pituitrin and Cardiac-Output--Low

The authors summarize some current views regarding the pharmacologic therapies of hepatorenal and cardiorenal syndromes, respectively. A common pathogenetic background of the two edematous disorders is outlined, consisting in reduced effective blood arterial volume ‑ due to the splanchnic vasodilation in the hepatorenal syndrome (HRS) and to the fall in cardiac output and the rise in central venous pressure in cardiorenal syndrome (CRS). In both diseases, arterial underfilling elicits multiple water- and sodium- retentive mechanisms, by activating sympathetic nervous system and stimulating both rennin-angiotensin-aldosterone and vasopressin systems. These neurohormonal adjustments subsequently concur to a vasomotor nephropathy which originates - as a same kind of vasoconstrictor reflex renal response ‑ from the splanchnic vasodilation, in the case of liver cirrhosis, or from the fall in renal perfusion and filtration gradients in the case of cardiorenal syndrome. Despite these pathogenetic similarities, the renal insufficiency of HRS compared to that of CRS is treated using diametrically opposite approaches: actually withdrawal of diuretics and administration of vasoconstrictor agents is the first choice in the case of HRS, while CRS is tackled by forcing diuretic regimen and by continuing vasodilator treatment with ACE-inhibitors. The pros and cons of these strategies ‑ which are still matter of debate among the physicians and researchers ‑ are then succinctly presented and discussed.

Topics: Angiotensin-Converting Enzyme Inhibitors; Cardiac Output, Low; Cardio-Renal Syndrome; Diuretics; Hepatorenal Syndrome; Humans; Renin-Angiotensin System; Vasoconstrictor Agents; Vasodilation; Vasodilator Agents; Vasopressins

Topics: Amino Acid Sequence; Animals; Calcium Signaling; Cardiac Output, Low; Cytokines; Endothelins; Humans; Hypertension; Mineralocorticoid Receptor Antagonists; Molecular Sequence Data; Natriuretic Peptide, Brain; Peptide Hydrolases; Renin-Angiotensin System; Sodium-Hydrogen Exchangers; Vasopressins

Vasopressin, like all the other neuro-hormonal systems, is activated in patients with cardiac insufficiency. Vasopressin attaches itself to two distinct specific receptors. It is through the intermediary of the renal V2 receptor, controlling the reabsorption of water by the collecting duct, that vasopressin finely regulates the blood osmolarity. The ubiquitous V1a receptor is essentially responsible for the vasoconstrictor effect of the hormone. Some specific antagonists for these two receptors have now been evaluated in various pathologies such as SIADH, cirrhosis or cardiac insufficiency. In this situation the mixed antagonists, anti-V1a-V2, seem more appropriate than the specific V1a or V2 receptor antagonists. The results of the first human studies are encouraging. The mixed antagonists reduce the pulmonary capillary pressure and increase diuresis and clearance of free water. But further studies are necessary to confirm these results and to demonstrate a reduction in morbidity and mortality before adding this class of medication to the therapeutic arsenal for our patients with cardiac insufficiency.

Topics: Antidiuretic Hormone Receptor Antagonists; Cardiac Output, Low; Clinical Trials as Topic; Hemodynamics; Humans; Morbidity; Mortality; Receptors, Vasopressin; Vasopressins; Water-Electrolyte Balance

Topics: Atrial Natriuretic Factor; Cardiac Output, Low; Diastole; Endothelins; Hormones; Humans; Myocardial Stunning; Renin-Angiotensin System; Sympathetic Nervous System; Vasopressins

