pre-excitation syndrome in the elderly
Introduction
Introduction to pre-excitation syndrome in the elderly Preexcitationsyndrome is a clinical syndrome characterized by abnormal atrioventricular conduction pathway, characterized by abnormal electrophysiological manifestations and multiple tachyarrhythmias. In 1930, by White, Parkison and Wolff First reported, it is called (WPW syndrome). In 1944, Ohnell proposed the term "pre-excited." basic knowledge The proportion of the disease: the incidence rate of the elderly over 60 years old is about 0.1% Susceptible people: the elderly Mode of infection: non-infectious Complications: hypotension, syncope, sudden death
Cause
The cause of pre-excitation syndrome in the elderly
Most patients with WPW syndrome have no structural heart disease, and a few have congenital or acquired heart disease, such as tricuspid valve down, hypertrophic cardiomyopathy, and some have a familial tendency.
Pathogenesis:
Pre-excitation syndrome is an abnormality of atrioventricular conduction, which is characterized by atrial impulses reaching the ventricle in advance through part or all of the atrioventricular pathway, and is prone to rapid arrhythmia.
The anatomical basis of the pre-excitation is outside the special conduction tissue of the atrioventricular, and there are some muscle bundles composed of common working myocardium, which are connected between the atrium and the ventricle, called the atrioventricular bypass. The paraventricular tract is a residual connection between the developmental disorders. In the embryonic development of the human heart, the muscular connections of the inter-chambered cupping network are gradually separated or degenerated by the annulus fibrosis between the compartments. After the atrium and ventricle are fully developed, His bundle is the only muscle channel of the inter-room health search. The atrial health search is transmitted to the ventricle. If the atrioventricular annulus is poorly developed or the intermuscular connection is degraded, It may cause abnormal passage between the atrioventricular compartments. The atrioventricular bypass is mainly distributed in the atrioventricular ring area except the left and right fiber triangles. Except for some of the atrioventricular bypass roads located in the normal compartment junction area and adjacent to AVN-HPS, most of them are located. The left and right free wall areas of the atrioventricular ring are cupping nets.
Prevention
Pre-excitation syndrome prevention in the elderly
In order to effectively prevent the recurrence of tachycardia, two drugs should be used, while inhibiting the forward and reverse conduction of the reentry loop, such as quinidine and propranolol or procainamide and verapamil, application of IC Class and class III antiarrhythmic drugs (amiodarone, sotalol) are also effective.
Complication
Elderly pre-excitation syndrome complications Complications, hypotension, syncope
More than 80% of WPW syndrome is a tachycardia episode, such as a longer duration, can lead to heart failure, hypotension, syncope, concurrent atrial fibrillation, atrial flutter and even sudden cardiac death.
Symptom
Symptoms of Pre-excitation Syndrome in the Elderly Common Symptoms Sudden Heart Failure Angina Pectoris Heart Rate Increased Cardiac Ventricular Arrhythmia Hypertension Hypotension Black Blood
Symptom
(1) Asymptomatic: Pre-excitation syndrome itself does not cause symptoms. Patients with pre-excitation syndrome electrocardiogram are prone to tachycardia and increase with age.
(2) Symptoms: When the frequency of tachycardia is too fast (especially atrial fibrillation), there may be signs such as palpitations, angina pectoris, hypotension, sputum, syncope, and even heart failure, shock, sudden death, etc. .
2. Signs
(1) No signs of cupping network: Pre-excitation syndrome, if you do not have a tachycardia episode, you can have no signs.
(2) elderly patients: due to hypertension and coronary heart disease, showing signs of underlying diseases.
(3) There are signs of cupping network: When the pre-excitation syndrome combined with tachycardia episodes, there may be corresponding signs of cupping network, such as fast ventricular rate, neat or uneven, weak heart sounds, low blood pressure and so on.
