JOIN USAbout 50 percent of all cardiac deaths are abrupt and unexpected, making SCA a serious public health problem, warns Dr Sreekanth Shetty...
Sudden Cardiac Arrest (SCA) is the unanticipated loss of heart function which leads to Sudden Cardiac Death (SCD). Over the last few years the incidence of SCDs has been increasing at an alarming rate. Approximately 50 percent of all cardiac deaths are abrupt and unexpected, making SCA a serious public health problem.
SCA occurs when the electrical function of the heart gets impaired and becomes erratic. This causes arrhythmias, which is characterised by dangerously fast and abnormal heart rhythms. The blood supply to the body is jeopardised and the person gets unconscious within minutes, due to lack of blood flow in the brain.
Death soon follows, unless prompt emergency treatment is given. Delayed treatment will lead to permanent brain damage, even if the person is revived.The most dreaded thing about SCD is that, in more than half of the cases it does not present any prior warning symptoms. In some instances, the person may experience dizziness and vigorously throbbing heart beats.
However, these symptoms develop just minutes before the cardiac arrest. The only way to avoid this fatally dangerous event is to know the risk factors and work on them. Some of the general risk factors include family history of coronary artery disease (CAD), smoking, high blood cholesterol levels, hypertension, diabetes, obesity and sedentary style of living.
Appropriate dietary and lifestyle measures along with medical consultation and regular health check-ups can resolve these issues to a great extent.
Patients with reduced efficiency of the heart because of dilated cardiomyopathy or a heart attack in the past are at the highest risk of SCA. Dilated Cardiomyopathy (DC) is a disease of the heart muscle, primarily affecting the left ventricle which is the heart's main pumping chamber. The left ventricle becomes dilated and fails to supply blood to the body with the same force as a healthy heart does.
Other common reasons for a weak heart are high blood pressure, hardening and narrowing of the arteries (also known as atherosclerosis or coronary artery disease), alcohol and drug abuse, certain viral or bacterial infections of the heart as well as genetics and birth defects.
Fatigue, palpitations, chest pain, shortness of breath, dizziness and swelling in the abdomen and lower part of the body are the early indications of a failing heart. Consulting a heart specialist is highly recommended in case one experiences these symptoms.
Once heart failure is diagnosed, the doctor initiates the therapy to treat the underlying cause and to improve the heart function. Based on the individual’s symptoms, drugs like beta-blockers, ACE inhibitors, Angiotensin II receptor blockers and blood thinners are given. These drugs not only improve the symptoms but also help the patient live longer.
However, to reduce the risk of SCA in these patients the doctor may also prescribe the use of special pacemaker called implantable cardioverter defibrillator (ICD). This device is implanted under the skin near the collarbone. It monitors the heart rhythm and when the rhythm becomes chaotic it delivers a shock to restore normal rhythm. It is a life saver, as it significantly reduces risk of mortality in patients with poor heart function.
Similarly, there is another pacemaker which is called Biventricular pacemaker (also called CRT) which improves the heart function and reduces risk of heart failure. This may be suitable for some patients with poor heart function, who have not got better with medications.
A combo device, also called Cardiac Resynchronization Therapy Defibrillation (CRT-D), combines the functions of a defibrillator with a biventricular pacemaker.
SCA is a mortal condition which can be devastating for a person’s family. Nothing could be more agonising than the sudden, unexpected loss of a loved one.
It is imperative that people follow a healthy lifestyle and pay heed to heart symptoms so that they receive timely treatment. With appropriate medical intervention, it is now possible to lead a reasonably active and normal life.
(The writer is a senior consultant cardiologist at Sakra World Hospital, Bangalore)