Unstable stenocardia

Description:

Unstable stenocardia - the most difficult period of an exacerbation of coronary heart disease, urozhayushchiya development of a myocardial infarction or sudden death. On clinical manifestations and predictive value is intermediate between the ischemic heart diseases main kliniko-morphological forms - stable stenocardia and an acute myocardial infarction.

Symptoms of Unstable stenocardia:

Unstable stenocardia is shown by typical attacks, however when collecting the anamnesis it is possible to reveal characteristic signs of progressing of stenocardia.
For the last 1-2 months the quantity, expressiveness and duration of attacks of an angina of exertion increased.
Attacks never arose earlier, appeared no more than 1 months ago (for the first time the arisen stenocardia, de novo stenocardia).
Attacks of stenocardia began to appear at rest or at night.
Important clinical sign of unstable stenocardia consider absence or easing of effect of nitroglycerine which stopped stenocardia attacks earlier.
The leading clinical implication of unstable stenocardias - pain syndrome. The main state from which it is necessary to differentiate unstable stenocardia is the myocardial infarction, and first of all - melkoochagovy (without Q tooth).
The ECG at unstable stenocardia is characterized by changes of a final part of a ventricular complex: a segment of ST inversion of a tooth of T - at 20%, passing raising of a segment of ST - at 5% is found in 30% of patients. At the same time the normal ECG does not exclude existence of unstable stenocardia. Unfortunately, the ECG does not give the chance of differential diagnosis of unstable stenocardia and a myocardial infarction without Q tooth as in both cases there are changes of a final part of a ventricular complex. The ECG at rest helps to differentiate a macrofocal myocardial infarction and unstable stenocardia as at the first there is a pathological tooth of Q.
Daily monitoring of an ECG allows to reveal the changes characteristic of unstable stenocardia, especially episodes of bezbolevy ischemia of a myocardium.
Fermental diagnosis. The MV fraction of KFK increases in 6-12 h, the maintenance of a myoglobin accrues in 3 h, тропонин T and I react along with MV fraction of KFK after a necrosis of cardiomyocytes that allows to differentiate unstable stenocardia from a myocardial infarction. At unstable stenocardia of substantial increase of activity of enzymes (more than 40% of initial level) does not happen. Normal biochemical indicators do not exclude existence of unstable stenocardia.

Reasons of Unstable stenocardia:

So far became obvious that the reasons of the progressing current of an ischemic heart disease are caused by changes from an atherosclerotic plaque, an endothelium and thrombocytes. At the same time the size of plaques has relative value for development of critical states. Existence of a "vulnerable" plaque which features are the big lipidic kernel and a thin tire is necessary.

Treatment of Unstable stenocardia:

All patients with an unstable angina of exertion are subject to urgent hospitalization in chambers (blocks) of intensive observation and treatment. In parallel with treatment record ECG in dynamics, the general blood test, definition of activity of cardiospecific enzymes, whenever possible EHOKG, a myocardium stsintigrafiya is carried out. Round-the-clock clinical and monitor observation.

Problems of treatment is stopping of a pain syndrome, prevention of repeated attacks of stenocardia, the prevention of development acute to THEM and the related complications. In this regard medical tactics is defined by the main pathogenetic mechanisms of its development. As it was already told, the main mechanism in most cases is the disturbance of integrity of an atherosclerotic plaque leading to activation of thrombocytes, their aggregation and formation of blood clot that leads to partial or full obstruction of a coronary vessel. Therefore treatment should be begun with aspirin reception. Protivotrombotichesky action of ASK is based on irreversible inhibition of cyclooxygenase of thrombocytes. Thereof thrombocytes lose ability to synthesize A2 (TXA2) thromboxane which induces aggregation of thrombocytes and has vasoconstrictive properties. As a result the possibility of aggregation of thrombocytes and formation of blood clot decreases.