I had just received news that a physician Dr. M, whom I had taught in medical school had been found dead in his room. As my mind was processing this shocking and sad news, my nurse showed in my next follow up patient for the morning. Mr C is a Chinese gentleman in his late 60s. 12 years ago he had walked into the emergency room of my hospital complaining of chest discomfort. The electrocardiogram (ECG) showed a heart attack ; as the medical officer was attending to him, his heart stopped and Mr C lost consciousness. CPR or cardiopulmonary resuscitation was immediately started. When attempts to restart Mr C’s heart immediately, failed, I was called to come and assist. About 30 minutes had passed since Mr C collapsed. His heart was still in ventricular fibrillation (see below) and multiple defibrillations (see below) had been delivered unsuccessfully. Guideline recommended drugs had been given. I decided to try an old drug – this worked and temporarily stabilized Mr C. We then rushed him to the Catheterization Laboratory (see below) where we saw as predicted by the ECG an artery supplying blood to his heart completely blocked. Coronary angioplasty (PTCA) – see below – was performed successfully. Mr C went home 5 days later and has since been well. This was a man who was clinically dead for 30 minutes, 12 years ago and literally brought back to life to continue to live a productive and meaningful life. Looking at Mr C smiling in my clinic, I could not stop wondering about my friend Dr M – what if …?
Mr C is alive thanks to the miracle of modern day CPR.
The most common cause for a human heart to stop (“cardiac arrest”) is sudden occlusion (blockage) of an artery supplying blood to the heart muscle. This is commonly referred to as a “heart attack”, the medical term is “myocardial infarction”. Though this is an illness that afflicts older people, patients can be as young as 30 years of age especially if they have certain risk factors. Several conditions can predispose a person to suffer a heart attack. A family history of heart attack especially in young relatives, diabetes, hypertension, very high levels of blood cholesterol and smoking are some common conditions, also termed as risk factors by doctors. Other conditions that will cause the heart to stop suddenly are far less common but include abnormalities of the heart muscle (a condition called hypertrophic cardiomopathy, has been the cause of several young athletes suffering a cardiac arrest on the playing field) and abnormalities of electrical conduction in the heart.
How does the heart stop ? The most common mechanism is the development of a sudden irregular beating of the heart (the medical term is “arrthymia”) termed ventricular fibrillation. The heart will immediately stop contracting. The ECG will show a diagnostic pattern. The blood pressure will plunge to zero and blood supply to every organ in the body will stop. This will result in termination of vital oxygen supply and nutrients to all body cells. Organs will begin to die, starting with the most sensitive organ – the brain. Research over the years has shown that we have a critical interval of about 4 minutes to re establish blood supply to the brain before irreversible brain damage occurs. If blood pressure is not re established in 10 minutes, clinical death occurs.
Witnessing this in the coronary care unit (CCU) as I have, several times in my years of practice, is dramatic. I would be talking to the patient, when suddenly the monitor will show ventricular fibrillation. As there will still be oxygen from the last heart beat in the brain, the patient will still be oblivious to what is happening and continue talking. However, about 10 – 15 seconds later, as the oxygen supply is used up, the patient would lose consciousness, his eyes would roll up, the face will freeze, the upper limbs will stiffen and pull up and he would throw a fit – all signs of brain anoxia (absence of oxygen). In the CCU everyone (nurses and doctors) is trained to recognize this and provide treatment immediately. A machine called a defibrillator will be immediately hooked up to the patient and used to deliver a controlled electrical shock to the heart (defibrillation) through the chest wall. Most times we would be successful at the first attempt; the heart will start contracting normally, blood pressure will be reestablished and the patient will regain consciousness immediately – there may be a short period of confusion before he becomes aware of his surroundings – he will have no recollection of what happened. Many factors determine how responsive the patient is to the effects of a defibrillatory shock described above, to reverse ventricular fibrillation to normal rthymn. One key factor is the duration of time that lapses from the onset of ventricular fibrillation to delivery of the electrical shock – the longer the delay, the lesser the chance of success. The importance of this is described below.
Why does myocardial infarction cause ventricular fibrillation. The abrupt cessation of blood supply to the heart because of this illness will cause the heart muscle to become irritable, resulting in this fatal arrthymia.
