"It is remarkable how many family members also have heart rhythm disorders"

The first outpatient clinic specifically for patients with familial atrial fibrillation has been opened at the Erasmus MC in Rotterdam. An interdisciplinary team will investigate the possible heredity of this type of heart rhythm disorder and its possible causes. Suzanne (63) and Louwrens (68) Boomsma are brother and sister and are participating in this research.

"It was three years ago on my husband's birthday," says Suzanne Boomsma. "My brother, who is a general practitioner, came to visit and I told him that I had been feeling tired for a while and couldn't understand why. Even climbing stairs was a problem. He felt my pulse and said that my heartbeat was much too high and irregular. I had to call my general practitioner immediately."

"Normally, when you feel a heartbeat, you feel regularity," adds Louwrens Boomsma. "In my sister's case, it was very irregular. I have atrial fibrillation myself and was able to quickly make the suspected diagnosis. On the advice of her own general practitioner, we called an ambulance and Suzanne went to the hospital. That's where the process started."

Everyone finds it remarkable how much it occurs in the familySuzanne: "In hindsight, I may have had it before. But then the heart went back by itself. It is not entirely clear what causes it. I don't drink a lot of alcohol or coffee, and I live a healthy life. Given my age, it was thought to be a familial form. Now that I am participating in the study, I have asked various family members if they also have problems with heart rhythm. Everyone finds it remarkable how much it occurs in the family."

"Our father died of a stroke, and sometimes he also had an irregular heartbeat," says Louwrens. "But atrial fibrillation was not diagnosed in him and therefore not treated. And from an old electrocardiogram of his father, my grandfather, we could deduce that he had heart rhythm disorders. My father's sister and two of her sons also have it."

Determined by genetics

In approximately twenty percent of patients, atrial fibrillation, also known as atrial flutter, determined by genetics. It is generally believed that several genetic variations may underlie this condition. Researchers from the Medical Delta Cardiac Arrhythmia Lab scientific program opened the first outpatient clinic specifically for patients with familial atrial fibrillation in the Netherlands earlier this year at Erasmus MC. This outpatient clinic is part of a national network for research on familial atrial fibrillation.

The research examines the relationship between genetic variations and their effects on a heart muscle cell, among other things. The research is an example of the increasing integration of scientific disciplines that come together in Medical Delta research. From different perspectives, researchers search for possible causes of familial atrial fibrillation, together with patients.

Suzanne: "After my diagnosis, I searched the internet and found the patient association AFIP. They were looking for people for family research. I was immediately interested and signed up. I am now what is called an index patient. My brother and nephews participate with me. We all give a blood sample for genetic research and fill out a family history questionnaire. This is a survey about how you live. Whether you smoke, how much alcohol you drink, or whether you experience a lot of stress. All things that can be external factors."

Louwrens: "According to my cardiologist, it has little added value for me personally to participate in this research because I already have a pacemaker. Nevertheless, I think it is important to participate. My son is a very enthusiastic marathon runner. With all his exercise, he is at higher risk for heart problems. I hope that this research yields something that reduces the risk for him.

It would be nice if we could prevent things in an early stageAs a general practitioner, prevention was one of my areas of focus. Being able to recognize diseases at an earlier stage is very important. Also in the case of my son. If you know that this exists in my family, you can be careful with certain things, such as drinking alcohol or coffee. It would be nice if we could prevent things in an early stage."

Suzanne: "I also think that when you are young, it is good to know that this exists and that it has an impact. That you recognize it and adapt your lifestyle, monitor it more, and take it into account more. Professor Natasja de Groot, one of the researchers, told me that in the past, people used to think, 'I'm just old,' and then accepted it. But there are now treatments and much more is possible.

I hope above all that the research yields a more precise treatment. I understand that it can be the case that due to a genetic abnormality, you are missing a certain substance that ensures good electrical conduction. If you can take that substance instead of beta blockers and anticoagulants with all their side effects, that would be fantastic."

Family research

Meanwhile, investigations have started in several families at the special outpatient clinic. It is a comprehensive and lengthy process that demands a lot from the participants, but the researchers note that people are willing to cooperate for a longer period of time for the benefit of science.

Suzanne: "What I find difficult about heart arrhythmias is that it is hard to feel what it really is. In the beginning, you are mainly very tired. That seems relatively harmless, but if you ignore it, you can get serious symptoms. It would be good if people who read this become more alert to the signals of the body."

Former GP Louwrens has one final tip. "There is a lot of patient information available online at www.thuisarts.nl, also about atrial fibrillation. A good place to start if you have any questions."

What causes familial atrial fibrillation?

Atrial fibrillation is the most common heart arrhythmia. The risk of atrial fibrillation is higher in some families and occurs there even at a young age or without other medical conditions. In most cases, it is unclear what causes this so-called "familial atrial fibrillation." In some rare cases, it has been shown that changes in certain genes may be responsible. However, more research is needed to clarify the genetic factors associated with familial atrial fibrillation and to determine the (functional) consequences for heart muscle cells. This will allow the role of these genes in the development of atrial fibrillation to be investigated.

From various perspectives, the researchers at the outpatient clinic are searching for the possible causes of familial atrial fibrillation. "We go through the whole process: from doctor to biologist to engineer," says Medical Delta professor Dr. Natasja de Groot (Erasmus MC, TU Delft). The first patients have already been examined through the AFIP foundation. "With our research, we hope to unravel and understand the molecular causes of hereditary atrial fibrillation. This knowledge may help develop new therapies for this heart arrhythmia in the near future," says Prof. Dr. Bianca Brundel (Amsterdam UMC), one of the scientific leaders of the Medical Delta Cardiac Arrhythmia Lab program.

Read more about the outpatient clinic for familial atrial fibrillation here.