Sinus arrhythmia refers to an arrhythmia in which the irregular excitement frequency of the sinus node causes an uneven heart rate and a significant increase.

Sinus arrhythmia is divided into respiratory sinus arrhythmia, non-respiratory sinus arrhythmia, free sinus arrhythmia, sinus arrhythmia related to ventricular contraction and 心律不正原因, and sinus rhythm caused by ectopic heart rhythm. Abnormal.

Inhalation sinus arrhythmia is the most common type of sinus arrhythmia, which occurs in children, adolescents and the elderly. The mechanism is due to changes in the tension of the vagus nerve and sympathetic nerves in the body during the breathing process, so that the autonomy of the sinus node also changes periodically and regularly. The heart rate increases during inhalation, slows down during exhalation, and normal during exhalation.

Non-inhalation sinus arrhythmia is rare, the cause is unknown, and may be related to mood swings or the use of drugs such as digitalis and morphine.

The excitement of the sinus node migrating rhythm is not fixed, but it moves in the sinus node.

Abnormal ventricular contraction and drainage can cause sinus node blood supply disorders, change the self-regulation of the sinus node, and lead to arrhythmia.

Sinus arrhythmia induced by ectopic rhythm may be caused by excitatory points in other parts of the myocardium except the sinoatrial node, most of which are ectopic excitement of the atrium. These ectopic excitement may affect the rhythm of the sinus node, make the excitement of the sinus node occur earlier, and cause sinus arrhythmia.

What does an arrhythmia on an electrocardiogram look like?

1. Sinus arrhythmia

1. Sinus Rhythm: The agitated heart rhythm originates from the sinus node, which is a normal heart rhythm. The characteristics of its electrocardiogram are as follows: heart rate is 60-100 beats/min. The p wave in lead avR is inverted, and the p wave in leads LnLm and avF is upright, also known as sinus p wave. The pR interval is greater than 0.12 seconds. The difference between the R wave intervals is less than 0.12 seconds.

Sinus tachycardia: the same as the characteristics of sinus rhythm, only the heart rate is greater than 100 beats per minute. Generally less than 160 times/min.

Sinus bradycardia: the same sinus rhythm, only the heart rate is less than 60 beats/min. Generally not less than 40 times/min. Sinus arrhythmia: Same as sinus rhythm, only the difference in R wave interval is greater than 0.

2. pre-term contraction

A certain part of the heart other than the sinus node emits electrical excitement in advance to temporarily control the heartbeat, which is called premature contraction.

Atrioventricular nodal zone premature contraction: The QRS wave shape and width appearing before the period are the same as the sinus QRS wave, with no p wave in front or retrograde p wave in the opposite direction to the sinus p wave, and then there is a complete compensation interval.

The shape and width of the QRS wave appearing in advance are the same as the sinus QRS waveform, and there is no p wave before it or there is a retrograde p wave opposite to the sinus p wave (the R lead p wave is upright, and the LnLm and avFp waves are inverted).

Ventricular premature contraction: The QRS wave that appears before the period is usually longer than 0.12 seconds. The shape is wide and deformed. There is no p wave in the front. The direction of the T wave is mostly opposite to the direction of the QRS main wave, and there is a complete compensation interval afterwards.