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PubMed2003

Antagonism of the acute hemodynamic effects of captopril in decompensated congestive heart failure by aspirin administration.

The concomitant use of angiotensin-converting enzyme inhibitors and aspirin may cause pharmacological antagonism. Hence we examined the effect of aspirin on the neurohormonal function and hemodynamic response to captopril in heart failure patients. Between April 1999 and August 2000, 40 patients were randomized into four equal groups: 1) captopril, 2) aspirin, 3) captopril-aspirin: captopril was given alone on the first day, followed by aspirin on the remaining days, and 4) aspirin-captopril: aspirin was given alone on the first day, followed by captopril on the remaining days. Hemodynamic, norepinephrine and prostaglandin measurements were performed pre- and post-medication for 4 days. Captopril (50 mg) was given orally every 8 h and 300 mg aspirin was given on the first day, and 100 mg/day thereafter. In the captopril group and only on the first day of captopril-aspirin, captopril produced increases in cardiac index (2.1 +/- 0.6 to 2.5 +/- 0.5 l min-1 m-2, P<0.0001), and reduced peripheral vascular resistance (1980 +/- 580 to 1545 +/- 506 dyn s-1 cm-5/m , P<0.0001) and pulmonary wedge pressure (20 +/- 4 to 15 +/- 4 mmHg, P<0.0001). In contrast, aspirin alone or associated with captopril showed no significant hemodynamic changes. Norepinephrine decreased (P<0.02) only in the captopril group. Prostaglandin levels did not differ significantly among groups. Thus, aspirin compromises the short-term hemodynamic and neurohormonal effects of captopril in patients with acute decompensated heart failure.

Aged↗
PubMed1982

Long-term follow-up of patients who have undergone valve replacements for acquired valvular disease: a clinical and hemodynamic study.

Thirty-three cases, comprizing 5 of mitral regurgitation (MR), 11 of mitral stenosis (MS), 11 of aortic regurgitation (AR) and 6 of AR and mitral steno-regurgitation (MSR), underwent both preoperative and postoperative heart catheterization in association with a muscle exercise test. Comparisons were made between preoperative and postoperative clinical symptoms, hemodynamics and cardiac functions. The following results were obtained: 1) Improvements in clinical symptoms and hemodynamics at rest were observed in all but two patients. 2) Abnormalities in hemodynamics were obtained after the muscle exercise test, even in cases exhibiting normal hemodynamics at rest. 3) An increase in pulmonary artery mean pressure was noted in MR and MS groups after the muscle exercise test. 4) The cardiac function index values in both the MR and MS groups showed lower levels than those in both the AR and AR + MSR groups. 5) The presence of atrial fibrillation and extent of myocardial fibrosis were related to improvements in postoperative cardiac functions.

Adult↗
PubMed2005

Endothelial nitric oxide synthase gene/gender interactions and the renal hemodynamic response to angiotensin II.

Endothelial function is dependent on the generation of nitric oxide (NO) by the enzyme endothelial NO synthase (eNOS). One functional coding polymorphism of the eNOS gene (G894-->T) is associated with reduced enzyme activity, increased coronary heart disease, and the development of end-stage renal failure. Because gender and renin-angiotensin system activation also play key roles in the development of renal and cardiovascular disease and because NO plays a role in the response to angiotensin II (AngII), it was hypothesized that the eNOS gene G894-->T polymorphism would be a determinant of the systemic and renal vascular response to AngII. Fifty young, healthy, normotensive individuals who were on a controlled sodium and protein diet for 1 wk underwent assessment of BP and renal hemodynamic function at baseline and during AngII infusion (4 ng/kg per min for 45 min). Participants were genotyped for the eNOS gene G894-->T polymorphism and then segregated into groups on the basis of gender and genotype (GG versus GT/TT). Baseline values for renal blood flow, effective renal plasma flow, and GFR were lower in men with the T allele compared with men who were homozygous for the G allele (P = 0.03), but the polymorphism was not associated with renal hemodynamic function in women. The BP responses to AngII were similar in men and women regardless of genotype. Both multivariate linear regression and analysis of covariance (ANCOVA) revealed a relationship between gender and genotype. Men with the GT/TT genotype exhibited a significantly greater decrease in GFR (P = 0.04) in response to AngII than did those with the GG genotype. This association was not observed in women. The eNOS gene G894-->T polymorphism is a determinant of both baseline renal hemodynamic function and the hemodynamic response to AngII in men but not in women.

