scholarly journals Persistent Alterations of the Autonomic Nervous System after Noncardiac Surgery 

1998 ◽  
Vol 89 (1) ◽  
pp. 30-42 ◽  
Author(s):  
David Amar ◽  
Martin Fleisher ◽  
Carol B. Pantuck ◽  
Harry Shamoon ◽  
Hao Zhang ◽  
...  

Unlabelled BACKGROUND. Changes in the sympathetic nervous system may be a cause of postoperative cardiovascular complications. The authors hypothesized that changes in both beta-adrenergic receptor (betaAR) function (as assessed in lymphocytes) and in sympathetic activity (assessed by plasma catecholamines and by heart rate variability [HRV] measurements obtained from Holter recordings) occur after operation. Methods The HRV parameters were measured in 28 patients having thoracotomy (n = 14) or laparotomy (n = 14) before and for as long as 6 days after operation. Transthoracic echocardiography was performed before and on postoperative day 2. Lymphocytes were also isolated from blood obtained before anesthesia and again on postoperative days 1, 2, 3, and 5 (or 6). They were used to examine betaAR number (Bmax) and cyclic adenosine monophosphate (cAMP) production after stimulation with isoproterenol and prostaglandin E1. In addition, plasma epinephrine, norepinephrine, and cortisol concentrations were determined at similar intervals. Results After abdominal and thoracic surgery, most time and all frequency indices of HRV decreased significantly, as did Bmax and basal and isoproterenol-stimulated cAMP production. The decrements in HRV correlated with those of Bmax and isoproterenol-stimulated cAMP throughout the first postoperative week and inversely correlated with the increase in heart rate. Plasma catecholamine concentrations did not change significantly from baseline values, but plasma cortisol levels did increase after operation in both groups. Left ventricular ejection fraction was normal in both groups and unaffected by surgery. Conclusions Persistent downregulation and desensitization of the lymphocyte betaAR/adenylyl cyclase system correlated with decrements in time and frequency domain indices of HRV throughout the first week after major abdominal or thoracic surgery. These physiologic alterations suggest the continued presence of adaptive autonomic regulatory mechanisms and may explain why the at-risk period after major surgery appears to be about 1 week or more.

1985 ◽  
Vol 248 (1) ◽  
pp. E95-E100 ◽  
Author(s):  
D. Baum ◽  
J. B. Halter ◽  
G. J. Taborsky ◽  
D. Porte

The effects of intravenous pentobarbital were studied in dogs. Plasma pentobarbital concentrations were inversely related to epinephrine and norepinephrine concentrations. Plasma catecholamines appeared fully suppressed at pentobarbital levels greater than 25-30 micrograms/ml. Furthermore, pentobarbital levels were negatively related to rectal temperature, heart rate, and mean blood pressure. The methods of pentobarbital administration influenced plasma pentobarbital as well as epinephrine and norepinephrine levels, temperature, heart rate, and blood pressure. These observations suggest the possibility that pentobarbital inhibits the sympathetic nervous system, which in turn may affect temperature, heart rate, and blood pressure. Because pentobarbital anesthesia affects plasma catecholamine concentrations, the regimen used in animal models requires consideration when interpreting data potentially influenced by the sympathetic nervous system.


2001 ◽  
Vol 281 (5) ◽  
pp. E1029-E1036 ◽  
Author(s):  
Raymond R. Russell ◽  
Deborah Chyun ◽  
Steven Song ◽  
Robert S. Sherwin ◽  
William V. Tamborlane ◽  
...  

Insulin-induced hypoglycemia occurs commonly in intensively treated patients with type 1 diabetes, but the cardiovascular consequences of hypoglycemia in these patients are not known. We studied left ventricular systolic [left ventricular ejection fraction (LVEF)] and diastolic [peak filling rate (PFR)] function by equilibrium radionuclide angiography during insulin infusion (12 pmol · kg−1 · min−1) under either hypoglycemic (∼2.8 mmol/l) or euglycemic (∼5 mmol/l) conditions in intensively treated patients with type 1 diabetes and healthy nondiabetic subjects ( n = 9 for each). During hypoglycemic hyperinsulinemia, there were significant increases in LVEF (ΔLVEF = 11 ± 2%) and PFR [ΔPFR = 0.88 ± 0.18 end diastolic volume (EDV)/s] in diabetic subjects as well as in the nondiabetic group (ΔLVEF = 13 ± 2%; ΔPFR = 0.79 ± 0.17 EDV/s). The increases in LVEF and PFR were comparable overall but occurred earlier in the nondiabetic group. A blunted increase in plasma catecholamine, cortisol, and glucagon concentrations occurred in response to hypoglycemia in the diabetic subjects. During euglycemic hyperinsulinemia, LVEF also increased in both the diabetic (ΔLVEF = 7 ± 1%) and nondiabetic (ΔLVEF = 4 ± 2%) groups, but PFR increased only in the diabetic group. In the comparison of the responses to hypoglycemic and euglycemic hyperinsulinemia, only the nondiabetic group had greater augmentation of LVEF, PFR, and cardiac output in the hypoglycemic study ( P < 0.05 for each). Thus intensively treated type 1 diabetic patients demonstrate delayed augmentation of ventricular function during moderate insulin-induced hypoglycemia. Although diabetic subjects have a more pronounced cardiac response to hyperinsulinemia per se than nondiabetic subjects, their response to hypoglycemia is blunted.


