Serum Catecholamine Concentrations Research Articles

The Association Between Ventricular Fibrillation and Serum Catecholamine Levels.

Background and objective Epinephrine (Ep) is the first choice as a vasoconstrictor in cardiopulmonary resuscitation (CPR) for patients with cardiopulmonary arrest (CPA); however, the Ep concentration in the serum of CPA patients is still unclear. The aim of this study was to evaluate the association between serum Ep levels and achieving the return of spontaneous circulation (ROSC) in out-of-hospital cardiac arrest (OHCA) patients with ventricular fibrillation (VF). Methods This was a prospective, observational clinical study involving OHCA patients with VFtransferred to our hospital from July 2014 to July 2017. The measurement of serum catecholamines [Ep, norepinephrine (Nep), and dopamine (DOA)] and vasopressin [antidiuretic hormone (ADH)] levels was performed with blood samples obtained immediately upon patients' arrival at our hospital. Patients were classified into two groups: the ROSC(+) group and ROSC(-) group; the serum concentrations of catecholamines and ADH were compared between these two groups. Results The serum Ep and Nep levels were lower in the ROSC(+) group than those in the ROSC(-) group and the difference was statistically significant. On the other hand, no significant differences were found in serum DOA and ADH levels between the two groups. Conclusions The results of this study suggest that an increment in serum Ep levels does not promote achieving ROSC in OHCA patients with VF.

Functionality of beta-adrenergic receptors in patients with cirrhosis treated chronically with non-selective beta-blockers.

In patients with cirrhosis, beta-adrenoceptors expressed on peripheral blood mononuclear cells have a reduced response to catecholamine stimulation. This study aimed to determine if chronic treatment with beta-blockers influences these changes. Blood samples were collected from patients with cirrhosis treated in outpatient clinics. Differences in cyclic AMP production before and after stimulation of mononuclear cells with epinephrine and/or N-Formylmethionine-leucyl-phenylalanine (fMLP) was used as a marker of beta-adrenoceptors activity in patients treated (N = 19) versus not treated (N = 55) with beta-blockers. In addition, we studied the gene expression of different types of adrenoceptors and possible associations with the activity of beta-adrenoceptors, the serum concentrations of catecholamines and cytokines, and the presence of bacterial antigens such as DNA or gram-negative bacterial endotoxin in patients' blood. The increase in intracellular cAMP concentrations after stimulation of adrenergic receptors with epinephrine was significantly higher in samples from patients treated with beta-blockers. Older patients showed lower responses to epinephrine stimulus, while the response increased linearly with the duration of the beta-blocker treatment. mRNA expression levels of adrenoceptors β1, β2, β3 and α1-A, B and D showed no significant differences according to treatment with beta-blockers. Neither serum cytokines nor catecholamines levels were significantly associated with the intracellular production of cAMP after adrenergic stimulation. Chronic treatment with beta-blockers in patients with cirrhosis enables beta-adrenoceptors to respond to catecholamine stimulation irrespective of the degree of systemic adrenergic or immune activations of the patient at the time of sampling.

Effects of Adrenergic Agonists and Antagonists on Cardiopulmonary Function During Normobaric Hypoxia in Rat.

