Peter Marstrand, 30, is receiving a Lundbeck Foundation 2020 Talent Prize. He is being honoured for his studies of hereditary and potentially fatal arrhythmias
If you ask, ‘could you die from the sound of the doorbell ringing in your hall?’, most people would say, ‘no, I don’t think so; it sounds a bit far-fetched’.
However, this would not be Dr Peter Marstrand’s answer, because he knows that loud noises – and even contact with cold water – can cause dramatic effects in people who have certain hereditary arrhythmias. He has studied the phenomenon in great detail.
These studies form the basis for the PhD thesis Dr Marstrand will be defending at the beginning of November, and these same studies are now being rewarded for their high quality in the form of a Lundbeck Foundation Talent Prize.
The prize is worth DKK 500,000: DKK 150,000 of the amount is a personal honorary award, and the rest is to spend on his research.
The group of hereditary arrhythmias Dr Marstrand is studying is named long QT syndrome. He explains that the syndrome causes problems with the electrical activity of the heart:
‘Long QT syndrome is caused by mutations primarily affecting the potassium channels – ion channels – that control the electrical activity that makes the heart beat. The period of rest between two heart beats is called the QT interval, and if the electrical activity of the heart is disrupted, this interval can become so long that the heart stops.’
There are around 500 long QT patients in Denmark, and most can keep the hereditary arrhythmias in check with beta blockers – medicine that regulates the heart’s rhythm. Approximately a third of all long QT patients also have an implantable cardioverter defibrillator (ICD) that delivers an electric shock to start the heart if it stops.
‘Thanks to beta blockers and ICDs, most long QT patients have a good quality of life and good life expectancy. But there are a few well-known long QT mutations that have special triggers, and these are some of the factors I’m studying in more depth,’ explains Peter Marstrand. He conducted his research at Herlev-Gentofte Hospital and Harvard Medical School in the US.
One of these long QT mutations causes the patient’s heart to stop if they are exposed to a sudden loud noise such as a doorbell, a telephone or an alarm clock. Another mutation can lead to cardiac arrest if the patient comes into contact with cold water, usually while swimming in the sea or a pool, evoking the diving reflex.
A death due to the first of these categories was what piqued Dr Marstrand’s interest in long QT syndrome a few years ago. He says:
‘My PhD project was inspired by the case of a young Danish man who was found dead at work, and there was no obvious reason for his cardiac arrest.’
When the tragic course of events was later examined by cardiologists, it turned out that someone had tried to call the man on the telephone. The examination showed that he had the mutation that causes loud noises to lead to cardiac arrest. The same long QT mutation was also found in some of his family members.
In the course of his research into long QT syndrome, Dr Marstrand has conducted studies with patients who have this sound-sensitive mutation, and he has demonstrated that beta blockers provide good protection against cardiac arrest due to loud noises.
During his secondment to Harvard, Peter Marstrand was involved in a project on the genetics of a different kind of cardiac disease – hypertrophic cardiomyopathy (HCM), whereby a thickening of the muscular wall of the heart makes it harder for the heart to pump.
In time, he and his American mentor, Associate Professor Carolyn Ho, aim to construct a ‘genetic calculator’ that will calculate a patient’s risk of sudden cardiac arrest based on an analysis of the patient’s HCM mutations.
‘This will give us a more nuanced basis than we have today for assessing whether a patient with a thickened heart muscle should be given an ICD,’ explains Peter Marstrand.
He is currently completing his basic clinical training as a doctor. The plan is then to return to the USA to continue his cardiac research, partly aided by the funding provided by the Lundbeck Foundation Talent Prize.