Sinus tachycardia in children
Introduction
Introduction to sinus tachycardia in children Sinus tachycardia (sinustachycardia) refers to the increased frequency of sinus node pulsation, is the body's normal compensatory response, often occurs in fever, crying, exercise or emotional stress, the baby's heart rate per minute is more than 140 times, 1 ~6 years old more than 120 times per minute, 6 years old or more per minute more than 100 times, P wave is sinus, is sinus tachycardia. basic knowledge The proportion of sickness: 0.00352% Susceptible people: children Mode of infection: non-infectious Complications: heart failure
Cause
Causes of sinus tachycardia in children
(1) Causes of the disease
In childhood, many reasons can cause sinus tachycardia, often in fever, crying, exercise or emotional stress, if it occurs in sleep, you should examine the cause, such as anemia, chronic infectious diseases, congenital Sexual heart disease, myocarditis, rheumatic fever, heart failure and hyperthyroidism, and the use of adrenaline or atropine.
1. Physiological exercise, crying, emotional stress or excitement, etc. cause sympathetic stimulation and increase heart rate.
2. Pathological various infections, fever, anemia, hypoxia, dehydration, shock, various heart diseases and hyperthyroidism in older children can increase heart rate.
3. Drug-based application of sympathomimetic drugs such as: adrenaline, isoproterenol, steroids such as atropine, scopolamine, anisodamine (654-2) and ephedrine drugs, heart rate can be increased to varying degrees.
(two) pathogenesis
1. Excited origin is abnormal
Many parts of the heart have self-regulatory cells, which are self-disciplined. The electrophysiological basis is the 4-phase diastolic autodepolarization activity. The normal sinus node is the most self-disciplined, and the frequency of impulse is the fastest. The following is the atrial special. Conductive tissue, junction zone, His bundle, bundle branch and Purkinje fiber, due to the fastest depolarization rate of sinus node diastole, the impulse is reached earlier and reaches the threshold potential, and is transmitted to the heart, other parts The pacing cells have been excited by the impulse transmitted by the sinus node before the membrane potential rises to the threshold, so their autonomy is inhibited. When the myocardial lesions, such as injury, ischemia, hypoxia, etc., the sinus node is exposed. Inhibition, the underlying self-regulatory cells are forced to release impulses, which is a protective mechanism that can produce escape or escape rhythm. If the autonomicity of the diseased cardiomyocytes is abnormally increased, the frequency of impulses is increased, exceeding the sinus node. , the active ectopic rhythm occurs, one or two consecutive times are pre-systolic, three or more times are tachycardia, ectopic beats occur continuously and the frequency is faster but the ruler is fluttering, Rules were to quiver.
2. Excitatory conduction disorder
Reentry is a common mechanism of supraventricular tachyarrhythmia, especially in pre-excitation syndrome. The condition for completing reentry is: one-way block; conduction slowing; reentry anterior myocardial regains stress quickly. Such excitement is blocked in the proximal end of the one-way block, and then transmitted through another path, and then reversed through the one-way block. At this time, if the original excited part has left the refractory period, the excitement can re-enter the ring. Road, so repeated cycles to produce a reentry rhythm.
Prevention
Prevention of sinus tachycardia in children
Depending on the cause, attention should be paid to the prevention of various infectious diseases, prevention of anemia, dehydration, etc., prevention of various heart diseases, avoiding horror stories and animations, movies, etc.
Complication
Complications of sinus tachycardia in children Complications heart failure
Severe can cause heart failure, which can reduce exercise tolerance.
Symptom
Symptoms of sinus tachycardia in children Common symptoms Tachycardia, anti-feeding heart rate, heart palpitations, restless heart failure
Generally no special clinical manifestations, sudden increase in heart rate of older children can complain of heart palpitations, infant heart rate can increase irritability, refusal to eat, long-term sinus tachycardia can reduce exercise tolerance, even heart failure, cardiac auscultation The heart rhythm is uniform, and the heart sounds are consistent.
Examine
Examination of sinus tachycardia in children
In the case of infection, peripheral blood leukocytes increase, hemoglobin decreases in anemia, red blood cell count decreases, blood sedimentation increases in rheumatic fever, and anti-"O" increases.
1. ECG can appear T wave and P wave overlap or fusion, need to be differentiated from paroxysmal tachycardia, the frequency of sinus tachycardia is gradually increasing, PP interval is slightly uneven, stimulation of vagus nerve can make heart rate Slightly slow down.
2. Regular X-ray and echocardiography.
Diagnosis
Diagnosis and diagnosis of sinus tachycardia in children
According to the characteristics of the electrocardiogram and the cause of the increase in heart rate, the general diagnosis is not difficult and needs to be differentiated from the atrial tachycardia.
When the baby is irritated and crying, the sinus tachycardia can reach 220 times per minute. The overlap of T wave and P wave in the ECG needs to be differentiated from paroxysmal tachycardia. The ECG characteristics and compression of the carotid sinus can reduce the heart rate. Slow, and paroxysmal atrial tachycardia sudden, sudden, ECG characteristics PP interval is very uniform, compression of the carotid sinus is terminated or ineffective, and the main identification of paroxysmal atrial tachycardia is: 1 The former has clear reasons, the latter has no direct cause. 2. The former frequency is variability, and it is gradual, and the latter suddenly stops. 3. The former has a slightly irregular rhythm, while the latter is absolutely uniform. 4. The former P The shape of the wave before and after the wave is the same, while the P group is different from the P wave in the interictal interval, and sometimes the atrial premature contraction is seen.
