Progressive myocardial dysfunction associated with increased vascular resistance

1980 ◽  
Vol 239 (4) ◽  
pp. H477-H477 ◽  
Author(s):  
Joseph A. Franciosa ◽  
Richard Heckel ◽  
Catherine Limas ◽  
Jay N. Cohn

To study heart failure from a myocardial lesion, we injected glass beads into the circumflex coronary artery of 11 conscious dogs and followed hemodynamics for 10 mo. Heart rate remained unchanged. Control mean arterial pressure of 112.3 ± 3.0 (SE) mmHg was unchanged at 1 and 3 mo, but rose to 127.2 ± 8.5 to 84.0 ± 7.6 ml . kg-1 . min-1 at 10 mo (P < 0.02), but was unchanged at 1 and 3 mo. Left ventricular end-diastolic pressure (LVEDP) averaged 4.6 ± 0.8 mmHg at control and rose to 11.8 ± 1.4 mmHg at 1 mo and 14.9 ± 2.5 mmHg at 10 mo (both P < 0.01). Systemic vascular resistance rose significantly by 10 mo. The ratio of stroke work to LVEDP fell from 13.1 ± 0.1 at control to 3.8 ± 0.5 by 10 mo (P < 0.01). In this dog model, left ventricular dysfunction is manifest early by increased LVEDP and later by high systemic vascular resistance with low cardiac output, thus suggesting a role of the peripheral circulation in the progression of heart failure.

1995 ◽  
Vol 78 (5) ◽  
pp. 1642-1650 ◽  
Author(s):  
C. F. Pilati ◽  
M. B. Maron ◽  
F. J. Bosso

This study was undertaken to determine whether endothelium-derived relaxing factor (EDRF) modulates the pulmonary and systemic hemodynamic responses to massive sympathetic nervous system (SNS) activation and, in so doing, also modulates the degree of SNS-induced left ventricular (LV) dysfunction and the likelihood for pulmonary edema formation. The SNS of 13 anesthetized untreated rabbits and 14 anesthetized rabbits pretreated with the EDRF inhibitor, N omega-nitro-L-arginine (L-NNA, 20 mg/kg), was massively activated with an intracisternal injection of veratrine. Pulmonary and systemic arterial pressures increased to the same extent in both groups, but LV end-diastolic pressure was significantly lower in untreated rabbits. During this time, cardiac output decreased by 37% in L-NNA pretreated rabbits compared with 8% in untreated animals. Peak systemic and pulmonary vascular resistances increased significantly in L-NNA rabbits, whereas only systemic vascular resistance increased significantly in untreated rabbits. However, this increase in systemic vascular resistance was threefold less than that observed for L-NNA-treated animals. Although the degree of LV dysfunction was greater in the L-NNA rabbits, pulmonary edema developed less frequently in this group. We suggest that when EDRF release is inhibited during massive SNS activity, pulmonary vascular resistance increases markedly, which causes the right ventricle to fail. We further suggest that the reduced right ventricular output maintains pulmonary microvascular pressure below levels required for edema development.


2000 ◽  
Vol 88 (3) ◽  
pp. 1051-1060 ◽  
Author(s):  
Ling Chen ◽  
Quihu Shi ◽  
Steven M. Scharf

