Investigation of Pathophysiology, Interventions, Prognostic and Mortality Factors in Conditions Requiring Cardiopulmonary Resuscitation
Pál-Jakab Ádám
Cardiovascular Medicine and Research Division
Dr. Merkely Béla
Városmajori Szív- és Érgyógyászati Klinika, 3. emeleti előadóterem. 1122 Gaál József utca 9.
2026-09-09 15:00:00
Cardiovascular Disorders: Physiology and Medicine of Ischaemic Circulatory Diseases
Dr. Merkely Béla
Dr. Zima Endre István
Dr. Jambrik Zoltán
Dr. Kanizsai Péter László
Dr. Nyirády Péter
Dr. Turóczi Zsolt
Dr. Lőrincz István
This dissertation investigated out-of-hospital cardiac arrest (OHCA) using the nationwide
database of the Hungarian National Ambulance Service within an integrated micro-,
meso-, and macro-level framework, along three objectives: the relationship between
arterial blood gas parameters and defibrillation energy requirement, the association
between meteorological factors and OHCA incidence, and urban-rural disparities in
survival.
The defibrillation threshold study was performed in an experimental canine model, with
113 determinations in 15 animals. Higher energy requirement was predictable from
arterial blood gas parameters with 83% accuracy using an Extra Trees Classifier; the most
important, moderately strong predictors were hematocrit (ρ = 0.247, p = 0.008), sodium
(ρ = 0.372, p < 0.001), and the partial pressure of arterial oxygen (ρ = −0.267, p = 0.004).
In the meteorological study, 114,830 cases were analyzed between 2018 and 2023. Each
1 °C decrease in temperature was associated with a 1.4% higher daily incidence (IRR =
0.986, 95% CI: 0.984-0.987, p < 0.001), with 17.8% higher case numbers during the
winter months and 31.9% higher on days of extreme weather. The XGBoost model
identified temperature and wind speed as the most important predictors.
In the urban-rural study, 130,258 cases were analyzed (urban 70.1%, rural 29.9%). A
significant survival disparity persisted even after propensity score matching (urban 9.4%,
rural 8.3%, p < 0.001): urban location was associated with 26% higher odds of return of
spontaneous circulation (OR = 1.26, 95% CI: 1.20-1.32, p < 0.001). The advantage was
most pronounced with rapid response (≤8 minutes: OR = 1.59) and shockable rhythms
(OR = 1.57).
OHCA outcomes are determined by modifiable, hierarchically interrelated factors. Our
findings support the rationale for data-driven, coordinated interventions: meteorological
early warning, the expansion of public-access defibrillation programs and community
resuscitation training, and the optimization of physiological-parameter-guided,
individualized treatment in monitored settings.
