sinus arrhythmia
Introduction
Introduction to sinus arrhythmia The sinus arrhythmia (sinusarrhythmia) sinus node is significantly irregular, causing irregular rhythms in the atria and ventricles. Sinus arrhythmia generally has no special symptoms. It can only cause palpitations, dizziness and even fainting when the heart rate is too low or too fast. During physical examination, the heartbeat and pulse may be irregular or periodic. basic knowledge The proportion of illness: 1% Susceptible people: no specific people Mode of infection: non-infectious Complications: dizziness, syncope
Cause
Cause of sinus arrhythmia
Respiratory sinus arrhythmia :
Respiratory sinus arrhythmia is the most common type of sinus arrhythmia, occurring in all age groups, most commonly seen in children and young adults, and also in the elderly, a physiological manifestation, the majority of sinus The cardiac function of arrhythmia is normal, and can also be seen in the recovery period of acute infectious diseases or after morphine injection and in patients with valvular heart disease.
Non-respiratory sinus arrhythmia:
Non-respiratory sinus arrhythmia is rarer than respiratory sinus arrhythmia, and has nothing to do with respiratory cycle. It can be seen in the elderly, occasionally in healthy people. Heart disease patients are more common than patients without heart disease, especially those with coronary heart disease. Increased pressure, cerebrovascular accidents, and brain dysfunction can also occur. Mental factors, drug factors (such as the application of digitalis, morphine, atropine, etc.) can also cause non-respiratory sinus arrhythmia.
Ventricular sinus arrhythmia:
Ventricular sinus arrhythmia is a special type of sinus arrhythmia, which means that the presence of QRS complex can change the time interval of sinus PP interval. The ventricular sinus arrhythmia is more common in sinus rhythm combined with second degree and third. Patients with degree atrioventricular block were also seen in patients with complete commensurate intermittent and no retrograde atrial conduction of ventricular premature contraction and atrioventricular junctional premature contraction.
Pathogenesis
1. Mechanism of respiratory sinus arrhythmia When sinus arrhythmia occurs, the change of heart rate is closely related to the respiratory cycle. During the breathing process, the excitability of sympathetic nerve and vagus nerve changes, and the self-discipline of sinus node is also A cyclical change occurs in response to it. When inhaling, the carotid sinus and the baroreceptor of the aortic arch are stimulated. The reflex causes the sympathetic nerve to excite, the release of catecholamines increases, the sinus PP cycle is gradually shortened, and the heart rate is accelerated. When exhaling, Reflexively causing increased vagal tone to produce acetylcholine, causing excessive polarization of the sinus node, the slope of the auto-depolarization of the sinus node diastolic phase is reduced, the sinus PP interval is gradually prolonged, the heart rate is slowed, and the heart rate is slow and slow. Equal to a breathing cycle, suspending breathing, sinus arrhythmia can be turned into a rule.
2, the mechanism of non-respiratory sinus arrhythmia may be due to unstable sinus node pacemaker cells.
3. Mechanism of ventricular sinus arrhythmia At present, there are four possibilities for the mechanism of ventricular sinus arrhythmia:
(1) Patients with QRS complex in the PP interval have improved blood supply to the sinus node due to ventricular contraction, increased autonomicity of the sinus node, shortened PP interval, and increased heart rate, between PPs that do not contain QRS complexes. In the period, due to the relative decrease in blood supply to the sinus node, the self-discipline of the sinus node is reduced, and the heart rate is slightly slower.
(2) When the ventricle contracts, the sinus node can be pulled to increase its self-discipline, so that the PP interval is shortened.
(3) The mechanical contraction of the ventricle can reflexively increase the self-discipline of the sinus node and shorten the PP interval. This is because the aortic arch reflex occurs when the ventricle contracts. The acceleration or slowing of the next sinus impulse depends on the ventricular contraction. The time relationship between the time and the P wave before it.
(4) The sinus node artery passes through the sinus node. When the ventricle contracts, it can cause the expansion and contraction of the sinus node artery. The sinus node arteries contract, the sinus node is self-disciplined, and the sinus node is dilated. The self-discipline of the sinus node is reduced.
At present, it is considered that ventricular sinus arrhythmia is actually caused by the positive chronotropic effect of the hook phenomenon.
Prevention
Sinus arrhythmia prevention
prevention
1. Active prevention and treatment of primary disease, timely elimination of primary causes and incentives is the key to preventing the occurrence of this disease.
