Variabilidad circadiana en la frecuencia de episodios extrahospitalarios de parada cardiorrespiratoria

Abstract

ObjectiveTo evaluate the circadian variability in the frequency and characteristics of out-of-hospital sudden cardiac arrests. MethodsAn observational retrospective study, confined to the Basque Country (Spain), was performed. It was recovered clinical data from cardiologic etiology cardiac arrests considered for resuscitation by basic life support ambulances during 18months. All cases were stratified according to time to emergency alert in 3 sections of 8hours and it was studied the statistical association with the frequency of events and the main characteristics defined in Utstein style records. ResultsWe analyzed 269 events of cardiac arrest. During the first time slot (8:00 to 15:59h) 127 events (47.2%, 95%CI 41.2 to 53.2) were recorded, 93 cases (34.6%, 95%CI 28.9 to 40.3) on the second slot (16:00 to 23:59h) and 49 (18.2%, 95%CI 13.6 to 22.8) in the third (24:00 to7:59h). The 51.2% (95%CI 42.2 to 60.1) of electrocardiographic rhythms detected in the 8:00 to 15:59 time range were shockable, a significantly higher proportion than other time slots. We also founded a lower probability that a bystander initiate any resuscitation to the arrival of the ambulance (14.3%, 95% CI 5.9 to 27.4) during the night (24:00 to 7:59h). ConclusionsThe frequency of events of sudden cardiac death is highest during the morning hours and the probability of having a defibrillation electrocardiographic rhythm. The number of resuscitations performed by bystanders before the arrival of the first medical team is low, especially in the night time.