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Tripling survival from sudden cardiac arrest via early defibrillation without traditional education in cardiopulmonary resuscitation
Arrhythmias
Results: The police and EMS were dispatched to 420 cardiac arrests, and the police were the first to arrive in 56%. The initial rhythm recorded at the scene was ventricular tachycardia (VT) or ventricular fibrillation (VF) in 39% of patients. The time to arrive at the scene was shorter for the police (6.2 minutes) than for EMS (7.6 minutes). The survival to hospital discharge with the dual-dispatch system was 17%, compared to 9% in the historical control group. Conclusions: Deployment of AEDs to the police shortens the response time to cardiac arrest and almost doubles the survival rate when the cause of cardiac arrest is VT/VF. Perspective: A striking finding of the study is that a decrease in response time of only 1.4 minutes translated to an almost 100% improvement in survival from a VT/VF cardiac arrest. This underscores the importance of defibrillation at the earliest possible time after cardiac arrest. FM
Abstracts Public Use of Automated External Defibrillators Caffrey SL, Willoughby PJ, Pepe PE, Becker LB. N Engl J Med 2002;347:1242–7. Study Question: How often are victims of cardiac arrest successfully resuscitated by bystanders who have access to an automatic external defibrillator (AED)? Methods: This was a prospective, observational study conducted at three airports in Chicago. Seventy AEDs were deployed throughout the airports a brisk 60 –90 –second walk apart. Opening the glass cabinet that housed the AED triggered a dispatch alert to emergency medical services. The neurologic status of the patient was assessed at the scene, at the hospital and 1 year later. Results: During the 2 years of this study, the AED was used for 20 patients with a witnessed, nontraumatic cardiac arrest, and 18 were found to have ventricular fibrillation (VF). Seven of the 18 patients with VF died, and 11 eventually regained consciousness. All 11 had good neurologic outcomes and 10 were still alive 1 year later. Long-term survival among the 18 patients with VF was 56%, and was 67% when defibrillation occurred within 5 minutes. There were no complications associated with use of the AEDs. Conclusions: Readily accessible AEDs can be used effectively by untrained bystanders to resuscitate victims of cardiac arrest. Perspective: The typical long-term survival rate after out-ofhospital cardiac arrest is approximately 5%. Therefore, although this study was uncontrolled, it does provide compelling evidence that readily accessible AEDs can vastly improve the odds of survival when used by bystanders. FM
Tripling Survival From Sudden Cardiac Arrest Via Early Defibrillation Without Traditional Education in Cardiopulmonary Resuscitation Cappuci A, Aschieri D, Piepoli MF, et al. Circulation 2002;106: 1065–70. Study Question: Can survival from out-of-hospital cardiac arrest be improved by training lay volunteers in the use of the automatic external defibrillator (AED)? Methods: 39 AEDs were deployed in public areas, police cars and fire vehicles, in Piacenza, Italy, which has a population of 173,114 inhabitants. Four hours of training in the use of the AED was provided to 1285 lay volunteers. During a 22-month study period, emergency calls for possible cardiac arrests were relayed to both the Emergency Medical System (EMS) and to lay volunteers located near the closest AED. The end points of the study were survival to hospital admission and survival to hospital discharge. Results: There were 354 cardiac arrests, with 87% occurring in the home. The first responder was a lay volunteer in 40% of cases (mean response time 4.8 minutes), and EMS in 60% of cases (mean response time 6.2 minutes). Overall, compared to first treatment by EMS, first treatment by a lay volunteer was associated with higher survival to admission (13 vs. 7%), and higher survival to hospital discharge (11 vs. 3%). Among witnessed cardiac arrests, first treatment by a lay volunteer also was associated with higher survival to admission (20 vs. 9%), and higher survival to hospital discharge (15 vs. 4%). Conclusions: The deployment of AEDs in public places, along with the training of lay volunteers in its use, can more than triple the rate of survival to hospital discharge among patients with out-of-hospital cardiac arrest. Perspective: In this study, ⬎75% of patients had a nonshockable rhythm when first evaluated. This suggests that inclusion of cardiopulmonary resuscitation (CPR) into the training program of lay volunteers might lead to a greater
Impact of Community-Wide Police Car Deployment of Automated External Defibrillators on Survival From Out-of-Hospital Cardiac Arrest Myerburg RJ, Fenster J, Velez M, et al. Circulation 2002;106: 1058 – 64. Study Question: Does deployment of an automated external defibrillator (AED) to police officers improve survival in patients with out-of-hospital cardiac arrest? Methods: In 1999 in Miami-Dade County, an AED was deployed to 1900 police officers who received 4 hours of training in its use. After deployment, 911 medical emergency calls were simultaneously relayed to the police and emergency rescue system (EMS). If the police arrived first, the AED was employed and basic life support was provided until EMS arrived. If EMS arrived first, the police were diverted. Survival was compared to a historical control group of patients with cardiac arrest in whom the sole responder was EMS.
