Use of an ultra short-acting beta-blocker in patients with acute myocardial ischemia

Esmolol is a new ultra short-acting (half-life [t1/2] beta 9 min) beta 1-adrenergic-receptor antagonist reported to have no intrinsic sympathomimetic activity. The safety and efficacy of esmolol in lowering the ventricular rate and rate-pressure product in patients with acute myocardial infarction (n = 5), postmyocardial infarction angina (n = 10), or acute unstable angina (n = 4), and without cardiogenic shock were studied. After a 30 min observation period, esmolol was titrated to a maximum dose of 300 micrograms/kg/min and infused for up to 420 min. The ventricular rate fell from 92 +/- 11 (mean +/- SD) to 77 +/- 13 beats/min (p less than .01) and the systolic arterial pressure decreased from 120 +/- 13 to 97 +/- 11 mm Hg (p less than .01) during the initial 30 min titration period. There was no significant change during the maintenance phase, and both the ventricular rate and arterial pressure returned rapidly toward baseline values within 30 min of termination of the infusion. The cardiac index fell from 2.8 +/- 0.6 to 2.2 +/- 0.6 liters/min/m2 (p less than .01) during the same period, and also returned to the baseline level 30 min after termination of the infusion. There was no significant change in the pulmonary capillary wedge pressure, respiratory rate, or PR interval. Five patients required termination of infusion because of hypotension and all recovered uneventfully within 30 min of stopping the esmolol. One patient required a brief infusion of dopamine to restore hemodynamic stability.(ABSTRACT TRUNCATED AT 250 WORDS)     

Comparative efficacy and tolerance of esmolol to propranolol for control of supraventricular tachyarrhythmia

This multicenter, double-blind, randomized, parallel study compared the effectiveness and tolerance of intravenous esmolol with intravenous propranolol in patients with supraventricular tachyarrhythmia (heart rate [HR] greater than 120 beats/min). Efficacy was evaluated in 53 patients receiving esmolol and in 57 patients receiving propranolol. Patients randomized to esmolol received infusions of various doses of esmolol ranging from 50 to 300 micrograms/kg/min (each dose infused for 5 minutes) over a 30-minute titration period with intermittent placebo boluses of propranolol. Those randomized for propranolol received 1 mg/min for the first 3 minutes, and then another 3 mg from minutes 5 to 8 with continuous placebo esmolol infusion during the 30-minute titration period. A therapeutic response, defined by 20% or greater reduction in HR, HR less than 100 beats/min or conversion to normal sinus rhythm, was achieved in 72% of patients on esmolol compared with 69% of patients on propranolol (difference not significant). The therapeutic response was maintained in 67% of patients on esmolol and 58% of patients on propranolol (difference not significant) during a 4-hour maintenance period. Conversion to normal sinus rhythm occurred in 14% of esmolol patients and 16% of propranolol patients during titration and 10% of esmolol and 8% of propranolol patients during maintenance. After discontinuation of study drugs, a more rapid reversal of the reduction in HR was observed in esmolol patients compared with those patients receiving propranolol. Adverse reactions were seen in 29 (45%) patients on esmolol and 11 (18%) patients on propranolol. The principle adverse reaction was hypotension, which was predominantly asymptomatic and found in 23 patients receiving esmolol and 4 receiving propranolol.(ABSTRACT TRUNCATED AT 250 WORDS)     

Use of an ultrashort-acting beta-receptor blocker (esmolol) in patients with acute myocardial ischemia and relative contraindications to beta-blockade therapy

The hemodynamic responses to esmolol, an ultrashort-acting (t1/2 = 9 min) beta 1-adrenergic receptor antagonist, were examined in 16 patients with myocardial ischemia and compromised left ventricular function as evidenced by a mean pulmonary capillary wedge pressure of 15 to 25 mm Hg. Esmolol was infused intravenously to a maximal dose of 300 micrograms/kg body weight per min for less than or equal to 48 h in 16 patients: 9 with acute myocardial infarction, 6 with periinfarction angina and 1 with acute unstable angina. The sinus rate and systolic arterial pressure declined rapidly in all patients from baseline values of 99 +/- 12 beats/min and 126 +/- 19 mm Hg to 80 +/- 14 beats/min (p less than 0.05) and 107 +/- 20 mm Hg (p less than or equal to 0.05) during esmolol treatment. Rate-pressure product decreased by 33% and cardiac index by 14% during esmolol treatment, but pulmonary capillary wedge pressure was not significantly altered by drug infusion (19 +/- 3 mm Hg at baseline versus 19 +/- 5 during treatment, p = NS). In all patients there was a rapid return toward baseline hemodynamic measurements within 15 min of stopping administration of esmolol, and virtually complete resolution of drug effect was evident within approximately 30 min. During infusion of esmolol, four of nine patients receiving intravenous nitroglycerin required downward adjustment of nitroglycerin infusion rate to maintain systolic blood pressure greater than 90 mm Hg.(ABSTRACT TRUNCATED AT 250 WORDS)     