Sodium and water retention is characteristic of edematous disorders including cardiac failure, cirrhosis, nephrotic syndrome and pregnancy. In recent years the use of a sensitive radioimmunoassay for plasma vasopressin has implicated the role of nonosmotic vasopressin release in the water retention of these edematous disorders. In experimental studies and studies in humans it has been found that the nonosmotic release of vasopressin is consistently associated with activation of the sympathetic nervous and renin-angiotensin-aldosterone systems. Moreover, the sympathetic nervous system has been shown to be involved in the nonosmotic release of vasopressin (carotid and aortic baroreceptors) and activation of the renin-angiotensin system (renal beta-adrenergic receptors). These findings have led to our proposal that body fluid volume regulation involves the dynamic interaction between cardiac output and peripheral arterial resistance. In this context neither total extracellular fluid (ECF) volume nor blood volume are determinants of renal sodium and water excretion. Rather, renal sodium and water retention is initiated by either a fall in cardiac output (e.g. ECF volume depletion, low-output cardiac failure, pericardial tamponade or hypovolemic nephrotic syndrome) or peripheral arterial vasodilation (e.g. high-output cardiac failure, cirrhosis, pregnancy, sepsis, arteriovenous fistulae and pharmacologic vasodilators). With a decrease in effective arterial blood volume (EABV), initiated by either a fall in cardiac output or peripheral arterial vasodilation, the acute response involves vasoconstriction mediated by angiotensin, sympathetic mediators and vasopressin. The slower response to restoring EABV involves vasopressin-mediated water retention and aldosterone-mediated sodium retention. The renal vasoconstriction which accompanies those states that decrease EABV, by either decreasing cardiac output or causing peripheral arterial vasodilation, limits the distal tubular delivery of sodium and water thus maximizing the water-retaining effect of vasopressin and impairing the normal escape from the sodium-retaining effects of aldosterone. The elevated glomerular filtration rate and filtered sodium load in pregnancy allows increased distal sodium and water delivery in spite of a decrease in EABV, thus limiting edema formation during gestation.

Topics: Blood Volume; Cardiac Output; Cardiac Output, Low; Edema; Female; Fibrosis; Humans; Kidney; Natriuresis; Nephrotic Syndrome; Pre-Eclampsia; Pregnancy; Renin-Angiotensin System; Sympathetic Nervous System; Vascular Resistance; Vasodilation; Vasopressins

Depressed hemodynamics stimulates arginine vasopressin (AVP) release, but the relationship between plasma AVP levels (P-AVP) and cardiac parameters, especially in patients with stage D heart failure (HF) receiving guideline-directed medical therapy, has not examined. METHODS AND RESULTS: Data including P-AVP were obtained from 162 in-hospital patients with stage D HF and from 80 patients receiving ventricular assist device (VAD, n=46) or heart transplantation (HTx, n=34) at 3 months after surgery. In the HF group, considerably high P-AVP (5.9±6.1 pg/ml) negatively correlated with serum sodium concentration (S-Na, 135.3±5.8 mEq/L, r=-0.548 [P<0.01]) and cardiac index (CI, 2.2±0.5 L·min(-1)·m(-2), r=-0.458 [P<0.01]). After VAD/HTx treatment, improvement in the CI (2.7±0.5 L·min(-1)·m(-2)[P<0.01] vs. HF) was accompanied by normalization of serum sodium concentration (S-Na; 138.2±2.0 mEq/L [P<0.01] vs. HF) and suppressed release of AVP (1.7±3.4 pg/ml [P<0.01] vs. HF). P-AVP positively correlated with only S-Na (r=0.454 [P<0.01]), whereas no correlation was observed with CI after VAD/HTx treatment. P-AVP ≥5.3 pg/ml well predicted poor 2-year survival in HF group (60% [P<0.01] vs. 90%).. Low cardiac output stimulates AVP release via a non-osmotic process that results in hyponatremia and poor prognosis in patients with stage D HF. After sufficient recovery of cardiac output by cardiac replacement therapy, AVP release is suppressed and is mainly regulated by serum osmolality.

Topics: Adult; Aged; Cardiac Output, Low; Heart Failure; Humans; Hyponatremia; Middle Aged; Vasopressins; Water-Electrolyte Balance

