What is it about ?
The heart is made up of two upper chambers (the atria) and two lower chambers (the ventricles). The heart muscle (myocardium) contracts under the influence of a small electric current. This electric current originates in the sinus node, a node of nerves that is in the right atrium. The current is transmitted from the sinus node to the muscle of the heart by a specific system of nerves. The muscle of the ventricles contracts when current reaches it. Normally, the heart beats between 60 and 100 times per minute.
The sinus node must be able to accelerate the heart rate during exercise (as during a sporting activity, but also in case of stress). The heart thus guarantees sufficient circulation of blood when necessary.
Sinus disease refers to the set of symptoms that occur when the sinus node is not functioning properly. It can be sometimes too fast, sometimes too slow. In this case, the heart function no longer meets the needs of our body. Most often, this phenomenon is combined with other heart conditions affecting the elderly, such as heart rhythm disturbances. But it can also be triggered by certain medications. If left untreated, the disease can lead to further heart rhythm disturbances and heart failure.
How to recognize it?
Symptoms of sinus disease vary widely: palpitations, syncope (fainting), feeling of empty head, faster shortness of breath on exertion and pain in the chest.
The main characteristic is a heart rate that is sometimes too fast, sometimes too slow. This symptom is present in half of the cases. Occasionally, the heartbeat even pauses, the heart stopping beating for a few seconds. During exercise, the heart rate does not accelerate sufficiently, which explains the symptoms such as shortness of breath, dizziness and chest pain. When the heart rate is extremely slow and the pauses are longer, you also experience a tendency to faint.
How is the diagnosis made?
The diagnosis is made on the basis of an electrocardiogram (ECG), performed when the person is having symptoms. This is not always easy, as these symptoms are not present all the time. This is the reason why a Holter monitoring is often carried out. It is actually a 24 hour ECG. The heart specialist (cardiologist) will also perform an ultrasound and put you through a stress test on a bicycle. As you pedal, the doctor will be able to see whether or not your heart rate is increasing normally.
What can you do ?
If you have the impression that your heart is beating too slowly, take your pulse regularly for a minute. If it is less than 40, you need to see the doctor. Also take your pulse after exercising, especially if you notice that you are quickly tired. Normally, your heart rate should be high after exercise and gradually come back down at rest.
What can your doctor do?
The doctor will first check whether the symptoms are caused by drugs that slow down the heartbeat. If this happens, he will start by stopping these medicines for a while. If the symptoms do not go away despite this, you will probably need a pacemaker.
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