Nineteen years' experience of out-of-hospital cardiac arrest in Gothenburg--reported in Utstein style

OBJECTIVE: To describe the outcome in the Utstein style for out of hospital cardiac arrest in Gothenburg, over a period of 19 years. METHODS: All consecutive cases of cardiac arrest between 1980 and 1999 in which the emergency medical service (EMS) system responded and attempted resuscitation were reported and followed up for 1 year. RESULTS: In all, there were 5270 attempts. 3871 (73%) of which were regarded as being of a cardiac aetiology. In these cases, information on witnessed status was missing in 782 cases (20%). Of the remaining 3089 cases, 2066 (67%) were bystander witnessed, 791 (26%) were unwitnessed and 232 (8%) crew witnessed. The median interval between a call for the ambulance and the arrival of the first ambulance was 5 min. Thirteen percent of the bystander-witnessed cases were discharged from hospital. Of the unwitnessed cases, only 2% were discharged from hospital, whereas 22% of the crew-witnessed cases were discharged. Of the patients with a bystander-witnessed cardiac arrest of a cardiac aetiology found in ventricular fibrillation (VF), 20% were discharged from hospital. CONCLUSION: In this large Utstein style study of out of hospital cardiac arrest stretching over almost 19 years, we report high survival rates both for patients suffering a bystander-witnessed cardiac arrest, and for the subgroup suffering a bystander-witnessed cardiac arrest with VF as the first recorded rhythm. These high survival rates can in part be explained by the short time intervals from calls being received by the emergency dispatch centre (EDC) to the arrival of the emergency medical service at the scene.     

'Event tree' analysis of out-of-hospital cardiac arrest data: confirming the importance of bystander CPR

OBJECTIVE: The British National Service Framework (NSF) for heart disease commended the 'Utstein style' for auditing out-of-hospital cardiac arrests. The NSF also set standards for pre-hospital treatment and response times. To increase the flexibility of Utstein, an 'event tree' technique is proposed as an audit tool. Event trees consist of nodes and branches on which numbers, percentages or probability values are entered. METHODS: Using the London Ambulance Service's (LAS) 1997 database on 3,759 out-of-hospital cardiac arrests, 2,772 arrests witnessed by lay bystanders or unwitnessed were analysed focusing on bystander cardiopulmonary resuscitation (BCPR) and response times. RESULTS: The Utstein template showed that witnessed arrests in ventricular fibrillation (VF) or ventricular tachycardia (VT) who had received BCPR achieved a return of spontaneous circulation (ROSC) in the field significantly more often than non-BCPR recipients-26 versus 16% (P=0.006). But the likelihood of being admitted to a hospital bed, and discharged alive, was only marginally better for BCPR recipients. To examine the influence of BCPR on the presenting rhythm an event tree showed that in 48% of witnessed BCPR cases the presenting rhythm was VF/VT, whereas, for witnessed non-BCPR cases, 27% were in VF/VT (P<0.0001). With unwitnessed arrests, 31% of BCPR cases were in VF/VT compared with 18% for non-BCPR cases (P<0.0001). Call to scene time was less than 8 min for 66% of all VF/VT arrests. CONCLUSION: The event trees, when combined with the Utstein template, demonstrated the importance of examining comprehensively datasets for both witnessed and unwitnessed cardiac arrests when monitoring performance standards. The analyses also emphasised the relevance of community programmes in Greater London for teaching basic life saving skills.     

Factors affecting short- and long-term prognosis among 1069 patients with out-of-hospital cardiac arrest and pulseless electrical activity.

AIMS: To describe the epidemiology, resuscitation factors and prognosis among a consecutive population of patients suffering from out-of-hospital cardiac arrest (OHCA) where pulseless electrical activity (PEA) was the first arrhythmia recorded on emergency medical services (EMS) arrival. METHODS: Analysis of data collected prospectively on all patients regardless of age succumbing to OHCA during 1980-1997 in the community of Gothenburg where EMS initiated resuscitative measures. RESULTS: 4662 patients with OHCA were attended by the EMS during the study period. Of these, 1069 (23%) were judged as having PEA as the first recorded arrhythmia; 158 (15%) of these were admitted alive to hospital and 26 (2.4%) were discharged alive. Survivors to discharge had a significantly larger share of bystander cardiopulmonary resuscitation (CPR) (28 vs. 8%, P=0.008), significantly higher levels of consciousness (8% awake vs. 0%, P<0.001) and higher median systolic blood pressure (145 vs. 106 mmHg, P<0.001) on arrival at hospital. No patient with unwitnessed cardiac arrest and PEA over 80 years old survived. CONCLUSION: Survival among patients suffering from OHCA and PEA is poor, especially among the elderly unwitnessed cases and those who do not receive bystander CPR. The latter seems to be of utmost importance among these patients.     