Pulmonary edema (PE) is an issue widely noted in acute exposure to hypoxia as seen in high altitude climbers, yet the etiology of this is not defined. Previous studies in rats showed that both hypoxia and strong sympathetic activation may induce PE. As acute exposure to hypoxia is accompanied by sympathetic activation, we assume that this may impair pulmonary circulation and contribute to the development of hypoxic PE. The aim of the present study was to investigate the effects of adrenergic agonists and antagonists as models for overstimulation and suppression, respectively, of sympathetic activity on cardiovascular function and formation of PE in hypoxic rats. Norepinephrine or adrenergic blockers were infused to rats exposed to normobaric hypoxia with 10% O2 over time intervals up to 24 h. Normoxic and hypoxic controls received 0.9% NaCl infusion. We evaluated hemodynamic function and lung histology. A significant decrease of left ventricular systolic function was observed after 6 h of hypoxia. This effect was less pronounced with α-adrenergic blockade but was more severe with combined α-plus β-adrenergic blockade. Norepinephrine delayed the onset of hypoxic left ventricular depression but did not reduce its degree. Significant PE developed after 16 h of hypoxia. It regressed under α- but not with β-adrenergic blockade, and was aggravated by combining hypoxia with norepinephrine. Almost half of the animals exposed to hypoxia over 16–24 h suffered cardiorespiratory arrest during the experiment and presented with signs of acute right ventricular failure. They had significantly elevated serum catecholamine concentrations and significantly stronger PE than the others. Notably, most of them had received norepinephrine or combined adrenergic blockade. Mild changes in serum catecholamine concentrations indicated that hypoxic sympathoadrenergic activation was only weak. Hence, it was not sufficient to prevent left ventricular depression. However, the results show that α-adrenergic mechanisms contribute to the formation of hypoxic PE. Adrenergic blockade but also sympathetic overactivity may induce pulmonary congestion, PE and acute right ventricular failure indicating that a fine balance of sympathetic activation under hypoxic conditions is crucial. This has important implications for climbers to high altitude as well as for patients suffering from hypoxia.

Abstract TP400: Acute Catecholamine Surge Reflects the Prognosis in Patients With Aneurysmal Subarachnoid Hemorrhage

Objective: We investigated that the characteristics of serum catecholamine concentration at the hyper-acute phase of aneurysmal subarachnoid hemorrhage (SAH) and its relationship between patient outcome and delayed vasospasm. Methods: Patients with aneurysmal SAH (n=170) were prospectively enrolled between 2008 and 2011. Baseline demographic data and physiological parameters, including plasma concentrations of adrenaline (AD), noradrenaline (NA) and dopamine (DP) were evaluated. Results: On admission, plasma AD, NA and DP levels were significantly higher in patients with a poor clinical grade on admission (Hunt and Kosnik: IV-V), compared to those with a good clinical grade on admission (Hunt and Kosnik: I-III). AD showed a significantly high concentration immediately after the onset of SAH and then rapidly decreased. The levels of NA peaked within 6 hours after onset, then significantly decreased. The time course of the elevation of DP showed a similar trend to that of NA. The each catecholamine levels significantly correlated with each other. Multivariate analyses demonstrated age, poor clinical grade, plasma AD and NA levels were predictors of poor patient outcome. Poor clinical grade, Fisher scale and plasma AD level were predictors of the development of delayed vasospasm. Conclusion: The present study suggests that sympathetic activation in patients in the acute phase of SAH reflects the severity of SAH, and is closely related to the development of delayed vasospasm, leading to the subsequent immune response and inflammatory reactions. Suppressing catecholamine surge in hyper-acute phase may contribute to prevention of vasospasm and improvement of patient outcome.