Effects of esmolol on cardiac function: evaluation by noninvasive techniques

In a double-blind, randomized, crossover study, the effects of esmolol and propranolol were examined at rest and during peak upright exercise in 15 patients. At rest, both esmolol and propranolol significantly decreased heart rate, systolic blood pressure, rate-pressure product, left ventricular ejection fraction, cardiac index and right ventricular ejection fraction. During exercise, significant decreases were also found in heart rate, systolic blood pressure and cardiac index in both treatment groups. No significant differences were found between mean esmolol and mean propranolol measurements at rest and during exercise, except for the exercise systolic blood pressure, which was lower during esmolol infusion. Blood levels of esmolol decreased markedly by 30 minutes postinfusion, as did its beta-blocking action. Esmolol was well tolerated with no important local, systemic or laboratory abnormalities. Thus, the effects of esmolol on cardiovascular performance at rest and during exercise are similar to those of propranolol.     

术中预防性应用艾司洛尔对高龄心肌缺血患者的心肌保护作用

目的研究术中预防性应用艾司洛尔对高龄心肌缺血患者的心肌保护作用。方法选取年龄75岁以上,符合美国麻醉医师协会(ASA)分级Ⅱ～Ⅳ级,拟于全身麻醉下行全髋关节置换术、股骨头置换术或股骨颈骨折切开/闭合复位内固定手术的心肌缺血患者30例,完全随机法分为观察组和对照组各15例。分别记录患者入手术室后、静脉泵注艾司洛尔后、神经阻滞后、诱导后、气管插管后、拔管后的心率(HR)、收缩压(SBP)、舒张压(DBP)、平均动脉压(MBP)、心率-收缩压乘积(RPP)、心电图ST段变化及心肌缺血发生率。结果观察组诱导、插管、拔管后HR[(66±7)次/min,(67±8)次/min,(70±16)次/min]明显低于相同时点对照组[(78±8)次/min,(73±10)次/min,(97±12)次/min,均为P<0.05];在麻醉期间(T1～5)观察组RPP(10 279±1833,8188±869,6970±805,6659±1420,9141±1763)均明显低于对照组(12 198±1825,9336±671,8598±1473,8091±1757,10 082±1396,均为P<0.05)。观察组心肌缺血发生率及持续时间、麻醉中尼卡地平总用量[0.07%,(90±0)min,(1.00±1.53)mg]均明显小于对照组[20.0%,(233±91)min,(2.00±1.52)mg,均为P<0.05]。麻醉结束时观察组ST段下移值明显低于患者入手术室时基础值[(-0.04±0.02)mV比(-0.08±0.05)mV,P<0.05],而对照组ST段较前差异无统计学意义[(-0.04±0.03)mV比(-0.03±0.02)mV,P>0.05]。结论术中预防性应用艾司洛尔可降低高龄心肌缺血患者全身麻醉时的心肌氧耗及心肌缺血发生率。     

Intravenous esmolol for the treatment of supraventricular tachyarrhythmia: Results of a multicenter,baseline-controlled safety and efficacy study in 160 patients