CPR is the technique used to restart a heart after it has stopped. Modern day CPR has 2 vital steps to ensure a successful outcome. Immediate application of chest compressions and defibrillation. From the early 60’s techniques for CPR have been refined to increase the chances of a successful outcome. During chest compressions (closed chest massage) repeated compressions applied to the front of the chest (100 – 120 compressions per minute) will squeeze the heart to push blood out to vital organs during cardiac arrest. This is combined with periodic controlled inflations of the lungs (forcing air into the lungs to supply oxygen). All this is started as soon as possible once cardiac arrest has been confirmed, while preparations are made as quickly as is possible to carry out defibrillation. As mentioned earlier, success of restarting the heart and preventing damage to vital organs is dependent on how fast CPR is applied after a cardiac arrest.
Most heart attacks occur at home or in the workplace. 50% of deaths due to a heart attack occur outside the hospital and the majority of this is due to the development of ventricular fibrillation. So CPR if needed, can be started outside the hospital, many of these deaths can be prevented. CPR techniques can be learnt by the lay public and this has, over the years lead to many lives saved. There have been reports in the media, about even teenagers who have learnt CPR, saving the lives of their parents who have collapsed at home after a heart attack. Since the early 60’s lead by the American Heart Association, CPR techniques have been refined and taught both to medical personnel and lay persons all over the world. There are different grades of expertise taught but the basic steps today will train the individual to perform proper chest massage and deliver a defibrillatory shock. To aid the trained layperson to deliver defibrillations, automated defibrillation machines are now available. These are placed in public places where people gather eg : airports and shopping malls. When connected to the body of a collapsed individual, these machines can automatically diagnose ventricular fibrillation and deliver an electric shock to terminate the abnormal rthymn. These machines have helped save the lives of many people all over the world. One of my friends, while on holiday in Germany many years ago, collapsed at the airport while waiting to collect his bag. He was saved by early use of the defibrillator by rescuers. These days, in some cities in Europe, once emergency services are alerted, drones are being used to transport defibrillators quickly to the place where a person has collapsed, to help trained 1st responders (see below), identify ventricular fibrillation if present and help defibrillate the person. In addition to all these of course, the neighboring hospital has to be alerted as quickly as is possible to come collect the patient for furthur treatment to stabilise him.
In Malaysia, the St. John’s Ambulance, the National Heart Association of Malaysia and some medical schools periodically run CPR courses for the general public. The lay person can enroll in these courses, usually held over 1 day and get certified to perform CPR.
CPR should be properly performed. Some years back there were reports in the media about a patient who had collapsed at a concert in Singapore. The report went on to describe how bystanders had repeatedly slapped the elbow of the victim and brought him back to life. Purportedly in traditional medicine connections between the heart and elbow has been described and this was the explanation given for the successful outcome in this patient. This report does not stand up to the scrutiny of modern science. The report is completely illogical and the public must not be mislead by reports such as this as it may cost a patient his life. What most likely happened in this case was that the person had experienced a simple faint from which he spontaneously recovered.
CPR is a lifesaving technique that everyone should learn how to perform.
Medical Terminologies used in the article :
ECG: Electrocardiogram : A graph showing pattern of electrical activity in the heart
Ventricular fibrillation : A serious abnormal rthymn of the heart, which causes the heart to stop contracting and which will result in death if not immediately terminated.
Defibrillation: The passing of a controlled electrical current through the heart to terminate ventricular fibrillation.
Defibrillator: A machine that enables a controlled electrical shock to be applied to the heart to terminate abnormal rthymns like ventricular fibrillation and re establish normal heart rthymn. Pads that conduct electricity are placed on the patient’s chest in pre determined locations and then connected to the defibrillator to enable this.
Arrthymia: Abnormal electrical rthymn in the heart
Catheterization Laboratory: A sterile room in a hospital where invasive procedures on the heart are carried out under close monitoring.
Coronary Angioplasty (PTCA): A procedure where tiny balloons are treaded into arteries supplying blood to the heart to clear blockages.
First responders: Persons who are the first to arrive to help a collapsed person
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