Correlation of Heart Activity in Different Time Intervals Post Cardiac Arrest and Its Response to CPR or Defibrillator Intervention

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Aarav Dubey, Diya Thapliyal, Daksh Mathur, and Professor Sunil Tiwari

Abstract

Cardiopulmonary resuscitation, commonly referred to as CPR, is a life-saving medical technique used to maintain blood flow to both the brain and heart during emergency situations. Out of the many scenarios in which CPR is applied, cardiac arrest, a sudden stop in heart function, breathing, or consciousness, is one of the most common.

Although timely CPR is required to receive the best results, it is uncertain as to what attributes to the extended harm done by longer reaction times to cardiac arrest. Therefore, this research intends to examine and investigate the heart activity in different intervals of a cardiac arrest in order to determine what is occurring within the body that is contributing to greater harm to the victim. Through this research, we hope to determine what bodily malfunctions contribute to a decreasing survival rate during cardiac arrest and how CPR decreases the susceptibility for these detriments.

Three different size data samples (county, state, country) were used for statistical analysis. A negative trend in survival rate is found in association with not only the time of first CPR administration, but also of EMS arrival and defibrillation, which is consistent with the biology of the heart after cardiac arrest.

Introduction

This paper will be investigating and examining the following question: What of the heart’s activity in different intervals of cardiac arrest contributes to greater harm to the victim? With cardiac arrest being a leading cause of hospitalization and death worldwide, the relevance of this question is unquestionable. Many patients suffer despite having survived through cardiac arrest, leaving the question of why it occurs and what attributes to the suffering post-attack. If we are able to pinpoint what is attributing to the harm done after cardiac arrest, then professional medicine practitioners may use this research to procure a solution to decrease the detriment done to the body post-cardiac arrest.

The root of the problem lies in the heart’s connectivity to the body and its central role of providing oxygen to vital organs. Therefore, we hypothesize that the sudden halt of blood circulation is the primary cause of harm done, as it severely impacts the brain and its core functions as oxygen are unable to reach it. This leads to an increased susceptibility for brain damage which results in memory loss and detriments the victim’s motor skills.

Following our research, the following questions have arisen: What correlation would other independent variables have with the survival rate of cardiac arrest. These independent variables include age, gender, qualifications of the giver of CPR, and pre-existing medical conditions. These prospect independent variables are the controls of the report; however, all came up in several of the sources used for this report.

Literary Review

The article “The relationship between time to arrival of emergency medical services (EMS) and survival from out-of-hospital ventricular fibrillation cardiac arrest” written by Laura S Gold, Carol Fahrenbruch, Thomas D. Rea, and Mickey S. Eisenberg (Gold L, 2010) from the scholarly journal Resuscitation is the first of the sources used to extract data for this research. The journal, originating from the Elsevier archive, one of the leading scientific, technical, and medical databases in the world, has a variety of articles centering around the clinical and scientific research of acute care medicine and cardiopulmonary resuscitation. This article in particular provides specific data values that compare the decline in survival rate overtime to the arrival of EMS.

The second of the sources used was the article “Timely bystander CPR improves outcomes despite longer EMS times” written by Gwan Jin Park, Kyoung Jun Song, Sang Do Shin, Kyung Won Lee, Ki Ok Ahn, Eui Jung Lee, Ki Jeong Hong, and Young Sun Ro (Park G, 2017) from the scholarly journal American Journal of Emergency Medicine. The article has several data tables charting the findings between the interval from collapse to CPR by EMS providers amongst different demographics. This article is relevant due to its organized flow of data and abundance of different comparisons with several different variables to consider. 

Through these sources, three predominant variables came up: Emergency Medical Service arrival time, first defibrillation time, and first hands-only CPR times. Furthermore, we used research from John Hopkins (Eid S, 2018), Texas Heart Institute (Institute, 2019), Very Well Health (Brouhard, 2019), and TechTimes (Diaz, 2017) articles to study what occurs in the body in different intervals of time after a cardiac arrest.

Three different sizes of cardiac arrest victim data were used for statistical analysis with different medical interventions. The North Carolina data set is analyzed with the first defibrillator given, The King’s county data set is analyzed with EMS arrival time, and The Japan data set is analyzed with the first CPR given. All three analyses found a negative correlation of cardiac victim survival rate. The research concludes that medical intervention is most effective within the first 5 minutes and almost non-effective after 12 minutes.

Analysis

Time(Minutes)What occurs within the body
1/3Unconsciousness
1The victim’s chances of survival will have reduced by 10%.
3Global cerebral ischemia (lack of blood flow to the entire brain) can lead to progressively worsening brain injury. By this point, the victim’s chances of survival will have reduced by another 10%.
4All brain activity is thought to cease minutes from the moment the heart stops.
5Using AED alongside CPR will boost the victim’s survival chance from 6% to 74%.
6At this point, tissue-death of the heart muscle and brain will occur if no proper treatment is provided. The victim’s chance of survival will have now been reduced to between 40 and 60%.
7If the victim does not receive proper treatment. By this point, the victim’s chance of survival will now reduce to between 30 and 40%.
9Severe and irreversible brain damage is likely.
10The chances of survival are 10%
Hansen C, Figure 1, North Carolina Survival Rates of Cardiac Arrest in correlation to time from the first defibrillation.

