Preterm contractions in old age
Introduction
Introduction to premenstrual contraction in the elderly Premature contraction, also known as premature beat, referred to as premature beat, is the heart beat caused by the early impulse of ectopic pacemaker. According to the pacing point, it can be divided into atrial and borderline, and the two are collectively called supraventricular, and there is ventricular contraction. basic knowledge The proportion of illness: 0.01%-0.03% Susceptible people: the elderly Mode of infection: non-infectious Complications: premature beats, syncope, angina, heart failure
Cause
Preclinical contraction cause in the elderly
(1) Causes of the disease
Both supraventricular and ventricular premature contractions can be seen in normal elderly, mental stress, excessive fatigue, ventricular premature contractions are more common in hypertension, coronary heart disease, acute myocardial infarction, cardiomyopathy, myocarditis, mitral valve prolapse , digitalis or quinidine poisoning, hypokalemia and so on.
(two) pathogenesis
It can be produced in a variety of ways.
1. Impulsive abnormality caused by abnormal self-discipline
1 Under certain conditions, such as the sinus impulse to reach the ectopic pacemaker point, due to the Weijinsky phenomenon, the threshold potential is lowered and the diastolic slope is changed to cause premature beat.
2 The lesions of the atrium, ventricle or Pu'er field cell membrane change the permeability of different ions, so that the fast-reacting fiber is converted into slow-reacting fiber, the auto-depolarization in the diastolic phase is accelerated, the self-discipline is enhanced, and the premature beat is generated.
2. Reentry phenomenon - circular reentry or focal micro-reentry. If the reentry pathway is the same, the premature beat pattern is consistent. If the conduction velocity is consistent in the reentry, the pairing time of the premature beat and the previous beat is fixed.
3. Parallel contraction.
4. Triggered activity.
5. Mechanical feedback theory
It is believed that there is a stretch-activated channel in cardiomyocytes, and increasing left ventricular volume can activate more stretch channels. Therefore, heart enlargement is prone to ventricular arrhythmia, and compensatory interval after ventricular premature contraction leads to prolongation of diastole. Premature ventricular contraction, the stretch of scar tissue protruding from the systolic phase after myocardial infarction is the cause of ventricular arrhythmia.
Prevention
Premenstrual contraction prevention in the elderly
For the prevention of premature contraction in patients with structural heart disease, it is mainly to actively carry out etiological treatment, such as improving coronary insufficiency, limiting the scope of AMI, removing ventricular aneurysm, improving cardiac function, correcting electrolyte imbalance, etc. Those who are poisoned, such as digitalis or some antiarrhythmic drugs, should be reduced or discontinued. If they are nervous, emotional or excessive fatigue should be relaxed, pay attention to rest or appropriate application of sedatives.
Complication
Premature contraction complications in the elderly Complications, early convulsions, angina pectoris, heart failure
Frequent premature contractions (premature beats) can be accompanied by syncope, angina, heart failure and so on.
Symptom
Premenstrual contraction symptoms in the elderly Common symptoms Difficulty in breathing, angina, dizziness, heart sound, weak heart, weak pulse, chest tightness
Generally, sporadic pre-contraction does not cause any discomfort. When the contraction occurs frequently or continuously in the current period, the cardiac output can be decreased and the vital organ perfusion can be reduced. There may be palpitations, chest tightness, fatigue, dizziness, sweating, angina or breathing. Difficulties and other symptoms, sudden heartbeat can be heard suddenly during auscultation, the first heart sound is louder than normal, the second heart sound is weak or inaudible, and then there is a long compensatory interval, the pulse diagnosis can touch the weak pulse that appears early. Then there is a longer compensatory interval.
For symptomatic patients, a 24-h dynamic electrocardiogram (Holter) should be performed. Qualitative and quantitative analysis should be performed on the pre-systolic contraction. The ventricular premature contraction should be graded according to Lown, and benign (Lown grade <III grade), malignant (Lown grade > Level III).
Examine
Examination of premenstrual contraction in the elderly
Hypokalemia can cause arrhythmia.
1. Atrial contraction
(1) The P wave appears in advance, and the shape is different from the sinus P wave. It can be positive or negative, and is called P. The PR interval is 0.12 s.
(2) After the atrial P-wave, the QRS complex is normal, and there is no QRS complex called pre-atrial contraction and not transmitted. When there is indoor differential conduction, the QRS complex with wide deformity may also appear. Note the identification of systolic pre-systolic contractions.
(3) The compensatory interval after pre-systolic contraction is often incomplete, that is, the time between the two sinus fluctuations before and after the pre-systolic contraction is less than twice the interval of the normal RR.
2. Junctional (conjunctival) pre-contraction
(1) The QRS wave group appears in advance, and the form is supraventricular.
(2) Before the QRS complex appearing in advance, no P wave is seen. If there is a P wave, it should be retrograde, and PR<0.12s, RP<0.20s.
(3) The compensation interval after the pre-systolic contraction is often complete.
3. ventricular premature contraction
(1) The QRS wave group appears in advance, and there is no P wave before it.
(2) The QRS complex has a large deformity with a time limit of >0.12 s, T wave and Q3. Premature ventricular contraction.
(3) The compensatory interval after pre-systolic contraction is mostly complete, and a few pre-systolic contractions can occur between two sinus fluctuations in the normal PP interval, called metastatic pre-contraction.
(4) Parallel heart rhythm: There is no fixed pairing time between pre-systolic contraction and previous heart beat. There is one greatest common divisor between the pre-systolic contraction intervals, and there is often a ventricular fusion wave.
Diagnosis
Diagnosis of premenstrual contraction in the elderly
1. Clinical needs are differentiated from sinus arrhythmia and sinus rest.
2, old age, debilitation, obesity and severe anemia, can produce labor dyspnea, but no other signs of acute left heart failure.
3, chronic pulmonary heart disease caused by pulmonary insufficiency, but also have difficulty breathing, but there are chronic bronchial, lung and thoracic disease history, there are signs of emphysema. The heart enlarges mainly in the left ventricle, and the hair is more difficult than breathing.
4, should pay attention to the elderly patients can coexist with cardiopulmonary dysfunction, chronic pulmonary heart disease with coronary heart disease patients are not uncommon, then if it is not easy to rule out acute left heart exhaustion, treatment should be taken into consideration.
