Immediate emergency department external cardiac pacing for prehospital bradyasystolic arrest

Approximately 25% of patients in prehospital cardiac arrest present in bradyasystolic rhythms, and their long-term prognosis is very poor. Our study was undertaken to determine the utility of immediate emergency department (ED) external cardiac pacing in this situation. Twenty patients presenting with bradyasystolic prehospital cardiac arrest were entered in the study. All received the usual advanced cardiac life support therapy, but also were externally paced immediately using an automated external defibrillator and pacemaker (AEDP). Only two of 20 patients showed evidence of electrical capture, and none developed pulses with pacing. Four of the 20 patients developed a sinus rhythm and blood pressure during resuscitation. Three survived to leave the ED, but none survived to leave the hospital. An increase in the rate of bradycardia and pulseless idioventricular rhythms that was independent of electrical capture or pharmacologic therapy was noted occasionally. Although survival was not enhanced using the AEDP, the device was reliable, easy to use, and free of complications. External cardiac pacing warrants further investigation in the prehospital setting.     

Pacemaker insertion for prehospital bradyasystolic cardiac arrest

We investigated the use of transvenous (TV) and transmyocardial (TM) pacemakers in the emergency department (ED) in 54 adult patients (42 men and 12 women) with bradyasystolic cardiac arrest. Down time prior to cardiopulmonary resuscitation (CPR) was 4.8 +/- 4.3 minutes. Time in the ED prior to pacer insertion was 26.9 +/- 17.7 minutes. Electrical capture rate was 63%. Pulse developed in 5%. Only 1.2% were admitted, and none was discharged alive. There was no significant difference in capture rate for TV versus TM pacers or in capture rate whether the pacer was inserted early or late after ED arrival. We conclude that ED pacer insertion for such patients does not alter survival rates.     

Successful resuscitation using external cardiac pacing in beta adrenergic antagonist-induced bradyasystolic arrest

We present a case of attempted suicide by propranolol overdose presenting as convulsions followed by bradyasystolic cardiopulmonary arrest successfully managed by external transcutaneous pacing. Inotropic support and the resulting clinical improvement permitted discontinuation of cardiac pacing after 75 minutes. Pharmacologic management included glucagon late in the patient's management when the persistent hypotension was established to be due to beta adrenergic blockade. A serum propranolol level of 2,331 ng/mL verified the overdose. This is the first report of successful transcutaneous pacing for beta adrenergic antagonist poisoning.     

Transcutaneous cardiac pacing: determination of myocardial injury in a canine model

Transcutaneous cardiac pacing holds promise as the initial cardiac pacing technique for emergency patients. Determination of the extent of myocardial injury associated with the use of commercial transcutaneous pacemaker devices has been limited. This study was undertaken to document electrocardiographic, enzymatic, and histologic changes following transcutaneous pacing. Ten mongrel dogs were paced with a transcutaneous cardiac pacemaker for 30 minutes. Electrical pulses of 100 mA lasting 20 ms each were delivered at a rate of 80/min via cutaneous electrodes on the anterior and posterior thorax. Myocardial damage was assessed by serial electrocardiograms (ECGs), serial creatine kinase (CK) determinations with myocardial band (MB) fractionation, and gross and microscopic pathologic examination. Double blind reading of the ECGs showed no significant changes after pacing. CK levels peaked an average of 78 units over baseline levels at 4 hours; however, there was no rise in the CK MB fraction. Pathologic examination revealed micro-infarcts adjacent to intramural vessels in 5 animals, but no clinically significant myocardial injury in the 10 dogs. The absence of enzymatic, cardiographic, and clinically significant pathologic findings was statistically significant (P less than .05). Transcutaneous pacing at low currents and for short periods appears to be a safe technique. This pacing technique deserves further evaluation, and may hold promise as a clinical tool during resuscitation.     