Initiation of resuscitation in patients with prehospital bradyasystolic cardiac arrest in Helsinki

The factors influencing the decision to initiate resuscitation in prehospital cardiac arrest patients encountered in bradyasystole due to presumed heart disease were studied. For this purpose, the characteristics and circumstances of arrest of the patients encountered in asystole and electromechanical dissociation, seen by a physician-staffed prehospital emergency care unit in a tiered emergency medical system, were reviewed. During the study period, resuscitation was initiated in 83 bradyasytolic patients. The characteristics of these patients were compared with those of 72 patients in asystole or electromechanical dissociation declared dead on the scene without resuscitation. The presence of EMD was the most important factor influencing the decision to resuscitate (P less than 0.001), even if the arrest was unwitnessed, while the patient's age was of less importance. For the patients with a witnessed arrest, the delay before treatment was initiated also affected the decision. Successful resuscitation and survival of the patients was similar to earlier reports. The results provide guidelines in the decision making of initiation of resuscitation when developing our emergency care system into one with non-physicians as advanced life support providers.     

An analysis of time factors in out-of-hospital cardiac arrest in Osaka Prefecture

OBJECTIVE: To ascertain important factors in the improvement of out-of-hospital cardiac arrest survival rates through analysis of data for Osaka Prefecture with the focus on time factors. DESIGN: Prospective cohort study according to the Utstein style. SETTING: Osaka Prefecture (population 8,830,000) served by a single emergency medical services system. PATIENTS: Consecutive prehospital cardiac arrests occurring between May 1998 and April 1999. MAIN OUTCOME MEASURES: One-year survival from cardiac arrest, and time factors. RESULT: Of the 5047 cases of confirmed cardiac arrests, resuscitation was attempted in 4871 subjects. Of the 982 cases of cardiac origin and witnessed by bystanders, 31 (3.2%) were still alive, and of the 576 cases of non-cardiac origin and witnessed by bystanders, ten (1.7%) were still alive at the 1 year follow-up. The median time from receipt of the emergency call until ambulance arrival was 5 min and that from receipt of the call until the start of cardiopulmonary resuscitation (CPR) was 7 min. For the 214 patients for whom defibrillation was attempted, the median time from receipt of the call until the first shock was 15 min. The median time from receipt of the call until departure of the ambulance from the scene was 16 min and that until arrival of the ambulance at a hospital was 22 min. CONCLUSIONS: This study using the standardized format according to the Utstein style clearly elucidates the specific delay of the start of defibrillation by paramedics and also indicates the inappropriate rule for this procedure in Japan.     

A randomised trial to investigate the efficacy of magnesium sulphate for refractory ventricular fibrillation

Study hypothesis: Intravenous magnesium sulphate given early in the resuscitation phase for patients in refractory VF (VF after 3 DC shocks) or recurring VF will significantly improve their outcome, defined as a return of spontaneous circulation (ROSC) and discharge from hospital alive.

Design: A randomised, double blind, placebo controlled trial. Pre-defined primary and secondary endpoints were ROSC at the scene or in accident and emergency (A&E) and discharge from hospital alive respectively.

Setting, participants, and intervention: Patients in CA with refractory or recurrent VF treated in the prehospital phase by the county emergency medical services and/or in the A&E department. One hundred and five patients with refractory VF were recruited over a 15 month period and randomised to receive either 2–4 g of magnesium sulphate or placebo intravenously.

Results: Fifty two patients received magnesium treatment and 53 received placebo. The two groups were matched for most parameters including sex, response time for arrival at scene and airway interventions. There were no significant differences between magnesium and placebo for ROSC at the scene or A&E (17% v 13%). The 4% difference had 95% confidence intervals (CI) ranging from -10% to +18%. For patients being alive to discharge from hospital (4% v 2%) the difference was 2% (95% CI –7% to +11%). After adjustment for potential confounding variables (age, witnessed arrest, bystander cardiopulmonary resuscitation and system response time), the odds ratio (95% CI) for ROSC in patients treated with magnesium as compared with placebo was 1.69 (0.54 to 5.30).