The purpose of this study was to examine the renal effects of a V2 receptor arginine vasopressin (AVP) antagonist in heart failure.. Arginine vasopressin has been implicated in the renal water retention and dilutional hyponatremia associated with chronic heart failure.. We examined the effects of the oral, non-peptide, selective V2 receptor antagonist lixivaptan in 42 diuretic-requiring patients with mild-to-moderate heart failure in a randomized, double-blind, placebo-controlled, ascending single-dose study. After overnight fluid deprivation, patients received single-blind placebo on day -1 (baseline) and double-blind study medication (placebo [n = 12] or lixivaptan 10, 30, 75, 150, 250, or 400 mg [n = 5 per dose group]) on day 1, followed by 4 h of continued fluid restriction and additional 20 h with ad libitum fluid intake.. At all but the 10-mg dose, lixivaptan produced a significant and dose-related increase in urine volume over 4 h, compared with placebo. During 24 h, increases in urine volume ranged from 1.8 l with placebo to 3.9 l after the 400-mg lixivaptan dose (p < 0.01). These increases in urine volumes were accompanied by significant increases in solute-free water excretion. At higher doses, serum sodium was significantly increased; AVP antagonism was well tolerated in these patients.. These observations confirm a role for AVP in the renal water retention associated with heart failure and suggest that the V2 receptor antagonist lixivaptan may be a promising therapeutic agent for the treatment of heart failure.

Topics: Administration, Oral; Antidiuretic Hormone Receptor Antagonists; Cardiac Output, Low; Chronic Disease; Diuresis; Dose-Response Relationship, Drug; Double-Blind Method; Electrolytes; Female; Hormones; Humans; Male; Middle Aged; Osmolar Concentration; Severity of Illness Index; Sodium; Vasopressins

To examine if the neuroendocrine link between volume sensing and renal function is preserved in compensated chronic heart failure [HF, ejection fraction 0.29 +/- 0.03 (mean +/- SE)] we tested the hypothesis that intravascular and central blood volume expansion by 3 h of water immersion (WI) elicits a natriuresis. In HF, WI suppressed ANG II and aldosterone (Aldo) concentrations, increased the release of atrial natriuretic peptide (ANP), and elicited a natriuresis (P < 0.05 for all) compared with seated control. Compared with control subjects (n = 9), ANG II, Aldo, and ANP concentrations were increased (P < 0.05) in HF, whereas absolute and fractional sodium excretion rates were attenuated [47 +/- 16 vs. 88 +/- 15 micromol/min and 0.42 +/- 0.18 vs. 0.68 +/- 0.12% (mean +/- SE), respectively, both P < 0.05]. When ANG II and Aldo concentrations were further suppressed (P < 0.05) during WI in HF (by sustained angiotensin-converting enzyme inhibitor therapy, n = 9) absolute and fractional sodium excretion increased (P < 0.05) to the level of control subjects (108 +/- 34 micromol/min and 0.70 +/- 0.23%, respectively). Renal free water clearance increased during WI in control subjects but not in HF, albeit plasma vasopressin concentrations were similar in the two groups. In conclusion, the neuroendocrine link between volume sensing and renal sodium excretion is preserved in compensated HF. The natriuresis of WI is, however, modulated by the prevailing ANG II and Aldo concentrations. In contrast, renal free water clearance is attenuated in response to volume expansion in compensated HF despite normalized plasma AVP concentrations.

Topics: Aldosterone; Angiotensin II; Angiotensin-Converting Enzyme Inhibitors; Atrial Natriuretic Factor; Blood Pressure; Blood Volume; Cardiac Output, Low; Enzyme Inhibitors; Fluid Shifts; Glomerular Filtration Rate; Heart Rate; Humans; Immersion; Kidney; Male; Middle Aged; Natriuresis; Sodium; Urine; Vasopressins; Water-Electrolyte Balance

This study was conducted to evaluate the degree of neurohumoral activation around the time of hospital discharge after myocardial infarction.. Because pharmacologic interventions that block the effects of neurohumoral activation improve the prognosis after infarction, we hypothesized that widespread neurohumoral activation persists in some patients until at least the time of hospital discharge and that the determinants of activation vary from one system to another.. Five hundred nineteen patients in the Survival and Ventricular Enlargement Study (SAVE) had plasma neurohormones measured before randomization at a mean of 12 days after infarction. All patients had left ventricular dysfunction (left ventricular ejection fraction < or = 40%) but no overt heart failure.. Although all neurohormones except epinephrine were increased compared with values in age-matched control subjects, plasma norepinephrine (301 +/- 193 vs. 222 +/- 87 pg/ml, p < 0.001), renin activity (3.0 +/- 3.7 vs. 1.2 +/- 1.2 ng/ml per h, p < 0.001), arginine vasopressin (1.9 +/- 6.9 vs. 0.7 +/- 0.3 pg/ml, p < 0.001) and atrial natriuretic peptide (75 +/- 75 vs. 21 +/- 9 pg/ml, p < 0.001) values ranged from normal to very high, indicating a wide spectrum of neurohumoral activation. Activation of one system did not correlate with activation of another. The clinical and laboratory variables most closely associated with neurohumoral activation were Killip class, left ventricular ejection fraction, age and use of diuretic drugs. The association between neurohumoral activation and clinical and laboratory variables varied from one neurohormone to another.. Neurohumoral activation occurs in a significant proportion of patients at the time of hospital discharge after infarction. Which neurohormone is activated and which clinical and laboratory variables determine this activation vary from one neurohormone to another.

