sinusrytmija

Sinusrytmija, often referred to as normal sinus rhythm, is the term used in electrocardiography (ECG) to describe the regular, rhythmic beating of the heart originating from the sinus node. The sinus node, located in the upper right chamber of the heart (the right atrium), acts as the heart's natural pacemaker. It initiates electrical impulses that cause the heart muscle to contract and pump blood.

In a healthy individual, the sinus node generates electrical impulses at a consistent rate, typically between 60 and 100 beats per minute at rest. Each impulse travels through the atria, causing them to contract, then passes through the atrioventricular (AV) node before reaching the ventricles, which contract to pump blood to the rest of the body.

An ECG recording of sinus rhythm shows a specific pattern. Each QRS complex, representing ventricular depolarization (contraction), is preceded by a P wave, which signifies atrial depolarization initiated by the sinus node. The interval between successive P waves and R waves (within the QRS complex) is regular, indicating a consistent heart rate.

While sinus rhythm is considered normal, variations in rate can occur. Sinus tachycardia refers to a heart rate faster than 100 beats per minute, often due to exercise, stress, or fever. Sinus bradycardia is a heart rate slower than 60 beats per minute, which can be normal in well-conditioned athletes or occur during sleep. These rate variations within the sinus rhythm are usually benign. Significant deviations from a regular sinus rhythm, such as arrhythmias, require further medical evaluation.