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improvement in survival than when training is limited to the use of the AED. FM
After recording the PV potentials during AF (spontaneous or induced) but prior to RFA transthoracic cardioversion was performed with observation for immediate recurrence of AF (IRAF). Results: 11 patients were in spontaneous AF and the remainder induced. Complete PV isolation was successful in all patients performed in AF and 96% in SR. The mean duration of RF energy applied was longer in AF than SR (7.4min Vs 5.2min, p⬍0.01). Before ablation, an IRAF occurred after cardioversion in 18 of the 40 patients, and IRAF was consistently abolished by PV isolation. The probability of AF termination during isolation of a PV was directly related to the extent of tachycardia in that vein. As each PV was isolated, induction of persistent AF by rapid pacing became less likely. Conclusions: Segmental ostial ablation guided by PV tachycardia during AF is feasible and as effective as during sinus rhythm. The responses following cardioversion, ablation, and rapid pacing observed imply that IRAF is triggered by the PVs and that PV tachycardias may play an important role in the perpetuation of atrial fibrillation. Perspective: This meticulous study adds considerably to the understanding of how AF originates and how it may be sustained. The ablation success rate occurred using a reasonable amount of procedure and fluoroscopy time and long-term success was accomplished without any significant PV stenosis in these 40 patients. MR
Torsade de Pointes Associated With Very-High-Dose Methadone Krantz MJ, Lewkowiez L, Hays H, Woodroffe MA, Robertson AD, Mehler PS. Ann Intern Med 2002;137:501– 4. Study Question: Is methadone associated with torsade de pointes, a potentially fatal type of type ventricular arrhythmia? Methods: A retrospective review of cases with torsade de pointes found in methadone treatment programs in the US and a pain management center in Canada. Charts were reviewed for arrhythmia risk factors and measurement of corrected QT interval (QTc). Results: 17 patients were identified with torsade de pointes with a QT ⬎500 msec. The mean daily methadone dose was 397 mg and mean QTc was prolonged to 615 ⫾ 77msec. 14 patients had at least one predisposing risk factor for arrhythmias including hypokalemia and other drugs with potential pro-arrhythmic activity. An AICD or pacemaker was placed in 14 patients, and all 17 survived. Conclusions: Very– high-dose methadone appears to be associated with torsade de pointes. Further investigation of these findings are warranted, particularly since methadone treatment is expanding into the primary care setting. Perspective: Methadone is prescribed daily to about 180,000 Americans as part of treatment of heroin addiction, and is an inexpensive therapy for chronic pain. High-dose (⬎60 mg/d) has greater efficacy for reducing illicit drug use than standard therapy (20 mg/d). Methadone is metabolized by the hepatic cytochrome P450 isoenzyme CYP3A4 and could increase the pro-arrhythmic effects of other drugs such as cisapride. Another mechanism is the production of bradycardia, which prolongs repolarization. The findings could be the tip of the iceberg, but may not apply to the 80% of patients taking ⬍100 mg/d. Only 0.1% are taking ⬎300 mg/d of methadone. MR