Topics: Aged; Aldosterone; Atrial Natriuretic Factor; Cardiac Output, Low; Dopamine; Female; Humans; Male; Middle Aged; Myocardial Infarction; Neurotransmitter Agents; Norepinephrine; Renin; Stroke Volume; Vasopressins; Ventricular Function, Left

Splanchnic vasodilation by inodilators is an argument for their use in critical cardiac dysfunction. To isolate peripheral vasoactivity from inotropy, such drugs were investigated, and contrasted to vasopressors, in a fixed low cardiac output (CO) model resembling acute cardiac dysfunction effects on the gastrointestinal tract. We hypothesized that inodilators would vasodilate and preserve the aerobic metabolism in the splanchnic circulation in low CO.. In anesthetized pigs, CO was lowered to 60% of baseline by partial inferior caval vein balloon inflation. The animals were randomized to placebo (n = 8), levosimendan (24 μg kg-1 bolus, 0.2 μg kg-1 min-1, n = 7), milrinone (50 μg kg-1 bolus, 0.5 μg kg-1 min-1, n = 7), vasopressin (0.001, 0.002 and 0.006 U kg-1 min-1, 1 h each, n = 7) or norepinephrine (0.04, 0.12, and 0.36 μg kg-1 min-1, 1 h each, n = 7). Hemodynamic variables including mesenteric blood flow were collected. Systemic, mixed-venous, mesenteric-venous, and intraperitoneal metabolites were analyzed.. Cardiac output was stable at 60% in all groups, which resulted in systemic hypotension, low superior mesenteric artery blood flow, lactic acidosis, and increased intraperitoneal concentrations of lactate. Levosimendan and milrinone did not change any circulatory variables, but levosimendan increased blood lactate concentrations. Vasopressin and norepinephrine increased systemic and mesenteric vascular resistances at the highest dose. Vasopressin increased mesenteric resistance more than systemic, and the intraperitoneal lactate concentration and lactate/pyruvate ratio.. Splanchnic vasodilation by levosimendan and milrinone may be negligible in low CO, thus rejecting the hypothesis. High-dose vasopressors may have side effects in the splanchnic circulation.

Topics: Animals; Cardiac Output, Low; Disease Models, Animal; Female; Gastrointestinal Tract; Male; Milrinone; Norepinephrine; Random Allocation; Simendan; Splanchnic Circulation; Swine; Vasodilator Agents; Vasopressins

Topics: Cardiac Output, Low; Heart Failure; Humans; Hyponatremia; Vasopressins; Water-Electrolyte Balance