Conclusion: Intravenous magnesium given early in patients suffering CA with refractory or recurrent VF did not significantly improve the proportion with a ROSC or who were discharged from hospital alive.

     

In-hospital cardiac arrest: Is outcome related to the time of arrest?

BACKGROUND: Whether outcome from in-hospital cardiopulmonary resuscitation (CPR) is poorer when it occurs during the night remains controversial. This study examined the relationship between CPR during the various hospital shifts and survival to discharge. METHODS: CPR attempts occurring in a tertiary hospital with a dedicated, certified resuscitation team were recorded prospectively (Utstein template guidelines) over 24 months. Medical records and patient characteristics were retrieved from patient admission files. RESULTS: Included were 174 in-hospital cardiac arrests; 43%, 32% and 25% in morning evening and night shifts, respectively. Shift populations were comparable in demographic and treatment related variables. Asystole (p < 0.01) and unwitnessed arrests (p = 0.05) were more common during the night. Survival to discharge was poorer following night shift CPR than following morning and evening shift CPR (p = 0.04). When asystole (being synonymous with death) was excluded from the analysis, the odds of survival to discharge was not higher for witnessed compared to unwitnessed arrest but was 4.9 times higher if the cardiac arrest did not occur during the night shift (p = 0.05, logistic regression). The relative risk of eventual in-hospital death for patients with return of spontaneous circulation (ROSC) following night shift resuscitation was 1.9 that of those with ROSC following morning or evening resuscitation (Cox regression). CONCLUSIONS: Although unwitnessed arrest is more prevalent during night shift, resuscitation during this shift is associated with poorer outcomes independently of witnessed status. Further research is required into the causes for the increased mortality observed after night shift resuscitation.     

Out-of-hospital unwitnessed cardiopulmonary collapse and no-bystander CPR: a practical addition to resuscitation termination guidelines

Cardiopulmonary resuscitation (CPR) provides possible survival from otherwise fatal cardiopulmonary collapse. Termination guidelines have been developed for use when resuscitation has no potential benefit for a victim. The purpose of this prospective cohort study was to determine if unwitnessed collapse combined with no-bystander cardiopulmonary resuscitation would support a decision to terminate attempted resuscitation. There were 541 patients analyzed during 6 months, with functional neurological survival the outcome of interest. There were no functional neurological survivors at hospital discharge among the 180 victims in the unwitnessed, no-bystander CPR subgroup (95% confidence interval [CI] 0.0%-2.1%). Functional neurological survival for witnessed collapse, bystander CPR was 6.0% (95% CI 2.8%-12.5%), for witnessed collapse, no-bystander CPR was 3.8% (95% CI 1.9%-7.7%), and for unwitnessed collapse, bystander CPR 1.3% (95% CI 0.2%-6.9%). With confirmation by further studies, unwitnessed collapse and lack of bystander CPR may be a practical addition to resuscitation termination guidelines.     

Out-of-hospital cardiac arrest due to drowning: An Utstein Style report of 10 years of experience from St. Mary's Hospital

Background

Drowning is a unique form of cardiac arrest and is often preventable. “Utstein Style for Drowning” was published in 2003 by the International Liaison Committee on Resuscitation (ILCOR) to improve the knowledge-base, to provide epidemiological stratification, to recommend appropriate treatments and to ultimately save lives. We report on the largest single-center study of the Utstein Style resuscitation for drowning.

Methods

All patients with out-of-hospital cardiac arrest (OHCA) due to drowning admitted to St. Mary's Hospital between 1998 and 2007 were included. Utstein Style variables and other time intervals not included in the Utstein Style guidelines were evaluated for their ability to predict survival. The primary end point of this study was survival to discharge.

Results

We enrolled 131 patients with OHCA due to drowning; 21 patients (16.03%) had survival to discharge and 9 patients (6.87%) were discharged with a good neurologic outcome, i.e., cerebral performance categories (CPC) of 1 or 2. For the Utstein Style variables witnessed, the duration of submersion and the time of first emergency medical systems (EMS) resuscitation attempt influenced survival. For other time intervals, the transportation time (i.e., time interval from witnessing of the drowning to EMS arrival at the hospital, or if events were not witnessed, the time interval from calling the EMS to EMS arrival at the hospital), the duration of advanced cardiovascular life support (ACLS) and the duration of total arrest time were associated with survival.

Conclusions

Our report is the largest single-center study of OHCA due to drowning reported according to the guidelines of the Utstein Style. Being witnessed, having a short duration of submersion, having early resuscitation by EMS, and rapid transportation are important for survival after drowning.     

