Previously been described electrocardiographic pattern of ischemia, and myocardial lesion, its electrophysiological basis and differential diagnosis. The articles examined the diagnostic value and indications for VCG, ECG exercise test, Holter monitoring and electrophysiologic study of intracavitary (VEFI) for coronary heart disease. This article will describe the changes observed at different stages of coronary heart disease, certain aspects of the correlation between coronary heart disease and clinical features, angiographic data, etc., and the common value of electrocardiography in the diagnosis and evaluation of heart disease.
Angina can be diagnosed on the basis of the pathophysiology and development. In terms of pathophysiology distinguish primary and secondary angina. The most characteristic manifestation of primary angina, the ECG (usually occurs at rest) is an electrocardiographic phenomenon of Prinzmetal. In this type of angina, ischemia is the result of a sharp decline in blood supply due to coronary artery spasm unchanged or, more rarely, organically modified coronary artery in this type of angina is not always observed preceding an increase in oxygen consumption. Secondary angina corresponds to the classical angina, and ischemia is due to the fact that critically stenosed coronary artery can not adapt to increased blood flow in the increased needs (increased oxygen consumption).
Increasingly there are reports that one and the same patient observed primary and secondary attacks of angina at various stages of the disease (a type of mixed angina).
From an evolutionary perspective can be stable angina (stable ischemic heart disease), and unstable.
Angina can be diagnosed on the basis of the pathophysiology and development. In terms of pathophysiology distinguish primary and secondary angina. The most characteristic manifestation of primary angina, the ECG (usually occurs at rest) is an electrocardiographic phenomenon of Prinzmetal. In this type of angina, ischemia is the result of a sharp decline in blood supply due to coronary artery spasm unchanged or, more rarely, organically modified coronary artery in this type of angina is not always observed preceding an increase in oxygen consumption. Secondary angina corresponds to the classical angina, and ischemia is due to the fact that critically stenosed coronary artery can not adapt to increased blood flow in the increased needs (increased oxygen consumption).
Increasingly there are reports that one and the same patient observed primary and secondary attacks of angina at various stages of the disease (a type of mixed angina).
From an evolutionary perspective can be stable angina (stable ischemic heart disease), and unstable.
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| Coronary heart disease. ECG in ischemic heart disease |
ECG in ischemic heart disease
These include post-infarction patients with stable clinical picture and patients with all types of stable angina without previous myocardial infarction. Patients with angina usually have angina, although they may have bouts of angina in primary dormant (mixed angina). Less commonly, seizures occur only at rest.
A. ECG at rest. ECG at rest remains normal in almost 50% of patients without previous myocardial infarction and in 5-30% of patients with prior myocardial previously]. Therefore, the ECG alone is not a very sensitive method. The specificity of its slightly higher but similar ECG changes were observed in other clinical situations. On the other hand, in patients with anginal attacks of the same gravity, and there are different and similar ECG signs.
a. Changes in repolarization. If angina or angina with negative or mixed flattened T waves or ST segment depression observed in approximately 50% of patients with prior myocardial previously, especially with anterior wall infarction, ST-segment elevation persists and in some cases there is a negative spike U, which often indicates lesion anterior descending coronary artery. In patients with predominantly or exclusively of primary angina (Prinzmetal angina) ECG alone is not changed in almost 50% of cases.
b. Abnormal Q waves detected in 30-40% of patients with angina or mixed angina. However, 15% of patients with abnormal Q waves were observed before signs of a heart attack. On the other hand, the tooth of Q, indicating a heart attack, not 25% of patients with lesions of the three vessels and 20% of patients with a history of heart attack.
a. Arrhythmias. The incidence of arrhythmias on the ECG at rest in all types of coronary heart disease is relatively small. However, patients with premature ventricular beats, registiruemymi ECG at rest, have a poor prognosis. It is obvious that the frequency of arrhythmias is much higher in holteovskom monitoring.
Patients with recurrent sustained ventricular tachycardia in the chronic stage podostroi or heart attack often have asinergicheskie area and a poor prognosis, because the onset of sudden death is possible. Currently, they represent one of the most difficult categories of patients, requiring the use of large doses of antiarrhythmic agents for the prevention of sudden death and / or non-pharmacological treatments (surgery, fulguration, defibrillator Mirovska). There are three prognostic indicator of electrical instability in patients with myocardial infarction:
- Identification of arrhythmias using Holter ECG and exercise;
- Programmed electrical stimulation with imposed by ventricular arrhythmias.
- Registration of late potentials ryamaya depolarization, which was considered by some authors as an indicator of propensity to malignant ventricular arrhythmias reentry. It was shown that the disappearance of late potentials after surgery for ventricular tachycardia observed in cases in which it helped to avoid a recurrence of arrhythmia, but not marked with the introduction of anti-arrhythmic drugs.
These include post-infarction patients with stable clinical picture and patients with all types of stable angina without previous myocardial infarction. Patients with angina usually have angina, although they may have bouts of angina in primary dormant (mixed angina). Less commonly, seizures occur only at rest.
A. ECG at rest. ECG at rest remains normal in almost 50% of patients without previous myocardial infarction and in 5-30% of patients with prior myocardial previously]. Therefore, the ECG alone is not a very sensitive method. The specificity of its slightly higher but similar ECG changes were observed in other clinical situations. On the other hand, in patients with anginal attacks of the same gravity, and there are different and similar ECG signs.
a. Changes in repolarization. If angina or angina with negative or mixed flattened T waves or ST segment depression observed in approximately 50% of patients with prior myocardial previously, especially with anterior wall infarction, ST-segment elevation persists and in some cases there is a negative spike U, which often indicates lesion anterior descending coronary artery. In patients with predominantly or exclusively of primary angina (Prinzmetal angina) ECG alone is not changed in almost 50% of cases.
b. Abnormal Q waves detected in 30-40% of patients with angina or mixed angina. However, 15% of patients with abnormal Q waves were observed before signs of a heart attack. On the other hand, the tooth of Q, indicating a heart attack, not 25% of patients with lesions of the three vessels and 20% of patients with a history of heart attack.
a. Arrhythmias. The incidence of arrhythmias on the ECG at rest in all types of coronary heart disease is relatively small. However, patients with premature ventricular beats, registiruemymi ECG at rest, have a poor prognosis. It is obvious that the frequency of arrhythmias is much higher in holteovskom monitoring.
Patients with recurrent sustained ventricular tachycardia in the chronic stage podostroi or heart attack often have asinergicheskie area and a poor prognosis, because the onset of sudden death is possible. Currently, they represent one of the most difficult categories of patients, requiring the use of large doses of antiarrhythmic agents for the prevention of sudden death and / or non-pharmacological treatments (surgery, fulguration, defibrillator Mirovska). There are three prognostic indicator of electrical instability in patients with myocardial infarction:
- Identification of arrhythmias using Holter ECG and exercise;
- Programmed electrical stimulation with imposed by ventricular arrhythmias.
- Registration of late potentials ryamaya depolarization, which was considered by some authors as an indicator of propensity to malignant ventricular arrhythmias reentry. It was shown that the disappearance of late potentials after surgery for ventricular tachycardia observed in cases in which it helped to avoid a recurrence of arrhythmia, but not marked with the introduction of anti-arrhythmic drugs.
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