We commonly hear the term 'Heart attack' in reference to patient being either hospitalised with any cardiac ailment or after a sudden unexpected death. But the term in itself is very misleading or can as there are innumerable reasons whereby a person can suffer a sudden death due to cardiac cause or be hospitalised for the same and correct diagnosis is crucial to timely treatment. A death is termed as sudden if time between onset of symptoms and death is less than one hour .To name a few reasons of sudden cardiac death, I would like to mention -

Myocardial Infarction - Due to 'complete' occlusion of a coronary artery which supplies blood to heart muscle. It can be life threatening and be associated with many complications which impair the quality of life significantly and hence requires urgent treatment in the form of thrombolysis (an iv medication to help dissolve the clot) or angiography and subsequent angioplasty. Treatment strategy depends upon the clinical scenario and available resources.
Myocardial ischemia- Due to a significant but 'incomplete' blockage of a coronary artery. It generally causes angina or chest pain to the patient or may present as difficulty in breathing on exertion. It can be treated with medications and may need a stent to reduce symptoms.
Heart block or bradyarrythmias- It can be of various degrees ranging from first degree which is generally managed conservatively, to a complete heart block which requires a pacemaker insertion.
Pulmonary embolism - Due to a clot in the lung vasculature .
Heart Failure - It can be due to numerous reasons and it can cause a sudden death.
Arrythmias (supraventricular/ Acquired) -Can be congenital or acquired.
Pericardial effusion and tamponade -Due to accumulation of fluid around the heart. It is treated by inserting a needle beneath the rib cage into the pericardial space around the heart.
Aortic dissection- can be catastrophic if not treated on time. It is a tear in the lining of aorta.

The above-mentioned causes are among the common causes of sudden cardiac arrest and treatment are crucial in order to save patient life and minimize future complications. Always remember the age-old adage 'Time is muscle'. Prevention cardiac arrest Best cardiologist in india Dr. Saurabh Chopra