Long-term survival after out-of-hospital cardiac arrest: an 8-year follow-up.

Between 1988 and 1994, 441 patients were successfully resuscitated outside hospital in the city of Rotterdam, of whom 276 (63%) were discharged from hospital alive. Long-term survival was studied amongst those who were discharged alive. The duration of follow-up averaged 6.71 years. A survival rate of 88% after 1 year, 81% after 3 years, 77% after 5 years and 73% after 7 years was found. After multivariate analysis, age, diagnosis and gender were found to be independent and significant predictors of survival. No significant difference in survival was found in patients who had been resuscitated by emergency personnel, physicians and bystanders. Patients who were still alive were sent a EuroQol-questionnaire. No differences in outcomes between the four groups were found. Since long-term prognosis after out-of-hospital resuscitation is satisfactory, learning programmes for resuscitation should be continued.     

Family witnessed resuscitation: The views and preferences of recently resuscitated hospital inpatients, compared to matched controls without the experience of resuscitation survival

Aim of the study

To compare the preferences of patients who survived resuscitation with those admitted as emergency cases about whether family members should be present during resuscitation.

Methods

We used a case control design and recruited, from four large hospitals, 21 survivors of resuscitation and 40 patients admitted as emergency cases without the experience of resuscitation (control group) who were matched by age and gender at a ratio of 1:2. Data collection involved face-to-face interviews using a standardised 22 item questionnaire. Data analysis sought to identify differences between the two groups.

Results

Both groups were broadly supportive of the practice, however resuscitated patients were more likely to favour witnessing the resuscitation of a family member (72% versus 58%), preferred to have a relative present in the event they required resuscitation (67% versus 50%) and believed that relatives benefited from such an experience (67% versus 48%). Additionally, both groups indicated that staff should seek patient preferences about family witnessed resuscitation following hospital admission, and stated that they were unconcerned about confidential matters being discussed with family members present during resuscitation (91% and 75%, respectively). However none of these differences between the two groups achieved statistical significance.

Conclusion

Hospitalised patients report a favourable disposition towards family witnessed resuscitation, and this view appears to be strengthened by successfully surviving a resuscitation episode. Practitioners should strive to facilitate family witnessed resuscitation by establishing, documenting and enacting patient preferences. Research exploring the perceptions of the wider public would help further inform this debate.     

What Are the Etiology and Epidemiology of Out‐of‐hospital Pediatric Cardiopulmonary Arrest in Ontario,Canada?

Background: Pediatric cardiopulmonary arrest (CPA) outside of the hospital has a very high mortality rate. Objectives: To evaluate the etiology and initial compromise of pediatric CPA cases in hopes of developing strategies to improve out‐of‐hospital resuscitation. Methods: The Ontario Prehospital Advanced Life Support (OPALS) study was a large multicenter initiative to evaluate the impact of emergency medical services (EMS) programs on 17 communities with 40,000 critically ill and injured patients who were older than 11 years. As part of this study, the authors conducted a retrospective observational cohort study that included all children younger than 18 years of age with out‐of‐hospital CPA, during an 11‐year period from 1991–2002. CPA was defined as patient being pulseless, apneic, and requiring chest compressions. Data were collected from ambulance call reports and centralized dispatch data and were reviewed by two independent investigators. Results: There were 503 children with CPA in the sample. Mean age was 5.6 years (range, 0–17 yr); 58.4% of patients were male, and 37.8% were younger than 1 year of age. Cardiopulmonary resuscitation (CPR) first was started by a bystander in 32.4% of cases, whereas 66.0% were unwitnessed arrests. Initial rhythms were asystole 77.2% of the time, pulseless electrical activity 16.4% of the time, and ventricular fibrillation or ventricular tachycardia 4% of the time. Annual incidence was 9.1/100,000 children. CPA was witnessed in 34.0% of cases; 80.7% of these were bystander‐witnessed, and 18.1% were EMS‐witnessed. Primary pathogenic cause of arrest was medical in 61.2% of cases, trauma in 37.2% of cases, and indeterminate in 1.6% of cases. Initial underlying physiologic compromise of witnessed arrests was judged to be respiratory in 39.8% of cases, sudden collapse (presumed electrical) in 16.4% of cases, progressive shock in 1.2% of cases, and indeterminate in 42.6% of cases. Presumed etiology was trauma, 37.6%; sudden infant death syndrome (SIDS), 20.3%; and respiratory disease, 11.6%, most commonly. Survival to hospital discharge was 2.0%. Conclusions: This is one of the largest population‐based, prospective cohorts of pediatric CPA reported to date, and it reveals that most pediatric arrests are unwitnessed and receive no bystander CPR. Those that are witnessed most often are caused by respiratory arrests or trauma. Trauma, SIDS, and respiratory disease are the most common etiologies overall. These data are vital to planning large resuscitation trials looking at specific interventions (i.e., increasing bystander CPR) and highlight the need for better strategies for prevention and early recognition.     

