What is a stroke and what causes it?
There are two main types of stroke.
One is caused by a blockage in an artery supplying blood to the brain, sometimes by a blood clot that travelled from the heart. The other type of stroke is caused by a bleed in or around the brain. Both lead to the blood supply to part of your brain being cut off, causing cells in the brain to become damaged or die.
People with heart failure are two to three times more likely to have a stroke. Atrial Fibrillation (AF) is a major risk factor for stroke. It’s a common abnormal heart rhythm where the top chambers of the heart don’t beat properly. This is felt as an irregular and sometimes fast heartbeat, or pulse. This can increase the risk of a blood clot forming inside the heart, which can travel to the brain, triggering a stroke. Below you can hear the difference between a regular pulse and someone who has AF.
When Michelle was 26, she collapsed at work and was rushed to hospital. She went from being an active young mum to finding out she had a heart condition – and would need open heart surgery to replace her mitral valve.
Unfortunately, after the operation Michelle continued to feel tired and breathless, and was diagnosed with atrial fibrillation - a problem with her heart rhythm. She had five ablation operations and was finally fitted with a pacemaker, which eased her symptoms and meant she could get on with life.
But seven years after her collapse at work, Michelle and family were celebrating her daughter’s birthday, when she had a ‘mini stroke’ and collapsed again. Her son, who was just 11, bravely called an ambulance and got her the help she needed.
Michelle’s experience shows why we research more than just hearts. Heart and circulatory diseases are often connected. They can have the same risk factors and one can lead to another. That’s why our research starts with your heart, but doesn’t stop there.
Photo: Kate Dyomina
Our research to tackle stroke
One of the many stroke research projects we fund each year is being led by BHF Professor Barbara Casadei. It's focused on the connection between atrial fibrillation, stroke and brain function. Short episodes of atrial fibrillation are relatively common, particularly in the elderly, and tend to go unnoticed. But it’s possible that these silent episodes of atrial fibrillation could cause damage to the brain affecting how it functions. This could potentially be prevented by drugs if doctors were aware of silent episodes of atrial fibrillation.
Professor Casadei and her team are using a small device attached to the chest to monitor the heart rhythms of 20,000 people enrolled in the UK Biobank. They will measure people’s brain function and use brain scans to detect damage to blood vessels in the brain. They will see if ongoing, silent episodes of atrial fibrillation could be linked to future cases of hospitalisation, dementia, heart attacks, stroke or even death.
The ultimate goal is to identify a group of at-risk patients, who can then receive appropriate advice and treatment, potentially preventing many occurrences of stroke and decline in brain function.