What is sinus arrhythmia? This is a complication related to your heart. And it is related to sinus node. Sinus arrhythmia is referred to normal increase of heart rate when you take breathe in that is the increase of heart beats when normal inspiration takes place. This is a kind of natural response and happens more in children than in adults.
Sinus node refers to a group of some consequential cells that are found in the atrium of your heart. The atrium is the exact location where electrical impulse takes place with the help of such sinus node. These cells that is sinus nodes perform different functions. The sinus node on the right atrium acts like a pacemaker to regulate the heart beat and at the same the sinus nodes or cells produce proper rhythm in the electrical impulse that causes your heart to pump blood at regular intervals. If there is a dysfunction or some kind of abnormality in the sinus node and the heart beat increases as you breathe in than its called sinus arrhythmia.
What is sinus arrhythmia can also be explained as abnormal rhythm of sinus or simply in lay man's language the abnormal heart rhythm. This is also called respiratory sinus arrhythmia. If in one hand the heart rate increases with breathing in and then on the other hand the heart beat slows down during expiration of air from the lungs. Sinus arrhythmia affects the vagus nerve which is responsible for activating the nervous system-triggered parasympathetic input which regulates the heart beat.