Is female sex associated with increased survival after out-of-hospital cardiac arrest?

AIM: To evaluate survival after out-of-hospital cardiac arrest in relation to sex. METHODS: All patients with out-of-hospital cardiac arrest included in the Swedish Cardiac Arrest Registry between 1990 and 2000 in whom cardiopulmonary resuscitation (CPR) was attempted and who did not have a crew witnessed arrest were included. The registry covers 85% of the inhabitants of Sweden (approximately 8 million inhabitants). P-values were adjusted to differences in age. Survival was defined as patients being hospitalised alive and being alive one month after cardiac arrest. In all, 23,797 patients participated in the survey of which 27.9% were women. RESULTS: Among women 16.4% were hospitalised alive versus 13.2% among men ( P<0.001). After one month 3.0% among women were alive versus 3.4% among men (NS). In a multivariate analysis considering differences in age and various factors at resuscitation female sex was an independent predictor for patients being hospitalised alive (odds ratio 1.66; 95% confidence limits 1.49-1.84) and for being alive after one month (odds ratio 1.27; 95% confidence limits 1.03-1.56). Women differed from men as they were older ( P<0.001 ), had a lower prevalence of witnessed cardiac arrest ( P=0.01), a lower occurrence of bystander CPR (P<0.001), a lower occurrence of ventricular fibrillation as initial arrhythmia (P<0.001) and a lower occurrence of cardiac disease judged to be the cause of cardiac arrest ( P<0.0001 ). On the other hand they had a cardiac arrest at home more frequently ( P<0.001 ). CONCLUSION: Among patients suffering out-of-hospital cardiac arrest in Sweden which was not crew witnessed and in whom resuscitation efforts were attempted, female sex was associated with an increased survival.     

Use of artificial circulation in resuscitation of drowned dogs

The effectiveness of artificial circulation by the method of Bryukhonenko and his colleagues in the resuscitation of dogs that had died from drowning in fresh- or salt-water was studied. Eight out of ten dogs were revived after freshwater drowning ‘death’ lasting from 10.5 to 21 min, when a variant of the artificial circulation method, dog donor with a venous pump of the artificial heart, was used. Resuscitated dogs remained alive from 3 to 72 h and died from pulmonary oedema. Artificial circulation appeared to be more effective in resuscitation of dogs drowned in saltwater. Their clinical ‘death’ lasted up to 31.5 min; clinically signs of pulmonary oedema were not observed in any of them, though some signs of oedema were revealed by histological studies. Of the 42 dogs in this series, all the main functions of the central nervous system were restored in 18 with clinical ‘death’ for up to 25 min. Resuscitation was performed by one of two methods, either the dog donor plus venous pump of the artificial heart, or the method of Bryukhonenko. The effectiveness of artificial circulation for resuscitation of dogs from drowning was demonstrated.     

Use of artificial circulation in resuscitation of drowned dogs.

The effectiveness of artificial circulation by the method of Bryukhonenko and his colleagues in the resuscitation of dogs that had died from drowning in fresh- or salt-water was studied. Eight out of ten dogs were revived after freshwater drowning 'death' lasting from 10.5 to 21 min, when a variant of the artificial circulation method, dog donor with a venous pump of the artificial heart, was used. Resuscitated dogs remained alive from 3 to 72 h and died from pulmonary oedema. Artificial circulation appeared to be more effective in resuscitation of dogs drowned in saltwater. Their clinical 'death' lasted up to 31.5 min; clinically signs of pulmonary oedema were not observed in any of them, though some signs of oedema were revealed by histological studies. Of the 42 dogs in this series, all the main functions of the central nervous system were restored in 18 with clinical 'death' for up to 25 min. Resuscitation was performed by one of two methods, either the dog donor plus venous pump of the artificial heart, or the method of Bryukhonenko. The effectiveness of artificial circulation for resuscitation of dogs from drowning was demonstrated.     