2000 ◽  
Vol 99 (1) ◽  
pp. 27-35 ◽  
Author(s):  
Stephan SCHMIDT-SCHWEDA ◽  
Christian HOLUBARSCH

In the failing human myocardium, both impaired calcium homoeostasis and alterations in the levels of contractile proteins have been observed, which may be responsible for reduced contractility as well as diastolic dysfunction. In addition, levels of a key protein in calcium cycling, i.e. the sarcoplasmic reticulum Ca2+-ATPase, and of the α-myosin heavy chain have been shown to be enhanced by treatment with etomoxir, a carnitine palmitoyltransferase inhibitor, in normal and pressure-overloaded rat myocardium. We therefore studied, for the first time, the influence of long-term oral application of etomoxir on cardiac function in patients with chronic heart failure. A dose of 80 mg of etomoxir was given once daily to 10 patients suffering from heart failure (NYHA functional class II–III; mean age 55±4 years; one patient with ischaemic heart disease and nine patients with dilated idiopathic cardiomyopathy; all male), in addition to standard therapy. The left ventricular ejection fraction was measured echocardiographically before and after a 3-month period of treatment. Central haemodynamics at rest and exercise (supine position bicycle) were defined by means of a pulmonary artery catheter and thermodilution. All 10 patients improved clinically; no patient had to stop taking the study medication because of side effects; and no patient died during the 3-month period. Maximum cardiac output during exercise increased from 9.72±1.25 l/min before to 13.44±1.50 l/min after treatment (P < 0.01); this increase was mainly due to an increased stroke volume [84±7 ml before and 109±9 ml after treatment (P < 0.01)]. Resting heart rate was slightly reduced (not statistically significant). During exercise, for any given heart rate, stroke volume was significantly enhanced (P < 0.05). The left ventricular ejection fraction increased significantly from 21.5±2.6% to 27.0±2.3% (P < 0.01). In acute studies, etomoxir showed neither a positive inotropic effect nor vasodilatory properties. Thus, although the results of this small pilot study are not placebo-controlled, all patients seem to have benefitted from etomoxir treatment. Etomoxir, which has no acute inotropic or vasodilatory properties and is thought to increase gene expression of the sarcoplasmic reticulum Ca2+-ATPase and the α-myosin heavy chain, improved clinical status, central haemodynamics at rest and during exercise, and left ventricular ejection fraction.


Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Ramtin Anousheh ◽  
David E Krummen ◽  
Navinder S Sawhney ◽  
Wei Chung Chen ◽  
Linda Tone ◽  
...  

To investigate the association between resting heart rate (HR) and defibrillation threshold (DFT) in patients (pts) undergoing ICD implantation. DFT testing is usually considered standard of care during ICD implantation. However, the risk factors for high DFTs remain ill defined and the extent of testing required at implant has not been well defined. Baseline HR has been associated with higher DFTs in prior studies. We studied 128 pts undergoing ICD implantation. Baseline HR and DFTs were determined. HR was determined using ECGs obtained in the resting position on the day of ICD implantation. DFT testing was done during ICD implantation. We excluded 13 pts who were on amiodarone. The baseline characteristics of pts in the study are shown below in the table below (values in parenthesis represents standard error of the mean): First, a multivariate analysis of the association between baseline HR and DFT was performed, adjusting for left ventricular ejection fraction (LVEF), gender, body surface area (BSA) and beta blocker therapy. For every 10 beat increase in heart rate, DFT increased by 1 joule (p=0.02). Gender and beta blocker therapy did not effect this association. Second, pts were dichotomized based on DFTs to low (<15 joules) and high (≥15 joules). Mean resting HR was significantly higher among pts with high DFT (79 bpm) compared to those with low DFT (70 bpm) after adjusting for LVEF and BSA (p=0.01). Baseline resting HR is a risk factor for high DFT and may help define a higher risk pt population undergoing DFT testing.