Transcutaneous and transvenous cardiac pacing for early bradyasystolic cardiac arrest

Emergency transcutaneous cardiac pacing was studied prospectively in 19 patients presenting to the emergency department with a bradyasystolic cardiopulmonary arrest of 20 minutes duration or less. Pacing was initiated when conventional advanced cardiac life support (including atropine administration) and a fluid challenge failed to restore a pulse. Seventeen patients also had placement of transvenous pacemaker electrodes for cardiac pacing. Transcutaneous cardiac pacing rapidly established a blood pressure in the two patients who for clinical reasons did not receive a transvenous pacemaker. Five patients were transcutaneously paced within five minutes of cardiac arrest (Group 1) and the remaining 14 were paced between five and 20 minutes following cardiac arrest (Group 2). Two of the Group 1 patients were admitted and subsequently recovered full neurological and prearrest cardiac function. Fewer Group 2 patients developed a blood pressure (P = .04), and there were no patients with full neurologic recovery in this group (P = .06). Similar results were found for transvenous cardiac pacing; there was a greater incidence of a palpable pulse and measurable blood pressure (P = .05 for both) in the Group 1 patients than in the Group 2 patients. No difference in clinical outcome was noted between the two pacing techniques. These results support the concept that cardiac pacing must be initiated early if the outcome of bradyasystolic cardiac arrest is to be altered.     

体外无创性临时心脏起搏的临床应用

目的　评价体外无创性临时心脏起搏 ( ENCP)对心脏骤停及急性严重缓慢性心律失常的抢救效果、安全性。方法　 19例心脏骤停患者和 18例有严重临床症状缓慢性心律失常患者紧急行 ENCP。结果　所有病人均在 1～ 5 min内在床边得到 ENCP。心脏骤停组 12例起搏成功 ,其中 5例复苏 ,起搏成功者平均起搏阈值 ( 10 5 .2± 15 .6) m A,起搏成功率 63 .1% ,起搏成功并复苏2 6.3 %。严重缓慢性心律失常组 17例 ENCP后临床症状迅速明显改善 ,平均起搏阈值 ( 75 .3± 2 1.5 ) m A,起搏成功率 94.4%。严重缓慢性心律失常组的起搏成功率明显高于心脏骤停组 ,起搏阈值明显低于心脏骤停组。所有患者起搏过程中均出现与起搏脉冲同步的胸部肌肉抽动 ,但只有 1例因胸痛在 ENCP维持下安装了经静脉临时心脏起搏器 ,其余病人虽有不适 ,均能接受 ENCP。所有 ENCP患者均未发现皮肤、软组织损伤及严重心律失常等不良反应。结论　体外起搏是心脏骤停、急性严重缓慢性心律失常行之有效的治疗手段。     

Traumatic cardiac arrest: scope of paramedic services

The challenge of the 1960s to ambulance care provision was the stimulus for the emergence of prehospital advanced life support (ALS) being provided by paramedic personnel. While services for cardiac disease have been accepted, paramedic activities for the trauma victim continue to be a concern for many trauma surgeons. The capability and success rate of treatment, and the time spent at the scene and during transport to the hospital have raised questions about the overall need for paramedic services. Our study period was from January 1, 1981, to December 31, 1982, and it covered 95 clinically dead trauma victims who were first seen and subsequently treated by paramedics working in a medically controlled emergency medical services system. Endotracheal intubation was successful in 81 of the patients (85%). Esophageal obturator airway use was viewed as unsuccessful intubation. Intravenous (IV) access utilizing 16-gauge angiocaths was placed successfully by a peripheral or jugular vein in 70 patients (74%). Thirty-three patients averaged 860 mL volume infusion (30 to 3,000 mL). Average scene time was 22 minutes. Scene time of patients with unsuccessful IV and endotracheal intubation was 14 minutes (P = .07). Fourteen patients (14.7%) were admitted to the operating room or intensive care unit. Only three of the study group (3.2%) survived.     