Efficacy and safety of esmolol in the treatment of supraventricular tachyarrhythmias (SVT) was evaluated in this open-label, baseline-controlled, multicenter study. One hundred sixty patients with SVT received an intravenous infusion of esmolol in doses ranging from 25 to 300 μg/kg/min for up to 24 hours. All of the 160 patients were evaluated for safety, and 147 of them were eligible for evaluation of therapeutic response. Therapeutic response was defined as ≥ 15% reduction in the average baseline heart rate or conversion to normal sinus rhythm. Seventy-nine percent (116 of 147) of the patients exhibited a therapeutic response. The cumulative percentage response increased significantly with increasing esmolol doses up to 200 μg/kg/min. The mean (±SEM) dose of esmolol producing a therapeutic response was 97.2 ± 5.5 μg/kg/min. Among all patients (n = 160), 39% exhibited hypotension. In 58% of these patients, hypotension resolved with or without adjustment of the esmolol dose while the infusion continued; among almost all of the remaining patients, hypotension resolved within 30 minutes after esmolol was discontinued. Most patients at risk for adverse effects during beta blockade (i.e., those with diabetes mellitus, congestive heart failure, asthma, etc.) tolerated esmolol therapy, and there were no clinically important trends among the reported changes in laboratory variables. The results of the study indicate that esmolol is effective and well tolerated for the treatment of SVT.     

A new dosing regimen for esmolol to treat supraventricular tachyarrhythmia in Chinese patients

Objective. The purpose of this study was to find a safe dosing regimen for esmoiol infusion to rapidly control supraventricular tachyarrhymia after cardiac surgery to Chinese patients.Background. Tachycardia increase cardiac work but reduces myocardial perfusion. Thus, in the critical period immediately after cardiac surgery, tachycardia itself warrants urgent intervention. Esmolol an ultrashort-acting beta-adrenergic blocking agent, has been reported In western published reports to have good remits and few side effects In the treatment of supraventricular tachyarrhythmia. However, its clinical application in Chinese patients has not yet been reported.Methods. When supraventricular tachyarrhymia with a rapid ventricular response (>110/min) was found early after surgery esmolol infusion with a different dosing regimen was used to control the tachyarrhythmia.Results. With the dosing regimen recommended in western published reports (repeated loading infusion with stepwise increment), acute hypotension with systolic pressure <80 mm Hg occurred in all ste patients after 1 min of loading infusion of esmolol (500 μg/kg body weight per min). To avoid the aforementioned complications, a new dosing regimen was constructed. The initial infusion rate of esmolol was set at 150 or 100 μg/kg per min, depending on the patient's age and blood pressure. When the desired heart rate was achieved, the initial infusion rate was reduced to the maintenance infusion rate to maintain the therapeutic effect [Maintenance infusion rate = Initial infusion rate x (1 − e^−0.077t), where t is the time period in minutes required by the initial infusion of esmolol to achieve the therapeutic effect]. With this new dosing regimen, tachycardia in most patients (9 of 11) could be controlled within 10 mm, and no one experienced the side effect of hypotension. The maintenance infusion rate of esmolol needed to control supraventricular tachyarrhythmia in our patients was only 73 ± 42 μg/kg per min (mean ± SD), much less than that noted hi western reports.Conclusions. The dosing reghnen for esmolol infusion recommended in western studies is not suitable for Chinese patients. In this report we propose a new dosing regimen for esmolol infusion that is both safe and rapid in the treatment of supraventricular tachyarrhythmia in Chinese patients.     

静脉注射艾司洛尔治疗急性心肌梗死并发急性心力衰竭的疗效及安全性

目的探讨静脉注射艾司洛尔治疗急性心肌梗死(AMI)并发急性心力衰竭(AHF)的临床疗效。方法入选11例AMI患者并发AHF、心功能KillipⅡ～Ⅲ级,在常规标准抗缺血、抗心力衰竭治疗效果欠佳,且伴有血压和心率较基线水平升高的条件下,给予静脉注射艾司洛尔(负荷剂量0.5 mg/kg 1 min内静脉注射,继之0.05 mg.kg-1.min-1持续静脉泵入),观察患者治疗前后生命体征、临床表现及X线胸片肺淤血程度的变化。结果 (1)与治疗前比较,11例患者接受静脉注射艾司洛尔治疗(中位给药时间38.5 h)后,收缩压降低[(109±16)mm Hg比(136±18)mm Hg]、舒张压降低[(61±8)mm Hg比(77±11)mm Hg]、心率减慢[(71±11)次/min比(96±31)次/min],差异均有统计学意义(均为P<0.05);(2)11例患者经治疗后,心力衰竭症状均明显缓解,肺部啰音均明显减少,X线胸片肺淤血程度均明显减轻;(3)11例患者治疗过程中均未发生低血压、严重缓慢性心律失常等不良反应。结论对于AMI患者,若病程中发生以缺血为诱因的AHF且伴有血压、心率较基础水平升高,可在常规治疗基础上,加用静脉注射艾司洛尔,可以获得良好的临床疗效,并且无明显不良反应。     