Thyrotoxic and pheochromocytoma multisystem crisis: a case report

BackgroundThyrotoxic crisis and pheochromocytoma multisystem crisis are rare, life-threatening, emergency endocrine diseases with various clinical manifestations. Here we report a case of a patient who simultaneously developed thyrotoxic crisis and pheochromocytoma multisystem crisis and required intensive cardiovascular management.Case presentationA 60-year-old Asian man experienced nausea and vomiting, and subsequently developed dyspnea and cold sweats while farming. His serum free thyroxine, free triiodothyronine, and thyrotropin receptor antibody levels were elevated at 2.9 ng/dL, 7.2 pg/dL, and 4.7 IU/L, respectively. Serum thyrotropin levels were suppressed at less than 0.01 μIU/mL. Thyroid echography demonstrated no thyroid swelling (23 × 43 mm).A whole body computed tomography was performed for systemic evaluation. This revealed exophthalmos and a mass of size 57 × 64 mm in the anterior pararenal space. Based on these findings, we made an initial diagnosis of thyrotoxic crisis secondary to exacerbation of Grave’s hyperthyroidism. Treatment was begun with an iodine agent at a dose of 36 mg/day, thiamazole at a dose of 30 mg/day, and hydrocortisone at a dose of 300 mg daily for 3 consecutive days. To control tachycardia, continuous intravenously administered propranolol and diltiazem infusions were given. At the same time, small doses of doxazosin and carvedilol were used for both alpha and beta adrenergic blockade. On hospital day 5, his blood pressure and serum catecholamine concentrations (adrenalin 42,365 pg/mL, dopamine 6409 pg/mL, noradrenalin 72,212 pg/mL) were still high despite higher beta blocker and calcium channel blocker doses. These findings contributed to the diagnosis of pheochromocytoma multisystem crisis with simultaneous thyrotoxic crisis. We increased the doses of doxazosin and carvedilol, which stabilized his hemodynamic status. On hospital day 16, metaiodobenzylguanidine scintigraphy showed high accumulation in the right adrenal gland tumor. After retroperitoneal laparoscopic adrenalectomy on hospital day 33, his condition stabilized. He was discharged on hospital day 58.ConclusionsSince he required more intensive cardiovascular management for thyrotoxic crisis, beta blockade was increased under intensive care unit monitoring even though initial alpha blockade is recommended in pheochromocytoma. When these crises occur simultaneously, cardiovascular management can be very challenging.

Abstract WP386: Acute Catecholamine Surge in Patients with Aneurysmal Subarachnoid Hemorrhage: Characteristics and Prognostic Value

Objectives: The characteristics of serum catecholamine concentration at the hyper-acute phase of aneurysmal subarachnoid hemorrhage (SAH) and its relationship between patient outcome and delayed vasospasm were investigated. Methods: Patients with aneurysmal SAH (170) were prospectively studied between August 2008 and June 2011. Baseline demographic data and physiological parameters, including plasma concentrations of adrenaline (AD), noradrenaline (NA) and dopamine (DP) were evaluated for all patients. Results: On admission, plasma AD, NA and DP levels were significantly higher in patients with a poor clinical grade on admission (Hunt & Kosnik: IV-V), compared to those with a good clinical grade on admission (Hunt & Kosnik: I-III). AD showed a markedly high concentration immediately after the onset of SAH and then rapidly decreased. NA levels peaked within 6 hours after onset, then significantly decreased. The increase of DP with time was not significant, but showed a similar trend to that of NA. The level of each catecholamine showed significant mutual correlation. Multivariate analyses demonstrated age, poor clinical grade, plasma AD and NA levels were predictors of poor patient outcome, and.poor clinical grade, Fisher scale and plasma AD level were predictors of the development of delayed vasospasm. Conclusions: The present findings suggest that sympathetic activation in patients in the acute phase of SAH reflects the severity of SAH, and is closely related to the development of delayed vasospasm, leading to the subsequent immune response and inflammatory reactions. Strategies for suppressing catecholamine at the hyperacute phase may contribute to vasospasm prevention and improve patient outcome.

Reliability of serum catecholamine concentrations in reflecting depth of dexmedetomidine-based gene-ral anesthesia