Urocortin 1 (Ucn1) may be involved in the pathophysiology of heart failure (HF), but the impact of Ucn1 administration on progression of the disease is unknown. The aim of this study was to investigate the effects of Ucn1 in sheep from the onset of cardiac overload and during the subsequent development of HF. Eight sheep underwent two 4-day periods of HF induction by rapid left ventricular pacing (225 beats/min) in conjunction with continuous infusions of Ucn1 (0.1 microg.kg(-1).h(-1) iv) and a vehicle control (0.9% saline). Compared with control, Ucn1 attenuated the pacing-induced decline in cardiac output (2.43 +/- 0.46 vs. 3.70 +/- 0.89 l/min on day 4, P < 0.01) and increases in left atrial pressure (24.9 +/- 1.0 vs. 11.9 +/- 1.1 mmHg, P < 0.001) and peripheral resistance (38.7 +/- 9.4 vs. 25.2 +/- 6.1 mmHg.l(-1).min, P < 0.001). Ucn1 wholly prevented increases in plasma renin activity (4.02 +/- 1.17 vs. 0.87 +/- 0.1 nmol.l(-1).h(-1), P < 0.001), aldosterone (1,313 +/- 324 vs. 413 +/- 174 pmol/l, P < 0.001), endothelin-1 (3.8 +/- 0.5 vs. 2.0 +/- 0.1 pmol/l, P < 0.001), and vasopressin (10.8 +/- 4.1 vs. 1.8 +/- 0.2 pmol/l, P < 0.05) during pacing alone and blunted the progressive increases in plasma epinephrine (2,132 +/- 697 vs. 1,250 +/- 264 pmol/l, P < 0.05), norepinephrine (3.61 +/- 0.73 vs. 2.07 +/- 0.52 nmol/l, P < 0.05), and atrial (P < 0.05) and brain (P < 0.01) natriuretic peptide levels. Ucn1 administration also maintained urine sodium excretion (0.75 +/- 0.34 vs. 1.59 +/- 0.50 mmol/h on day 4, P < 0.05) and suppressed pacing-induced declines in creatinine clearance (P < 0.05). These findings indicate that Ucn1 treatment from the onset of cardiac overload has the ability to repress the ensuing hemodynamic and renal deterioration and concomitant adverse neurohumoral activation, thereby delaying the development of overt HF. These data strongly support a use for Ucn1 as a therapeutic option early in the course of the disease.

Topics: Aldosterone; Animals; Blood Pressure; Cardiac Output, Low; Corticotropin-Releasing Hormone; Endothelin-1; Epinephrine; Female; Heart Conduction System; Infusions, Intra-Arterial; Kidney; Norepinephrine; Renin; Sheep; Urocortins; Vascular Resistance; Vasopressins; Ventricular Function, Left

Because of the possibility of vasopressin-mediated coronary vasospasm, this study was designed to assess effects of vasopressin compared to saline placebo on left anterior descending (LAD) coronary artery blood flow. Twelve anaesthetized domestic swine were prepared for LAD coronary artery blood flow measurement with ultrasonic flow probes, using cardiopulmonary by-pass adjusted to 10% of the prearrest cardiac output. This 10% value approximates that reported for cardiac output during conventional closed-chest CPR. After 4 min of untreated ventricular fibrillation, and 3 min of cardiopulmonary by-pass blood flow, 12 pigs were randomly assigned to receive intravenously, every 5 min, either vasopressin (0.4, 0.4, and 0.8 U/kg; n = 6) or saline placebo (n = 6). The mean +/- S.D. LAD coronary artery blood flow in the vasopressin and placebo pigs was comparable before cardiac arrest, and during cardiopulmonary by-pass low flow; but increased significantly (P < 0.05) 90 s after each of three vasopressin injections compared to placebo (78 +/- 1 versus 42 +/- 2 ml/min; 62 +/- 2 versus 36 +/- 1 ml/min; and 54 +/- 1 versus 27 +/- 1 ml/min), respectively. Coronary vascular resistance decreased significantly (P < 0.05 ) 90 s after each of three vasopressin and placebo injections. In this model, repeated bolus administration of vasopressin, given during simulated extremely low cardiac output improved LAD coronary artery blood flow to prearrest levels without affecting coronary vascular resistance.. during extremely low blood flow using cardiopulmonary by-pass, vasopressin improves LAD coronary artery blood flow without affecting coronary vascular resistance.

Topics: Animals; Cardiac Output, Low; Cardiopulmonary Bypass; Coronary Circulation; Female; Male; Swine; Vascular Resistance; Vasopressins

