteric, and carotid vascular beds, while there was a relative preservation of renal blood flow. When the dose of propranolol was increased to 0.5 mg/kg, there were no further significant hemodynamic alterations.
 ...
PMID:Effects of beta-receptor blockade on regional blood flows during acute left ventricular failure in dogs. 245 Feb 33


<< Previous 1 2 3 4 5 6 7 8 9 10 Next >>