Pathology
Heart failure (H.F):It is pathological in which impaired cardiac function render the heart unable to eject the blood delivered to it by venous system . Excluding from definition in which inadequate output occur due to reduction in blood volume or impair venous return to heart .
Causes of left side H.F:
ischemic heart disease .
Systemic hypertension.
Aortic & mitral valve disease.
Non ischemic myocardial disease.
Right side H.F :
1-majority of cases complicate left side H,F,2-Tricusp or pulmonary valve disease .
3-interestial or vascular pulmonary disease & the condition called corpulmonale .
Ischemic heart diseases(IHD) :
Groups of diseases arise from imbalance between the myocardial oxygen demand & the blood supply .It is a leading cause of death in developed countries & affect male more than female .
Effect of myocardial ischemia (clinical syndrome) :
1- angina pectoris .
2- myocardial infarction .
3- sudden death .
4-ch ischemic heart diseases.
Pathogenesis :
1- Atherogenic cause : Sever & ch atherosclerosis that cause narrowing in the lumen of one or more coronary artery with 75% reduction ( critical stenosis ) so any increase in O2 demand give rise to classical angina .
* Acute plague changes in the form of bleeding & fissuring cause enlargement of the plague & enhance platelet aggregation with thrombosis result in unstable angina & acute MI.
* Coronary artery thrombosis occur due to rupture of plaque &exposure of sub endothelial collagen which initiate thrombosis .If occlusion is complete this will result in MI or death but if occlusion is incomplete this will lead to sub endocardial infarction or unstable angina .
* Coronary artery vasospasm ..
2- Non atherogenic causes : account for 10%
* emboli arise from vegetation in the heart or vasculitis .* sever systemic hypotension with preexisting coronary atherosclerosis.
*Increase O2 demand due to left ventricular hypertrophy as in systemic hypertension .
Angina pectoris :
Intermittent chest pain caused by transient & reversible myocardial ischemia . the pain is central radiating to the left arm . It is of 3 types :1- Typical ( stable) angina :
* pain associated with fixed atherosclerotic narrowing (75%).
*The pain occur at exercise & relieve by rest or vasodilator .
2-Prinzmetal angina :
*it is due to coronary artery spasm , the cause of which is unknown.
* pain occur at rest or awake the patient from sleep & respond to vasodilator .
3-unstable angina:
* caused by acute plaque change , embolism ,or partial thrombosis.
* the pain is more frequent , occur by less exercise , more intense &last longer.
Acute myocardial infarction :
Necrosis of cardiac muscle due to hypoxia.
Types of infarction :
1- Transmural ( full thickness) infarction caused by sever atheroma with acute plaque changes .causing complete obstruction .2- Subendocranial infarction :limited to inner thickness of the myocardium due to reduce perfusion caused by atherosclerosis .
Site of infarction : depend on the site of occluded coronary artery , However left ventricles is the most common chamber involved follow by right ventricle , right atrium While left atrium is protected.
Clinical features :
Crushing central chest pain radiate to left arm , epigastrium or jaw , pain last few hrs , not relieve by vasodilator .associated with rapid weak pulse ,& dyspnoea .Mic :------------------------------
Laboratory diagnosis :1- serum markers :
a- lactic dehydrogenase : not specific , present in different organ , begin to rise after 24 hours & reach the peak in the 3rd day.
b-creatinin kinase(CPK) :CPK MB is mainly secreted by cardiac muscle , Increase 2-4 hr after the onset of infarction,disappear within 3 days .
c- cardiac troponin : specific to cardiac muscle , increase after 2-4 hours after the onset of infarction , reach the peak at 24 hr & remain up to 7 days.
2- ECG changes : St elevation , T inversion & wide Q wave .
Complication:
1- Sudden death from arrhythmia.
2-cardiac arrhythmia.
3- left ventricular failure with pulmonary oedema.
4- cardiogenic shock.
5- rupture of cardiac muscle .
6- thrombo-embolism within 24 hrs .
7-ventricular aneurysm.
8-Fibrinous pericarditis.
Chronic ischemic heart disease:
Progressive congestive heart failure result from long term ischemic myocardial injury .usually associated with history of angina or may precipitated by myocardial infarction .Hypertensive heart disease :
The presence of left ventricular hypertrophy( in the absence of other causes of hypertrophy )with history or pathological feature of hypertension .
Pericarditis :
Usually secondary to disorder involve the heart or adjacent mediastinal structures ( e.g MI , trauma , tumour . radiation , infection & surgery ) or less frequently to systemic disorders ( e.g uremia & autoimmune) . It is of many types :* Fibrinous : most common clinical form , seen in MI .
* Serous pericarditid : Due to non bacterial cause as rheumatic fever , SLE, uremia ,tumour & viral cause .* Purulant pericarditis :due to bacterial , fungal , or parasitic infection reaching the heart by direct extension f , hematogenous , lymphatic spread or during cardiotomy .
*Hemorrhgic pericarditis :It follow cardiac surgery or associated with T.b or malignancy .
Casseous pericaditis : Usually due to T.b reach the heart by direct extension from neighboring L.N or less commonly due to mycotic infection .
Congenital heart disease (CHD) :
Seen in 1% of live birth , the incidence increase in premature .
Type of CHD :
a- Right to left shunt :associated with cyanosis lead to clubbing of nails & toe & polycythemia as :
1- fallot of tetralogy .
2-transposition of great vessel.
3-Tricusp atresia.
4-persistant truncus arteriosus.
5-Total anomaly of pulmonary venous connection .
b- left to right shunt :initially there is no cyanosis but later due to pulmonary hypertension shunt reversed from right to left cause cyanosis as :
1-Aterial septal defect(ASD).
2-Ventricular septal defect(VSD).
3-Patent ductus arteriosus.
4-aterioventricular septal defect.
c- Obstructive Congenital heart disease :
1-Coarectation of aorta .2-Aortic valve stenosis .
3-pulmonary valve stenosis.
ASD :
Most common congenital heart disease seen in adult.
Types :
1- ostium secendum seen in 75% of cases occur if secendum septum not enlarge to cover ostium secendum .
2- ostium primum seen in 15% occur if septum primum & endocardhioial cushion not fuse .
3-sinous venous 10%deffect high in the septum near entry of superior vena cava.
VSD:
the most common CHD seen at birth but majority are small & close spontaneously in childhood & in 30% it occur as isolated lesion.Tetralogy of Fallot :
most common cause of congenital cyanotic heart disease.compose of :1-VSD.
2-Dextaposed aorta.
3-pulmonary valve stenosis.
4-right ventricular hypertrophy.