Rhythm Analysis during Cardiopulmonary Resuscitation: Past, Present, and Future

Abstract

Survival from out-of-hospital cardiac arrest depends largely on two factors: early cardiopulmonary resuscitation (CPR) and early defibrillation. CPR must be interrupted for a reliable automated rhythm analysis because chest compressions induce artifacts in the ECG. Unfortunately, interrupting CPR adversely affects survival. In the last twenty years, research has been focused on designing methods for analysis of ECG during chest compressions. Most approaches are based either on adaptive filters to remove the CPR artifact or on robust algorithms which directly diagnose the corrupted ECG. In general, all the methods report low specificity values when tested on short ECG segments, but how to evaluate the real impact on CPR delivery of continuous rhythm analysis during CPR is still unknown. Recently, researchers have proposed a new methodology to measure this impact. Moreover, new strategies for fast rhythm analysis during ventilation pauses or high-specificity algorithms have been reported. Our objective is to present a thorough review of the field as the starting point for these late developments and to underline the open questions and future lines of research to be explored in the following years.

Application of Entropy-Based Features to Predict Defibrillation Outcome in Cardiac Arrest

“…BLS treatment recommendations for OHCA patients include 2-min series of chest compressions followed by a pause to assess the patient's heart rhythm [4,5]. The pause is needed because compression movement artifacts during CPR cannot be effectively removed from the ECG [9]. During the analysis pause, the defibrillator's shock advisory algorithm analyzes the ECG waveform [10], then if VF is detected, the defibrillator is charged, and a shock is delivered to the patient.…”

Fully automatic rhythm analysis during chest compression pauses

“…12 However, interruptions for rhythm analysis are necessary because chest compression artefacts may confound the diagnosis of the shock advice algorithm (SAA) in current AEDs. 13 These interruptions contribute to the pre-shock pause, which lasts between 5.2 and 28.4 s 14 and may compromise the survival of the patient. 6 Currently chest compressions are interrupted every 2 min to reassess the rhythm.…”

“…16,17 Over the years, considerable effort has been dedicated to develop methods for rhythm analysis during CPR. 13 Several approaches have been studied such as adaptive artefact filters [18][19][20] or new SAAs designed to analyse either the artefacted 21,22 or the filtered ECG. 23 When tested on short strips (< 20 s) of OHCA data from defibrillators, only a recently published SAA 23 produced sensitivity and specificity results above 90% and 95%, the performance goals recommended by the American Heart Association (AHA).…”

Manual Versus Semiautomatic Rhythm Analysis and Defibrillation for Out-of-Hospital Cardiac Arrest

“…[7][8][9][10][11] Rapid improvements in technology are also yielding modernday SAEDs with shorter delays in rhythm analysis. 12 Internationally, EMS systems are utilizing SAED as either a stand-alone defibrillation strategy or in combination with manual defibrillation mode. [13][14][15] Although SAED results in faster times to defibrillation and higher cardioversion rates compared with manual defibrillation, 10,11 there are no studies that have translated these differences into better survival outcomes from OHCA.…”