Preservation of left ventricular function by insulin in experimental catecholamine cardiomyopathy

1980 ◽  
Vol 238 (2) ◽  
pp. H257-H262
Author(s):  
J. C. Werner ◽  
J. C. Lee ◽  
S. E. Downing

We have shown previously that insulin reduces myocardial injury associated with norepinephrine (NE) infusion in the rabbit (Am. J. Pathol. 93:399--353, 1978). In the present study, left ventricular function (LVF) was assessed from afterload curves obtained by progressive aortic constriction 2--4 days following NE infusion. The initial slope of the function curves (SFC), maximum dP/dt and left ventricular end-diastolic pressure at 120 mmHg ((LVEDP120) were used for comparison. In 4 controls, SFC averaged 23.8 mmHg/cmH2O. In 10 rabbits given NE, the mean slope was 8.4 (P less than 0.01). However, animals pretreated with insulin before being given NE did not differ from controls (SFC, 19.7 mmHg/cmH2O). These performance data were supported by measurements of LVEDP120, which were 2.8, 12.3 and 3.1 cmH2O, respectively (P less than 0.05 and less than 0.02). In spite of the higher LVEDP, max dP/dt120 was significantly lower in the NE group than in the group given insulin. Histological findings and postmortem measurements of LV volume and mass were consistent with the observed differences in LVF. It is concluded that NE damage reduces LVF and this is largely prevented by pretreatment with insulin.

1991 ◽  
Vol 30 (05) ◽  
pp. 183-188
Author(s):  
A. Aydrner ◽  
A. Oto ◽  
E. Oram ◽  
O. Gedik ◽  
C. F. Bekdik ◽  
...  

Left ventricular function including regional wall motion (RWM) was evaluated by 99mTc first-pass and equilibrium gated blood pool ventriculography and glycohemoglobin (HbA1c) blood levels determined by a quantitative column technique in 25 young patients with insulin-dependent diabetes mellitus without clinical evidence of heart disease, and in healthy controls matched for age and sex. Phase analysis revealed abnormal RWM in 19 of 21 diabetic patients. The mean left ventricular global ejection fraction, the mean regional ejection fraction and the mean 1/3 filling fraction were lower and the time to peak ejection, the time to peak filling and the time to peak ejection /cardiac cycle were longer in diabetics than in controls. We found high HbA1c levels in all diabetics. There was no significant difference between patients with and without retinopathy and with and without peripheral neuropathy in terms of left ventricular function and HbA1c levels.


1981 ◽  
Vol 4 (1) ◽  
pp. 28-33 ◽  
Author(s):  
A. S. Iskandrian ◽  
B. L. Segal ◽  
A. Hamid HAKKI

PEDIATRICS ◽  
1966 ◽  
Vol 38 (3) ◽  
pp. 457-464
Author(s):  
Norman S. Talner ◽  
Thomas H. Gardner ◽  
S. Evans Downing

The performance of the left ventricle in 20 newborn lambs was examined in a preparation which allowed precise control of aortic pressure, cardiac output, heart rate, and temperature. Reduction of arterial pH from a normal range (7.35 to 7.5) to severe acidemia (6.8 to 7.0) by hydrochloric or lactic acid infusion resulted in no significant impairment of left ventricular function. Prolonged acidemia (over 2 hours) failed to produce a reduction in left ventricular stroke volume or mean ejection rate for a given left ventricular end-diastolic pressure. Responsiveness of the left ventricle of the lamb to catecholamine stimulation was not diminished over the pH range 7.5 to 6.8. Under conditions of these investigations the apparent resistance of the myocardium of the newborn lamb, as well as the adult cat, to wide variations in pH may reflect a buffering capacity of cardiac muscle which would allow minimal change in intracellular pH, even though extracellular pH may indicate the presence of severe metabolic acidosis.


2012 ◽  
Vol 303 (9) ◽  
pp. H1135-H1142 ◽  
Author(s):  
Sarah Mahne ◽  
Gin C. Chuang ◽  
Edward Pankey ◽  
Lucy Kiruri ◽  
Philip J. Kadowitz ◽  
...  

Epidemiological studies have consistently linked inhalation of particulate matter (PM) to increased cardiac morbidity and mortality, especially in at risk populations. However, few studies have examined the effect of PM on baseline cardiac function in otherwise healthy individuals. In addition, airborne PM contain environmentally persistent free radicals (EPFR) capable of redox cycling in biological systems. The purpose of this study was to determine whether nose-only inhalation of EPFRs (20 min/day for 7 days) could decrease baseline left ventricular function in healthy male Sprague-Dawley rats. The model EPFR tested was 1,2-dichlorobenzene chemisorbed to 0.2-μm-diameter silica/CuO particles at 230°C (DCB230). Inhalation of vehicle or silica particles served as controls. Twenty-four hours after the last exposure, rats were anesthetized (isoflurane) and ventilated (3 l/min), and left ventricular function was assessed using pressure-volume catheters. Compared with controls, inhalation of DCB230 significantly decreased baseline stroke volume, cardiac output, and stroke work. End-diastolic volume and end-diastolic pressure were also significantly reduced; however, ventricular contractility and relaxation were not changed. DCB230 also significantly increased pulmonary arterial pressure and produced hyperplasia in small pulmonary arteries. Plasma levels of C-reactive protein were significantly increased by exposure to DCB230, as were levels of heme oxygenase-1 and SOD2 in the left ventricle. Together, these data show that inhalation of EPFRs, but not silica particles, decreases baseline cardiac function in healthy rats by decreasing cardiac filling, secondary to increased pulmonary resistance. These EPFRs also produced systemic inflammation and increased oxidative stress markers in the left ventricle.


