In the UK, cardiovascular disease is one of the biggest causes of death, accounting for around a quarter of all fatalities every year. It includes any conditions that affect the heart and circulatory system, such as coronary heart disease, strokes and heart failure.
And according to the British Heart Foundation (BHF), around 7.6 million people in the UK are currently living with cardiovascular disease, with this number expected to rise.
If not caught early and treated, cardiovascular disease can prove fatal. Therefore, spotting any warning signs is vital.
Some well known signs of a heart problem include chest pain and shortness of breath.
But new research has revealed one warning sign why one symptom is more likely to occur first thing in the morning.
A study, published in Circulation Research journal, explained that heart arrhythmias are far more common immediately after waking up.
An arrhythmia is an abnormal heart rhythm, which usually means your heart is beating too fast, too slow or irregularly.
It can cause:
- Palpitations (a thumping or fluttering sensation in your chest)
- Dizziness
- Feeling as if you may “black out”
- Breathlessness
- Chest discomfort
- Feeling tired.
Arrythmias can be caused by a dangerous underlying condition such as coronary heart disease, heart failure, cardiomyopathy or even a heart attack.
However, they can also be linked to something less serious such as a viral illness, alcohol, caffeine or medications.
They can also “strike” at any time and trigger deadly medical emergencies such as cardiac arrest.
According to the research, funded by the BHF, these “potentially lethal” heart rhythm disturbances are linked to the natural surge of the stress hormone cortisol, which peaks in our blood first thing in the morning.
In a study of mice, researchers at Imperial College London found that cortisol binds to a specific protein on the surface of heart cells.
The protein moves to a different part of the cell where it influences genes which control how easily the heart cells carry the electrical signals that tell them to beat.
As the activity of the genes changes, electrical impulses to the heart become less regular and more chaotic, leading to abnormal heart rhythms, or arrhythmia.
Cortisol’s circadian, or day-night, rhythm is affected by sleep, with an increase in cortisol just minutes before an individual wakes up.
Professor James Leiper, associate medical director at the BHF, explained: “Ventricular arrhythmias can strike at any time and, if left untreated, can lead to a loss of consciousness, sudden cardiac arrest, and death.
“It is crucial we continue to investigate the causes of these arrhythmias, so we can take action to prevent them.”
“This intriguing study in mice reveals a possible solution to the mystery of why ventricular arrhythmias are more common in the morning.
“Identifying a rise in cortisol as the culprit could allow us to explore new treatment options that could reduce arrhythmias in those most at risk.
“Further research will be necessary to establish whether these findings are also seen in humans.”
Other signs of cardiovascular disease include:
- Chest pain
- Pain, weakness or numb legs and/or arms
- Breathlessness
- Feeling dizzy, lightheaded or faint
- Fatigue
- Swollen limbs.
If you experience any symptoms or are concerned about your heart health you should speak to your doctor.