Ischemic heart disease

Ischemic heart disease is a group of disease states that have in common ischemia (i.e. a mismatch between oxygen demand and supply). We distinguish several forms of CHD:


 * {| class="wikitable"

!Acute forms of CHD!!Chronic forms of CHD
 * Acute myocardial infarction (STEMI, NSTEMI)
 * Status after completing AIM
 * Unstable angina pectoris||Stable angina pectoris
 * Sudden coronary death||Prinzmetal's angina pectoris
 * ||Coronary Syndrome X
 * ||Silent myocardial ischemia
 * ||ICHD manifesting in heart failure
 * ||ICHS manifested by arrhythmias
 * }
 * ||Silent myocardial ischemia
 * ||ICHD manifesting in heart failure
 * ||ICHS manifested by arrhythmias
 * }
 * ||ICHS manifested by arrhythmias
 * }
 * }

Causes of Ischemia

 * 1) Increased need for oxygen by the myocardium - tachycardia during increased physical exertion,
 * 2) decreased blood oxygen content - cyanotic VSV (with right-to-left shunt), severe anemia, CO poisoning, hypotension (shock), severe lung disease,
 * 3) reduced blood flow through the coronary arteries.

In more than 90% of CHD cases, reduced blood flow through the coronary arteries is applied, most often on the basis of coronary atherosclerosis.

Rarely then embolism to the main branches of the coronary arteries (vegetation in infectious or non-bacterial thrombotic endocarditis), dissection of the aorta (its spread to the coronary arteries), luetic aortitis', coronary arteritis' (polyarteriitis nodosa, Kawasaki disease) and congenital malformations of coronary arteries.



Coronary atherosclerosis
Atherosclerotic plaques can narrow the lumen of the coronary artery concentrically or eccentrically, the severity of the sclerosis is determined by the percentage of narrowing of the lumen of the artery (intra vitam - coronarography, post mortem - cross-sections):


 * 'AND. degree - up to 25%;
 * 'II. degree - up to 50%;
 * 'III. degree - up to 75%;
 * IV. grade - above 75%.

Clinically significant is degree IV, in the case of hypertrophy of the left heart (e.g. in aortic stenosis or systemic hypertension) so-called relative coronary insufficiency occurs ' even with a lesser degree of stenosis, as the hypertrophic myocardium has higher metabolic demands. Occlusions occur more in the left coronary artery (here most often in the first 2 cm of the RIA and RC course) than in the right (here most often in the first and third third of its course).

The plates are of two types:


 * 1) fibrous - hyalinized collagen tissue, few lipids, are the basis of chronic forms of CHD (stable angina pectoris, chronic CHD).
 * 2) atheroma - contains mushy masses containing lipids, the surface is covered with a cap of hyalinized tissue, is a predisposition to the development of acute forms of CHD (unstable angina pectoris, acute myocardial infarction, sudden coronary death), which the cause is an acute change in the plaque - rupture with encroaching thrombosis, bleeding into the plaque, spasm at the site of the plaque (caused by inadequate irritation of the vagus nerve) - does not occur in a healthy artery.

Risk Factors
Affectible: arterial hypertension, dyslipidemia, smoking, diabetes, hyperhomocysteinemia, obesity, lack of exercise.

Uninfluenceable: age, gender, family burden.

Links
Original text is from WikiSkripta https://www.wikiskripta.eu/w/Ischemick%C3%A1_choroba_srde%C4%8Dn%C3%AD


 * Cardioblog: Wellens syndrome
 * Acute coronary syndrome (TECHmED)

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 * Prinzmetal's angina pectoris
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