Adult↗
PubMed2004

Image-based computational fluid dynamics: a new paradigm for monitoring hemodynamics and atherosclerosis.

Complex blood flow dynamics are thought to play a key role in the development and treatment of atherosclerosis; however, the exact nature of this role is incompletely understood owing to the practical difficulties associated with measuring important local hemodynamic factors, notably wall shear stresses, in vivo. Only recently has it become possible to consider mapping these hemodynamic factors in a prospective, patient-specific manner via the coupling of in vivo medical imaging and computational fluid dynamics (CFD) modelling. CFD models derived from intravascular ultrasound have already been used to elucidate the role that hemodynamic forces play in mechanical and pharmacological interventions for coronary atherosclerosis. CFD models derived from magnetic resonance imaging and three-dimensional ultrasound provide a less invasive window into more superficial vessels such as the carotid bifurcation, and thus are promising tools for clarifying the role of, and eventually exploiting, purported local geometric and hemodynamic risk factors for atherosclerosis and its response to therapeutic options. Efforts to improve the ease and robustness with which these models are constructed have led to concomitant improvements in accuracy and precision, data for which are presented to facilitate estimation of sample sizes for future studies. Current limitations and anticipated future directions for these powerful new tools are discussed.

Arteriosclerosis↗
PubMed1995

Duplex sonography after transjugular intrahepatic portosystemic shunts (TIPS): normal hemodynamic findings and efficacy in predicting shunt patency and stenosis.

OBJECTIVE: Portal hemodynamics are altered by placement of a transjugular intrahepatic portosystemic shunt (TIPS). Normal duplex sonographic findings after TIPS placement and hemodynamic alterations indicating shunt failure have not yet been well described. The purposes of this study were to determine normal hemodynamic changes on duplex sonography after TIPS placement and to assess the efficacy of duplex sonography in detecting shunt dysfunction. SUBJECTS AND METHODS: Forty patients underwent TIPS placement and were entered into a study that included routine sonographic evaluation and portal venography at regular intervals. Portal venography was also performed if shunt velocities on duplex sonography changed from the baseline, which raised the question of shunt stenosis or occlusion. The pre-TIPS duplex sonographic study included determination of patency, velocity, and flow direction in the main, right, and left portal veins and in the hepatic artery. Follow-up sonography included the pre-TIPS examination in addition to velocity determinations in three segments of the shunt. Correlation was made between 82 concurrent sonographic and portal venographic studies. RESULTS: High-velocity blood flow (mean peak velocity, 135-200 cm/sec) was consistently seen within patent, well-functioning shunts. Hepatic artery peak systolic velocities increased from 79 cm/sec before TIPS placement to 131 cm/sec after TIPS placement (p < .001). Main portal vein velocities increased from 21.8 cm/sec before TIPS placement to 41.5 cm/sec after TIPS placement (p < .001). When compared with portal venography, duplex sonography was 98% sensitive and 100% specific in predicting the presence of blood flow within the stent. Sonography was highly sensitive and specific for detecting stent stenosis. Final sonographic criteria for shunt stenosis in angiographically documented cases were low-velocity shunt flow (< or = 60 cm/sec) in the entire stent, or low-velocity shunt flow with an associated focal velocity elevation. CONCLUSION: Consistent changes in portal venous and hepatic arterial hemodynamics are normally seen on duplex sonography after placement of a TIPS. Duplex sonography accurately predicts shunt patency and dysfunction when compared with portal venography. Duplex sonography is an effective, noninvasive method of evaluating shunt function and should be considered for use as the primary imaging technique in routine follow-up after TIPS placement.

Adolescent↗
PubMed1989

Prevention of hemodynamic and vascular albumin filtration changes in diabetic rats by aldose reductase inhibitors.

