- •27. Pathophysiology of heart.
- •27.1. What is insufficiency of circulation of the blood?
- •27.2 What is result of the insufficiency of circulation of the blood for organs, tissues and organism in whole?
- •27.3 What is cardiac insufficiency?
- •27.4 What is the classification of cardiac insufficiency?
- •27.5 Give short characteristic of different pathogenic variants of cardiac insufficiency.
- •27.6. What types of heart’s overloading can cause the development of cardiac insufficiency?
- •27.7. What mechanisms can provide the compensation of heart during the effect of the increased leading on it?
- •27.8. What is the essence of the heterometric mechanism of the compensation of the heart?
- •27.9. What is the essence of the homeometric mechanism of the compensation of the heart?
- •27.10. What is the essence of the chronoinotropic mechanism of the compensation of the heart?
- •27.11. What is the roll of catecholamines in the realization of mechanisms of urgent compensation of the heart?
- •27.12. Name the variants of prolonged adaptation of the heart to the effect of ladings.
- •27.13. What mechanism lay on the base of development of the heart’s hypertrophy?
- •Hypertrophy
- •27.14. What phases can be distinguished in the process of development of compensatory hypertrophy of the heart? Give their characteristics.
- •27.14 What strategy allocate during development compensatory hypertrophies of heart? Give their characteristic.
- •27.15 What features of the hypertrophied heart are the precondition of its development of decompensation?
- •27.16. What can cause the development of the myocardial insufficiency of heart?
- •27.17. What is hearts arhythmy? How does they classified?
- •27.18. What arhythmias of heart can be a result of infringement of function of automatism?
- •27.19 What reasons and mechanisms of development of a sinus tachycardia and bradycardia?
27.11. What is the roll of catecholamines in the realization of mechanisms of urgent compensation of the heart?
The participation of catecholamines in the realization of mechanisms of urgent compensation of the heart to the increased leadings is connected with the ability of adrenalin and noradrenalin to increase the power of heart’s contractilities directly – with positive inotropic effect.
It is ascertained that under the influence of catecholamines increases the quantity of the sarolemm Ca-cannels which are able to open during the potential of the effect (the catecholamines thought the CAMP mediated mechanism causes the transformation of the Ca-cannels’ proteins. As a result of these processes increases the enlistment of the calcium ions into sarcoplasm where they concentration increases and as a result increases the power of cardiomiocytes contractilities because the quality of organizing calcium-troponin complexes also increases.
Inotropic effect of the catecholamines (but not the Franks-Starling law) is the leading mechanism of the adaptation of heart to the physical leadings. During this the indicators of cardiodynamics change in such a way:
a) increases the percussion volume;
b) increases the minute volume of the heart as because of the increase of the percussion volume and also because of the increase of heart contractilities’ frequency (positive chronoinotropic effect of catecholamines);
с) reduces the final diastolic volume (during the x-ray examination it is registered the reduction of heart’s volume;
d) reduced the final diastolic volume.
27.12. Name the variants of prolonged adaptation of the heart to the effect of ladings.
According to F. Meerson there are three variants of prolonged adaptation of the heart.
1. Sportsmen’s hypertrophy of the heart (“adapted” heart). Develops during the periodical ladings of increasing intensity, that is under the conditions of training it is the balanced hypertrophy during which all compound components of the heart increase proportionally. As a result of such hypertrophy increase the functional reserves of the heart in a substantial way.
2. Compensatory hypertrophy of the heart (“overadapted” heart). It is the result of pathological process which are connected with heart. There are two types of compensatory hypertrophy:
a) hypertrophy because of overloading (it develops simultaneously with the valvular disease of the heart, arterial hypertension);
b) hypertrophy because of injury (it is characteristic for atherosclerotic injuries, pathology of myocardium).
The development of the compensatory hypertrophy of the heart is characterized by the following peculiarities:
pathogenic factor which causes hypertrophy effects constantly;
compensatory hypertrophy in the contrast from sportsmen’s hypertrophy of the heart is non-balanced;
during the compensatory hypertrophy some time later develops the insufficiency of the heart.
Atrophy of myocardium (“unadapted” heart). It is characterized by the reducing of the heart’s mass as a result of prolonged гипокинезии and the reducing of ladings onto the heart.