Sudden Cardiac Arrest (SCA)

With two young sports stars dying suddenly, Sudden Cardiac Arrest (SCA) is in the news. DR VIJAY SURASE explains what it's all about.

Can happen to the fittest too...Photo: AFP

Football is often seen as the sport of the absolutely fit. After all, running across a field for more than over two hours needs the best of human ability and strength. But recently there have been a few shocking incidents on the field that are beyond comprehension. Former Italy Under-21 midfielder Piermario Morosini died after collapsing on the pitch and suffering a cardiac arrest during a match. He was 25. Indian football player D. Venkatesh (27) died after collapsing on the field during a local league game in Bangalore last month. These events have left us wondering: can a heart attack or Sudden Cardiac Arrest target even the fittest?

Who is at risk?

Sudden Cardiac Arrests (SCA) occurs in active outwardly healthy people with no known heart disease or other health problems. But this is not a random event. In 30 per cent of the cases, it is the first symptom of heart disease. Some contributors to SCD are:

Overdose on prescription drugs: 

Taking painkillers like Demerol and Oxycontin can lead to heart attacks, as they lower oxygen in the blood. Even medication like tranquilisers and sedatives, which lead to disturbed breathing, can cause SCD. Inadequate dosage of legal medications, such as beta blockers (commonly used for hypertension), can result in sudden cardiac arrest.

Earlier heart attack: 

75 per cent of those who die of SCD show signs of a previous heart attack.

Coronary artery disease: 

80 per cent of SCD victims have signs of coronary artery disease, in which the arteries that supply blood to the heart are narrowed or blocked.

Diagnosis

Electrocardiogram: A painless test in which electrodes are attached to the patient's chest to record the electrical activity of the heart in order to identify abnormal heart rhythms.

Echocardiogram: A painless test in which sound waves are used to create a moving picture of the heart. The test can measure the pumping ability of the heart.

Holter monitor: A Walkman-sized or even smaller recorder that patients attach to their chest for one to two days, recording a longer sampling of their heart rhythm.

Event recorder: A pager-sized device that also records the electrical activity of the heart over a longer period of time.

Electrophysiology study (EPS): A local anaesthetic is used to numb areas in the groin or neck and thin flexible wires called catheters are snaked up to the heart to record its electrical signals. During the study, the cardiologist-electrophysiologist studies the speed and flow of electrical signals through the heart and identifies rhythm problems.

Prevention and cure

Living a healthy life is the best way to keep SCD at bay. This includes not smoking, exercising regularly, eating well and maintaining an optimum weight. Monitoring and treating problems such as diabetes, high blood pressure and cholesterol also help prevent SCD. For some patients, treating abnormal heart rhythms is the only way of keeping SCD away. This can be done by:

Medication: Certain medications control abnormal heart rhythms or treat other conditions that may contribute to heart disease or SCD.

Implantable cardioverter defibrillators (ICDs): Like a pacemaker, ICDs are implanted under the skin. Wires run from the ICD to the heart, and the device monitors the heart to detect abnormal rhythms. If a dangerous rhythm is detected, the ICD delivers an electrical shock to restore normal rhythm and prevent sudden cardiac death.

Catheter Ablation: In this technique, radiofrequency energy (heat), cryotherapy (freezing), or other energy forms are used to abort electrical functions in small areas of heart muscle that give rise to the abnormal electrical signals that cause irregular heart rhythms.

Danger signs

An abnormal heart rate or rhythm

An unusually rapid heart rate that comes and goes, even when the person is at rest

Episodes of fainting due to unknown cause

A low heart pumping/ejection fraction (EF). Ejection fraction measures how much blood is 

pumped by the ventricles with each heart beat. A healthy heart pumps 55 per cent or more of its blood with each beat. People at highest risk for SCD have ejection fractions of less than 40 per cent.

Source : The Hindu