Successful resuscitation using external cardiac pacing

The resuscitation of a patient with failure of a permanent artificial pacemaker is described. A mechanically inactive heart showed a variety of ineffective rhythms, and dissociation could not be overcome by drug therapy. The urgent need for artificial pacing presented problems that eventually were overcome. The time required to establish effective transvenous pacing would have prevented a favorable outcome if external cardiac pacing had not been available. External pacing maintained effective cardiac action for two hours and 55 minutes. The need for external cardiac pacing capability in EDs is considered.     

Primary cardiac non-Hodgkin's lymphoma diagnosed by transthoracic echocardiography

Primary cardiac lymphomas are extremely rare and can be diagnosed by echocardiography. We present the case of a 79-year-old man with an intracardiac mass, shown to be an aggressive large B-cell lymphoma by mediastinal aspiration, who had rapid regression of the tumor following one cycle of chemotherapy.     

食管调搏作为临时起搏器治疗心跳骤停53例临床分析

食管调搏（TEP）对室上速的诊断和治疗作用大家非常熟悉,也常见有人报道,但TEP作为临时起搏器抢救突发心跳骤停患者却十分罕见。本研究就此问题探讨TEP的临床应用价值。     

A standard comparison of esophageal obturator airway and endotracheal tube ventilation in cardiac arrest

A comparison of esophageal obturator airway (EOA) and endotracheal tube (ET) ventilation was performed while standardizing the method of oxygen delivery and assuring true sampling of arterial blood. Forty-eight victims of prehospital cardiac arrest had an arterial blood gas drawn in the emergency department while being ventilated with an EOA. Endotracheal intubation was performed immediately thereafter and another blood gas was drawn. All patients without a pulse were sampled through an arterial line placed by cutdown. Patients who developed a pulse during the resuscitation were sampled percutaneously or by arterial line. Patients with a perfusing rhythm (N = 19) had the following mean EOA blood gas values: pH, 7.34 +/- .17; PCO2, 28 +/- 8 mm Hg; and PO2, 420 +/- 125 mm Hg. Their subsequent mean ET blood gas values were pH, 7.40 +/- .13; PCO2, 25 +/- 8 mm Hg; and PO2, 390 +/- 100 mm Hg. Pulseless patients (N = 29) had mean EOA blood gas values of pH, 7.36 +/- .26; PCO2, 32 +/- 21 mm Hg; and PO2, 285 +/- 192 mm Hg. Their subsequent mean ET blood gas values were pH, 7.30 +/- .21; PCO2, 36 +/- 26 mm Hg; and PO2, 260 +/- 185 mm Hg. There was no statistically significant difference in the PCO2 or PO2 obtained with EOA compared with ET ventilation. There was a significant difference in the pH corrected for respiratory acidosis in pulseless patients, but not in patients with a perfusing rhythm.(ABSTRACT TRUNCATED AT 250 WORDS)     

生理性起搏对老年缓慢型心律失常伴心功能不全患者的作用

目的　探讨生理性及非生理性起搏对伴有心功能不全的老年缓慢型心律失常患者的作用。方法　在常规强心药物治疗的同时安置永久起搏器。非生理性起搏组 5 4例 ,生理性起搏组 36例 (使用DDD起搏为 12例 )。于术前、术后 1周及术后 6个月时用超声多普勒分别测定心功能参数。结果　生理性起搏组术后 1周时左室射血分数(LVEF)、每搏量 (SV)及心排量 (CO)均明显改善 ,血流加速时间 (AT)缩短 ,主动脉峰值血流速度 (PV)加快。 6个月后上述参数进一步改善 ,左室舒张末期内径 (LVd)亦显著缩小。该组患者术后 1周及术后 6个月时心功能改善情况均明显优于非生理性起搏器。DDD起搏者A V间期为 10 0ms时心功能参数最理想。结论　采用药物 +生理性永久起搏术治疗老年缓慢型心律失常患者的心功能不全 ,可取得满意的近期和远期效果。