3. ECG performance
(1) ECG performance of typical pre-excitation syndrome:
The 1P-R interval is shortened, less than 0.12 s, and the cupping net is generally 0.08 to 0.10 s.
The 2QRS complex is greater than or equal to 0.12 s.
3 There is a pre-shock, that is, the beginning of the QRS wave is frustrated or notched, and the shape is similar to the Greek "delta wave" (delta wave), which can take 0.02 to 0.08 s, and the direction is the same as the direction of the QRS main wave.
The 4P-J interval is within the normal range, generally less than 0.27s.
5 typical pre-excitation sinus rhythm P wave often merges with the pre-shock wave cupping network, so that the PR segment disappears.
6 Secondary ST-T changes, the ST segment of the lead with the R wave as the main sputum drops, the T wave is flat, bidirectional or inverted.
7 reflects the ventricular interventricular activation lead I caused V5, V6 usually q wave disappears, the presence of pre-shock is the main feature of the electrocardiogram of the health search of the syndrome, the typical pre-excitation syndrome is divided into two types: A type is V1 ~ The pre-shock on the V6 lead is positive, the QRS main wave is all up and healthy search, the PR interval is shortened, the B-type is V1, and the pre-shock and QRS groups of the V2 lead are both downward, showing QS, QR. Or the main wave on the RS type, V5, V6 lead is upward.
(2) Concealed stimulating syndrome: due to occult atrioventricular pathway, the electrocardiogram is normal under sinus rhythm, no pre-shock or pre-shock is atypical, or only shows a corresponding change in concurrent arrhythmia.
(3) Intermittent pre-excitation syndrome: On the electrocardiogram, the performance of typical pre-excitation syndrome sometimes occurs, sometimes this manifestation disappears, and the electrocardiogram of the atrioventricular accessory pathway is pre-excited in the ventricle, but sometimes under certain conditions. Next, the atrioventricular bypass does not show the ability to advance, and the ECG is completely normal and healthy.
4. Pre-excitation syndrome with arrhythmia ECG performance Pre-excitation syndrome can be combined with various types of arrhythmia, the most common are atrioventricular reentry tachycardia, atrial fibrillation and atrial flutter, and even ventricular fibrillation Health search.
(1) Atrioventricular reentry tachycardia (AVRT): the highest incidence rate, reaching 70% to 80%, the mechanism of occurrence is the presence of the atrioventricular pathway, which constitutes an anatomical basis for the reentry, and the reentry loop involves The atria, ANV-HPS, ventricles, and atrioventricular pathways are characterized by sudden onset, sudden termination, and durations ranging from hours to hours or days.
AVRT is divided into two types: antegrade atrioventricular reentry tachycardia and retrograde atrioventricular reentry tachycardia.
1 cis-type atrioventricular reentry tachycardia: This tachycardia is transmitted from the normal path, from the side road, the direction of excitement is: atrium atrioventricular node Hippo system ventricle atrioventricular bypass Mainly caused by occult bypass, the electrocardiogram is:
A. Heart rate 150 to 240 times / min.
B. Heartbeats that induce tachycardia often have no prolongation of PR interval.
C. Approximately 25% of patients present with functional left or right bundle branch block and a wide QRS type tachycardia at the onset of tachycardia.
D. may be accompanied by QRS wave voltage alternation, E.II, III, avF lead QRS wave behind retrograde P wave, PR> RP indicates that room conduction is faster than early conduction.
2 reverse type atrioventricular reentry tachycardia: in the case of reverse-type reentry tachycardia, the direction of activation: atrial atrioventricular bypass ventricle His bundle atrioventricular node atrial, this type is relatively rare, about 20%, tachycardia frequency 140 ~ 250 times / min, the symptoms are heavy, the risk is large, the QRS wave wide deformity on the electrocardiogram, the pre-shock is obvious, if you can see the reversed P wave, then PR (2) Atrial flutter, atrial fibrillation: The incidence of pre-excitation syndrome complicated with atrial fibrillation is different. It is generally considered that between 11.5% and 30%, atrial flutter is rare, and the characteristics of ECG are:
1 Atrial fibrillation is a paroxysmal health search, repeated attacks.
2 The ventricular rate was more than 200 beats/min.
3QRS wave width deformity, visible S wave and variability, sometimes full pre-excitation, sometimes incomplete pre-excitation, such as occult bypass and atrial fibrillation, the QRS complex is narrow, no pre-shock, large amplitude of room .
