Severe diastolic dysfunction with preserved energy conversion efficiency after countershock

1997 ◽  
Vol 273 (2) ◽  
pp. H583-H592 ◽  
Author(s):  
S. Yasuda ◽  
T. Shishido ◽  
Y. Goto
Keyword(s):  
Diastolic Dysfunction ◽  
Mechanical Performance ◽  
Diastolic Pressure ◽  
Mechanical Energy ◽  
Systolic Pressure ◽  
Myocardial Edema ◽  
Energy Conversion Efficiency ◽  
Left Ventricular ◽  
Stunned Myocardium ◽  
Before And After

The left ventricular (LV) mechanical performance and the LV myocardial oxygen consumption (VO2)-to-pressure-volume area (PVA; LV total mechanical energy index) relationship were measured in isovolumic contraction of isolated blood-perfused dog hearts before and after direct current (DC) countershocks. At a constant LV volume, DC shocks increased LV end-diastolic pressure progressively and strikingly with the progression of myocardial edema and a marked prolongation of the time constant of LV pressure decay. In contrast, DC shocks changed neither the slope of the LV end-systolic pressure-volume relationship nor the contractile efficiency (the slope of the Vo2-PVA relationship). The oxygen cost of contractility (the slope of the relationship between PVA-independent VO2 and LV contractility) increased 27% after DC shocks. However, the magnitude of this change was considerably smaller than that previously reported in postischemic stunned myocardium (123%), suggesting that the adverse effect of DC shocks on the energy cost of excitation-contraction coupling is relatively minor. Thus, despite the severe diastolic dysfunction, DC shocks do not substantially impair either the efficiency of cross-bridge cycling or calcium cycling. Myocardial interstitial edema is more likely a potential mechanism of diastolic dysfunction after DC shocks.

Left ventricular function of isoproterenol-induced hypertrophied rat hearts perfused with blood: mechanical work and energetics

2009 ◽  
Vol 297 (5) ◽  
pp. H1736-H1743 ◽  
Author(s):  
Chikako Nakajima-Takenaka ◽  
Guo-Xing Zhang ◽  
Koji Obata ◽  
Kiyoe Tohne ◽  
Hiroko Matsuyoshi ◽  
...  
Keyword(s):  
Relaxation Rate ◽  
Diastolic Pressure ◽  
Mechanical Energy ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Mechanical Work ◽  
Linear Relations ◽  
Rat Hearts ◽  
Total Mechanical Energy ◽  
Heart Preparation

We investigated left ventricular (LV) mechanical work and energetics in the cross-circulated (blood-perfused) isoproterenol [Iso 1.2 mg·kg−1·day−1 for 3 days (Iso3) or 7 days (Iso7)]-induced hypertrophied rat heart preparation under isovolumic contraction-relaxation. We evaluated pressure-time curves per beat, end-systolic pressure-volume and end-diastolic pressure-volume relations, and myocardial O2 consumption per beat (V̇o2)-systolic pressure-volume area (PVA; a total mechanical energy per beat) linear relations at 240 beats/min, because Iso-induced hypertrophied hearts failed to completely relax at 300 beats/min. The LV relaxation rate at 240 beats/min in Iso-induced hypertrophied hearts was significantly slower than that in control hearts [saline 24 μl/day for 3 and 7 days (Sa)] with unchanged contraction rate. The V̇o2-intercepts (composed of basal metabolism and Ca2+ cycling energy consumption in excitation-contraction coupling) of V̇o2-PVA linear relations were unchanged associated with their unchanged slopes in Sa, Iso3, and Iso7 groups. The oxygen costs of LV contractility were also unchanged in all three groups. The amounts of expression of sarcoplasmic reticulum Ca2+-ATPase, phospholamban (PLB), phosphorylated-Ser16 PLB, phospholemman, and Na+-K+-ATPase are significantly decreased in Iso3 and Iso7 groups, although the amount of expression of NCX1 is unchanged in all three groups. Furthermore, the marked collagen production (types I and III) was observed in Iso3 and Iso7 groups. These results suggested the possibility that lowering the heart rate was beneficial to improve mechanical work and energetics in isoproterenol-induced hypertrophied rat hearts, although LV relaxation rate was slower than in normal hearts.