Objective To evaluate the reliability of serum catecholamine concentrations in reflecting the depth of dexmedetomidine-based general anesthesia. Methods Forty patients, aged 30-45 yr, of American Society of Anesthesiologists physical statusⅠ-Ⅱ, undergoing elective laparoscopic hysterectomy under general anesthesia, were divided into 2 groups(n=20 each)using a random number table: dexmedetomidine-based general anesthesia group(groupⅠ)and general anesthesia group(group Ⅱ). Dexmedetomidine was intravenously infused as a loading bolus of 1 μg/kg over 10 min before induction of anesthesia, followed by an infusion of 0.5 μg·kg-1·h-1 until 30 min before the end of operation in groupⅠ.The equal volume of normal saline was given instead of dexmedetomidine in group Ⅱ.Anesthesia was induced with iv midazolam 0.05 mg/kg, propofol 1 mg/kg, cisatracurium 0.15 mg/kg and sufentanil 0.4 μg/kg.Anesthesia was maintained with iv infusion of remifentanil 0.1-0.3 μg·kg-1·min-1, 1%-2% sevoflurane inhalation and intermittent iv boluses of cisatracurium.Before administration of dexmedetomidine, at the end of administration of the loading dose, at the end of intubation, at the end of skin incision, after establishment of pneumoperitoneum and at the end of operation(T0-5), venous blood samples were taken from the peripheral vein for determination of concentrations of epinephrine(E)and norepinephrine(NE)in serum(by enzyme-linked immunosorbent assay). Results Compared with group Ⅱ, the serum NE and E concentrations were significantly decreased at T1-4 in groupⅠ(P<0.05). Compared with the baseline at T0, the serum NE and E concentrations were significantly decreased at T1 in groupⅠ, and increased at T2-4 in group Ⅱ(P<0.05). Conclusion The serum catecholamine concentration produces poor reliability in reflecting the depth of dexmedetomidine-based general anesthesia, and thus it is not a suitable monitoring index. Key words: Dexmedetomidine; Catecholamine; Anesthesia, general

Methadone Increases and Prolongs Detomidine-Induced Arterial Hypertension in Horses, but These Effects Are Not Mediated by Increased Plasma Concentrations of Arginine Vasopressin or Serum Concentrations of Catecholamines

Catecholamines and arginine vasopressin (AVP) release can affect arterial blood pressure (ABP) and hemodynamic stability in standing, sedated horses. Six mature horses were included in this prospective, randomized, crossover, blinded, experimental study. All the horses were sedated with detomidine (DET) alone (0.01 mg/kg, IV) or combined with methadone (MET) (0.01 mg/kg DET and 0.2 mg/kg MET, IV). Cardiopulmonary data and blood samples were collected 30 minutes before (prebaseline and baseline) and for 120 minutes postinjection. The combination DET/MET produced a significant increase (31%) in mean ABP (MAP) 5 minutes after drug administration which lasted for 120 minutes. Detomidine alone induced only a short-term increase in MAP (15%) at 5 minutes compared with baseline. There were significant differences between groups at 5, 15, and from 60 to 120 minutes. Plasma AVP concentrations were higher in horses receiving the treatment DET from 60 to 120 minutes than those in the combination group, for the same period. There were no significant differences in norepinephrine and epinephrine serum concentrations respect to baseline and between treatments. Detomidine induces a short-term MAP increase, and this effect was prolonged and potentiated by MET association. There is no evidence of AVP, norepinephrine, and epinephrine involvement in this effect.

Characteristics and prognostic value of acute catecholamine surge in patients with aneurysmal subarachnoid hemorrhage

Objectives: The characteristics of serum catecholamine concentration at the hyper-acute phase of aneurysmal subarachnoid hemorrhage (SAH) and its relationship between patient outcome and delayed vasospasm were investigated.Methods: Patients with aneurysmal SAH (170) were prospectively studied between August 2008 and June 2011. Baseline demographic data and physiological parameters, including plasma concentrations of adrenaline (AD), noradrenaline (NA), and dopamine (DP) were evaluated for all patients.Results: On admission, plasma AD, NA, and DP levels were significantly higher in patients with a poor clinical grade on admission (Hunt and Kosnik grade: IV–V), compared to those with a good clinical grade on admission (Hunt and Kosnik grade: I–III). AD showed a markedly high concentration immediately after the onset of SAH and then rapidly decreased. NA levels peaked within 6 hours after onset, then significantly decreased. The increase of DP with time was not significant, but showed a similar trend to that of NA. The level of each catecholamine showed significant mutual correlation.Our multivariate model demonstrated that age, poor clinical grade at admission, plasma AD and NA levels were good predictors of poor patient outcome [receiver operating characteristic (ROC) area: 0·83]. And that poor clinical grade at admission, Fisher scale, blood sugar level and plasma AD level were good predictors of the development of delayed vasospasm (ROC area: 0·81) (1·3).Conclusions: The present findings suggest that sympathetic activation in patients in the acute phase of SAH reflects the severity of SAH, and is closely related to the development of delayed vasospasm, leading to the subsequent immune response and inflammatory reactions. Strategies for suppressing catecholamine at the hyper-acute phase may contribute to vasospasm prevention and improve patient outcome.