Our previous studies indicated that in the human paraventricular (PVN) and supraoptic (SON) nuclei, tyrosine hydroxylase (TH)--the first and rate-limiting enzyme in catecholamine synthesis--is localized mainly in magnocellular neurons and that antemortem factors regulate its expression. The purpose of the present study was to investigate the distribution of TH-immunoreactive (TH-IR) perikarya of the hypothalami of a large sample of well-documented adult subjects without neurological, psychiatric or endocrinological disease in order to identify factors that could regulate the expression of TH in the human neurosecretory neurons. Our material consisted of the hypothalami of 38 subjects studied immunohistochemically for TH using the peroxidase-antiperoxidase method. Striking individual differences were observed among the subjects studied concerning the number and distribution of TH-IR perikarya within the PVN and SON. These differences were evident throughout the entire rostrocaudal length of the hypothalamus and appeared to be related neither to the age or sex of the subjects nor to the postmortem interval or staining procedures. In the sample studied, a large number of TH-IR perikarya were observed specifically in all subjects that had suffered from right-sided heart failure due to pulmonary hypertension, liver cirrhosis or dehydration. In all the above illnesses, increased production and secretion of vasopressin (VP) are reported to occur due to a decrease in 'effective' blood volume or to osmotic stimulation. We conclude that somatic illnesses leading to prolonged osmotic or nonosmotic stimulation of VP release may induce increased expression of TH immunoreactivity in the human neurosecretory neurons related to neuronal activation.

Topics: Adult; Aged; Aged, 80 and over; Cardiac Output, Low; Dehydration; Disease; Female; Humans; Hypertension, Pulmonary; Immunohistochemistry; Liver Cirrhosis; Male; Middle Aged; Neurons; Osmosis; Paraventricular Hypothalamic Nucleus; Supraoptic Nucleus; Time Factors; Tyrosine 3-Monooxygenase; Vasopressins

We hypothesized that excessive sympathoactivation observed during strenuous exercise in subjects with heart failure (HF) may result from tonic activation of the muscle metaboreflex (MMR) via hypoperfusion of active skeletal muscle. We studied MMR responses in dogs during treadmill exercise by graded reduction of terminal aortic blood flow (TAQ) before and after induction of HF by rapid ventricular pacing. At a low workload, in both control and HF experiments, large decreases in TAQ were required to elicit the MMR pressor response. During control experiments, this pressor response resulted from increased cardiac output (CO), whereas in HF CO did not increase; thus the pressor response was solely due to peripheral vasoconstriction. In HF, MMR activation also induced higher plasma levels of vasopressin, norepinephrine (NE), and renin. At a higher workload, in control experiments any reduction of TAQ elicited MMR pressor responses. In HF, before any vascular occlusion, TAQ was already below MMR control threshold levels and reductions in TAQ again did not result in higher CO; thus SAP increased via peripheral vasoconstriction. NE rose markedly, indicating intense sympathetic activation. We conclude that in HF, the MMR is likely tonically active at moderate workloads and contributes to the tonic sympathoactivation.

Topics: Animals; Aorta; Biomechanical Phenomena; Blood Pressure; Cardiac Output; Cardiac Output, Low; Dogs; Female; Male; Muscle, Skeletal; Norepinephrine; Physical Exertion; Reflex; Regional Blood Flow; Renin; Vasopressins

Pleural effusions are a troublesome complication following bidirectional Glenn and Fontan procedures. It was our hypothesis that effusions may be related to alterations in hormones that regulate fluid homeostasis. We made serial determinations (by radioimmunoassay) of antidiuretic hormone, cortisol, aldosterone, angiotensin II, and renin in patients undergoing bidirectional Glenn (n = 16) and Fontan procedures (n = 24). There were six patients who developed effusions following surgery. These patients had a different endocrinological pattern characterized by persistent elevation in renin (28 +/- 9 vs 9 +/- 5 ng/mL per hour, p < 0.01) and angiotensin II (110 +/- 33 vs 33 +/- 14 ng/L, p < 0.01) on the fifth postoperative day as compared to patients who did not develop effusions. These data demonstrate that patients who develop effusions following bidirectional Glenn and Fontan procedures have activation of their renin-angiotensin system.

