Sinus reentrant tachycardia

Introduction to sinus reentry tachycardia Sinustrial reentry tachycardia (SART), also known as sinusnodisreentrant tachycardia (SNRT), means that reentry agonism occurs between the sinus node and its adjacent atrial tissue, especially the sinus Patients with lesions in the room. basic knowledge Sickness ratio: 0.0001% Susceptible people: good age is 40 to 60 years old Mode of infection: non-infectious complication:

Cause of sinus reentry tachycardia

(1) Causes of the disease

Most of them occur in elderly patients with structural heart disease, common in patients with sick sinus syndrome and coronary heart disease, but also in cardiomyopathy, rheumatic heart disease, hypertensive heart disease, congenital heart disease, lung Heart disease, etc., single or double sinus node reentry also occurs in the above diseases.

(two) pathogenesis

The P cells in the sinus node are slow-reacting cells, the depolarization rate is slow, the amplitude is low, and the agonistic conduction is slow. Under normal conditions, there are differences in pacing frequency and conduction performance between the P cells of each group. There are functional differences between groups, which can lead to different refractory periods between cell groups, which makes the sinus node form several conduction pathways in function, which is beneficial to the formation of reentry. In addition, there is still around the sinus node. There is a region between the sinus node (slow response) and the atrial muscle (fast response), that is, the sinus node, and the periorbital fibers in the periorbital region have a functional longitudinal separation of the two-path. The heterogeneity of conduction and refractory period can become the occurrence of reentry and constitute the pathological basis of reentry.

Under the condition of the disease, the difference of the refractory period of the cells in the sinus node and the periorbital region is increased, and the conduction velocity in these cells is also significantly slowed down. In the early stage of the cardiac cycle, these conditions can be more obvious, so timely After the atrial contraction into the sinus node, the agitation is slowly transmitted to the original block of the sinus node. If the area and the previously excited atrium have been removed from the refractory period, the sinus can be excited again. Sexual echo, repeated circulatory reentry to form sinus reentry tachycardia, clinical manifestations and cardiac stimulation can be repeatedly induced and terminated, indicating that the mechanism of sudden tachycardia is reentry, but also Found in patients with no structural heart disease.

Sinus reentry tachycardia prevention

1. During chronic treatment, drug treatment may control the recurrence by directly acting on the reentry loop. The indications for drug treatment include those patients who have frequent episodes, affect normal life or have severe symptoms and are unwilling or unable to receive catheter radiofrequency ablation. For patients with sporadic, short-lived, or mild symptoms, medication may not be necessary, or medication may be needed when a tachycardia episode is needed.

2. Avoid spicy, irritating food; quit smoking and alcohol, coffee should be light.

Sinus reentry tachycardia complications Complication

There are usually no special complications.

Symptoms of sinus reentry tachycardia Common symptoms Dizziness, palpitations, hemodynamics, tachycardia, shortness of breath, short chest tightness, tachycardia

The disease can be seen at any age, with a good age of 40 to 60 years old, common in the elderly, more males, accounting for about 60%.

The onset of tachycardia is paroxysmal, that is, sudden and sudden termination, the duration of each episode varies from a few seconds to a few hours, and the heart rate during the attack is 100 to 200 beats/min, most of which is 100 to 130 beats/min. The average is 130 beats/min. The symptoms at the time of attack are determined by the heart rate at the time of onset, the duration and the condition of the underlying heart disease. Most of them are accompanied by palpitations, shortness of breath, chest tightness, dizziness, and only a few may be accompanied by blood flow. Dynamic dysfunction, often caused by emotional excitement, stress, exercise and other tachycardia, some cases have no obvious incentives, the frequency of seizures can increase year by year, the duration of seizures gradually prolonged with the course of the disease.

Sinus reentry tachycardia

Electrocardiogram examination

(1) Typical ECG performance:

1 tachycardia consisting of three consecutive sinus pre-contraction: frequency is 100-160 beats/min, with an average of 130 beats/min.

The 2P' wave morphology is identical or similar to the normal sinus P wave.

The length of the 3P'-R interval is related to the frequency of tachycardia, but is usually greater than 0.12 s and less than 0.20 s.

4R-P' interval > P'-R interval.

5 The P'-P' interval can be abruptly prolonged before the termination of tachycardia.

6 ventricular rate rules can also be irregular: at the beginning of tachycardia, the ventricular rate is often irregular, and tends to be neat in the future, short-term attacks are often irregular.

7 tachycardia is paroxysmal: sudden onset, sudden termination, the duration of the attack is generally short, only 10 to 20 beats in one burst, and the duration of arrest is generally longer than the control sinus cycle.

8 atrial premature contraction can induce and terminate tachycardia.

(2) A detailed description of typical ECG features:

The 1P' wave morphology, time duration and P'-R interval are basically consistent with the sinus P wave before tachycardia. This is an important basis for diagnosis, but sometimes it can be slightly different, depending on the atrial premature contraction retrograde. Does the route of introduction into the sinus node affect the order of sinus echoes in addition to the atrium? If the efferent pathway is the same as the normal sinus, and the atrial depolarization does not change much, the sinus echo morphology is consistent with the normal sinus, otherwise it will Slightly different.

