PhD defence D. (Danny) Veen

Below is a brief summary of the dissertation:

Atrial fibrillation (AF), also known as atrial fibrillation, is the most common heart rhythm disorder in both men and women and leads to an irregular and usually fast heartbeat. 
This is because the upper chambers of the heart, the atria, contract chaotically and rapidly, resulting in the heart being unable to efficiently pump blood to the rest of the body. People with AF often experience palpitations, shortness of breath, and/or fatigue. Women generally report more and more severe symptoms than men, while AF is more common and occurs at a younger age in men. Also, the treatments for AF are less effective in women. 
However, it is still unknown why these differences between men and women exist. The aim of this dissertation is therefore to investigate differences in the electrical properties of the atria between men and women. 
Little is also known about sex differences in electrical conduction during the normal heart rhythm, the sinus rhythm. During open-heart surgeries, we measured electrical signals directly on the surface of the heart and showed that there are more electrical abnormalities in the right atrium of the heart in women. We also examined the shape of electrical signals. 
The shape of an electrical signal can be influenced by the structure of the underlying heart muscle tissue. If the signals change shape, this indicates local damage to the heart muscle tissue. The women in this study showed shape changes in the signals. As a result, women may be more susceptible to arrhythmias. 
AF also often occurs (about 30%) after open-heart surgery, even in people who have never had arrhythmias before the operation. However, little is known about sex differences in post-operative arrhythmias. Our studies showed that only on the third day after heart surgery, women experienced an AF episode more frequently than men. Despite surgical treatment for AF, women had more and longer-lasting AF episodes after the operation compared to men. 
In summary, the results of my research indicate clear gender differences in the electrical conduction properties of the atria and the electrical properties of the arrhythmia AF. It is important to unravel the mechanisms behind these differences and use the insights gained to optimize the treatment of both men and women with AF.