Implantable cardioverter defibrillator revolutionises cardiac treatment

Chennai: An implantable cardioverter defibrillator (ICD), a specialised device designed to directly treat a cardiac tachydysrhythmia, has revolutionised the treatment of patients at risk for sudden cardiac death due to ventricular tachyarrhythmias.

It monitors the heart beat and diagnoses the problems and automatically treats while keeping track of the number of episodes a person experiences. “It is a permanent implanted pacemaker device that provides electrical stimuli, thereby causing cardiac contraction when intrinsic myocardial electrical activity is inappropriately slow or absent,” said Dr Joy M. Thomas, city’s renowned cardiac surgeon and cardiac electrophysiologist.

“But I always give my patients the option to have an ICD implanted,” he said while talking about the treatment options for people who develop sudden heart attack. ICD is commonly used in the US. In India, electrophysiologists do not advise for all heart patients. “This is recommended for persons with the ejection fraction less than 30 per cent. Normally, the ejection fraction should be 55 per cent and above,” he said.

According to the Heart Rhythm society, the ejection fraction (EF) refers to the amount, or percentage of blood that is pumped (or ejected) out of the ventricles with each contraction.

This percentage, or EF number, helps the health care provider determine if one has heart failure or other types of heart diseases.

With each heartbeat, the heart contracts (or squeezes) and relaxes. Every contraction pushes blood out of the two pumping chambers (ventricles). When heart relaxes, the ventricles refill with blood.

A normal heart pumps just over half the heart's volume of blood with each beat – a normal EF is 50 to 75 percent. EF is typically measured by a simple, painless test called an echocardiogram.

Favouring a nation-wide survey of “at risk” population to detect cardiac problems early and thereby take up appropriate treatment to prolong life, said Dr Joy who performed the first Radiofrequency ablation in Tamil Nadu in January 1997.

The survey should be made for all sections of the people, especially children and adults taking part in high endurance sports, those with family history of sudden cardiac arrest, besides others leading a stressful life.

 “It’s a pity the fast paced urbanisation and high cost of land is denying recreational playground for children and adults and as a result our health is becoming the first casualty owing to not exercising at all,” Dr Joy said.