운동 강도별 동일 회복이 혈중 Cortisol과 Catecholamine 호르몬 변화에 미치는 영향

Abstract This study set out to investigate the effects of the same amount of resting(30 minutes) after VO 2 max 20%, 40%, and 60% exercise on the variation of cortisol and catecholamine, serum stress hormones. The research efforts led to the following conclusions:First, there were no significant differences in serum cortisol concentration between the VO 2 max 20% group and theVO 2 max 40% group, but there were some significant differences in the significance level of p=.002 in the VO 2 max 60% group.Second, there were no significant differences in serum catecholamine concentration between the VO 2 max 20% groupand the VO 2 max 40% group, but there were some significant differences in the significance level of p=.001 in theVO 2 max 60% group.Third, no significant differences were found in the changing rates of serum cortisol concentration between right afterexercise and during break among different levels of exercise intensity according to measuring time. Fourth, there weresignificant differences in the changing rates of serum catecholamine concentration in the significance level of p=.000right after exercise and in the significance level of p=.034 during break In short, there were significant differencesonly in the VO

Endovascular radiofrequency renal denervation in treating refractory arterial hypertension: a preliminary experience

This study was done to investigate the efficacy and safety of percutaneous renal denervation with the Symplicity catheter for reducing blood pressure in patients with essential hypertension resistant to medical therapy (systolic blood pressure >160 mmHg despite the use of three or more antihypertensive drugs, including a diuretic). In September 2010, five patients affected by essential hypertension resistant to medical therapy were treated. All patients were studied by computed tomography angiography (CTA) of the renal arteries before the procedure and underwent follow-up at 30 and 60 days with colour Doppler ultrasound (CDUS) with evaluation of resistive index, glomerular filtration rate (GFR), 24-h blood pressure and serum catecholamine concentration. Student's t test was used to assess the effectiveness of the procedure in lowering blood pressure. In treated patients, mean blood pressure at baseline was 171/100 mmHg [standard deviation (SD) ± 8/10]; mean GFR was 91.6 ml/min/1.73 m(2) (SD ± 15). Blood pressure after the procedure was reduced by -18/-5 and -13/-10 mmHg at 30 and 60 days, respectively, with a mean medication reduction of 3.6. No complications occurred during the intra- or periprocedural period or during short-term follow-up. The Symplicity system proved to be efficacious and without serious adverse events in reducing blood pressure and antihypertensive medication use in patients affected by essential hypertension resistant to medical therapy. Although encouraging, our data are preliminary and need to be validated by larger prospective randomised studies.

Improvement in renal dysfunction and symptoms after laparoscopic adrenalectomy in a patient with pheochromocytoma complicated by renal dysfunction

A 70-year-old patient who was undergoing treatment for diabetes mellitus and chronic hepatitis was admitted to our hospital for evaluation of a tumor in the left adrenal gland (50 x 45 mm) and renal failure. On the basis of the patient's increased serum concentrations of catecholamines and other metabolites and the results of positron emission tomography (PET), the patient was diagnosed with a pheochromocytoma; iodinated metaiodobenzylguanidine ([(131)I]MIBG) scintigraphy was insufficient to establish this diagnosis. Subsequently, he underwent surgery for tumor resection. Histological examination suggested the tumor to be a malignant pheochromocytoma. After left adrenalectomy was performed, the elevated catecholamine and metabolite concentrations and the blood pressure were restored to normal, and the patient's symptoms of severe headaches and vertigo reduced. Furthermore, his renal function improved (Cr 2.0-1.2 mg/dl). Our patient exhibited a rare condition of pheochromocytoma complicated by renal failure, which was successfully treated with laparoscopic surgery.

