This page provides an introduction to sinus rhythms and links to our lessons and drills.
A normal sinus rhythm refers to both a normal heart rate and rhythm. Normal heart rates are from 60 to 100 beats per minute. The shape of the electrocardiogram (EKG) tracing will exhibit certain key attributes to be considered normal, as discussed below. With normal sinus rhythms, the heart beat's electrical impulse originates in the sinoatrial node (SA). The P waves are upright and appear before each QRS and have the same shape. The intervals between the P waves are regular although some variations can occur with respiration. Sinus rhythms are classified as:
- Normal Sinus Rhythm
- Sinoatrial Block
- Sinus Pause
- Sinus Arrhythmia
- Sinus Bradycardia
- Sinus Tachycardia
Sinus Rhythm Categories
Sinus arrhythmia looks normal except for slight irregularities. A frequency cause of sinus arrhythmia can be rhythm variations caused by respiration.
Sinus bradycardia is a sinus rhythm with a rate of 40-60 bpm.
Sinus tachycardia is a normal sinus rhythm but with a heart rate over 100 bpm. It is a normal response to exercise, excitement and some illnesses.