Author(s):  
N. Zhhilova

The activation of the sympathetic nervous system plays an important pathophysiological role in the development of heart failure, in particular, in the development of left ventricular insufficiency. Although high blood pressure is considered as the main determinant of structural changes in the left ventricle, sex, salt intake, obesity, diabetes, as well as neurohumoral and genetic factors can affect the mass and left ventricular geometry. The usual concept of hypertonic re-modeling. In the comparative analysis of clinical and neurological manifestations in patients with chronic cerebral ischemia and chronic heart failure with a preserved and reduced release fraction, changes in the nervous system that showed a tendency to increase the disturbances and deviations from the norm with increasing heart failure, the fraction of release and the presence of hypertensive encephalopathy In the correlation analysis, a direct correlation between the quality of life indicator and the degree of heart failure (r = 0.56), the presence of myocardial infarction in the history (r = 0.42), arterial hypertension (r = 0.33) and the presence of valvular pathology the heart (r = 0.31) and the inverse correlation dependence on the indicator of the left ventricular ejection fraction (r = -0.69). A comparative analysis of correlation relationships indicates a reliable clinical and social significance of the left ventricular ejection fraction in patients with chronic cerebral ischemia and chronic heart failure.


2019 ◽  
Vol 25 (4) ◽  
pp. 389-406 ◽  
Author(s):  
E. V. Kokhan ◽  
G. K. Kiyakbaev ◽  
Z. D. Kobalava

Numerous studies have demonstrated the negative prognostic value of tachycardia, both in the general population and in specific subgroups, including patients with coronary artery disease (CAD), arterial hypertension (HTN) and heart failure with preserved ejection fraction (HFpEF). In the latest edition of the European guidlines for the treatment of HTN the level of heart rate (HR) exceeding 80 beats per minute is highlighted as a separate independent predictor of adverse outcomes. However, the feasibility of pharmacological reduction of HR in patients with sinus rhythm is unclear. Unlike patients with reduced ejection fraction, in whom the positive effects of HR reduction are well established, the data on the effect of pharmacological HR reduction on the prognosis of patients with HTN, CAD and/or HFpEF are not so unambiguous. Some adverse effects of pharmacological correction of HR in such patients, which may be caused by a change in the aortic pressure waveform with its increase in late systole in the presence of left ventricular diastolic dysfunction, are discussed. The reviewed data underline the complexity of the problem of clinical and prognostic significance of increased HR and its correction in patients with HTN, stable CAD and/or HFpEF.


Author(s):  
N. P. Mitkovskaya ◽  
E. M. Balysh ◽  
T. V. Statkevich ◽  
N. A. Ladygina ◽  
E. B. Petrova ◽  
...  

The aim of the study was to investigate the features of clinically suspected myocarditis complicated by the left ventricular systolic dysfunction development. 93 patients with clinically suspected myocarditis were examined. The average age was 36.63 ± 1.15 years. In 43.01 % of patients the disease was accompanied by a decrease in left ventricular systolic function. In the group of patients with left ventricular systolic dysfunction in comparison with those with preserved left ventricular ejection fraction, a significantly lower proportion of men (75 % versus 81 %, respectively, χ2 = 9.3, p < 0,01) and a higher average group age (40.7 ± 1.87 versus 33.6 ± 1.3 years, respectively, p <  0,01) were revealed. The course of the disease in patients with left ventricular systolic dysfunction was characterized by a more frequent development of rhythm disturbances (65 % versus 43.3 %, respectively, χ2  = 4.3, p  < 0,05) and a higher heart rate at admission (94.5 (75‒100) and 85 (70‒89) beats per minute, respectively, p = 0.006). The structural and functional state of the heart according to echocardiography in patients with a reduced left ventricular ejection fraction versus comparison group was characterized by larger heart chambers sizes, more pronounced violations of local left ventricular contractility, more frequent involvement of the right ventricle in the pathological process (56.3  % versus 22.2  %, respectively, χ2   =  6.4, p  < 0,05). The relationships between the left ventricular ejection fraction Весці Нацыянальнай акадэміі навук Беларусі. Серыя медыцынскіх навук. 2020. Т. 17, № 4. C. 452–460 453 and the patient’s age (r = ‒0.36), the value of the heart rate at admission (r = ‒0.32), the severity of heart failure at admission, the degree of impaired local contractility of the left ventricle, the degree of right ventricular function (TAPSE, r  =  0.58), the severity of myocardial fibrosis according to cardiovascular magnetic resonance imaging (r = ‒0.32) were revealed.


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