Successful Use of Intravenous B-blocker Therapy in Cardiogenic Shock Supported With Venoarterial Extracorporeal Membrane Oxygenation: A Case Series

Tachycardia in cardiogenic shock (CS) might reduce the cardiac output (CO) by decreasing the ventricular filling time. Nevertheless, heart rate (HR) control with agents that possess negative inotropy might decrease the CO. Therefore, controlling the tachycardia in the setting of CS remains controversial. We herein describe four cases of patients presenting with myocardial infarction complicated with CS that required rescue venoarterial extracorporeal membrane oxygenation (VA-ECMO) initiation. Tachycardia was present with HR ～130-140 beats per minute after VA-ECMO initiation, and hence esmolol was infused continuously at a starting dose of 10-20 mcg/kg/min and titrated according to HR. With the use of esmolol to control the HR in the setting of CS supported with VA-ECMO, lactate cleared, and echocardiographic parameters improved, allowing the four cases to be successfully decannulated from ECMO. Our report indicates that short-acting beta-blocker could be safely used in the complex scenario of severe tachycardia while supported with VA-ECMO.     

On the possibility of accelerating thrombolytic therapy in the acute phase of myocardial infarction: efficacy of and tolerance to the infusion of 1.5 million units of streptokinase in 30 minutes

To evaluate efficacy and tolerability of the systemic infusion of 1,500,000 streptokinase units in 30', we treated 26 consecutive patients with acute myocardial infarction within 3 hours of the onset of chest pain. They were 23 men and 3 women, mean age was 59 +/- 8 years. None of them had a history of previous myocardial infarction. From clinical and electrocardiographic data, as well as from creatine kinase curves, we assumed myocardial reperfusion in 19 patients (73%). Within 30' after infusion, thrombin time increased to more than 300" in 25/26 patients (96%). Streptokinase induced hypotension (which we defined as a decrease in systolic blood pressure of more than 30 mmHg) in 13 patients (50%), and in 5 of them (19%) systolic blood pressure fell below 90 mmHg. Hypotension was counteracted by adopting the Trendelenburg position in 7 patients, and by an intravenous infusion of atropine in 5. In the remaining patient, streptokinase infusion was slowed down. Due to these interventions, a non-significant decrease in systolic blood pressure was observed from 129 +/- 26 to 112 +/- 20 mmHg at the end of the infusion. Streptokinase-induced hypotension was not predicted either by clinical, or electrocardiographic, or chest X-ray film data, or laboratory findings. No other side-effects occurred. Hence, the infusion of 1,500,000 streptokinase units in 30' in the acute phase of myocardial infarction is active, and well tolerated. It must be emphasized, however, that during the infusion, hypotension occurs frequently and unpredictably, sometimes reaching alarm levels. This makes the monitoring of systolic blood pressure imperative during streptokinase infusion.     

盐酸艾司洛尔心电生理学特性的研究

目的观察国产盐酸艾司洛尔(esmolol)对中国人的电生理学效应,以评价其临床应用前景.方法对20例行心内电生理检查的患者分别于静脉注射盐酸艾司洛尔前及注射过程中测定各项心脏电生理指标,包括窦房结、心房、房室结、心室以及希-浦系功能,同时,观察血压、心率与心电图各项参数(PR、QRS、QT间期)的变化.结果用药时与基础状态比较窦房结恢复时间(SNRT)、心房有效不应期(A-ERP)、房室结有效不应期(AVN-ERP)、房室结前传文氏点(AVN-WCL)、AH间期明显延长,有显著性差异(P＜0.05～0.01),而窦房结传导时间(SACT)、PA间期、HV间期、心室有效不应期(V-ERP)以及心电图各项参数无明显改变;对收缩压无影响,但可降低舒张压、平均动脉压、心率及心率血压乘积(RPP),有显著性差异(P＜0.05～0.01),从而降低心肌耗氧量,而在停药后20*!min内心率,血压,心率血压乘积即基本恢复至基础状态.结论国产盐酸艾司洛尔主要作用于窦房结、心房与房室结,对希-浦系和心室功能无影响,起效迅速,停药后临床作用消失快,可根据临床状况的变化及时调整剂量,并可作为临床状况不稳定的室上性心动过速患者的首选抗心律失常药物之一.     

