MEDICAL BIOLOGY, HUMAN ANATOMY, PHYSIOLOGY AND PATHOLOGY - Y.I. Fedonyuk 2010

ANATOMY, PHYSIOLOGY, PATHOLOGY

CHAPTER 5. BLOOD AND LYMPH CIRCULATION PROCESSES AND THEIR PATHOLOGY

CARDIOVASCULAR SYSTEM DISEASES

CORONARY HEART DISEASE

2. CHRONIC CORONARY HEART DISEASE

Chronic CORONARY Heart DISEASE encompasses conditions with a chronic clinical course: stable angina pectoris, diffuse Atherosclerotic Cardiosclerosis, and Post-infarction cardiosclerosis. The Development of chronic coronary heart disease is driven by coronary insufficiency, which results from an imbalance between myocardial oxygen demand and the capacity for its Blood-borne delivery. Insufficient oxygen supply to the myocardium leads to ischemia. The Pathogenesis of ischemia differs depending on whether the coronary Arteries are altered or unaltered.

The primary mechanism of coronary insufficiency in morphologically unaltered vessels is arterial spasm triggered by impaired neurohumoral regulatory mechanisms.

Myocardial ischemia clinically manifests as attacks of angina pectoris, various ectopic arrhythmias, and the gradual development of atherosclerotic cardiosclerosis. In cardiosclerosis, the replacement of Muscle fibers by Connective Tissue progressively impairs myocardial contractility and leads to Heart Failure.

There are three variants of cardiosclerosis: ischemic (atherosclerotic), which develops slowly with diffuse damage to The Heart muscle; post-necrotic (post-infarction), characterized by a large focal area of fibrosis at the site of a prior necrosis; and a transitional or mixed variant, in which focal fibrotic areas periodically form against the Background of slow, diffuse connective tissue proliferation following recurrent myocardial infarctions.