COMMENT | Covid-19 was declared a pandemic by the World Health Organisation in March 2020. Alarmingly, we are now experiencing surges of Covid-19 cases globally with the emergence of highly contagious and easily transmissible Covid-19 variants that can cause more severe disease or evade previously acquired immunity.

Although Covid-19 primarily manifests as a respiratory syndrome, it is also associated with significant multiple organ dysfunction, including severe cardiac impairment. The most common new complication after being hospitalised with Covid-19 is an irregular heartbeat, followed by blood clots in the legs or lungs, heart failure, heart attack, and stroke. Pre-existing medical illnesses such as hypertension, diabetes, and cardiovascular disease are associated with a greater severity and higher fatality rate of Covid-19.

 A growing number of studies suggest many Covid-19 survivors experience some type of heart damage, even if they did not have underlying heart disease and were not sick enough to be hospitalised. So, how does Covid-19 specifically affect the heart? Covid-19 can affect the heart by invading the heart muscle itself, causing inflammation within it, as well as inducing permanent damage by muscle scarring or muscle cell death in severe cases.

On top of that, inflammation can also build up in the heart as a result of a person's immune system overreacting to the infection, flooding the body with what is called a 'cytokine storm'. This mechanism of damage is said to be much more common. This inflammation within the heart muscle is commonly known as myocarditis and is one of the causes of heart failure.

Covid-19 can also cause inflammation in the lining of the blood vessels that transport blood and nutrients throughout the body. This can lead to an increase in blood clot formation and a higher possibility of these clots sticking to blood vessel walls, increasing the risk of heart attack or stroke and perhaps causing low blood oxygen levels.

Further damage to the heart happens if blood oxygen levels are compromised and fall so low that the heart muscle no longer receives enough oxygen from the lungs.

For people with pre-existing heart conditions, it weakens the body’s ability to survive the stress of Covid-19. Generally, a person with a vulnerable heart is more likely to succumb to the effects of fever, low oxygen levels, unstable blood pressures, and blood-clotting disorders — all possible consequences of Covid-19 — than someone previously healthy.

Tips to stay healthy

Although life in a pandemic is stressful, now is not the time to let heart-healthy habits lapse. Being home may give you the opportunity to pay more attention to your health. Here are several strategies you can adopt to look after your heart:

• Eat heart-healthy food. Make healthy food choices like more fruits, vegetables, whole grains, lean meats, fish, and low-fat dairy products. Eat less salt (less than five grams per day), saturated fat, and sugar.
  
  
• Get active. Your heart is a muscle and, as with any muscle, exercise is what strengthens it. Accumulate 30 minutes of exercise at least five days a week.
  
  
• Watch your weight. If you are overweight, even just a small amount of weight loss can improve your blood pressure.
  
  
• Manage stress. Stress can increase inflammation in your body, which in turn is linked to factors that can harm your heart, such as high blood pressure and lower ‘good’ HDL cholesterol. Getting enough sleep and doing things you enjoy can help relieve stress.
  
  
• Give up smoking. Smoking damages the blood vessels leading to your heart, brain, and other parts of your body. Smokers may also have reduced lung capacity, which will put them more at risk of Covid-19. 
  
  
• Continue to take prescribed medications. If you take medicine to treat high cholesterol, high blood pressure, or diabetes, follow your doctor’s instructions carefully. 

Everyone should adopt healthy behaviours to strengthen their defence against Covid-19 while also reducing the long-term risk from cardiovascular disease itself. Something is better than nothing and more is definitely better.

DR NUR ABD RAHIM, DR ALIA DANIELLA ABDUL HALIM, DR MOY FOONG MING, and DR NORAN NAQIAH MOHD HAIRI are attached to the Public Health Department, Universiti of Malaya Medical Centre (UMMC).

The views expressed here are those of the authors/contributors and do not necessarily represent the views of Malaysiakini.