Circular Mapping and Ablation of the Pulmonary Vein for Treatment of Atrial Fibrillation. Impact of Different Catheter Technologies Marrouche NF, Dresing T, Cole C, et al. J Am Coll Cardiol 2002; 40:464 –74. Study Question: How effective are various techniques for pulmonary vein isolation in curing atrial fibrillation? Methods: There were 211 patients with atrial fibrillation (AF) that was paroxysmal (113), persistent (34) or permanent (64). In 21 patients (Group 1), radiofrequency energy was delivered inside the arrhythmogenic pulmonary vein (PV), and in 190 patients (Group 2), radiofrequency energy was delivered at the ostia to isolate all four veins. In Group 2, ablation was performed with a conventional 4-mm tip catheter (47), an 8-mm tip catheter (21) or a cooled-tip catheter (122). Results: AF recurred in 24% of patients in Group 1 during a mean follow-up of 11 months. In Group 2, at mean follow-up intervals of 4 –10 months, the recurrence rate of AF was 21% with the 4-mm tip catheter, 15% with the cooled-tip catheter, and 0% with the 8-mm tip catheter. The long-term success rates in Group 2 were 94% for paroxysmal AF, 90% for persistent AF and 89% for permanent AF. The prevalence of severe PV stenosis was 14% in Group 1 compared to 1% in Group 2.
Segmental Ostial Ablation to Isolate the Pulmonary Veins During Atrial Fibrillation. Feasibility and Mechanistic Insights Oral H, Knight BP, Ozaydin M, Chugh A, et al. Circulation 2002; 106:1256 – 62. Study Question: What are the feasibility and mechanistic implications of segmental pulmonary vein (PV) ostial radiofrequency ablation during atrial fibrillation (AF). Methods: In 40 patients undergoing ostial RFA in 125 PVs the ablation was performed during AF in 70 veins and during sinus rhythm (SR) in 55 veins. During AF the RFA was performed near the Lasso catheter electrode that recorded a tachycardia with a shorter cycle length than adjacent left atrium and during SR was guided by PV potentials.
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Results: The police and EMS were dispatched to 420 cardiac arrests, and the police were the first to arrive in 56%. The initial rhythm recorded at the scene was ventricular tachycardia (VT) or ventricular fibrillation (VF) in 39% of patients. The time to arrive at the scene was shorter for the police (6.2 minutes) than for EMS (7.6 minutes). The survival to hospital discharge with the dual-dispatch system was 17%, compared to 9% in the historical control group. Conclusions: Deployment of AEDs to the police shortens the response time to cardiac arrest and almost doubles the survival rate when the cause of cardiac arrest is VT/VF. Perspective: A striking finding of the study is that a decrease in response time of only 1.4 minutes translated to an almost 100% improvement in survival from a VT/VF cardiac arrest. This underscores the importance of defibrillation at the earliest possible time after cardiac arrest. FM
Abstracts Public Use of Automated External Defibrillators Caffrey SL, Willoughby PJ, Pepe PE, Becker LB. N Engl J Med 2002;347:1242–7. Study Question: How often are victims of cardiac arrest successfully resuscitated by bystanders who have access to an automatic external defibrillator (AED)? Methods: This was a prospective, observational study conducted at three airports in Chicago. Seventy AEDs were deployed throughout the airports a brisk 60 –90 –second walk apart. Opening the glass cabinet that housed the AED triggered a dispatch alert to emergency medical services. The neurologic status of the patient was assessed at the scene, at the hospital and 1 year later. Results: During the 2 years of this study, the AED was used for 20 patients with a witnessed, nontraumatic cardiac arrest, and 18 were found to have ventricular fibrillation (VF). Seven of the 18 patients with VF died, and 11 eventually regained consciousness. All 11 had good neurologic outcomes and 10 were still alive 1 year later. Long-term survival among the 18 patients with VF was 56%, and was 67% when defibrillation occurred within 5 minutes. There were no complications associated with use of the AEDs. Conclusions: Readily accessible AEDs can be used effectively by untrained bystanders to resuscitate victims of cardiac arrest. Perspective: The typical long-term survival rate after out-ofhospital cardiac arrest is approximately 5%. Therefore, although this study was uncontrolled, it does provide compelling evidence that readily accessible AEDs can vastly improve the odds of survival when used by bystanders. FM
Tripling Survival From Sudden Cardiac Arrest Via Early Defibrillation Without Traditional Education in Cardiopulmonary Resuscitation Cappuci A, Aschieri D, Piepoli MF, et al. Circulation 2002;106: 1065–70. Study Question: Can survival from out-of-hospital cardiac arrest be improved by training lay volunteers in the use of the automatic external defibrillator (AED)? Methods: 39 AEDs were deployed in public areas, police cars and fire vehicles, in Piacenza, Italy, which has a population of 173,114 inhabitants. Four hours of training in the use of the AED was provided to 1285 lay volunteers. During a 22-month study period, emergency calls for possible cardiac arrests were relayed to both the Emergency Medical System (EMS) and to lay volunteers located near the closest AED. The end points of the study were survival to hospital admission and survival to hospital discharge. Results: There were 354 cardiac arrests, with 87% occurring in the home. The first responder was a lay volunteer in 40% of cases (mean response time 4.8 minutes), and EMS in 60% of cases (mean response time 6.2 minutes). Overall, compared to first treatment by EMS, first treatment by a lay volunteer was associated with higher survival to admission (13 vs. 7%), and higher survival to hospital discharge (11 vs. 3%). Among witnessed cardiac arrests, first treatment by a lay volunteer also was associated with higher survival to admission (20 vs. 9%), and higher survival to hospital discharge (15 vs. 4%). Conclusions: The deployment of AEDs in public places, along with the training of lay volunteers in its use, can more than triple the rate of survival to hospital discharge among patients with out-of-hospital cardiac arrest. Perspective: In this study, ⬎75% of patients had a nonshockable rhythm when first evaluated. This suggests that inclusion of cardiopulmonary resuscitation (CPR) into the training program of lay volunteers might lead to a greater
Impact of Community-Wide Police Car Deployment of Automated External Defibrillators on Survival From Out-of-Hospital Cardiac Arrest Myerburg RJ, Fenster J, Velez M, et al. Circulation 2002;106: 1058 – 64. Study Question: Does deployment of an automated external defibrillator (AED) to police officers improve survival in patients with out-of-hospital cardiac arrest? Methods: In 1999 in Miami-Dade County, an AED was deployed to 1900 police officers who received 4 hours of training in its use. After deployment, 911 medical emergency calls were simultaneously relayed to the police and emergency rescue system (EMS). If the police arrived first, the AED was employed and basic life support was provided until EMS arrived. If EMS arrived first, the police were diverted. Survival was compared to a historical control group of patients with cardiac arrest in whom the sole responder was EMS.