Anestesia total intravenosa para recolocación de un desfibrilador automático implantable en paciente con síndrome de QT-largo

We report the case of a 27-year-old woman with congenital long QT syndrome (LQTS) who was scheduled for surgery to reposition an implantable defibrillator. Given the risk of sudden death due to fatal ventricular arrhythmia, the woman required implantation of a defibrillator with pacemaker capability. Combined anesthesia-analgesia was used in order to minimize the risk of ventricular arrhythmia caused by increased serum concentrations of catecholamines. When cardioversion, defibrillation and anti-tachycardia functions had been deactivated, anesthesia was induced with propofol, fentanyl and rocuronium. Anesthesia was maintained with an infusion of propofol and remifentanil. We describe the pathophysiology and treatment of LQTS and discuss anesthetic management for repositioning a defibrillator in a patient with congenital LQTS.

Anesthetic management of simultaneous coronary artery bypass grafting and cardiac pheochromocytoma resection under cardiopulmonary bypass

We experienced simultaneous coronary artery bypass grafting and cardiac pheochromocytoma resection under cardiopulmonary bypass in a 79-year-old woman with atherosclerotic angina. During manipulation of the tumor under cardiopulmonary bypass, the serum norepinephrine concentration increased to over seventy times the normal limit, and there was a 25-mmHg rise in mean arterial pressure. Cardiopulmonary bypass has been recommended for the resection of cardiac pheochromocytoma to isolate the heart from the systemic circulation, and thus prevent massive catecholamine release when handling the tumor. However, the serum catecholamine concentration surged in our patient during tumor manipulation under cardiopulmonary bypass, probably because of the reperfused blood from the operating field. We suggest that cardiopulmonary bypass be performed for the anesthetic management of cardiac pheochromocytoma resection, because excessive hypertension can be avoided during cardiopulmonary bypass, even if the catecholamine concentration increases excessively when handling the tumor.

Warming of Intravenous Fluids Prevents Hypothermia During Off-Pump Coronary Artery Bypass Graft Surgery

Even mild perioperative hypothermia (34 degrees -36 degrees C) can cause numerous adverse outcomes, including morbid cardiac events, coagulopathy with increased blood loss, and a decreased resistance to surgical wound infection. The purpose of this study was to evaluate the effect of fluid warming on preventing hypothermia during off-pump coronary artery bypass (OPCAB) surgery. A prospective randomized clinical study. A tertiary care university hospital. Forty patients undergoing OPCAB procedures. Patients were randomized into control (n = 20) and Hotline (n = 20) groups. In the Hotline group, all intravenous fluids were warmed to 41 degrees C by using 2 Hotline (SIMS Inc, Rockland, MD) systems. All patients (control and Hotline groups) were managed with standardized institutional practice by using a combination of increased ambient operating room temperature (to 25 degrees C) and the use of a warmed water mattress (38 degrees C). Temperatures were recorded every hour after the induction of anesthesia at the pulmonary artery, nasopharynx, rectum, and bladder. In the Hotline group, temperatures were maintained or increased. In the control group, temperatures gradually decreased. There were no significant differences between the 2 groups in hemodynamic parameters, serum catecholamine concentrations, duration of intensive care unit stay, or duration of ward stay. The results show that the warming of intravenous fluids by using the Hotline system prevents decreases in systemic temperatures during OPCAB surgery.