The graph above compares the time from 911-call to defibrillation in minutes to the percent of defibrillated patients. The relationship between the time from 911-call and the percent of patients defibrillated by bystanders is a moderately linear negative correlation, as seen in the graphic above. The more time from the 911-call, the lower the chance of the patient being defibrillated by bystanders. This is because the patient’s condition worsens, and it is advised that a bystander not touch the patient’s body after a significant amount of time has passed as it can only cause more harm. The correlation between time from 911-call to first responder defibrillating is not strictly positive or negative. From 2 to 9 minutes after the 911-call, the correlation is positive. But, at the endpoints of the call, when the time reaches more than 10 mins or is less than 2 minutes, the correlation is negative. The correlation between EMS arrival and time from making a 911-call is positive because emergency medical services are trained to treat the patients in a timely manner. At any point of time from the 911-call, EMS is the best way to handle a patient.

When an automated external defibrillator (AED) cushion is joined to an individual’s chest, the AED promptly concludes whether that individual’s heart is in cardiovascular arrhythmia, a state in which the patient has an irregular heartbeat. The heart demonstrates whimsically and can’t pump enough siphon blood to the cerebrum and outer limits of the body when an AED conveys a stun. On the off chance that the heart is in some other state or is not beating, the AED won’t deliver a stun. At the point when a shockable mood is distinguished, the AED’s battery charges its capacitors in readiness to stun somewhere in the range of 150 to 360 Joules. This stun depolarizes the heart muscle and kills the lethal arrhythmia by entirely halting the heart out and out. After the heart has halted, it resets its characteristic pacemaker and starts pulsating once more.

Gold L, Figure 2, King County Survival Rates of Cardiac Arrest according to the EMS times (minutes). The graph depicts a negative correlation between EMS time and survival rate.

The graph above shows the relationship between survival rate and time in seconds it takes the EMS to arrive. There is a strong negative linear correlation between survival rate and EMS time to arrival, meaning that as more time passes after a person experiences a cardiac arrest, the survival rate goes down. The data point (0, 42.6) is an outlier as it is a point not corresponding to the negative linear correlation. Furthermore, the point at (9, 22.3) is an outlier as well as it does not fit the negative linear correlation either. These are the two sole data points that do not follow the negative correlation. From the graph, it can be inferred that if the EMS arrives in less than 2 minutes, EMS workers will be able to boost the survival rate of a person by providing suitable treatment. This is because EMS is equipped with the proper equipment and training to handle the victim in the early stages of cardiac arrest. Although, as time exceeds two minutes, EMS is not able to maintain the survival rate. This is because the condition of the body worsens and blood flow ceases in most parts of the body, making any treatment given less effective. When the time is between 8-10 minutes it can be observed that the survival rate bumps up a little bit, which could be because EMS has made some progress in reviving the heartbeat and it starts a little blood flow in the body. As time exceeds 12 minutes, the victim has no blood flow in the body or brain, it’s too late for the victim.

Goto Y, Figure 3, Japan Survival Rates of Cardiac Arrest in Accordance to Hands-Only CPR.

The graph above relates EMS response time with survival rate in percent of a patient over the course of one month. The graph compares different ways a bystander tries to help the patient with respect to the time it takes for EMS to arrive. The more time it takes for EMS to arrive, the more the survival rate decreases. The graph also compares the most effective ways for a bystander to help the patient. As seen from the graph, the most successful way for a bystander to help is through defibrillation since the survival rate drops slowly as a result of defibrillation, whereas with conventional CPR and chest-compression-only CPR survival rate drops down to less than 10% immediately before then slowly decreasing to 1%. The most effective way for a bystander to keep a patient alive is by defibrillation and not CPR.

At the point when rescuers convey CPR to heart failure exploited people, they basically become the injured individual’s pulse. The chest compressions physically crush blood out of the heart and push it all through the body, conveying some oxygen-rich blood to the unfortunate casualty’s mind and organs. The body’s cardiovascular framework needs to keep up a base measure of strain to keep blood moving through the body. Studies show that during CPR, it takes around ten back-to-back chest compressions at the correct profundity to raise the circulatory strain to sufficient levels and start the circulation of blood to the brain. Rescuers quit conveying chest compressions so as to perform salvage breathing—and that makes the pulse drop. That implies each time a rescuer quits performing chest compressions to give salvage breaths, the unfortunate casualty’s pulse drops and the way toward reestablishing bloodstream needs to start from the very beginning once more.

The cerebrum can maintain activity for up to approximately six minutes after the heart stops. The motivation to learn cardiopulmonary revival (CPR) is that if CPR is begun within six minutes of heart failure, the cerebrum may endure the absence of oxygen. After around six minutes without CPR, the cerebrum begins to halt all activity. As indicated by Parnia, giving the patient a cardiopulmonary revival (CPR) could supply blood to the cerebrum for around 15 percent of what’s expected to work. This method is adequate to defer the demise direction of synapses, in any case, it’s not adequate to kick the cerebrum to work once more, the motivation behind why patients have no reflexes when doing mouth to mouth. 

Conclusion

It can be concluded that efficient CPR, timely emergency medical service arrival, and defibrillation all positively impact the survival rate of CPR. The data above shows how increased EMS arrivals lead to ineffective CPR which subsequently results in a decreased survival rate. What causes this is the lack of blood flow in the body due to the sudden stopping of the heart, which ceases the transfer of oxygen to all the vital organs of the human body, therefore negatively impacting the survival rate. This proves the hypothesis proposed as the data shows that in fact, the correlation between longer EMS timing and survival rate of cardiac arrest is negative.