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improvement in survival than when training is limited to the use of the AED. FM
After recording the PV potentials during AF (spontaneous or induced) but prior to RFA transthoracic cardioversion was performed with observation for immediate recurrence of AF (IRAF). Results: 11 patients were in spontaneous AF and the remainder induced. Complete PV isolation was successful in all patients performed in AF and 96% in SR. The mean duration of RF energy applied was longer in AF than SR (7.4min Vs 5.2min, p⬍0.01). Before ablation, an IRAF occurred after cardioversion in 18 of the 40 patients, and IRAF was consistently abolished by PV isolation. The probability of AF termination during isolation of a PV was directly related to the extent of tachycardia in that vein. As each PV was isolated, induction of persistent AF by rapid pacing became less likely. Conclusions: Segmental ostial ablation guided by PV tachycardia during AF is feasible and as effective as during sinus rhythm. The responses following cardioversion, ablation, and rapid pacing observed imply that IRAF is triggered by the PVs and that PV tachycardias may play an important role in the perpetuation of atrial fibrillation. Perspective: This meticulous study adds considerably to the understanding of how AF originates and how it may be sustained. The ablation success rate occurred using a reasonable amount of procedure and fluoroscopy time and long-term success was accomplished without any significant PV stenosis in these 40 patients. MR
Torsade de Pointes Associated With Very-High-Dose Methadone Krantz MJ, Lewkowiez L, Hays H, Woodroffe MA, Robertson AD, Mehler PS. Ann Intern Med 2002;137:501– 4. Study Question: Is methadone associated with torsade de pointes, a potentially fatal type of type ventricular arrhythmia? Methods: A retrospective review of cases with torsade de pointes found in methadone treatment programs in the US and a pain management center in Canada. Charts were reviewed for arrhythmia risk factors and measurement of corrected QT interval (QTc). Results: 17 patients were identified with torsade de pointes with a QT ⬎500 msec. The mean daily methadone dose was 397 mg and mean QTc was prolonged to 615 ⫾ 77msec. 14 patients had at least one predisposing risk factor for arrhythmias including hypokalemia and other drugs with potential pro-arrhythmic activity. An AICD or pacemaker was placed in 14 patients, and all 17 survived. Conclusions: Very– high-dose methadone appears to be associated with torsade de pointes. Further investigation of these findings are warranted, particularly since methadone treatment is expanding into the primary care setting. Perspective: Methadone is prescribed daily to about 180,000 Americans as part of treatment of heroin addiction, and is an inexpensive therapy for chronic pain. High-dose (⬎60 mg/d) has greater efficacy for reducing illicit drug use than standard therapy (20 mg/d). Methadone is metabolized by the hepatic cytochrome P450 isoenzyme CYP3A4 and could increase the pro-arrhythmic effects of other drugs such as cisapride. Another mechanism is the production of bradycardia, which prolongs repolarization. The findings could be the tip of the iceberg, but may not apply to the 80% of patients taking ⬍100 mg/d. Only 0.1% are taking ⬎300 mg/d of methadone. MR
Circular Mapping and Ablation of the Pulmonary Vein for Treatment of Atrial Fibrillation. Impact of Different Catheter Technologies Marrouche NF, Dresing T, Cole C, et al. J Am Coll Cardiol 2002; 40:464 –74. Study Question: How effective are various techniques for pulmonary vein isolation in curing atrial fibrillation? Methods: There were 211 patients with atrial fibrillation (AF) that was paroxysmal (113), persistent (34) or permanent (64). In 21 patients (Group 1), radiofrequency energy was delivered inside the arrhythmogenic pulmonary vein (PV), and in 190 patients (Group 2), radiofrequency energy was delivered at the ostia to isolate all four veins. In Group 2, ablation was performed with a conventional 4-mm tip catheter (47), an 8-mm tip catheter (21) or a cooled-tip catheter (122). Results: AF recurred in 24% of patients in Group 1 during a mean follow-up of 11 months. In Group 2, at mean follow-up intervals of 4 –10 months, the recurrence rate of AF was 21% with the 4-mm tip catheter, 15% with the cooled-tip catheter, and 0% with the 8-mm tip catheter. The long-term success rates in Group 2 were 94% for paroxysmal AF, 90% for persistent AF and 89% for permanent AF. The prevalence of severe PV stenosis was 14% in Group 1 compared to 1% in Group 2.
Segmental Ostial Ablation to Isolate the Pulmonary Veins During Atrial Fibrillation. Feasibility and Mechanistic Insights Oral H, Knight BP, Ozaydin M, Chugh A, et al. Circulation 2002; 106:1256 – 62. Study Question: What are the feasibility and mechanistic implications of segmental pulmonary vein (PV) ostial radiofrequency ablation during atrial fibrillation (AF). Methods: In 40 patients undergoing ostial RFA in 125 PVs the ablation was performed during AF in 70 veins and during sinus rhythm (SR) in 55 veins. During AF the RFA was performed near the Lasso catheter electrode that recorded a tachycardia with a shorter cycle length than adjacent left atrium and during SR was guided by PV potentials.
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