This study investigated hemodynamic changes in diabetic rats and their relationship to changes in vascular albumin permeation and increased metabolism of glucose to sorbitol. The effects of 6 wk of streptozocin-induced diabetes and three structurally different inhibitors of aldose reductase were examined on 1) regional blood flow (assessed with 15-microns 85Sr-labeled microspheres) and vascular permeation by 125I-labeled bovine serum albumin (BSA) and 2) glomerular filtration rate (assessed by plasma clearance of 57Co-labeled EDTA) and urinary albumin excretion (determined by radial immunodiffusion assay). In diabetic rats, blood flow was significantly increased in ocular tissues (anterior uvea, posterior uvea, retina, and optic nerve), sciatic nerve, kidney, new granulation tissue, cecum, and brain. 125I-BSA permeation was increased in all of these tissues except brain. Glomerular filtration rate and 24-h urinary albumin excretion were increased 2- and 29-fold, respectively, in diabetic rats. All three aldose reductase inhibitors completely prevented or markedly reduced these hemodynamic and vascular filtration changes and increases in tissue sorbitol levels in the anterior uvea, posterior uvea, retina, sciatic nerve, and granulation tissue. These observations indicate that early diabetes-induced hemodynamic changes and increased vascular albumin permeation and urinary albumin excretion are aldose reductase-linked phenomena. Discordant effects of aldose reductase inhibitors on blood flow and vascular albumin permeation in some tissues suggest that increased vascular albumin permeation is not entirely attributable to hemodynamic changes. We hypothesize that 1) increases in blood flow may reflect impaired contractile function of smooth muscle cells in resistance arterioles and 2) increases in vascular 125I-BSA permeation and urinary albumin excretion reflect impaired vascular barrier functional integrity in addition to increased hydraulic conductance secondary to microvascular hypertension associated with decreased vascular resistance.

Albuminuria↗
PubMed2005

Hemodynamic effects of orally administered carvedilol in healthy conscious dogs.

OBJECTIVE: To evaluate the hemodynamic effects of orally administered carvedilol in healthy dogs with doses that might be used to initiate treatment in dogs with congestive heart failure. ANIMALS: 24 healthy dogs. PROCEDURE: Dogs were randomly allocated to receive carvedilol PO at a dose of 1.56, 3.125, or 12.5 mg, twice daily for 7 to 10 days; 6 dogs served as controls. Investigators were blinded to group assignment. Hemodynamic variables were recorded prior to administration of the drug on day 1 and then 2, 4, and 6 hours after the morning dose on day 1 and days 7 to 10. Change in heart rate after IV administration of 1microg of isoproterenol/kg and change in systemic arterial blood pressure after IV administration of 8 microg of phenylephrine/kg were recorded 2 and 6 hours after administration of carvedilol. RESULTS: Administration of carvedilol did not significantly affect resting hemodynamic variables or response to phenylephrine. The interaction of day and carvedilol dose had a significant effect on resting heart rate, but a significant main effect of carvedilol dose on resting heart rate was not detected. Increasing carvedilol dose resulted in a significant linear decrease in heart rate response to isoproterenol. CONCLUSIONS AND CLINICAL RELEVANCE: In healthy conscious dogs, orally administered carvedilol at mean doses from 0.08 to 0.54 mg/kg given twice daily did not affect resting hemodynamics. Over the dose range evaluated, there was a dose-dependent attenuation of the response to isoproterenol, which provided evidence of beta-adrenergic receptor antagonism.

Administration, Oral↗
PubMed1997

Effects of endoscopic variceal ligation on systemic and splanchnic hemodynamics in patients with cirrhosis.

It has been shown that patients with cirrhosis and portal hypertension have hyperdynamic systemic and splanchnic circulation. This study was designed to assess how endoscopic variceal ligation may influence systemic and splanchnic hemodynamics. Sixteen patients with cirrhosis and esophageal varices were studied. Cardiac output and flow volume of the portal vein and the superior mesenteric artery were determined by means of duplex Doppler ultrasonography. Mean arterial pressure was also recorded. These hemodynamic measurements were performed before and after initial (3 days after initial session) and repeated (7 days after last session) variceal ligation. No significant changes in cardiac output and mean arterial pressure were found after either initial or repeated variceal ligation. Thus, systemic vascular resistance was not modified. In splanchnic hemodynamics, portal vein blood flow significantly increased after initial variceal ligation (27%, P < 0.01) but it returned to the baseline value after repeated variceal ligation. In contrast, superior mesenteric artery blood flow significantly decreased after initial variceal ligation (17%, P < 0.01) and it returned to the baseline value after repeated variceal ligation. Effect of variceal ligation on splanchnic hemodynamics is transient and variceal ligation has very little effect on systemic circulation. Thus, patients with cirrhosis underwent repeated variceal ligation still have abnormal systemic and splanchnic circulation.

Aged↗
PubMed1990

Gastric hemodynamic disturbance induced by hemorrhagic shock in rats. Role of platelet-activating factor.

