Incidence, duration and survival of ventricular fibrillation in out-of-hospital cardiac arrest patients in Sweden

• Published in: Resuscitation 2000-03, Vol.44 (1), p.7-17
• Main Authors: Holmberg, Mikael, Holmberg, Stig, Herlitz, Johan
• Format: Article
• Language: English
• Subjects: Adolescent; Adult; Age Distribution; Aged; Aged, 80 and over; Anesthesia. Intensive care medicine. Transfusions. Cell therapy and gene therapy; Biological and medical sciences; Cardiopulmonary Resuscitation; Child; Child, Preschool; Duration; Electrocardiography; Emergency and intensive cardiocirculatory care. Cardiogenic shock. Coronary intensive care; Emergency Medical Services - methods; Female; Heart arrest; Heart Arrest - diagnosis; Heart Arrest - mortality; Heart Arrest - therapy; Humans; Incidence; Intensive care medicine; Male; Medical sciences; Middle Aged; Probability; Registries; Regression Analysis; Risk Factors; Sex Distribution; Survival; Survival Rate; Sweden - epidemiology; Ventricular fibrillation; Ventricular Fibrillation - diagnosis; Ventricular Fibrillation - epidemiology; Ventricular Fibrillation - therapy
• ISSN: 0300-9572; 1873-1570; 1873-1570
• DOI: 10.1016/S0300-9572(99)00155-0

The chance of survival from ventricular fibrillation (VF) is up to ten times higher than those with other cardiac arrest rhythms. To calculate the effect of out-of-hospital resuscitation organisations on survival, it is necessary to know the percentage of cardiac arrest patients initially in VF and the relationship between delay time to defibrillation and survival. Aim: To study the incidence of VF at the time of cardiac arrest and on first ECG, the duration of VF and the relation between time to defibrillation and survival. Method: The Swedish Cardiac Arrest Registry has collected standardised reports on out-of-hospital cardiac arrests from ambulance organisations in Sweden, serving 60% of the Swedish population. Results: In 14 065 cases of out-of-hospital cardiac arrest collected between 1990 and 1995, resuscitation was attempted in 10 966 cases. Incidence: The first ECG showed VF in 43% of all patients. The incidence of VF at the time of cardiac arrest was estimated to be 60–70% in all patients and 80–85% in the cases with probable heart disease. Duration: The estimated disappearance rate of VF was slow. Thirty minutes after collapse ≈40% of the patients were in VF. Survival: Overall survival to 1 month was only 1.6% for patients with non-shockable rhythms and 9.5% for patients found in VF. With increasing time to defibrillation, the survival rate fell rapidly from ≈50% with a minimal delay to 5% at 15 min. Conclusions: This study suggests a high initial incidence of VF among out-of-hospital cardiac arrest patients and a slow rate of transformation into a non-shockable rhythm. The survival rate with very short delay times to defibrillation was ≈50%, but decreased rapidly as the delay increased.