Because of similar physiological changes such as increased left ventricular (LV) afterload and sympathetic tone, an exaggerated depression in cardiac output (CO) could be expected in patients with coexisting obstructive sleep apnea and congestive heart failure (CHF). To determine cardiovascular effects and mechanisms of periodic obstructive apnea in the presence of CHF, 11 sedated and chronically instrumented pigs with CHF (rapid pacing) were tested with upper airway occlusion under room air breathing (RA), O2 breathing (O2), and room air breathing after hexamethonium (Hex). All conditions led to large negative swings in intrathoracic pressure (−30 to −39 Torr) and hypercapnia ([Formula: see text] ∼60 Torr), and RA and Hex also caused hypoxia (to ∼42 Torr). Relative to baseline, RA increased mean arterial pressure (from 97.5 ± 5.0 to 107.3 ± 5.7 Torr, P < 0.01), systemic vascular resistance, LV end-diastolic pressure, and LV end-systolic length while it decreased CO (from 2.17 ± 0.27 to 1.52 ± 0.31 l/min, P < 0.01), stroke volume (SV; from 23.5 ± 2.4 to 16.0 ± 4.0 ml, P < 0.01), and LV end-diastolic length (LVEDL). O2 and Hex decreased mean arterial pressure [from 102.3 ± 4.1 to 16.0 ± 4.0 Torr ( P < 0.01) with O2 and from 86.0 ± 8.5 to 78.1 ± 8.7 Torr ( P < 0.05) with Hex] and blunted the reduction in CO [from 2.09 ± 0.15 to 1.78 ± 0.18 l/ml for O2 and from 2.91 ± 0.43 to 2.50 ± 0.35 l/ml for Hex (both P< 0.05)] and SV. However, the reduction in LVEDL and LV end-diastolic pressure was the same as with RA. There was no change in systemic vascular resistance and LVEDL during O2 and Hex relative to baseline. In the CHF pigs during apnea, there was an exaggerated reduction in CO and SV relative to our previously published data from normal sedated pigs under similar conditions. The primary difference between CHF (present study) and the normal animals is that, in addition to increased LV afterload, there was a decrease in LV preload in CHF contributing to SV depression not seen in normal animals. The decrease in LV preload during apneas in CHF may be related to effects of ventricular interdependence.


1994 ◽  
Vol 267 (1) ◽  
pp. H182-H186 ◽  
Author(s):  
T. Nishikimi ◽  
K. Miura ◽  
N. Minamino ◽  
K. Takeuchi ◽  
T. Takeda

To investigate the role of endogenous atrial natriuretic peptide (ANP) in rats with heart failure (HF), we administered HS-142-1 (HS; 3 mg/kg body wt iv), a novel nonpeptide ANP-receptor antagonist, to rats with surgically induced myocardial infarction and sham-operated rats. HF was characterized by a higher left ventricular end-diastolic pressure and higher plasma ANP concentration vs. controls. HS administration significantly reduced the plasma and urinary levels of guanosine 3',5'-cyclic monophosphate in rats with HF [plasma concentration 10.6 +/- 2.6 vs. 2.7 +/- 0.4 nM (P < 0.05); urinary excretion 48 +/- 8 vs. 12 +/- 2 pmol/min (P < 0.05)]. Systemic and renal hemodynamics were unaffected by HS administration. Urine flow (-35%) and urinary sodium excretion (-50%) were significantly decreased after HS only in those rats with HF that had no changes in systemic and renal hemodynamics. These results suggest that the elevated ANP levels in HF do not contribute directly to the maintenance of systemic hemodynamics but rather compensate for the HF mainly via diuresis and natriuresis, achieved by the inhibition of renal tubular reabsorption rather than by renal vasodilatation.


2000 ◽  
Vol 89 (4) ◽  
pp. 1445-1454 ◽  
Author(s):  
Ivar Sjaastad ◽  
Ole M. Sejersted ◽  
Arnfinn Ilebekk ◽  
Reidar Bjørnerheim

We evaluated postinfarction myocardial function in rats and determined echocardiographic criteria for congestive heart failure (CHF) using high performance echocardiography. Extensive myocardial infarction (MI) was induced in rats by left coronary occlusion. Sham-operated animals served as controls. Five weeks later, high-frame rate (∼200 Hz), fully digitized, shallow-focus (10–25 mm), two-dimensional, M-mode and Doppler echocardiography was performed. A J-tree cluster analysis was performed using parameters indicative of CHF. Reproducibility was examined. The cluster analysis joined the animals into one Sham and two MI clusters. One of the MI clusters had clinical characteristics of CHF and elevated left ventricular end diastolic pressure. Among the echocardiographic variables, only posterior wall shortening velocity separated the failing and nonfailing MI clusters. We conclude that, by high frame rate echocardiography, it is possible to obtain high- quality recordings in rats. It is feasible to distinguish MI rats with CHF due to myocardial dysfunction from those without failure and to perform longitudinal studies on myocardial function.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Qiufang Ouyang ◽  
Tao You ◽  
Jinjian Guo ◽  
Rong Xu ◽  
Quehui Guo ◽  
...  