The role of platelet-activating factor (PAF) in the induction of rat gastric mucosal damage by ischemia-reperfusion was examined with reference to hemodynamic characteristics. Gastric mucosal hemodynamics was measured continuously, using laser-Doppler flowmetry and reflectance spectrophotometry. Not only gastric mucosal damage but also characteristic hemodynamic change--that is, ischemia with congestion--was observed in the PAF infusion and reperfusion periods of the ischemia-reperfusion model. CV-6209, a specific PAF antagonist, significantly alleviated gastric mucosal damage and hemodynamic disturbance induced by ischemia-reperfusion. These results strongly suggest that PAF is a potent mediator of gastric mucosal damage during reperfusion in the ischemia-reperfusion model.

Animals↗
PubMed1983

Hemodynamic actions of diuretic agents.

The blood pressure lowering effect of diuretics in hypertensive disease is well documented. The hemodynamic actions underlying this antihypertensive effect differ in the early phase from the effects observed during long-term treatment. This article first describes new experiments on the hemodynamic effects of three diuretics, viz. hydrochlorothiazide, chlorthalidon and furosemide in conscious, chronically instrumented spontaneously hypertensive rats. This animal model was chosen in view of its good applicability for the study of the hemodynamics of antihypertensive drug action. Results show a marked early fall in stroke volume and cardiac index with all three diuretics. Mean arterial blood pressure was decreased only after a delay of several hours, because of an early large increase in total peripheral resistance. This article furthermore discusses possible mechanisms involved in the long-term return of peripheral resistance close to or below pre-treatment values. On the basis of data in the literature it is concluded that adaptation of baroreceptor reflexes, auto-regulatory responses of the peripheral vascular resistance and enhanced production of endogeneous vasodilator substances play an increasingly important role during the long-term hemodynamic actions of diuretic agents.

Animals↗
PubMed1989

Effect of arotinolol on hemodynamics and plasma atrial natriuretic peptide at rest and during stress in spontaneously hypertensive rats.

We investigated the effects of chronic treatment with arotinolol, a beta-blocker with weak alpha-blocking potency, on hemodynamics and plasma levels of catecholamines and atrial natriuretic peptide (ANP) at rest and during stress in spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) rats. At rest, arotinolol treatment decreased mean arterial pressure (MAP), cardiac index (CI) and heart rate (HR), with no changes in total peripheral resistance index or regional hemodynamics in SHR. Acute stress caused more remarkable hemodynamic changes in SHR. During stress, arotinolol decreased MAP, CI and HR, and reduced myocardial and skeletal muscle flow and splanchnic, renal, cerebral and cutaneous vascular resistance in SHR. Arotinolol's effects were much less in WKY. Stress also increased the plasma catecholamine and ANP levels in SHR. Arotinolol raised these hormones in both strains at rest and in SHR during stress. Thus, arotinolol treatment exerted greater suppressive effects on the resting and stressed hemodynamics in SHR, with associated increases in the plasma catecholamine and ANP levels.

Adrenergic beta-Antagonists↗
PubMed1992

Hemodynamic effects of intraaortic versus intravenous protamine administration after cardiopulmonary bypass in man.

A hemodynamic study of men undergoing elective coronary artery bypass surgery was undertaken to elucidate the side effects of protamine given into the ascending aorta (group A, n = 16) or into the central venous line (group V, n = 16). After termination of extracorporeal circulation, protamine was infused over 120 seconds, and the hemodynamic profile was continuously recorded. During the first minute, the systemic arterial pressure fell to about 60% of the preprotamine level in both groups, but the hemodynamic changes occurred more rapidly (p < 0.05) in group V than in group A, with maximal pressure drop at 61.7 +/- 2.7 vs 74.4 +/- 4.9 seconds. Following spontaneous restoration of the systemic blood pressure, the pulmonary artery pressure rose considerably in both groups, as did the pulmonary capillary wedge and central venous pressures, reaching higher levels in the intravenous group. The cardiovascular responses were again more rapid in group V than in group A (p = 0.004). The degree of systemic hypotension thus did not benefit from use of the intraaortic rather than the intravenous route for administering protamine. The more pronounced and more rapid pulmonary circulatory changes in the intravenous group suggest that the hemodynamic effects of protamine are initiated in the lungs.

Aorta↗
PubMedDate not supplied

Hemodynamic comparison of mild and severe preeclampsia: concept of stroke systemic vascular resistance index.

