Paroxysmal supraventricular tachycardia in the elderly
Introduction
Introduction to paroxysmal supraventricular tachycardia in the elderly PSVT refers to tachycardia originating from the atrial or atrioventricular junction, mostly due to reentry excitability, and a few are caused by increased self-regulation and triggering activities. Electrocardiogram continuous more than 3 times of supraventricular premature beats called paroxysmal supraventricular tachycardia, including atrial and junctional tachycardia, sometimes difficult to identify on both electrocardiogram, collectively referred to as paroxysmal chamber Sexual tachycardia. basic knowledge The proportion of illness: 0.001% Susceptible people: the elderly Mode of infection: non-infectious Complications: syncope, angina, heart failure, sudden death
Cause
The cause of paroxysmal supraventricular tachycardia in the elderly
(1) Causes of the disease
Coronary heart disease, myocardial infarction, hypoxemia, hypokalemia, pre-excitation syndrome, heart failure, chronic obstructive pulmonary disease, various other organic heart disease or with atrial enlargement, digitalis or other drugs Toxic reactions, infections, fever, hyperthyroidism, can also be seen without any cause, or due to emotional excitement, excessive fatigue, smoking, drinking induced.
(two) pathogenesis
The electrophysiological mechanisms of supraventricular and ventricular tachycardia are mostly reentry. A few are abnormal autonomic or post-depolarization secondary excitatory. When supraventricular tachycardia occurs, reentry can occur between the sinus node and the adjacent atrial muscle. In the atrium, in the atrioventricular node, or in the interventricular (by side bundle), the reticular tachycardia is mostly located in the ventricle, and the bundle branch is rare. The electrophysiological difference between the fast and slow pathways at the junction of the atrioventricular, the former The conduction speed is fast, the refractory period is long, and the latter has a slow conduction speed and a short refractory period. It is the basis of the circular motion or reentry between the two. The predetermined direction of the loop is transmitted from the slow path, and the fast path is reversed (slow-fast type). More common, and vice versa (fast-slow) is rare. The difference in electrophysiological characteristics between the side bundle and the normal atrioventricular conduction system is the basis of the inter-room interventricular reentry. The common circular motion direction is from the atrioventricular node to the The ventricle is then transmitted back to the atria along the side stalk, and there are also changes in myocardial cell electrophysiological properties caused by local myocardial ischemia, necrosis or fibrotic lesions, which are transmitted to the ventricle by the side bundle and then reversed along the His bundle. The difference is the favorable formation of micro-reentry in the myocardium Basic, atrial and/or ventricular myopathic lesions can reduce the resting membrane potential of the corresponding cardiomyocytes. When the fast-reacting cells are converted to the electrophysiological properties of slow-reacting cells, conduction is slowed down and abnormally self-disciplined. Arousal can be caused by the increase of extracellular calcium ions, catecholamines and other drugs; and delayed depolarization triggering may be related to digitalis poisoning.
Prevention
Paroxysmal supraventricular tachycardia prevention in the elderly
First of all, we should pay attention to eliminate the factors that cause early room, such as mental mood fluctuations, work fatigue, smoking, drinking, etc., should be actively treated when frequent early room, you can try beta blockers such as propranolol or A Tirolol, etc., if it is ineffective, verapamil, diltiazem, propafenone, amiodarone or quinidine may be used sequentially. Digitalis is often effective in cases of cardiac insufficiency or cardiac enlargement, but should be Except for the early pregnancy caused by digitalis poisoning, combined with medication to prevent recurrence of refractory recurrent PSVT.
Complication
Complications of paroxysmal supraventricular tachycardia in the elderly Complications, syncope, angina, heart failure, sudden death
The tachycardia frequency exceeds 200 beats/min, which can cause heart, insufficient blood supply to the brain, blood pressure, syncope, seizures (asc.), angina, heart failure, and even sudden death.
Symptom
Symptoms of paroxysmal supraventricular tachycardia in the elderly Common symptoms Dyspnea, blood pressure, decreased urinary palsy, shock, dizziness, palpitations, tachycardia, angina, pulse, fine speed
1. Heart rate is fast, more than 160 ~ 220 times / min, rhythm rules.
2. There is a strong heartbeat in the heart or chest.
3. More urine, sweating, difficulty breathing.
4. Long duration can lead to severe circulatory disorders, causing angina and ST segment depression, dizziness, syncope, and even heart failure, shock.
5. Sudden seizures suddenly stop. When the seizure stops, the sinus rhythm interval is too long, and occasionally fainting occurs.
6. Stimulate the vagus nerve endings, which can cause 50% to 80% of PSVT to abruptly stop.
7. The heart sounds are absolutely identical in rules, the jugular vein does not appear as a cannon wave, the pulse speed is fine, and the blood pressure can be lowered.
In recent years, due to the research progress of cardiac electrophysiology, there are some new understandings of the mechanism and classification of paroxysmal supraventricular tachycardia, which are generally divided into six types according to their occurrence sites and mechanisms. The characteristics of the electrocardiogram are listed in Table 1, to identify, if the surface of the electrocardiogram P wave is unclear, you can do an esophageal lead ECG.
Examine
Examination of paroxysmal supraventricular tachycardia in the elderly
The tachycardia is caused by hyperthyroidism, and T3 and T4 can be abnormal.
1. The electrocardiogram shows three consecutive QRS waves, the frequency is 160-220 times/min, and the RR spacing is equal.
2. Dynamic ECG 24h heart rate changes are important for the qualitative and quantitative diagnosis of arrhythmia in patients.
Diagnosis
Diagnosis and diagnosis of paroxysmal supraventricular tachycardia in the elderly
Clinically, it needs to be differentiated from sinus tachycardia, atrial flutter, and non-paroxysmal tachycardia.