Blood ◽  
2005 ◽  
Vol 106 (11) ◽  
pp. 1675-1675
Author(s):  
Paul Kirk ◽  
Dudley J. Pennell

Abstract Background The myocardial T2* technique has been validated as a reproducible non-invasive measurement of myocardial iron load and is now widely used for measurement of myocardial iron in iron overload diseases such as thalassaemia. The reduction in myocardial T2* seen in iron overload conditions is substantially greater than is seen in any other clinical circumstance, but there has been no direct comparison of myocardial T2* in normals and other conditions such as increasing age, myocardial infarction or impairment in left ventricular function. We aimed therefore to compare the findings in patients affected by these conditions with normals. Method A total of 38 patients in total were scanned using the myocardial T2* technique. Fifteen patients had normal hearts, 18 had impaired LV function and 6 had chronic myocardial infarction affecting the anteroseptal wall, where myocardial T2* measurements are normally made. Results The mean myocardial T2* in normals was 36.0 +/− 6.4 ms, yielding a lower limit of normal of 23ms. In patients with impaired LV function, the mean myocardial T2* was 39.0 +/− 11.7ms (p= 0.37 vs normals). In patients with anteroseptal myocardial infarction, the mean myocardial T2* was 34.7ms +/− 3.9ms (p= 0.64 vs normals). The frequency distribution of the myocardial T2* values are shown in figure 1. These approximate to normal, and are very similar in distribution. In addition, the age distribution of myocardial T2* in the 15 normals is shown in figure 2. There was no significant relation between myocardial T2* and age (r2 = 0.066, p=0.82). Conclusion There is no significant reduction in myocardial T2* associated with fibrosis from chronic myocardial infarction, impairment of left ventricular function, or increasing age. This suggests that structural changes associated with remodelling, infarction and fibrosis, and ageing do not have significant effects on the absolute measure of myocardial T2*, and in particular do not cause a reduction below 20ms as is seen in myocardial overload conditions. Thus these date suggest that myocardial T2* is robust to these structural alterations, and that myocardial iron overload can be ascertained from reduced myocardial T2* values, in a similar manner to that which can be achieved in normals. Figure 1 Figure 1. Figure 2 Figure 2.


2014 ◽  
Vol 2014 ◽  
pp. 1-4 ◽  
Author(s):  
Wegdan Mawlana ◽  
Amr Donia ◽  
Doaa Elamrousy

Background. Most of the studies done on adults showed that red cell distribution width (RDW) can be used as a prognostic marker in patients with chronic heart failure. However, RDW has not been tested in children with heart failure. Methods and Results. 31 children with heart failure admitted to Cardiology Unit, Tanta University Hospital, during the period of January 2012 to December 2012 were included in this study, RDW as a component of routine blood count was evaluated and correlated to the echocardiographic parameters of left ventricle. The mean age of our cohort was 16.16 ± 14.97 months, congenital heart disease with left-to-right shunt represented 58.1% of the underlying causes of heart failure while dilated cardiomyopathy made 41.9%. The mean hemoglobin level was 9.14 ± 1.18 gm/dL; RDW level ranged from 10.7% to 27.7% with a mean of 16.01 ± 3.34. Hemoglobin was significantly correlated with RDW at any level. For the echo parameters, at cutoff point of 16.4%, RDW was significantly correlated with fraction shortening (FS), and A, E/A ratio, but it was not correlated with LVEDD, LVESD, and E/É at the same cutoff level. Conclusion. RDW, a simple, available test, can be used as a marker for the left ventricular function in children with heart failure until an echocardiography assessment for the patients is done.


2008 ◽  
Vol 294 (2) ◽  
pp. H810-H820 ◽  
Author(s):  
Carly LaCroix ◽  
Jessica Freeling ◽  
Alese Giles ◽  
Jürgen Wess ◽  
Yi-Fan Li

Suppressed parasympathetic nervous system (PSNS) function has been found in a variety of cardiovascular diseases, such as hypertension, heart failure, and diabetes. However, whether impaired PSNS function plays a significant role in ventricular dysfunction remains to be investigated. Cardiac regulation by the PSNS is primarily mediated by the M2muscarinic acetylcholine receptor (M2-AChR). In this study, we tested the hypothesis that lack of M2-AChR-mediated PSNS function may adversely impact cardiac ventricular function. Using M2-AChR knockout (KO) and wild-type (WT) mice, we found that the basal levels of heart rate and left ventricular function were similar in M2-AChR KO and WT mice. A bolus injection of isoproterenol (Iso) induced a greater increase in heart rate in M2-AChR KO mice than in WT mice. However, the responses of change in pressure over time (dP/d t) to Iso were similar in the two groups. After chronic infusion with Iso for 1 wk, the baseline values of left ventricular function were increased to similar extents in M2-AChR KO and WT mice. However, the M2-AChR KO mice exhibited impaired ventricular function, indicated as attenuated dP/d t and increased end-diastolic pressure, during an increase in cardiac afterload induced by a bolus injection of phenylephrine. Furthermore, chronic Iso infusion significantly increased matrix metalloproteinase (MMP) activity in the heart in M2-AChR KO mice. In primary culture of mixed neonatal rat cardiac fibroblast and cardiomyocytes, cotreatment with muscarinic agonist bethanechol reversed phenylephrine-induced increase in MMP-9 activation. These data suggest that M2-AChR may mediate an inhibitory regulation on MMP function. The overall results from this study suggest that M2-AChR-mediated PSNS function may provide cardiac protection. Lack of this protective mechanism will increase the susceptibility of the heart to cardiac stresses.


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