Pulseless electrical activity and unsuccessful out-of-hospital resuscitation: what is the cause of death?

AIMS: To study the cause of deaths after witnessed cardiac arrest followed by pulseless electrical activity and unsuccessful of out-of-hospital resuscitation; and to detect any differences between causes of death determined at autopsy and those inferred from clinical history. METHODS: In this prospective observational study, data were collected from 91 individuals treated by the emergency medical services in three urban communities in southern Finland. RESULTS: Cause of death was determined at autopsy in 59 cases and without autopsy in 32 cases. There were significantly more diagnoses of acute myocardial infarction and fewer of pulmonary embolism and aortic dissection and rupture among cases without autopsy compared with those followed by autopsy. CONCLUSION: In unsuccessful resuscitation from out-of-hospital cardiac arrest with pulseless electrical activity as initial rhythm, an autopsy should be performed to determine the correct cause of death.     

Resuscitations in an observation unit.

The outcome of all resuscitations in a 20-bed observation unit of a large teaching hospital over a 25-month period was reviewed. Resuscitation was defined as a patient receiving one or more of the following: external chest compressions; defibrillation, assisted ventilation (e.g. intubation); and/or advanced cardiac life support drug therapy such as atropine or lidocaine for life threatening dysrhythmias including ventricular tachycardia, ventricular fibrillation, or asystole. There were nine patients out of 10,245 patients admitted to the observation unit (9/10,245 = 0.088% or approximately 0.09%) over the 26-month period from May 1994 to July 1996 who needed resuscitation. Each patient was initially successfully resuscitated. There was only one death (1/10,245 = 0.0098% or approximately 0.01%) in the observation unit. This patient was resuscitated with return of a spontaneous pulse and blood pressure only to expire while awaiting transfer to the Intensive Care Unit (ICU). Eight of the nine patients were admitted to the ICU, four of whom later died, making a total of five deaths (5/10,245 = 0.049% or approximately 0.05%). The other four patients were discharged neurologically intact and at 1 year follow-up were alive and doing well. Compared with resuscitation rates for the prehospital setting, the emergency department, the hospital medical/surgical floors, or the intensive care units, there is a higher successful resuscitation rate for the observation unit.     

Age and other determinants of survival after in-hospital cardiopulmonary resuscitation.

A retrospective review of 274 patients who received in-hospital cardiopulmonary resuscitation was performed to determine whether age is independently associated with survival to discharge. Eighty-two (29.9 per cent) of the 274 patients were resuscitated initially, but only 25 (9.1 per cent) were discharged alive. Survival to discharge was significantly poorer in patients aged greater than or equal to 70 years (6/175; 3.4 per cent) than in patients less than 70 years old (19/99; 19.2 per cent) (p less than 0.001). Severity of illness, assessed by the number of diagnoses and a multifactorial morbidity index, did not differ between the two age groups. The best results were obtained with witnessed arrests, ventricular arrhythmias and resuscitation lasting less than 5 minutes; however, elderly patients were less likely to be resuscitated in all circumstances. Age (r = -0.31, p less than 0.001) and the morbidity index (r = -0.18, p less than 0.05) were independently associated with survival by multivariate analysis. These results indicate that advanced age is an important independent determinant of survival after resuscitation. This should be taken into consideration when making in-hospital resuscitation decisions.     

Sudden cardiac arrest outside the hospital--value of defibrillators in ambulances.

In a region with a population of 250,000 people, all emergency calls for cardiac arrest were prospectively registered during a period of 6 years. Timing of events were carefully registered as were treatment and the participation of 3 ambulances equipped with defibrillators. When time until initial treatment of cardiac arrest was below 5 min, 12% could be resuscitated and discharged alive. This figure decreased to 2% in the period between 5 and 10 min and was zero to above 10 min. Similarly, a reasonable 12% of patients experiencing ventricular fibrillation at a public place could be resuscitated and discharged alive whereas only 5% of ventricular fibrillation occurring at the patients home could be successfully resuscitated. Asystolia was rarely treated successfully. Faster treatment improved results much and 63% of patients having ventricular fibrillation in the emergency room left hospital alive. Results of cardioversion in ambulances did not depend on time from initiation of cardiac arrest, but all patients receiving cardioversion later than 10 min died without regaining consciousness. The results were compared with other more effective programs. The study region apparently had much fewer cardiac arrest than a similar region in Seattle, U.S.A. In those cases where treatment could be initiated within 5 min, results were comparable.