Inhibition of NO production increases myocardial blood flow and oxygen consumption in congestive heart failure

2002 ◽  
Vol 282 (6) ◽  
pp. H2278-H2283 ◽  
Author(s):  
Jay H. Traverse ◽  
Yingjie Chen ◽  
Mingxiao Hou ◽  
Robert J. Bache
Keyword(s):  
Heart Failure ◽  
Congestive Heart Failure ◽  
Blood Flow ◽  
Oxygen Consumption ◽  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
No Production ◽  
Before And After ◽  
Rapid Ventricular Pacing

Coronary blood flow (CBF) and myocardial oxygen consumption (MV˙o 2) are reduced in dogs with pacing-induced congestive heart failure (CHF), which suggests that energy metabolism is downregulated. Because nitric oxide (NO) can inhibit mitochondrial respiration, we examined the effects of NO inhibition on CBF and MV˙o 2 in dogs with CHF. CBF and MV˙o 2 were measured at rest and during treadmill exercise in 10 dogs with CHF produced by rapid ventricular pacing before and after inhibition of NO production with N G-nitro-l-arginine (l-NNA, 10 mg/kg iv). The development of CHF was accompanied by decreases in aortic and left ventricular (LV) systolic pressure and an increase in LV end-diastolic pressure (25 ± 2 mmHg). l-NNA increased MV˙o 2 at rest (from 3.07 ± 0.61 to 4.15 ± 0.80 ml/min) and during exercise; this was accompanied by an increase in CBF at rest (from 31 ± 2 to 40 ± 4 ml/min) and during exercise (both P < 0.05). Althoughl-NNA significantly increased LV systolic pressure, similar increases in pressure produced by phenylephrine did not increase MV˙o 2. The findings suggest that NO exerts tonic inhibition on respiration in the failing heart.

Oxygen-saving effect of negative work in dog left ventricle

1988 ◽  
Vol 254 (1) ◽  
pp. H34-H44 ◽  
Author(s):  
H. Suga ◽  
Y. Goto ◽  
Y. Yasumura ◽  
T. Nozawa ◽  
S. Futaki ◽  
...  
Keyword(s):  
Left Ventricle ◽  
Diastolic Pressure ◽  
Mechanical Energy ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
External Work ◽  
Negative Work ◽  
Total Mechanical Energy ◽  
Saving Effect

We compared left ventricular oxygen consumptions (VO2) of contractions performing negative external work (EW less than 0) and positive external work (EW greater than 0) that developed comparable peak systolic pressures in the excised cross-circulated dog hearts. We changed the polarity of ventricular work with volume servo-pump and measured both left ventricular VO2 and systolic pressure-volume area (PVA). PVA represents the total mechanical energy generated by contraction and is equal to the area circumscribed by the end-systolic and end-diastolic pressure-volume (PV) relation curves and the systolic PV trajectory. For comparable peak systolic pressures of approximately 90 mmHg, contractions performing negative EW of -834 +/- 327 mmHg.ml.100 g left ventricle-1 had 27 +/- 11% smaller VO2 and 62 +/- 12% smaller PVA than those performing positive EW of 851 +/- 329 mmHg.ml.100 g-1. The smaller VO2 for negative EW could be accounted for by the linear VO2-PVA relation regardless of the polarity and magnitude of work. The results indicate that negative work can save VO2 of contractions to develop a given peak systolic pressure.

Effect of lidocaine on left ventricular pressure-volume curves during demand ischemia in pigs

1998 ◽  
Vol 274 (6) ◽  
pp. H2100-H2109 ◽  
Author(s):  
Masao Tayama ◽  
Steven B. Solomon ◽  
Stanton A. Glantz
Keyword(s):  
Diastolic Dysfunction ◽  
Diastolic Pressure ◽  
Systolic Function ◽  
Left Ventricular ◽  
Volume Curve ◽  
Pressure Volume Curve ◽  
Volume Relationship ◽  
Before And After ◽  
Lidocaine Injection ◽  
Pressure Volume Relationship