(3) pre-systolic sputum: pre-excitation syndrome patients can occur pre-contraction, atrial, borderline, ventricular premature contraction can be seen, more than supraventricular.
5. Dynamic electrocardiogram
(1) Dynamic electrocardiogram: When the calm ECG cannot be found, the dynamic ECG can be defined as follows:
1 shows typical ECG characteristics of intermittent and latent pre-excitation syndrome.
2 can determine the predisposing factors of atrioventricular reentry tachycardia, retrospective analysis, what causes tachycardia, such as atrial, ventricular premature contraction or heart rate increased.
3 helps to observe the evolution of pre-excitation syndrome combined with tachyarrhythmia.
4 dynamic electrocardiogram can be found in some of the symptoms and pre-excitation syndrome, such as paroxysmal palpitation, palpitations, syncope, etc. due to pre-excitation syndrome complicated by rapid arrhythmia.
(2) Exercise ECG health search: Observing ECG changes caused by different exercise load on the heart rate of patients with dominant pre-excitation syndrome, can evaluate the function of the forward conduction of the atrioventricular accessory pathway, and AVRT can be induced in the patient exercise test. It can be used as one of the assisted diagnosis methods. Exercise can accelerate the conduction of normal atrioventricular. After exercise, the heart rate is accelerated. The pre-shock is gradually reduced. The typical pre-shock is transformed into atypical health search. Some patients have a certain frequency after exercise. The shock wave can disappear.
(3) drug test: the effect of drug test on ECG changes in dominant pre-excitation syndrome, to evaluate the forward conduction function of the atrioventricular accessory pathway, and to develop AVN-HPS forward conduction to show or increase atrioventricular bypass Conduction makes ventricular pre-excitation more obvious, mainly procainamide test and adenosine triphosphate test.
(4) Electrophysiological examination of cupping network: including esophageal electrophysiology and intracardiac electrophysiological examination. The former is non-invasive.
1 It may be clear that the presence of the dominant atrioventricular pathway and part of the recessive atrioventricular pathway.
2 Simultaneously evaluate the forward conduction function of these bypasses.
3 Determine the approximate part of the atrioventricular pathway.
4 can identify atrioventricular reentry tachycardia, the basic method of cardiac electrophysiological examination is the cardiac procedure and intracardiac electrogram (including His bundle diagram) to trace its purpose:
A. Determine the diagnosis of patients with pre-shocks that are not obvious.
B. Identification of the atrioventricular bypass and other types of bypass.
C. Positioning of the bypass of the room.
D. Observe the occurrence and termination mechanism of WPW ring motion tachycardia.
E. Determine the refractory period of the bypass health search.
F. Evaluation of drug and surgical treatment effects.
G. Prepare conditions for pacemaker treatment.
H. Catheter radiofrequency ablation therapy used primarily to guide the health search of the atrioventricular pathway.
Examine
Examination of pre-excitation syndrome in the elderly
Laboratory inspection:
The blood is normal.
Other auxiliary inspections:
The calm ECG has typical ECG features of WPW syndrome. Secondly, the dynamic electrocardiogram is helpful for the arrhythmia. The intracardiac electrogram can identify the atrioventricular reentry tachycardia.
Diagnosis
Diagnosis and differentiation of pre-excitation syndrome in the elderly
About 5% of patients were retrograde atrioventricular reentry tachycardia, and QRS complex was malformed. It should be distinguished from ventricular tachycardia.
