For those at greatest risk of sudden cardiac death, an ICD may be inserted as a preventive treatment.
DEALING with the sudden death of a loved one is never easy. We have all heard of many instances when a person passes away without warning due to sudden cardiac arrest.
“Sudden cardiac death (SCD) is a sudden, unexpected death caused by the loss of heart contractions – in other words there is sudden cardiac arrest,” says Ara Damansara Medical Centre consultant cardiologist Dr Ahmad Nizar Jamaluddin.
“While a heart attack is caused by blood clot that obstructs the flow of blood supplying the muscles of the heart, in contrast SCD occurs when there is purely a malfunction of the electrical system of the heart.”
Like its name implies, SCD often occurs without warning. Those afflicted will experience symptoms that include sudden collapse, no pulse, no breathing and loss of consciousness.
“Sometimes a sensation of fast-beating, fluttering or pounding (palpitations) in the chest is felt preceding the sudden collapse,” he says.
According to Dr Ahmad Nizar, while there are many conditions that increase the risk of SCD, the two leading risk factors are a previous heart attack – the risk of SCD is higher during the first six months following a heart attack, particularly when the damaged caused by the heart attack is significant – and coronary artery disease, to which SCD is frequently linked.
Other risk factors include prior sudden cardiac arrest; a family history of SCD; heart failure; abnormal conduction and electrical system of the heart; scarring of the heart that may be caused by a previous infection, toxins and inflammation of the heart; genetic conditions; significant changes in blood levels of potassium and magnesium; recreational drug abuse; and, consuming certain drugs that may increase the risk of life-threatening abnormal heart rhythms.
People with any of these risk factors are advised to speak to their doctor about possible steps to reduce their risk.
“Your doctor will likely perform diagnostic tests to determine if you are at risk. This may include an electrocardiogram (ECG), ambulatory ECG monitoring, an exercise electrogram, echocardiogram, cardiac magnetic resonance imaging, cardiac catheterisation and electrophysiology studies,” says Dr Ahmad Nizar.
“It would greatly help to prevent the development of coronary artery disease with certain lifestyle changes such as improving or reversing insulin resistance, managing other health conditions including high blood pressure and raised levels of blood cholesterol, quitting cigarette smoking, maintaining an ideal body weight and getting regular exercise,” he adds.
He advises that for those at risk of SCD, their family members and colleagues at work should be educated and be able to perform cardiopulmonary resuscitation (CPR) if necessary.
Specific drugs are used to help reduce the risk of SCD, which may include sacubutril, valsartan, beta-blockers and other anti arrhythmic drugs.
For those at greatest risk, an implantable cardioverter-defibrillator (ICD) may be inserted as a preventive treatment.
The ICD is a small device that is able to detect and then correct a fast heart rate. It constantly monitors the heart rate and also records the data of each abnormal event to be viewed by the doctor using a special machine at the hospital.
While a cardiologist is equipped to deal with most heart diseases, sometimes the opinion of a cardiovascular subspecialist is required. Electrophysiology is one such subspecialty.
An electrophysiologist, also known as a cardiac EP, is a cardiologist who focuses on investigating and treating problems involving abnormal heart rhythm.
An automated external defibrillator offers the best chance of saving a person who suffers sudden cardiac arrest.
If you see someone experiencing sudden cardiac arrest, Dr Ahmad Nizar advises: “Call 999 immediately and initiate CPR (cardiopulmonary resuscitation). If done properly, CPR can save a person's life. If there is an automated external defibrillator (AED) available, use it because it offers the best chance of saving the person.”
