Cardiovascular surgeon Dr Jeremy London is warning people not to dismiss troubling changes in their health after his own unexpected heart attack in 2022. Despite 25 years of clinical experience, he initially ignored the most significant warning sign.

Dr London, who is based in Georgia, US, has since used social media to explain the symptoms that should prompt further investigation. His warnings focus on chest discomfort, shortness of breath, fainting, unusual fatigue and swelling in the legs.

“Well, the first one's a huge red flag, and that's chest pain, chest tightness, or shortness of breath that's brought on with exertion and relieved with rest,” he said in a recent YouTube video.

“This is a sign that you could have a blockage in one of the heart arteries.”

Before leaving for a hunting trip with his son, Dr London had experienced subtle changes, including low energy and fatigue. He also had occasional symptoms resembling heartburn, but dismissed them as minor problems.

The situation became more serious while he was sitting in a deer stand with his youngest son. Severe chest pain brought him to his knees in what he described as a classic presentation of cardiac ischemia.

Even then, Dr London attempted to continue with the activity. He drove about an hour back to his home, where the pain gradually eased with rest, a beta blocker and aspirin.

The relief did not last. The following morning, crushing chest pain returned as he climbed a flight of stairs, finally convincing him that the symptom could no longer be ignored.

Dr London contacted a cardiologist friend and underwent cardiac catheterization through his wrist. The procedure revealed a 99% blockage in a coronary artery at the back of his heart.

His experience now shapes the warning he shares with viewers. Although chest pain is a major concern, he said other physical changes can also justify medical investigation.

“The next one is passing out or nearly passing out, particularly if it's new,” Dr London said. “This could be an underlying problem with the electrical system or a valve problem.”

He also identified increasing fatigue, especially when it is out of proportion to the activity being performed. A sudden decline in the ability to complete familiar tasks can be one of the changes worth noticing.

“Three would be increasing fatigue or fatigue out of proportion to the activity,” he said. “In other words, you used to be able to walk three miles without stopping, now you have to stop and catch your breath.”

Dr London offered another example involving an ordinary trip outside the home. “Or you go to the grocery store and you come home and you're just bone tired and have to lay down.”

Swelling affecting both lower legs is another warning sign on his list. “And finally would be swelling in both lower extremities.”

He explained that when the heart becomes weak, fluid can back up into the body’s tissues. It then collects in places where gravity has the greatest effect, including the lower portion of the legs.

Dr London emphasized that none of these symptoms automatically proves that someone has a heart problem. However, he said they warrant investigation rather than being casually dismissed.

The British Heart Foundation says heart and circulatory diseases are responsible for a quarter of all deaths in the UK. That amounts to more than 170,000 deaths every year.

“Coronary heart disease (CHD), also known as ischaemic heart disease, is the most common type of heart disease,” the organization explains. It also identifies coronary heart disease as the most common cause of heart attack.

The NHS says a person is more likely to have a heart attack if they have a close relative who has experienced one. It also lists crushing or squeezing chest pain that can spread to the arm, neck and jaw among the possible symptoms.

Other listed symptoms include nausea, vomiting and sensations that can feel like indigestion. A person may experience burning in the chest, feel full or bloated, or develop pale, blue or grey skin.

Anyone experiencing possible symptoms of a heart attack, or who has concerns about their health, is advised to ring 999 or contact a local GP or healthcare professional immediately. Dr London’s account shows how even a cardiovascular surgeon initially tried to carry on despite crushing chest pain.