On a cold windy night in December, Satish Gupta had gone to a late night party. On his way back, his car began giving trouble and he had to push it for a while along with a colleague. Later, he felt some strain in the chest and thought that he had pulled a muscle. The nagging discomfort continued for the whole night. He applied a balm and used a hot water bottle to soothe the area. But the next morning, since he still felt restless, he went to the hospital. After the primary examination, the doctor asked for an ECG, which revealed a full fledged heart attack. He was admitted in the Cardiac Care Unit and had to undergo an angioplasty and stenting. He recovered but has been left with a weak heart, necessitating long-term drug treatment and the implantation of a defibrillator. His total hospital bill exceeded Rs 10 lakh and he is still incurring costs. The winter months are known to increase the chances of a heart attack and related problems. This is especially true for people who have one or more risk factors - high blood pressure, diabetes, tobacco use, obesity, high blood cholesterol levels etc.  

It is therefore important to recognise this fact and be careful and use preventive strategies during this period.
Why winter predisposes one to heart ailments
• The changed daylight to dark hour ratio adversely affects the hormone balance. The cortisol levels in the blood are altered. This is one of the possible reasons for increase in heart attacks.
• The low temperature leads to tightening or constriction of blood vessels. This reduces blood supply to the heart, which can aggravate angina and block of arteries - leading to heart attack.
• The oxygen demand of the heart increases because the heart has to work harder to keep the body warm.
• The early morning surge in blood pressure is an important reason for heart attacks being more common at that time. In winter, because of fewer daylight hours, people often have a tendency to finish outdoor work earlier in the day. The combination of cold temperature and hard work leads to a higher blood pressure.
• The shift of activities to morning hours also leads to a change in the circadian rhythm (body clock), leading to an increase in heart rate, blood pressure and cortisol levels. The combination reduces the threshold levels of events like heart attack and brain stroke.
The risk does not necessarily decrease if one migrates to relatively warmer places.
It has been seen that people predisposed to heart attacks who migrate to relatively warmer places during the colder months can get caught with cardiac problems there too. This is especially caused by attacks of infections like influenza, which prevail in places like Mumbai and Kolkata which are warmer than say Delhi in winters.
The inflammation and swelling caused by these diseases can spread to the arteries of the heart and lead to heart attacks.
The smoke and smog in these places during the winter are also unhealthy for the heart.
For people over 65 years in age, diabetics and cardiac patients, influenza vaccine should never be taken without medical supervision.

Executive Director and Dean,
Cardiology, Escorts Heart Institute & Fortis Hospital, Vasant Kunj, New Delhi