Intravenous versus Oral Beta-Blockers for Prevention of Post-CABG Atrial Fibrillation in High-Risk Patients Identified by Signal-Averaged ECG: Lessons of a Pilot Study

Atrial fibrillation (AF) is the most common complication of coronary artery bypass grafting (CABG), usually occurring on the second or third post-operative day. Post-operative AF is associated with prolonged hospital stay and increased costs. In several randomized trials, prophylactic oral beta-blocker reduced the incidence of post-operative AF. Theoretically, intravenous beta-blocker regimen with its rapid onset of action and ease of dose titration should be more efficacious than oral beta-blocker. We conducted an open-label randomized controlled pilot study, compared the efficacy of intravenous esmolol and an oral beta-blocker regimen for prevention of post-operative AF. Fifty patients at high-risk of developing post-operative AF (P wave duration >140 ms on signal averaged (SA) ECG) were randomized to either 24-hours of intravenous esmolol treatment post-CABG followed by oral beta-blocker or standard oral beta-blocker treatment. Seven (26%) out of 27 patients in the esmolol group and 6 (26%) out of 23 patients in the oral beta-blocker group developed post-operative AF (p = NS). The day of onset and duration of AF was similar between the two groups. In the esmolol group, 11 (41%) patients developed adverse effects, mostly hypotension, compared to only one patient (4%) in the oral beta-blocker group (p = 0.006). The result of this pilot study showed that intravenous esmolol compared to oral beta-blocker offers no advantage in preventing post-operative AF and is associated with increased adverse events. Thus, all patients without contraindication should receive oral beta-blocker before and after cardiac surgery to prevent post-operative AF.     

Save the Heart – Optimizing Our Methods

Background: We hypothesized that measurement of B-type natriuretic peptide could identify patients with non-ST elevation acute coronary syndromes at high risk for complications during beta-blocker (esmolol) infusion. Methods: We reviewed the records of 340 consecutive patients admitted with a non-ST elevation acute coronary syndrome. Seventy three (47 males, aged 62 ± 14 years) received esmolol up to a maximum dose of 300 μg/ kg/min until the symptoms were relieved or an adverse event occurred. Results: The median infusion rate at steady state was 175 μg/kg/min (median infusion time 18 h). Infusion was halted in 14 patients. The frequency of drug discontinuation increased across admission BNP quartiles. BNP > 141 pg/ml at admission had a 95% predictive value for subsequent withdrawal of esmolol. The presence of BNP > 141 pg/ml in combination with systolic blood pressure < 130 mmHg and left ventricular ejection fraction < 50% identified a group of patients at high risk for drug interruption (interruption frequency = 83%, 95% CI: 55–95%). Conclusions: In conclusion, BNP measurement in combination with systolic blood pressure and 2D echocardiography may identify patients with non-ST elevation acute coronary syndromes at high risk for adverse events during esmolol infusion.     

Use of intravenous esmolol to predict efficacy of oral beta-adrenergic blocker therapy in patients with neurocardiogenic syncope.

The usefulness of esmolol in predicting the efficacy of treatment with an oral beta-adrenergic blocking agent was evaluated in 27 consecutive patients with neurocardiogenic syncope. Seventeen patients had a positive head-up tilt test response at baseline and 10 patients required intravenous isoproterenol for provocation of hypotension. All patients were then given a continuous esmolol infusion (500 micrograms/kg per min loading dose for 3 min followed by 300 micrograms/kg per min maintenance dose) and rechallenged with a head-up tilt test at baseline or with isoproterenol. Of the 17 patients with a positive baseline tilt test response, 11 continued to have a positive response to esmolol challenge. Sixteen patients (including all 10 patients with a positive tilt test response with isoproterenol) exhibited a negative response to upright tilt during esmolol infusion. Irrespective of their response to esmolol infusion, all patients had a follow-up tilt test with oral metoprolol after an interval of greater than or equal to 5 half-lives of the drug. All 16 patients (100%) with a negative tilt test response during esmolol infusion had a negative tilt test response with oral metoprolol. Of the 11 patients with a positive tilt test response during esmolol infusion, 10 (90%) continued to have a positive response with oral metoprolol. It is concluded that in the electrophysiology laboratory, esmolol can accurately predict the outcome of a head-up tilt response to oral metoprolol. This information may be helpful in formulating a therapeutic strategy at the initial head-up tilt test in patients with neurocardiogenic syncope.     