Apelin plays important roles in cardiovascular homeostasis. However, its effects on the mechanoenergetics of heart failure (HF) are unavailable. We attempted to investigate the effects of apelin on the left ventricular-arterial coupling (VAC) and mechanical efficiency in rats with HF. HF was induced in rats by the ligation of the left coronary artery. The ischemic HF rats were treated with apelin or saline for 12 weeks. The sham-operated animals served as the control. The left ventricular (LV) afterload and the systolic and diastolic functions, as well as the mechanoenergetic indices were estimated from the pressure-volume loops. Myocardial fibrosis by Masson’s trichrome staining, myocardial apoptosis by TUNEL, and collagen content in the aorta as well as media area in the aorta and the mesenteric arteries were determined. Our data indicated that HF rats manifested an increased arterial load (Ea), a declined systolic function (reduced ejection fraction, +dP/dtmax, end-systolic elastance, and stroke work), an abnormal diastolic function (elevated end-diastolic pressure, τ, and declined −dP/dtmax), and decreased mechanical efficiency. Apelin treatment improved those indices. Concomitantly, increased fibrosis in the LV myocardium and the aorta and enhanced apoptosis in the LV were partially restored by apelin treatment. A declined wall-to-lumen ratio in the mesenteric arteries of the untreated HF rats was further reduced in the apelin-treated group. We concluded that the rats with ischemic HF were characterized by deteriorated LV mechanoenergetics. Apelin improved mechanical efficiency, at least in part, due to the inhibiting cardiac fibrosis and apoptosis in the LV myocardium, reducing collagen deposition in the aorta and dilating the resistant artery.


2009 ◽  
Vol 297 (6) ◽  
pp. F1678-F1688 ◽  
Author(s):  
Sophie C. Lütken ◽  
Soo Wan Kim ◽  
Thomas Jonassen ◽  
David Marples ◽  
Mark A. Knepper ◽  
...  

Heart failure (HF) was induced by ligation of the left anterior descending artery (LAD). Left ventricular end-diastolic pressure (LVEDP) >25 mmHg (at day 23 after LAD ligation) was the inclusion criterion. The rats were divided into three groups: sham-operated (Sham, n = 23, LVEDP: 5.6 ± 0.6 mmHg), HF ( n = 14, LVEDP: 29.4 ± 1.4 mmHg), and candesartan (1 mg·kg−1·day−1 sc)-treated HF (HF + Can, n = 9, LVEDP: 29.2 ± 1.2 mmHg). After 7 days (i.e., 29 days after LAD ligation) semiquantitative immunoblotting revealed increased abundance of inner medulla aquaporin-2 (AQP2) and AQP2 phosphorylated at Ser256 (p-AQP2) in HF. There was also markedly enhanced apical targeting of AQP2 and p-AQP2 in inner medullary collecting duct (IMCD) in HF compared with Sham rats, shown by immunocytochemistry. Candesartan treatment significantly reversed the increases in both AQP2 and p-AQP2 expression and targeting. In contrast, there were only modest changes in other collecting duct segments. Semiquantitative immunoblots revealed increased expression of type 3 Na+/H+ exchanger (NHE3) and Na+-K+-2Cl− cotransporter (NKCC2) in kidneys from HF compared with Sham rats: both effects were reversed or prevented by candesartan treatment. The protein abundance of α-epithelial sodium channel (α-ENaC) was increased while β-ENaC and γ-ENaC expression was decreased in the cortex and outer stripe of the outer medulla in HF compared with Sham rats, which was partially reversed by candesartan treatment. These findings strongly support an important role of angiotensin II in the pathophysiology of renal water and sodium retention associated with HF.


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