As a medical professional with expertise in cardiology, I can explain that a normal sinus rhythm refers to the heart's regular electrical activity that initiates each heartbeat. This rhythm is controlled by the sinoatrial (SA) node, which is the heart's natural pacemaker located in the right atrium. A sinus rhythm is considered normal when the heart rate is between 60 and 100 beats per minute (BPM) for adults at rest. The rhythm should be regular, meaning that the time between each heartbeat is consistent. On an electrocardiogram (EKG or ECG), a normal sinus rhythm is characterized by a P wave, which represents atrial depolarization, followed by a QRS complex, which indicates ventricular depolarization. The P wave should be upright and precede the QRS complex, and there should be a consistent PR interval, which is the time from the start of the P wave to the start of the QRS complex. This interval is typically between 0.12 and 0.20 seconds. read more >>

Sinus rhythm means a normal heart beat, both with respect to the heart rate and rhythm. Heart rate will fall between 60 and 100 beats per minute. The shape of the electrocardiogram (EKG) tracing will exhibit certain key attributes to be considered normal, as discussed below.read more >>