The diastolic pressure-volume curve shifts upward during demand ischemia, most likely because of changes in Ca2+ dynamics within the sarcomere. It is possible that agents that affect Na+/Ca2+exchange, such as lidocaine, a class 1b-type Na+-channel blocker that decreases intracellular Na+, could affect the diastolic pressure-volume relationship because of indirect effects on intracellular Ca2+. Lidocaine is a drug widely used to treat arrhythmias in patients with myocardial ischemia. We studied the effects of lidocaine on diastolic dysfunction associated with demand ischemia. We compared diastolic (as represented by the shift in the diastolic pressure-volume relationship) and systolic function during demand ischemia before and after lidocaine injection. We created demand ischemia in pigs before and after administering lidocaine (5 mg/kg) in eight open-pericardium anesthetized pigs. Demand ischemia was induced by constricting the left anterior descending coronary artery and then pacing at 1.5–1.8 times the baseline heart rate for 1.5–3 min. Hemodynamics were recorded during baseline, demand ischemia, baseline after lidocaine injection, and demand ischemia after lidocaine. Lidocaine did not affect systolic function or the time constant of isovolumic relaxation, but it increased the upward shift of the diastolic pressure-volume curve during demand ischemia compared with the increase that occurred before lidocaine was administered. This result suggests that lidocaine could aggravate diastolic dysfunction in patients with ischemic heart disease.

Influence of adenosine on left ventricular performance in conscious dogs

1990 ◽  
Vol 258 (2) ◽  
pp. H424-H430
Author(s):  
G. L. Freeman ◽  
J. T. Colston ◽  
J. Hultman
Keyword(s):  
Diastolic Pressure ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Stroke Work ◽  
Controlled Hypotension ◽  
Ventricular Performance ◽  
Systolic Volume ◽  
End Diastolic Volume ◽  
Before And After ◽  
Lv Volume

Adenosine, a potent vasodilator of both the peripheral and coronary vasculature, is increasingly used to produce controlled hypotension in the clinical and experimental setting. To define the influence of adenosine on left ventricular (LV) performance in conscious closed-chest dogs were studied six chronically instrumented autonomically blocked animals before and after the administration of 0.3, 0.6, and 1.2 microM.kg-1.min-1 infusions of adenosine. Systolic performance was quantified by the end-systolic pressure-volume (Pes-Ves) and stroke work end-diastolic volume (SW-EDV) relations. Active diastolic performance was quantified by the time constant of LV relaxation (T), whereas passive diastolic properties were assessed by comparing LV pressures at a common LV volume. Despite a decrease of mean arterial pressure of 51 mmHg, adenosine did not change the slope of the Pes-Ves relation or the end-systolic volume at a pressure of 100 mmHg. The slope of the SW-EDV relation was also unchanged, and its volume axis intercept was slightly reduced. There were no differences in T or in the diastolic pressure at a common LV volume. Thus adenosine appears to have little influence on systolic or diastolic LV performance aside from its marked affect on afterload, indicating it is a useful agent for producing controlled hypotension.

Estimation of Left Ventricular Wall Stiffness by Analysis of Late Diastolic Pressure Components

2011 ◽  
Author(s):  
Casandra L. Niebel ◽  
Kelley C. Stewart ◽  
Takahiro Ohara ◽  
John J. Charonko ◽  
Pavlos P. Vlachos ◽  
...  
Keyword(s):  
Heart Failure ◽  
Left Ventricle ◽  
Diastolic Dysfunction ◽  
Diastolic Pressure ◽  
Left Ventricular Diastolic Dysfunction ◽  
Left Ventricular ◽  
Ventricular Wall ◽  
Ventricular Relaxation ◽  
Wall Stiffness ◽  
Ventricular Diastolic Dysfunction

Left ventricular diastolic dysfunction (LVDD) is any abnormality in the filling of the left ventricle and is conventionally evaluated by analysis of the relaxation driven phase, or early diastole. LVDD has been shown to be a precursor to heart failure and the diagnosis and treatment for diastolic failure is less understood than for systolic failure. Diastole consists of two filling waves, early and late and is primarily dependent on ventricular relaxation and wall stiffness.

