Sinus rhythm

The normal, regular heartbeat of the people is called sinus rhythm. It originates in the sinus node in the right atrium. The excitation of the heart and then the heart muscle contraction spreads from there first via the atria to the AV node and then on to the ventricles from. A frequency of 60 to 100 beats per minute is referred to as normal. If the normal heart beat too slowly (eg during sleep ) this is called sinus bradycardia to fast heartbeat (eg, effort) is called sinus tachycardia. Pathological variations in the creation or transmission of the cardiac excitation are called arrhythmias.