Our purpose was to compare baseline hemodynamic parameters of mild and severe preeclampsia. Patients admitted to the Medical University Labor and Delivery Unit with the diagnosis of preeclampsia who had not received prior antihypertensive or magnesium sulfate therapy were recruited for noninvasive hemodynamic monitoring with thoracic electrical bioimpedance. After stabilization in the lateral recumbent position, hemodynamic monitoring was begun. Baseline hemodynamic parameters, mean arterial pressure (MAP), heart rate (HR), systemic vascular resistance index (SVRI), cardiac index (CI), and stroke index (SI) were recorded. Stroke systemic vascular resistance index (SSVRI), the resistance imposed by vasculature on each beat of the heart, was calculated for each patient by multiplying SVRI by HR. For statistical analysis, unpaired Student's t-tests (two-tailed) were utilized (P < 0.01). Forty-one preeclamptic patients (20 mild, 21 severe) were enrolled. Mean gestational age of severe patients was 32.2 +/- 4.0 and of mild patients was 37.0 +/- 3.5. MAP, SBP, diastolic blood pressure, HR, and SSVRI were higher in the severe group. SVRI, CI, cardiac output, and SI did not differ significantly between groups. Severe preclampsia appears to be a more intensely vasoconstricted state than mild preeclampsia. Although CI is inversely proportional to SVRI, increased HR in severe preeclampsia prevents this expected decrease in cardiac output.

Cardiography, Impedance↗
PubMed2000

[Hemodynamics of the lower extremities in patients with decubitus ulcers using the ultrasonic Doppler method].

Our clinical experience indicates that decubitus ulcers with tissue loss/necrosis extending beyond the subcutaneous fat in aged patients are liable to become refractory and that most of these patients experience a cold feeling/cyanosis in the lower extremities. In order to determine the relationship between the severity of the decubitus ulcers and the hemodynamics in the lower extremities, we conducted a blood flow test using the ultrasonic Doppler method on the lower extremities in patients. Sixty-eight inpatients (38 men, 30 women, with an average age of 80.5 +/- 7.6 years old) were selected. B-mode tomographs were obtained with an ultrasonic diagnostic apparatus. The power Doppler method was used to measure blood flow rate, vascular lumen diameter, and intravascular blood flow at the dorsalis pedis artery, posterior tibial artery, peroneal artery furcation, and femoral artery. The subjects were divided into three groups: patients without decubitus ulcers; patients with mild to moderate decubitus ulcers of IAET Classification grade I-III; and patients with severe decubitus ulcers (IAET Classification grade IV), and the measurements were compared among the groups. The results revealed a tendency for the vascular lumen to become narrowed and intravascular blood flow to be reduced at all sites as decubitus ulcers increased in severity and showed the hemodynamics in the lower extremities to be particularly poor in the severe group. We measured the hemodynamics in the lower extremity with the ultrasonic Doppler method from the viewpoint of decubitus ulcer prevention and found differences in blood flow in the lower extremities according to the severity of decubitus ulcers. A reduction in blood flow in the lower extremities is considered to indirectly indicate a susceptibility to decubitus ulcers and to serve as a sign of its exacerbation. We consequently considered the test to be useful and concluded that deterioration of hemodynamics due to the progress of arteriosclerosis is one of the causes of decubitus ulcer exacerbation.

Aged↗
PubMed2005

Hemodynamic instability after carotid artery angioplasty and stent placement: a review of the literature.

In this review of the literature the goal was to determine the frequency and relevance of hemodynamic instability after carotid artery (CA) angioplasty and stent placement. Hemodynamic instability after CA angioplasty and stent placement is a well-recognized phenomenon that occurs in 29 to 51% of patients undergoing the procedure. In some patients this problem is severe enough to warrant treatment with vasopressor agents. Features observed on clinical and angiographic evaluation can help clinicians identify patients who are at risk. Hemodynamic fluctuations encountered as a result of CA angioplasty and stent placement may have adverse clinical consequences, including a higher incidence of myocardial infarction and stroke. Proposed measures to prevent this complication include prophylactic placement of transvenous pacemakers or pretreatment with atropine. Unfortunately, no randomized trials are currently available to assess the efficacy of these approaches. Hemodynamic instability is a common finding after CA angioplasty and stent placement. Clinicians can predict which patients are at risk by considering angiographic and clinical features.