Abstract 17266: Right Atrial Volumes Changes in Tetralogy of Fallot

Circulation ◽  
2018 ◽  
Vol 138 (Suppl_1) ◽  
Author(s):  
Ashish Patel ◽  
Divya Shakti ◽  
Chad Blackshear
Keyword(s):  
Diastolic Dysfunction ◽  
Diastolic Function ◽  
Tetralogy Of Fallot ◽  
Surgical Repair ◽  
Left Ventricular ◽  
Right Atrial ◽  
Before And After ◽  
Ventricular Diastolic Dysfunction ◽  
And Function ◽  
Averaged Model

Introduction & Hypothesis: There is limited information on right atrial (RA) function in the congenital heart defects. RA volume and function may give insight into the right ventricle (RV) diastolic function. We sought to assess RA function in tetralogy of Fallot (TOF) patients prior to and after complete surgical repair. Methods: Infants with TOF prior to complete repair were included for retrospective chart review and offline analysis of 2-dimensional echocardiograms (echo) before and after surgical repair. RA phasic volumes and stroke volumes were calculated. All volumes were indexed to body surface area. Results: There were 40 infants with TOF (45% females), of which 70% had pulmonary stenosis, 30% pulmonary atresia. Roughly 85% and 60% had 3, or more, echo available pre- and postoperatively. Table 1 (attached) shows the patient characteristics and phasic RA volumes. The indexed RA phasic volumes were in normal range in initial echo prior to surgery. We used normal index RA phasic volumes published by European Society of Echocardiography. There was the increasing trend of indexed RA phasic volume on follow up echo immediately before TOF repair. These phasic volumes continued to remain elevated after complete surgical repair (Table 1). Trends in RA stroke volumes for all available echos before and after surgery were modeled using a population-averaged model with an exchangeable within-panel correlation structure (Figure 2), showing no statistically significant difference after surgery. But there was statistical significance noted in RA ejection fraction. Please see attached image for statistical analysis and results of the study. Conclusions: The indexed RA phasic volumes in children with TOF are normal initially and increases before TOF repair and it continued to increase after TOF repair. The increase RA phasic volumes suggest RV diastolic dysfunction similar to the findings of LA phasic volumes and left ventricular diastolic dysfunction. Our findings indicate slow worsening RV diastolic function in patients with TOF after surgical repair. RA volume and function can be the novel marker to diagnose and monitor right ventricular diastolic dysfunction.

The Effect of Gypenosides on Cardiac Function and Expression of Cytoskeletal Genes of Myocardium in Diabetic Cardiomyopathy Rats

2009 ◽  
Vol 37 (06) ◽  
pp. 1059-1068 ◽  
Author(s):  
Min Ge ◽  
Shanfeng Ma ◽  
Liang Tao ◽  
Sudong Guan
Keyword(s):  
Cardiac Function ◽  
Diabetic Cardiomyopathy ◽  
Diastolic Pressure ◽  
Pure Water ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Control Group ◽  
Sprague Dawley ◽  
Gene Expressions ◽  
Ventricular Systolic Pressure

The relationship between changes of cardiac function and the gene expressions of two major myocardial skeleton proteins, titin and nebulin, and the effect of gypenosides on these gene expressions in diabetic cardiomyopathy rat were explored in the present study. Forty Sprague-Dawley rats were randomly divided into three groups: control group, diabetic cardiomyopathy group and gypenosides-treated diabetic cardiomyopathy group. The diabetic cardiomyopathy was induced in rats by injecting streptozotocin (STZ, 55 mg/kg) intraperitoneally. Seven weeks after the rats suffered from diabetes, the rats were treated with gypenosides 100 mg/kg per day orally for six weeks in gypenosides-treated group. In the meanwhile, the pure water was given to diabetic cardiomyopathy and the control groups. Subsequently, the cardiac functions, including left ventricular systolic pressure (LVSP), left ventricular end diastolic pressure (LVEDP), ± dP/dtmax and t–dP/dmaxt, as well as the mRNA content and proteins of titin and nebulin in myocardium were determined. The results indicated that (1) the diabetic cardiomyopathy rats had decreased LVSP and ± dP/dtmax, increased LVEDP, and prolonged t–dP/dtmax than normal rats; (2) LVSP and ± dP/dtmax in diabetic cardiomyopathy rats treated with gypenosides were significantly higher and LVEDP and t–dP/dtmax were significantly lower than those without giving gypenosides; (3) the mRNA contents and proteins of titin and nebulin in diabetic cardiomyopathy rats were remarkably lower than those in the control rats and gypenosides had no effect on mRNA and protein expression levels of titin and nebulin in diabetic cardiomyopathy rats. We conclude that (1) the cardiac function as well as the mRNA expressions of titin and nebulin decreased in diabetic cardiomyopathy rats; (2) gypenosides secure cardiac muscles and their function from diabetic impairment and these beneficial effects of gypenosides are not by changing the expressions of titin and nebulin.