β受体阻滞剂对军事训练后心血管病高危患者应激反应与心功能的影响

目的 观察β受体阻滞剂对心血管病高危患者军事训练后应激反应与心脏功能的影响.方法 采用问卷调查、体格检查和12导联心电图综合调查的方法,纳入某集团军心血管病高危人群同时心率≥60次/min者80例,随机分为高危给药组（n=40）和高危对照组（n=40）,另选取低危人群中心率≥60次/min且年龄相当者40例作为低危对照组.高危给药组在运动前5天起持续给予琥珀酸美托洛尔（23.75 mg,qd）,高危对照组和低危对照组予相同剂量安慰剂.比较三组5千米跑步运动前后心率、血压变化,以及肾上腺素（EPI）、超敏C反应蛋白（hs-CRP）、热休克蛋白70（HSP70）和脑钠肽（BNP）浓度的变化.结果 运动前三组心率血压乘积和各项生化指标无明显差异,运动后低危对照组、高危给药组和高危对照组心率血压乘积、EPI、hs-CRP、HSP70、BNP浓度均逐渐升高,两两之间都存在统计学差异（P＜0.05）.结论 心血管病高危患者军事训练后的应激反应及心脏功能改变较低危者明显,提前应用β受体阻滞剂可以改善这一趋势,有助于减少急性心血管病事件甚至心源性猝死的发生.     

Esmolol: a new ultrashort-acting beta-adrenergic blocking agent for rapid control of heart rate in postoperative supraventricular tachyarrhythmias

Prompt control of heart rate is important for successful treatment of supraventricular tachyarrhythmias early after open heart surgery when sympathetic tone is high and ventricular response rates may be rapid. Esmolol, a new ultrashort-acting (9 minute half-life) beta-receptor blocking agent, was given by continuous intravenous infusion for up to 24 hours in 24 patients (21 with isolated coronary bypass surgery and 3 with valve replacement) 1 to 7 days after surgery. Atrial fibrillation was present in 9 patients, atrial flutter in 2 and sinus tachycardia in 13. Eleven patients had received intravenous digoxin (average dose 0.6 mg, average serum level 1.19 mg/100 ml) before esmolol infusion without adequate control of the supraventricular tachyarrhythmia. After a 1 minute loading infusion of esmolol (500 micrograms/kg per min), maintenance dose, titrated to heart rate and blood pressure response, varied from 25 to 300 micrograms/kg per min. After esmolol administration, at an average dose of 139 +/- 83 micrograms/kg per min, mean heart rate decreased from 130 +/- 15 to 99 +/- 15 beats/min. Within 5 to 18 minutes after initiation of therapy, all patients had achieved a 15% reduction in heart rate at a maintenance dose of 150 micrograms/kg per min or less. A 20% reduction in heart rate was attained in 19 of the 24 patients, and conversion to sinus rhythm occurred during esmolol infusion in 5 of the 11 patients with atrial flutter or fibrillation. Transient asymptomatic hypotension (less than 90/50 mm Hg) was seen in 13 patients, requiring cessation of esmolol therapy in 2.(ABSTRACT TRUNCATED AT 250 WORDS)     

尼卡地平与硝普钠用于主动脉腔内修复术控制性降压效果的比较

目的:观察尼卡地平用于覆膜支架主动脉腔内修复术中控制性降压的效果,并与传统降压药物硝普钠进行比较。方法:选用40例Standford B型主动脉夹层拟经股动脉行覆膜支架主动脉腔内修复手术患者,随机分为尼卡地平(N)组和硝普钠(S)组。观察2组降压前、降压4 min和停止降压后10 min、20 min的心率(HR)、收缩压(SBP)、舒张压(DBP)、中心静脉压(CVP)和收缩压与心率乘积(RPP)的变化。结果:应用两种方法均呈现较明显的降压效果。与降压前比较,SBP、DBP明显下降(P<0.01),N组HR无显著变化,S组HR明显增快(P<0.05)。停止用药后,N组血压变化平稳,缓慢回升;S组有血压反跳现象(P<0.05)。降压4 min时,N组RPP明显下降(P<0.05),S组RPP无显著变化。CVP无显著变化。结论:尼卡地平用于夹层动脉瘤覆膜支架主动脉腔内修复术中的控制性降压作用迅速,用药后对心率无显著影响,其效果优于硝普钠,特别适用于伴有冠心病行主动脉夹层腔内修复术的患者。     

