Cardiac arrest does not have to lead to death -Expert

by: Oluwayinka Dada and Victoria Ipe
It is not uncommon nowadays to hear of people who suddenly dropped dead and were said to have suffered cardiac arrest.

All over the world, incidences of cardiac arrests are becoming more popular, with it accounting for 40 per cent of all deaths in Europe.

Cardiac arrest, also known as cardiopulmonary arrest or circulatory arrest, is the abrupt cessation of normal circulation of the blood due to failure of the heart to contract effectively during systole.

Speaking with Saturday Tribune, Dr Mudasiru Salami, a Consultant Cardio-Thoracic Surgeon in the University College Hospital (UCH) Ibadan, said “Cardiac arrest is when the sensation of activities of the heart completely stops.

“Cardiac arrest is a medical emergency that, in certain groups of patients, is potentially reversible if treated early enough.

When unexpected cardiac arrest leads to death, it is called sudden cardiac death (SCD).”

In the same vein, Dr Patience Sotunbi, Consultant Anaesthetist, College Of Medicine, University of Ibadan, UCH and president,  Life Resuscitation Society of Nigeria (LIRESON), said cardiac arrest is different from (but may be caused by) a heart attack (myocardial infarction), where blood flow to the still-beating heart is interrupted (cardiogenic shock).

“We often hear in news reports that some well-known person has died of a “heart attack” or a “cardiac arrest.” Or worse, after the sudden death of a loved one, a doctor might use one of these two terms to describe the cause of death. Unfortunately, these terms often seem to be used almost interchangeably by news reporters (and even, disturbingly, by some doctors). They are two different things.

 “Heart attack or myocardial infarction occurs when a coronary artery (one of the arteries that supply blood to the heart muscle) becomes suddenly blocked. The sudden blockage robs a portion of the heart muscle of its vital blood supply and the muscle dies. So, a heart attack is the death of a part of the heart muscle.

“Cardiac arrest, in contrast, is caused by a sudden heart arrhythmia called ventricular fibrillation. In ventricular fibrillation, the electrical signals within the heart suddenly become completely chaotic. Because these electrical signals control the timing and the organisation of the heartbeat, when those signals degenerate to total chaos, the heart suddenly stops beating. That is, it goes into

“cardiac arrest.” The most common outcome of a cardiac arrest is sudden death,” she said.

She further explained that “Arrested blood circulation prevents delivery of oxygen to ‘’all’’ parts of the body. Cerebral hypoxia, or lack of oxygen supply to the brain, causes victims to lose consciousness and to stop normal breathing, although agonal breathing may still occur. Brain injury is likely if cardiac arrest is untreated for more than five minutes, although new treatments such as induced hypothermia have begun to extend this time. To improve survival and neurological recovery, immediate response is paramount.”

 “The treatment for a cardiac arrest is to begin immediate cardiopulmonary resuscitation (CPR) to support the victim’s circulation, and, as soon as possible, to deliver a large electrical shock to the heart with a device called a “defibrillator.” The large shock allows the heart’s electrical signal to reorganise itself, and the heart starts beating again.

 “Unfortunately, because death occurs within a few minutes of cardiac arrest unless expert help is available, the large majority of individuals who suffer cardiac arrest are not successfully resuscitated,” she adds.

Cardiac arrest tends to be much more common in people who have various types of underlying heart disease — most commonly, a prior heart attack or any condition that produces heart failure. Indeed, many patients who have had either a heart attack or heart failure ought to be considered for insertion of an implantable cardiac defibrillator, a device that automatically resuscitates people who suffer cardiac arrests. Other causes of cardiac arrest include certain inherited heart abnormalities that tend to increase the risk of ventricular fibrillation (the most common of these being hypertrophic cardiomyopathy) and the use of various illicit drugs (especially cocaine).

 “If a close relative has died in a sudden manner, it is important to try to learn the precise cause of death. Your risk of heart attack, and of some types of cardiac arrest, may be higher if a close relative has experienced these events. Make sure you get as much information as you can. Ask the doctor to speak precisely to you about what actually happened,” she said

She further explains that, if possible, recognition of illness before the patient develops a cardiac arrest will allow the rescuer to prevent its occurrence. Early recognition that a cardiac arrest has occurred is key to survival - for every minute a patient is in cardiac arrest, their chances of survival drop by roughly 10 per cent: these areas often have first responder schemes, whereby members of the community receive training in resuscitation and are given a defibrillator, and called by the emergency medical services in the case of a collapse in their local area.

The period (either before or after) surrounding a cardiac arrest is known as the peri-arrest period. During this period, the patient is in a highly unstable condition and must be constantly monitored in order to halt the progression or repeat of a full cardiac arrest. The preventative treatment used during the peri-arrest period depends on the causes of the impending arrest and the likelihood such an event occurring.

In many cases lack of carotid pulse is the gold standard for diagnosing cardiac arrest, but lack of a pulse (particularly in the peripheral pulses) may be a result of other conditions (e.g. shock), or simply an error on the part of the rescuer. Studies have shown that rescuers often make a mistake when checking the carotid pulse in an emergency, whether they are healthcare professionals or lay persons.

Owing to the inaccuracy in this method of diagnosis, it has been suggested that the technique should be used only by healthcare professionals with specific training and expertise; and even then, that it should be viewed in conjunction with other indicators such as agonal respiration.

Cardiopulmonary resuscitation (CPR), including adjunctive measures such as defibrillation, intubation and drug administration, is the standard of care for initial treatment of cardiac arrest. However, most cardiac arrests occur for a reason, and unless that reason can be found and overcome, CPR is often ineffective; or if it does result in a return of spontaneous Circulatory system/circulation, this is short lived.