2 often accompanied by warm-up phenomenon, that is, in the first 3 to 5 cardiac cycle center rate can be irregular, often gradually increase and stabilize, there is cooling at the end of tachycardia, that is, in the last 3 to 5 cardiac cycle center rate After the gradual slowdown, the tachycardia is terminated.

3 The atrial premature contraction of sinus reentry tachycardia is equal to the interval between sinus and pre-systolic contraction. There is no compensatory interval, which can be contracted by sinus prematurely or occasionally. Pre-systolic induction and termination.

4 When excitement and stimulation of the vagus nerve, the heart rate can be slowed down or the tachycardia can be abruptly terminated.

5 Because the atrioventricular node and ventricle are not in the reentry path, at the same time, atrioventricular block or atrioventricular separation or bundle branch block can be combined. They do not terminate tachycardia and do not affect the frequency of tachycardia.

6 Some sinus reentry tachycardia have certain difficulties in relying on ECG diagnosis, as follows:

A. When the sinus echo is slightly different from the P wave morphology, it is difficult to distinguish it from the reentry tachycardia in the room.

B. Sinus reentry with significant sinus rhythm.

C. When the amplitude of the sinus P wave and the sinus echo is low.

D. When the sinusoidal echo overlaps the T wave of the previous cardiac cycle, its shape is often difficult to recognize.

Electrophysiological examinations are required for the above conditions for reliable diagnosis.

2. Electrophysiological examination features

(1) Timely atrial stimulation can induce and terminate tachycardia.

(2) There may be obvious, wide induced windows.

(3) The tachycardia can be repeatedly induced and terminated.

(4) vagal stimulation can terminate tachycardia.

(5) The induction of tachycardia has nothing to do with delay in atrioventricular conduction or delay in conduction in the room.

The diagnostic procedure for sinus reentry tachycardia is as follows:

1 If there is a sudden onset of seizures: combined with typical ECG performance at the time of onset, it can be diagnosed, but because the duration of tachycardia is often short-lived, surface electrocardiogram is not easy to capture, can rely on dynamic ECG to capture and confirm .

2 can do esophageal electrophysiological examination: can induce and terminate tachycardia through S1S2 or RS2 program stimulation, may encounter P wave morphological variation or poor identification, need to perform intracardiac electrophysiological examination.

3 Intracardiac electrophysiological examination has the value of definite diagnosis, mainly to observe and measure the sequence of atrial activation after tachycardia induction, when the order is consistent from top to bottom, from right to left, and is consistent with the atrial activation sequence of sinus rhythm At the time, the diagnosis can be confirmed.

Diagnosis and diagnosis of sinus reentry tachycardia

Diagnostic criteria

1. The shape of the P wave, the order of activation is the same as the sinus rhythm, the frequency is 100-160 times/min, the rhythm can be neat or irregular, and the tachycardia is sudden.

2. Timely premature atrial contraction, ventricular premature contraction can induce or terminate the seizure.

3. The presence of atrioventricular block does not affect the presence of sinus reentry tachycardia.

4. The interval after the termination of the tachycardia episode is equal to or slightly longer than the sinus cycle.

5. Vagal nerve stimulation can terminate the attack.

Differential diagnosis

1. Identification of sinus tachycardia with increased self-discipline

(1) SNRT is usually a sinus node with a lesion, while sinus tachycardia is a physiological response. It may also be a reflection of certain pathological conditions, but the sinus node is normal.

(2) SNRT is a sudden onset, abrupt termination, most of the duration of the attack is very short, and sinus tachycardia often occurs gradually, gradually stop, no sudden sudden stop characteristics, duration is also long, up to several hours, A few days or longer.

(3) SNRT esophageal atrial pacing stimulation can be induced or terminated, while sinus tachycardia cannot be induced and terminated.

(4) The SNRT stimulated vagus nerve can be terminated or the frequency is significantly slowed down, while for sinus tachycardia, the frequency can only be temporarily slowed down, but it cannot be abruptly terminated.

2. Identification of non-paroxysmal sinus tachycardia

Non-paroxysmal sinus tachycardia can be seen as a severe and stubborn sinus tachycardia, characterized by a much faster heart rate (>140 times/min during the day) and a longer duration (months or years) ), poor drug response, often leading to tachycardia cardiomyopathy, the identification method is the same as above.

3. Identification with atrial reentry tachycardia (IART)

(1) At the time of IART, the relative refractory period of the atrium leads to slow conduction in the room, while the sinus of the SNRT has no other conduction delay in the room.

(2) Atrial echo is significantly different from sinus P wave in IART.

(3) The intracardiac electrogram recording showed that the atrial activation sequence was different from the sinus P wave.

(4) Changes in the right atrial stimulation site during IART can not be repeated, and stimulation of different atrial sites can repeatedly induce sinus reentry.

4. Identification with autonomous atrial tachycardia (AAT)

Autonomic atrial tachycardia has the characteristics of sudden sudden arrest, but the frequency of attack is faster. The atrial P wave morphology is significantly different from the sinus P wave. Other methods are the same as the above sinus tachycardia.

5. Identification of fast-slow atrioventricular nodal reentry tachycardia

In the latter case, the RP interval is >P--R interval, but the P' wave is reversed from the ventricle, so the P-wave direction is opposite before and after the onset of tachycardia. II, III, aVF lead P' wave Inversion can be distinguished from SNRT.

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