New Delhi, Dec 6 : Even as temperatures have started to dip in the national capital, cardiologists on Wednesday called people, especially those with pre-existing heart conditions, to be mindful of the winter season -- known to increase risk of heart attacks. "As winter approaches, we have observed a concerning uptick in the number of heart patients, averaging between 12 to 14 cases weekly. Cold weather can exacerbate cardiovascular conditions, posing significant risks, particularly for individuals with pre-existing heart issues," Dr Vikas Chopra, Senior Consultant Interventional Cardiologist, Primus Super Speciality Hospital, told IANS. He explained that "the drop in temperature prompts physiological changes, leading to increased blood pressure and heart rate, as well as heightened demands on the cardiovascular system". "I strongly urge everyone, especially those with known heart conditions, to take proactive measures during the winter months. It is crucial to adhere to prescribed medications, maintain regular follow-ups with your healthcare provider, and adopt lifestyle adjustments such as staying physically active, managing stress, and adhering to a heart-healthy diet," Dr Chopra added. Studies from several countries have shown that winters are a concern for heart patients and a surge in cardiovascular deaths. A 2021 study in the journal Medicine found that overall, US cardiac arrests peak during December and January. Another study in the journal BMJ Open looked at deaths and daily temperatures in Finland , and found that cardiac death increased by approximately 19 per cent on "unusually cold days". "Colder weather thickens the blood, making it more likely to clot," Dr Sanjeeva Kumar Gupta, Consultant, Dept of Cardiology at the CK Birla Hospital, Delhi told IANS. In addition, disruption to the sleep cycle and hormonal balance impacts cardiovascular health, he said, noting that shovelling snow, engaging in winter sports, and other activities common in cold weather can put further stress on the heart. Dr Hemant Gandhi, Associate Director, Cardiology, Max Hospital, Gurugram, blamed "factors like reduced physical activity and changes in diet during winter" behind an increase in heart problems. He told IANS that individual health and lifestyle factors also play a significant role in heart health. Dr Gupta cited the role of "traditional food habits with a higher intake of salt and lipids of animal origin, which can lead to changes in metabolism, and ultimately affect the mechanism of atherogenesis, coagulation, and thrombogenesis". "It is also possible that the influence of day duration and lack of sunlight or UV light in this season, stimulate the synthesis of vitamin D3 in the skin and liposoluble cholesterol sulphate whose deficiency can favour atherosclerosis and inflammation, and be the cause of higher incidence and increased mortality during winter," he added. The doctors called for staying active by engaging in indoor activities or low-intensity outdoor exercise, dressing warmly to prevent chilling, and maintaining a balanced diet rich in fruits, vegetables, and whole grains. People must also manage stress effectively to avoid exacerbating cardiovascular risks, and patients should modify their lifestyle, particularly during the winter months with a diet rich in organic sulphate and vitamin D3 and if possible, exposure to sunlight, the doctors recommended. /IANS