Topics: Adolescent; Adult; Aldosterone; Angiotensin II; Cardiac Output, Low; Cardiac Surgical Procedures; Female; Humans; Hydrocortisone; Male; Pleural Effusion; Postoperative Complications; Renin; Vasopressins

The systemic and regional hemodynamic effects of arginine vasopressin receptor antagonism (AVPA) and angiotensin-converting enzyme inhibition (ACEi) were examined in rabbits with acute left ventricular failure induced by repetitive direct current (DC) shock. Hemodynamic measurements in 24 rabbits 24 h after DC shock compared with 6 sham-operated controls demonstrated a lowered cardiac output (602 +/- 26 vs. 920 +/- 35 ml/min, P less than 0.01), increased left ventricular end-diastolic pressure (LVEDP, 13.6 +/- 1.3 vs. 1.9 +/- 0.5 mmHg, P less than 0.01) and a raised peripheral resistance (9,734 +/- 495 vs. 6,479 +/- 305 dyn.s.cm-5, P less than 0.01). Cerebral blood flow was not altered in rabbits with acute left ventricular failure but intestinal (29 +/- 2 vs. 53 +/- 9 ml/min, P less than 0.01) and renal (82 +/- 6 vs. 130 +/- 8 ml/min, P less than 0.01) blood flows were significantly reduced. No hemodynamic changes were observed after AVPA alone in the acute heart failure group and ACEi alone reduced LVEDP and increased renal vascular conductance. Treatment with both drugs (i.e., AVPA + ACEi) resulted in a significant increase in cardiac output (21%) and a decrease in blood pressure (19%) and peripheral resistance (34%) and restored renal and intestinal blood flows to near normal levels. Thus both vasopressin and angiotensin contribute to the overall increase in peripheral resistance in this model and to the decrease in intestinal and renal blood flow observed. Presumably blockade of one system produced little hemodynamic change because of compensatory increases in the other system.

Topics: Acute Disease; Angiotensin II; Angiotensin Receptor Antagonists; Angiotensin-Converting Enzyme Inhibitors; Animals; Arginine Vasopressin; Blood Pressure; Cardiac Output, Low; Electroshock; Female; Heart Ventricles; Hemodynamics; Hormones; Male; Rabbits; Receptors, Vasopressin; Regional Blood Flow; Vasopressins

It has been hypothesized that a decreased activity of vagal afferents might contribute to the activation of neurohumoral systems in congestive heart failure. Therefore, we studied the effects of vagal nerve blockade by local anesthesia on neurohormones in six conscious dogs before and after induction of heart failure by rapid right ventricular pacing (250 beats/min, 10 days). In healthy dogs, vagal blockade significantly increased plasma vasopressin levels (from 1.5 +/- .6 to 13.7 +/- 10.5 pg/ml, p less than 0.02), without significantly affecting plasma catecholamines and renin. After 10 days of pacing, mean arterial pressure and cardiac output were decreased, right atrial and pulmonary arterial pressures and plasma levels of norepinephrine, dopamine, and atrial natriuretic peptide were increased. In this state, vagal blockade significantly increased plasma renin activity (from 1.52 +/- .43 to 3.18 +/- .54 ngAI/ml/h, p less than 0.02) and plasma vasopressin (from 4.2 +/- 3.3 to 89.1 +/- 54.9 pg/ml, p less than 0.02), this increase being significantly higher than in healthy dogs. We conclude that in these dogs with low cardiac output state, which resembles early heart failure, vagal afferent activity is increased and effectively suppresses renin and vasopressin. This does not exclude the possibility that in later stages of heart failure vagal afferent dysfunction may develop, resulting in neurohumoral disinhibition.

Topics: Aldosterone; Animals; Autonomic Nerve Block; Blood Pressure; Cardiac Output, Low; Cardiac Pacing, Artificial; Catecholamines; Dogs; Heart Rate; Renin; Vagus Nerve; Vasopressins

Plasma atrial natriuretic factor, aldosterone, renin activity, and antidiuretic hormone were studied in low output heart failure syndromes: cardiogenic shock in ten patients with acute myocardial infarction of the anterior wall (first group), hypovolemic shock after melena from peptic ulcer in ten subjects (second group), and hypotension with bradycardia syndrome in ten patients with acute myocardial infarction of the inferior wall (third group). Circulating atrial natriuretic factor in patients with cardiogenic shock (102.4 +/- 7.4 pg/ml) was significantly higher than in healthy volunteers matched for sex and age (8.4 +/- 0.3 pg/ml). In these patients there was a positive correlation between atrial natriuretic factor and central venous pressure values. Atrial natriuretic factor and central venous pressure values in the second and third groups were within normal range. Plasma aldosterone was high in all groups, plasma renin activity was elevated in the first and third groups, and high antidiuretic hormone was observed in the first and second groups. These findings indicate that in low output heart failure syndromes only hemodynamic changes affecting the atria stimulate atrial natriuretic factor release. No correlations were found between plasma atrial natriuretic factor and other hormones. In particular, high atrial natriuretic factor levels in the patients with cardiogenic shock did not inhibit release of aldosterone, renin, or antidiuretic hormone. It may be surmised that in these patients the hemodynamic effects override the inhibitory effects of atrial natriuretic factor.