2, such as sinus arrhythmia with sinus bradycardia, should be alert to the occurrence of sick sinus syndrome, further examination to confirm the diagnosis.
3, pay attention to life and emotional conditioning, should have diet, regular life, do not work.
4, active prevention and treatment of the primary disease, timely elimination of the primary cause and incentives is the key to prevent the occurrence of this disease.
Complication
Sinus arrhythmia complications Complications, dizziness, syncope
Dysfunctions such as dizziness and syncope may occur when the heart rate is too low or too fast.
Symptom
Symptoms of sinus arrhythmia Common symptoms Pulse apnea stun stun heart palpitations Low ejection fraction Heart rate increases atrial migratory rhythm
Sinus arrhythmia generally has no special symptoms. It can only cause palpitations, dizziness and even fainting when the heart rate is too low or too fast. During physical examination, the heartbeat and pulse may be irregular or periodic.
1. Diagnosis of respiratory sinus arrhythmia
(1) On the same lead, the adjacent sinus PP interval is greater than 0.16 s (0.12 s).
(2) The PP interval is shortened during inhalation, and the sinus heart rate is increased; the exhalation is prolonged, the sinus rhythm is slowed down, and the PP interval is gradually and gradually changing periodically.
2. Diagnosis of ventricular sinus arrhythmia
(1) Sinus P wave morphology is the same: this type of sinus arrhythmia occurs mostly in second-degree, high-degree, third-degree atrioventricular block and patients with premature systolic contraction and ventricular premature contraction. Careful measurements can be found.
(2) Compare the characteristics of the PP interval with and without the QRS complex: the difference between the two should be greater than 0.2s.
Examine
Sinus arrhythmia examination
There may be characteristics of laboratory tests related to primary disease that cause sinus arrhythmia.
Mainly rely on ECG diagnosis, different types of sinus arrhythmia ECG performance have their own characteristics.
1. ECG characteristics of respiratory sinus arrhythmia
(1) P wave: When the sinus arrhythmia is abnormal, the P wave is a sinus P wave, and the shape is constant, but in the II, III, aVF lead, the P wave shape may slightly change due to the change of the heart position caused by the breathing.
(2) PP interval: On the same lead, the longest PP interval and the shortest PP interval can differ by more than 0.16s (0.12s).
(3) PR interval: 0.12 to 0.20 s.
(4) Heart rate: The heart rate changes with the breath, the heart rate increases when inhaling, the heart rate slows down when exhaling, and the period of heart rate changes is equivalent to a breathing cycle.
2. ECG characteristics of non-respiratory sinus arrhythmia
The characteristics of electrocardiogram are similar to those of respiratory sinus arrhythmia. In the same lead, the adjacent sinus PP interval is more than 0.16s (0.12s), the difference is that the PP interval is independent of the respiratory cycle, heart rate. Often suddenly increased.
3. ECG characteristics of ventricular sinus arrhythmia
(1) The PP interval without the QRS complex is more than 0.2 s longer than the PP interval containing the QRS complex, and most of the ventricular sinus arrhythmias belong to this type.
(2) The PP interval containing QRS complex is more than 0.2s longer than the PP interval without QRS complex. This type is also called variant ventricular sinus arrhythmia.
Diagnosis
Diagnosis and differentiation of sinus arrhythmia
It should be identified with the following arrhythmias:
1, atrial contraction before the contraction
The P wave morphology should be identical in the sinus arrhythmia, or gradually change slightly: the P' wave of the atrial premature contraction is completely different from the sinus P wave shape, and the PP interval is not exactly the same during the sinus rhythm. The change of the pre-atrial contraction rhythm suddenly aroused in advance, and there was an incomplete compensation interval.
2, second degree I sinus block
During the sinus arrhythmia, the PP interval was gradually shortened and then gradually extended, while the PP interval of the second degree I sinus block was gradually shortened, followed by a long interval. After this interval, the PP interval was gradually shortened. Irrespective of the respiratory cycle, the change in the PP interval between sinus arrhythmias is related to the respiratory cycle, and the sinus arrhythmia disappears when the breathing is temporarily stopped.
3, irregular second sinus block
During the sinus arrhythmia, the PP interval was gradually shortened and prolonged. The change was closely related to the respiratory cycle; while the second interval sinus block was suddenly prolonged in the PP interval, which was not related to the respiratory cycle.