Effect of human urotensin-II infusion on hemodynamics and cardiac function

2003 ◽  
Vol 81 (2) ◽  
pp. 125-128 ◽  
Author(s):  
Ghada S Hassan ◽  
Fazila Chouiali ◽  
Takayuki Saito ◽  
Fu Hu ◽  
Stephen A Douglas ◽  
...  
Keyword(s):  
Cardiac Function ◽  
Diastolic Pressure ◽  
Cardiac Contractility ◽  
Systolic Pressure ◽  
Left Ventricular ◽  
Urotensin Ii ◽  
Ventricular Systolic Pressure ◽  
Wide Range ◽  
Dose Dependent Decrease

Recent studies have shown that the vasoactive peptide urotensin-II (U-II) exerts a wide range of action on the cardiovascular system of various species. In the present study, we determined the in vivo effects of U-II on basal hemodynamics and cardiac function in the anesthetized intact rat. Intravenous bolus injection of human U-II resulted in a dose-dependent decrease in mean arterial pressure and left ventricular systolic pressure. Cardiac contractility represented by ±dP/dt was decreased after injection of U-II. However, there was no significant change in heart rate or diastolic pressure. The present study suggests that upregulation of myocardial U-II may contribute to impaired myocardial function in disease conditions such as congestive heart failure.Key words: urotensin-II, rat, infusion, heart.

scholarly journals Tachycardia-induced myocardial ischemia and diastolic dysfunction potentiate secretion of ANP, not BNP, in hypertrophic cardiomyopathy

2006 ◽  
Vol 290 (3) ◽  
pp. H1064-H1070 ◽  
Author(s):  
Shinsuke Kido ◽  
Naoyuki Hasebe ◽  
Yoshinao Ishii ◽  
Kenjiro Kikuchi
Keyword(s):  
Hypertrophic Cardiomyopathy ◽  
Myocardial Ischemia ◽  
Diastolic Dysfunction ◽  
Diastolic Pressure ◽  
Systolic Function ◽  
Left Ventricular ◽  
Atrial Pacing ◽  
Catheter Tip ◽  
Lv Systolic Function ◽  
Lv Diastolic Dysfunction

The aim of this study was to investigate what factor determines tachycardia-induced secretion of atrial and brain natriuretic peptides (ANP and BNP, respectively) in patients with hypertrophic cardiomyopathy (HCM). HCM patients with normal left ventricular (LV) systolic function and intact coronary artery ( n = 22) underwent rapid atrial pacing test. The cardiac secretion of ANP and BNP and the lactate extraction ratio (LER) were evaluated by using blood samples from the coronary sinus and aorta. LV end-diastolic pressure (LVEDP) and the time constant of LV relaxation of tau were measured by a catheter-tip transducer. These parameters were compared with normal controls ( n = 8). HCM patients were divided into obstructive (HOCM) and nonobstructive (HNCM) groups. The cardiac secretion of ANP was significantly increased by rapid pacing in HOCM from 384 ± 101 to 1,268 ± 334 pg/ml ( P < 0.05); however, it was not significant in control and HNCM groups. In contrast, the cardiac secretion of BNP was fairly constant and rather significantly decreased in HCM ( P < 0.01). The cardiac ANP secretion was significantly correlated with changes in LER ( r = −0.57, P < 0.01) and tau ( r = 0.73, P < 0.001) in HCM patients. Tachycardia potentiates the cardiac secretion of ANP, not BNP, in patients with HCM, particularly when it induces myocardial ischemia and LV diastolic dysfunction.

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