Fentanyl for sedation during upper gastrointestinal endoscopy

The effects of sedation by intravenous fentanyl on the rate-pressure product (pulse rate x systolic blood pressure/100), arterial oxygen saturation, electrocardiographic change, and serum cortisol concentration were studied during gastroduodenoscopy in 84 patients randomized to receive fentanyl or no intravenous sedative (controls). Fentanyl administration increased the tolerance of patients and attenuated the endoscopy-induced rise in rate-pressure product and serum cortisol concentration. Desaturation of arterial oxygen was minimal and there was no difference in arterial oxygen saturation between the fentanyl group and the control group. Therefore, fentanyl appears to be a favorable sedative for upper gastrointestinal endoscopy, since its administration increased the tolerance of patients and decreased cardiac oxygen consumption.     

Comparison of the efficacy and safety of esmolol, a short-acting beta blocker, with placebo in the treatment of supraventricular tachyarrhythmias.The Esmolol vs Placebo Multicenter Study Group

The efficacy and safety of esmolol, a short-acting intravenous beta-adrenergic-blocking agent, and placebo were compared in patients with supraventricular tachyarrhythmias (heart rate greater than 120 bpm) in a multicenter, double-blind, partial-crossover study. Seventy-one patients were randomized to receive either esmolol (n = 36) or placebo (n = 35) as initial treatment. Therapeutic failures were crossed over to the other study medication. Therapeutic response was defined as greater than or equal to 20% reduction in heart rate, heart rate less than 100 bpm, or conversion to normal sinus rhythm. The therapeutic response to esmolol during the initial treatment period (72%) was similar to that obtained when esmolol was given as a second agent. The average esmolol dosage producing a therapeutic response was 97.5 micrograms/kg/min. Four patients (6%) converted to normal sinus rhythm during esmolol infusion. In the majority of patients (80%), therapeutic response was lost within 30 minutes following discontinuation of esmolol infusion, a finding indicative of rapid reversal of beta-adrenoceptor blockade. The most prevalent adverse effect during esmolol infusion was hypotension which occurred in eight patients (12%). Hypotension and associated symptoms resolved within 30 minutes after discontinuation of esmolol infusion, which is consistent with the short duration of action of esmolol (elimination half-life of 9.2 minutes).     

Safety and efficacy of intravenous esmolol before prospective electrocardiogram-triggered high-pitch spiral acquisition for computed tomography coronary angiography

Background In order to acquire a high quality image with a low radiation dose, prospective electrocardiogram （ECG）-triggered computed tomography coronary angiography （CTCA） requires a stable heart rate （HR） 〈 65 beats/min. Esmolol has the advantage of reduc-ing HR. The objective of this article is to assess the value of intravenous esmolol treatment before prospective ECG-tr/ggered high-pitch spiral acquisition for CTCA. Methods From March 2013 to June 2013, 313 patients underwent prospective ECG-triggered CTCA. Two hundred and thirty two of them received esmolol before angiography. We retrospectively analyzed clinical characteristics, esmolol dose, radiation exposure dose, and the change in HR and blood pressure in these 232 patients. Results A total of 232 patients with a HR 〉 65 beats/rain before CTCA examination received intravenous esmolol treatment （mean dose of 57.26±15.39 rag）, The mean initial HR （HR1）, slowest HR （HR2）, and the HR 30 min after HR2 （HR3） were 75.06± 5.59, 60.75 ±4.00, and 75.54 ± 5.96 beats/min, respectively （HR1 vs. HR2, P 〈 0.0001; HRI vs. HR3, P = 0.377）. The mean time from esmolol administration to HR2 was 24.25 ± 4.97 s and the mean effective radiation dose was 2.28 ± 0.02 mSv. Conclusions HR could be rapidly controlled at an optimum level with intravenous esmolol before prospective ECG-triggered high-pitch spiral acquisition for CTCA. Consequently, the patients received a very low radiation dose.