Effect of dietary soluble fiber on neurohormonal profiles in serum and brain of rats

This study was conducted to investigate the effect of dietary soluble fiber administration and /or high fat diet on serum and brain neurohormonal profiles, adipose tissue mass and body weight gain in Sprague-Dawley rats. Four groups of rats were respectively fed 10% fat diet (C), 10% fat plus pectin diet (P), 20% fat diet (HFC) and 20% fat plus pectin diet (HFP) for 4 weeks. In HFP group, the food and energy intake, body weight gain, FER including fecal excretion were the smallest (p<0.05). Serum HDL-cholesterol, triglyceride and glucose level were also the lowest in HFP group (p<0.05). The weight of brain, epididymal fat pad and adrenal gland except liver didn't show any significant differences among groups. Interestingly serum norepinephrine concentration of HFP group tended to be higher, but dopamine concentration tended to be lower than those of HFC group. However serum catecholamine concentration didn't show any significant differences among all groups. Norepinephrine and epinephrine contents of right portion of midbrain of P and HFP groups were remarkably lower than those of the C group. These results suggested that soluble fiber pectin consumption might affect neurohormonal profiles in serum and brain according to dietary fat level.

Cigarette Smoking and the Risk of Supraventricular and Ventricular Tachyarrhythmias in High‐Risk Cardiac Patients with Implantable Cardioverter Defibrillators

Nicotine elevates serum catecholamine concentration and is therefore potentially arrhythmogenic. However, the effect of cigarette smoking on arrhythmic risk in coronary heart disease patients is not well established. The risk of appropriate and inappropriate defibrillator therapy by smoking status was analyzed in 717 patients who received an implantable cardioverter defibrillator (ICD) in the Multicenter Automatic Defibrillator Implantation Trial-II. Compared with patients who had quit smoking before study entry (past smokers) and patients who had never smoked (never smokers), patients who continued smoking (current smokers) were significantly younger and generally had more favorable baseline clinical characteristics. Despite this, the adjusted hazard ratio (HR) for appropriate ICD therapy for fast ventricular tachycardia (at heart rates >or=180 b.p.m) or ventricular fibrillation was highest among current smokers (HR = 2.11 [95% CI 1.11-3.99]) and intermediate among past smokers (HR = 1.57 [95% CI 0.95-2.58]), as compared with never smokers (P for trend = 0.02). Current smokers also exhibited a higher risk of inappropriate ICD shocks (HR = 2.93 [95% CI 1.30-6.63]) than past (HR = 1.91 [95% CI 0.97-3.77]) and never smokers (P for trend = 0.008). In patients with ischemic left ventricular dysfunction, continued cigarette smoking is associated with a significant increase in the risk of life-threatening ventricular tachyarrhythmias and inappropriate ICD shocks induced by rapid supraventricular arrhythmias. Our findings stress the importance of complete smoking cessation in this high-risk population.

Assessment of serum catecholamine concentrations in patients with pheochromocytoma undergoing videolaparoscopic adrenalectomy

We analyzed the changes in serum catecholamine concentrations, i.e. adrenaline and noradrenaline, in response to surgical stress in patients with pheochromocytoma who undergone videolaparoscopic adrenalectomy. Between January 1998 and March 2002, 11 patients underwent 12 videolaparoscopic adrenalectomies. In one case, the adrenalectomy was bilateral. Serum catecholamines were measured at 6 surgical times: T0: control before induction; T1: following the induction, laryngoscopy and intubation sequence; T2: after installing the pneumoperitoneum; T3: during manipulation-exeresis of the pheochromocytoma; T4: following ablation of the pheochromocytoma; T5: in the recovery room following intervention when the patient was extubated and was hemodynamically stable. Mean concentrations of serum noradrenaline were significantly different when the T0 and T2 surgical times were compared (T0: 3161 pg/mL; T2: 40440 pg/mL; p < 0.01), T0 and T3 (T0: 3161 pg/mL; T3: 46021 pg/mL; p < 0.001), T1 and T3 (T1: 5531 pg/mL; T3: 46021 pg/mL; p < 0.01), T2 and T4 (T2: 40440 pg/mL; T4: 10773 pg/mL; p < 0.01) and T3 and T5 (T3: 46021 pg/mL; T5: 2549 pg/mL; p < 0.001). Mean concentrations of serum adrenaline were significantly different when the T0 and T3 surgical times were compared (T0: 738 pg/mL; T3: 27561 pg/mL; p < 0.01). The pneumoperitoneum significantly increases serum noradrenaline concentrations, manipulation of the adrenal gland significantly increases the serum concentrations of noradrenaline and adrenaline, and the pheochromocytoma ablation significantly decreases serum noradrenaline concentrations.