Topics: Adult; Aldosterone; Atrial Natriuretic Factor; Blood Volume; Bradycardia; Cardiac Output, Low; Female; Heart Failure; Humans; Male; Melena; Middle Aged; Myocardial Contraction; Myocardial Infarction; Peptic Ulcer Hemorrhage; Renin; Shock, Cardiogenic; Vascular Resistance; Vasopressins; Venous Pressure

The aim of this paper was to study plasma atrial natriuretic factor, renin activity, aldosterone and antidiuretic hormone in low-output heart failure syndromes such as cardiogenic shock, hypovolemic shock and hypotension with bradycardia syndrome. A total of 30 patients were investigated: 10 with cardiogenic shock due to acute myocardial infarction of the anterior wall (systolic and diastolic blood pressure 56.0 +/- 3.7/40.5 +/- 2.0 mmHg; heart rate 119.7 +/- 1.2 beats/min; central venous pressure 16.2 +/- 0.6 cmH2O) (I group), 10 with hypovolemic shock induced by melena in peptic ulcer (systolic and diastolic blood pressure 74.5 +/- 1.5/57.5 +/- 1.7 mmHg; heart rate 111.0 +/- 1.4; central venous pressure 6.3 +/- 0.5 cmH2O) (II group), 10 with hypotension with bradycardia syndrome which occurred in patients during acute myocardial infarction of the inferior wall (systolic and diastolic blood pressure 71.9 +/- 2.0/58.0 +/- 2.6 mmHg; heart rate 52.0 +/- 2.2 beats/min; central venous pressure 4.6 +/- 0.4 cmH2O) (III group). Plasma atrial natriuretic factor values were measured using radioimmunoassay after chromatographic pre-extraction; plasma renin activity, aldosterone and antidiuretic hormone values were calculated using radioimmunoassay. Circulating atrial natriuretic factor was significantly (p less than 0.01) higher in patients with cardiogenic shock (102.4 +/- 7.4 pg/ml) than in healthy volunteers (8.4 +/- 0.3 pg/ml). In the former there was a positive correlation between atrial natriuretic factor and central venous pressure values. Atrial natriuretic factor and central venous pressure values in the IInd and IIIrd groups of patients were in the normal range.(ABSTRACT TRUNCATED AT 250 WORDS)

Topics: Adult; Aged; Aldosterone; Atrial Natriuretic Factor; Bradycardia; Cardiac Output, Low; Female; Hemodynamics; Humans; Hypotension; Male; Middle Aged; Myocardial Infarction; Renin; Shock; Shock, Cardiogenic; Vasopressins

Application of isolated ultrafiltration (IUF) of blood in 70 out of 100 patients with refractory heart failure (HF) made it possible, acting on some mechanisms of water excretion disorders, to attain the compensation for the HF signs. At the same time the correction of the manifestations of secondary hyperaldosteronism, hypoproteinemia, hyperbilirubinemia, and azotemia was attained only thanks to the presence of the functional reserves of the liver and kidneys. In 35 patients with cachectic HF, IUF failure was determined by marked cardial liver cirrhosis together with depletion of the functional reserves of the cardiovascular system. The lack of sufficient diuresis, hyponatremia, hypoproteinemia, and hyperbilirubinemia may be unfavourable prognostic signs despite the reduction of HF intensity consequent on IUF.

Topics: Adult; Aged; Aldosterone; Cardiac Output, Low; Diuresis; Hematocrit; Hemofiltration; Humans; Middle Aged; Natriuresis; Potassium; Vasopressins