Sinus rhythm describes the normofrequency, regular heartbeat of humans. It arises in the sinus node in the right atrium . The excitation of the heart and subsequently the myocardial contraction spreads from there first through the atria to the AV node and then on to the ventricles . Based on this anatomical position and electrophysiological stimulus transmission, the electrical heart axis must point to the bottom left , in contrast to the ectopic atrial rhythm. H. a positive P-wave can be seen in the limb lead II in addition to the normal criteria in the ECG for a rhythmic heart action.
Criteria in the EKG
- Regular P waves
- Normally configured P-waves with normal atrial vector
- Constant PP intervals
- Each P-wave is answered by a QRS complex
Depending on age and gender, a frequency of 60 to 100 beats per minute is considered normal. If the normal heartbeat becomes too slow (e.g. when sleeping), this is called sinus bradycardia , and if the heartbeat is too fast (e.g. during exertion) it is called sinus tachycardia . Irregular sinus rhythms, i.e. irregular beat sequences of the heart that proceed from irregular stimulation of the sinus node, are called sinus arrhythmia .
Pathological deviations in the development (irritation disorder ) or transmission of the cardiac excitation (conduction disorder ) are referred to as cardiac arrhythmias and, in the case of their origin in the sinus node, also summarized under the term sick sinus syndrome .
- Electrocardiogram (EKG)
- H.-P. Schuster, H.-J. Bustard: Isabel's EKG course. , Georg Thieme Verlag .