Changes in catecholamine metabolism by ascorbic acid deficiency in spontaneously hypertensive rats unable to synthesize ascorbic acid

We have previously reported the establishment of a novel rat strain, SHR-od, with both spontaneous hypertension and a defect of ascorbic acid biosynthesis. Blood pressure in mature SHR-od fed an ascorbic acid-supplemented diet is over 190–200 mmHg, while it decreased to around 120 mmHg at 4–5 weeks after the cessation of ascorbic acid supplementation. With regard to possible mechanisms of blood pressure lowering, we focused on catecholamine synthesis in adrenal glands, since catecholamine is a major factor for blood pressure regulation and ascorbic acid is a co-factor of dopamine β-hydroxylase (DBH) in catecholamine biosynthesis. Male SHR-od (25-week-old) and normotensive ODS rats with a defect in ascorbic acid biosynthesis (25-week-old) were fed a Funabashi-SP diet with or without ascorbic acid (300 mg/kg diet) for 28 days or 35 days. In SHR-od, systolic blood pressure (191 ± 6 mmHg) began to decrease from day 21 in the ascorbic acid-deficient group, whereas no significant difference was found in ODS rats. In spite of significant lowering of blood pressure, no significant differences were found in catecholamine levels in serum, adrenal glands and brain on day 28. On day 35, however, urinary excretion of norepinephrine and epinephrine in the ascorbic acid-deficient SHR-od were higher at 490% ( P < 0.05) and 460% ( P < 0.05) of the respective control. Serum catecholamine concentrations and the adrenal catecholamine content tended to be higher in the ascorbic acid-deficient SHR-od than the control of SHR-od and reached to similar level in ODS rats. The administration of ascorbic acid (intraperitoneal injection, 60 mg ascorbic acid/kg body weight, once a day) to the ascorbic acid-deficient SHR-od restored blood pressure to the range 180–190 mmHg within two days. These findings indicate that ascorbic acid deficiency affects catecholamine metabolism in the adrenal glands of SHR-od in response to blood pressure lowering, suggesting catecholamines are not involved in the mechanism for the remarkable reduction in blood pressure in response to ascorbic acid deficiency.

Quantification of cardiac stress during EGD without sedation

Background: Although the complication rate of endoscopy is low, EGD may induce cardiac stress. The aim of this study was to quantify cardiac stress during EGD. Methods: Heart rate, blood pressure, cardiac output, and peripheral oxygen saturation were measured during endoscopy without sedation in 7 volunteers. Cardiac output was measured with an automated echocardiographic technique. Cardiac index, left ventricular work index, and rate-pressure product were calculated. Serum catecholamine concentrations were measured before and after the examination. Results: Heart rate increased significantly when the endoscope was located in the esophagus compared with the rate before insertion (p < 0.05). No significant changes in cardiac index and left ventricular work index were observed during endoscopy. Rate-pressure product increased significantly at the point of esophageal observation compared with that before insertion (p < 0.05). The rate-pressure product was maximally increased during esophageal observation at 66% over baseline (95% CI [45%, 86%]). Serum concentration of norepinephrine rose significantly after the examination (p < 0.05). Conclusions: Cardiac output did not increase during EGD without sedation in healthy male volunteers. Cardiac stress increased during EGD as indicated by a 66% increase in rate-pressure product. The cardiac stress was approximately equal to that observed in 3.3 to 5 metabolic equivalents of treadmill exercises. (Gastrointest Endosc 2002;55:58-64.)