What is Sinus Syndrome

Sick sinus syndrome

Definition: What is Sick Sinus Syndrome?

The sick sinus syndrome describes a disease of the sinus node in the heart. In a healthy state, the sinus node is responsible for the rhythm in which the heart contracts. If this clock is damaged, it comes to Cardiac arrhythmias . The most common is the so-called sinus bradycardia, in which the heart beats regularly but too slowly. Among other things, those affected feel one dizziness at rest or in a faint when they strain themselves.

Sick sinus syndrome causes

Through different Heart disease Sinus node cells may be lost or damaged. The causes include:

Diagnostics: Sick Sinus Syndrome EKG

The most important diagnostic tool for cardiac arrhythmias is the electrocardiogram (EKG). For this purpose, the electrical signals of the heart are derived and displayed via electrodes on the chest wall. This is a good way of assessing the conduction of the heart and the associated parameters. In many cases, an EKG is not enough because it is only a snapshot. The attending physician can ask the patient to wear a 24-hour EKG. It is a small device that continuously records an EKG throughout the day and can then be read out on the computer. An EKG under stress, e.g. cycling, can also provide useful information about a disease of the sinus node.

Therapy: Sick Sinus Syndrome pacemaker

The therapy for sick sinus syndrome depends on the patient's symptoms. In the case of bradycardia, i.e. a slowdown in the heart rhythm ‘, a Pacemakers are implanted . This always intervenes when the heart rate falls below a certain number of beats, so that a protection “downwards” takes place. The pacemaker is usually implanted under the skin above the right breast. If the heart beats too quickly, a healthy rhythm can be ensured by taking medication, e.g. beta blockers such as metoprolol.

Prognosis: Sick Sinus Syndrome Life Expectancy

If an existing bradycardia was treated with a pacemaker, the prognosis is good. Since the patients mostly suffer from a heart disease, this should also be treated well for a good prognosis. The individual life expectancy depends on the underlying disease and the other risk factors for a cardiovascular event, e.g. smoking, Obesity , high blood pressure and the like, as well as the general condition of the person concerned and therefore hardly predictable.


Herold et al .: Internal Medicine. Self-published 2012, ISBN 978-3-981-46602-7.

Hahn: Checklist internal medicine. 6th edition. Thieme 2010, ISBN 978-3-131-07246-7.