Angioplasty↗
PubMed2001

Cerebral hemodynamics in patients with carotid artery occlusion and contralateral moderate or severe internal carotid artery stenosis.

OBJECT: The purpose of this study was to evaluate cerebral hemodynamics in patients suffering from occlusion of the carotid artery (CA) and contralateral CA stenosis. METHODS: Using transcranial Doppler ultrasonography, the cerebrovascular reactivity to hypercapnia in the middle cerebral arteries was evaluated by calculating the breath-holding index (BHI) of 69 symptomatic patients suffering from internal CA (ICA) occlusion and moderate or severe contralateral ICA stenosis. To evaluate which variables influenced BHIs ipsilateral to the site of ICA occlusion, a multiple stepwise linear regression analysis was performed that included the following factors: patient age, percentage of contralateral ICA stenosis, contralateral BHI, number of collateral pathways, and presence of hypertension, diabetes, smoking, and hyperlipidemia. An analysis of variance was conducted to evaluate the impact of the type of collateral vessels on the BHI. A regression analysis showed that the BHI ipsilateral to the site of ICA occlusion could be accounted for by the contralateral BHI (which was entered at the first step of the analysis, p < 0.001) and by the number of collateral pathways (which was entered at the second step, p = 0.033). Neither the degree of contralateral ICA stenosis nor the other variables could be added to improve the model. The analysis demonstrated that the absence of collateral pathways and the presence of the anterior communicating artery (ACoA) alone were associated with lower BHI values than those found in the presence of two or three collateral vessels, regardless of the presence of an anterior collateral pathway. CONCLUSIONS: On the basis of these data one can infer that the cerebral hemodynamic status of patients with occlusive disease of the CA is influenced by individual anatomical and functional characteristics. Because improvement in contralateral hemodynamics after surgical correction of an ICA stenosis can only be expected in the presence of an ACoA, the planning of strategies for influencing cerebral blood flow distal to an ICA occlusion and, in particular, the consideration of a contralateral carotid endarterectomy, should be preceded by a careful evaluation of the intracranial hemodynamic adaptive status of the patient. Particular attention should be paid to cerebrovascular reactivity and the number and type of collateral vessels that are present.

Aged↗
PubMed1985

Effect of felodipine on renal hemodynamics and excretion in the dog.

The effects of felodipine on renal hemodynamics and excretion were evaluated in the anesthetized dog. Unilateral renal arterial infusion of felodipine produced ipsilateral increases in the absolute and fractional excretion of sodium and water which were greater than those of potassium; these effects occurred in the absence of changes in mean arterial pressure, renal blood flow, or glomerular filtration rate. There were no significant effects on renal hemodynamic or excretory function in the contralateral kidney. The unilateral renal arterial infusion of isotonic saline or vehicle produced no significant effects on renal hemodynamic or excretory function in either ipsilateral or contralateral kidney. Felodipine, a calcium antagonist with vasodilator antihypertensive properties, in doses which do not affect systemic or renal hemodynamics in the dog, increased urinary flow rate and sodium excretion by decreasing renal tubular water and sodium reabsorption. As a vasodilator antihypertensive agent, felodipine possesses potentially advantageous diuretic and natriuretic properties.

Animals↗
PubMed1991

Relationship of cardiac hemodynamic and biochemical adaptations to mortality during long-term aortic constriction.

To determine the biochemical and hemodynamic responses to aortic ligation, and to assess the survival rate after the induction of hypertension, 90 normotensive rats were subjected to surgical constriction of the abdominal aorta. Mortality, left ventricular hemodynamics, myocardial biochemical assays, and plasma renin assays were determined 1 week, 1 month, 3 months, or 1 year later. Mortality was greatest between 1 week and 3 months after aortic ligation, during which plasma renin activity was significantly elevated. The rate of left ventricular pressure rise, contractile index, and myocardial alpha-adrenoceptor number were increased at 1 month, but were comparatively depressed at 3 months after the operation, suggesting that the heart was in failure at this time. At 1 year after ligation, hemodynamic and biochemical parameters continued toward normalization. Our data suggest that, in this rodent model, cardiac pump failure occurs through a combination of time-dependent, pressure-induced mechanical adaptations and myocardial biochemical changes that involve both the renin-angiotensin and sympathetic nervous systems. The observed relationship between mortality, myocardial hemodynamics, and biochemical parameters may be used for additional basic research investigations concerning the early periods of cardiac failure.

Adaptation, Physiological↗