Histopathology Cardiovascular Disease Flashcards
Ischaemic Heart Disease Definition
Definition
Ischaemic Heart Disease Factors that contribute to the reduction of coronary artery perfusion which results in myocardial ischemia
- Atherosclerotic stenosis
- Platelet aggregation
- Coronary artery vasospasm
- Non-atherosclerotic coronary artery disease
- Systemic Haemodynamic derangement
Atherosclerotic Stenosis: Epi
- Over 90% of patients with ischaemic heart disease have significant (>75% of cross section of the vessel) stenosis of one or more of the three major coronary arteries.
- 30% have single vessel disease (left anterior descending- -LAD)/ Left circumflex/Right coronary.
- 30% → 2 vessels
- 40% triple vessel disease
Atherosclerotic Stenosis: Site of Stenosis
• Usually Proximal (within the first 4 cm) in the LCA (LAD or LC) and somewhat more distal in the RCA.
Platelet aggregation: Definition
Rupture and fissuring of atherosclerotic plaque seems to be the initiating factor in most acute cardiac events in IHD.
Platelet aggregation: The Exposure of the plaque content leads to
Platelet adherence and aggregation with the development of thrombus which may remain localised to occlude the vessel or may embolise downstream,
Vasospasm: Definition
Mechanisms unclear
Non-atheroscleroitc lesions of coronary arteries
• Coronary artery emboli
• Arteritis (Kawasaki’s syndrome, Polyarteritis nodosa)
Coronary artery dissection
Systemic haemodynamic derangements
Left ventricular failure
Vasospasm: Systemic haemodynamic derangements
A drop in blood pressure (shock, haemorrhage, operations etc) may severely reduce coronary artery perfusion in vessels which are already affected by fixed stenosis.
Myocardial infarction: Two classical patterns of infarction
- Localised transmural infarct in which the entire thickness of the wall is involved – definable occlusive disease.
- Subendocardial type where there is extensive infarction involving the inner third of the myocardium. Usually severe triple vessel disease but often-specific occlusive lesions are absent.
Myocardial infarction: LCA disease causes infarct in
Anterior wall, apex and anterior part of the interventricular septum
Myocardial infarction: LC disease causes infarct in
Lateral wall
Myocardial infarction: RCA disease causes infarct in
Posterior wall and posterior part of the septum?
Myocardial infarction: Complications in myocardial infarction
Sudden cardiac death – 25% Arrhythmias – more than 75% Mural (endocardial) thrombosis – 30% +. Clinically significant muscle – 1-5% Cardiogenic shock – 10% Pericarditis – 30% Left ventricular failure- 60%
Cor pulmonale Definition
A right ventricular enlargement secondary to pulmonary hypertension caused by disorders that affect either the structure or function of the lungs.
Cor pulmonale Excluded in the definition
Right ventricular enlargement caused by diseases of the left side of the heart or by congenital heart disease are excluded by this definition.
Cor pulmonale Morphological terms
There is right ventricular dilation (as for instance in PE) and, in those disorders causing chronic cor pulmonale, right ventricular hypertrophy. (RV thickness > 0.5 cm).
Cor pulmonale Disorders which predispose to Cor Pulmonale
Diseases of the lungs
Diseases of pulmonary vessels
Diseases affecting chest moement
Cor pulmonale Diseases of the lungs
Chronic onstructive airways disease (COAD)
Pulmonary fibrosis
Cystic fibrosis
Cor pulmonale Disease of pulmonary vessels
Pulmonary embolism
Primary pulmonary hypertension
Cor pulmonale Diseases affecting chest movement
Kyphoscoliosis
Marked obesity (Pickwickian syndrome)
Neuromuscular disorders
Cardiac Valvular Disease → Definition
A relatively restricted number of conditions are responsible for disorders of the cardiac valves.
Cardiac Valvular Disease →Types
Mitral Valve disease
Aortic Valve disease
Aortic Valve disease
Cardiomyopathy
Cardiac Valvular Disease → Mitral Valve disease
Stenosis
Regurgitation
Cardiac Valvular Disease → Regurgitation intrinsic valve lesions
- Rheumatic heart disease
- Bacterial endocarditis
- Floppy mitral valve
- Calcification of valve ring (senile)
Cardiac Valvular Disease → Regurgitation extrinsic valve lesions
- Papillary muscle dysfunction
- Rupture
- Fibrosis
- Rupture of chordae
Cardiac Valvular Disease → Aortic Stenosis
- Calcific disease
- Bicuspid valve with calcification
- Tricuspid valve
- Rheumatic pattern of disease
- Rheumatic damage with mitral disease
- Rheumatic damage with normal mitral valve
- Congenital valve stenosis
Cardiac Valvular Disease → Aortic valve regurgitation
- Tricuspid (normal valve)
- Rheumatic
- Aortic root disease
- Aortitis
- Non-inflammatory medial degeneration
- Post bacterial endocarditis
- Bicuspid valve
- Post bacterial endocarditis
- Without bacterial endocaritis
Cardiomyopathy: Definition
Intrinsic myocardial disease which does not arise from inflammatory disorders or from IHD
Cardiomyopathy: Three morphological patterns
Dilated
Hypertrophic
Restricted
Cardiomyopathy: Dilated cardiomyopathy
A number of diverse conditions are described as resulting in dilated cardiomyopathy
• Alcohol
• Pregnancy associated nutritional deficiency
• Genetic defect
• Post-viral myocarditis
Cardiomyopathy: Hypertrophic pattern
Autosomally dominant pattern of inheritance giving rise to asymmetric left ventricular hypertrophy in young people.
Cardiomyopathy: Restricted pattern
Usually the result o amyloid infiltration of the myocardium in the elderly
Sites of atheroma formation
- Coronary arteries
- Carotid arteries
- Distal aorta
- Femoral arteries
Aneurysm: Definition
Localised abnormal dilation of any vessel. Aneurysms developed as a result of a localised weakness, usually acquired, in the vessel wall.
Aneurysm: Large aneurysmal structures
Atherosclerotic (fusiform) aneurysm
Dissecting aneurysm (Acute aortic dissection))
Syphilitic (saccular) aneurysm
Aneurysm: Medium sized aneurysmal structures
Saccular (Berry) aneurysm o Circle of Willis
Mycotic aneurysm
Traumatic aneurysm
Congenital Fibromuscular dysplasia
Aneurysm: Microaneurysms
Charcot-Bouchrd aneurysms
Diabetic microaneurysms
Cerebral amyloid angioopathy
Vasculitis: Definition
Inflammation and necrosis of blood vessel walls.
Vasculitis: Large vessels effects
Predominant effect larger vessels the predominant effect will be ischaemia as a result of thrombotic occlusion of the vessel at the site of the inflammatory focus. The ischaemia will usually manifest itself as tissue necrosis.
Vasculitis: Smaller vessels
While tissue necrosis may occur, haemorrhage is commonly the redominant manifestation (eg vasculitic purpura; gastrointestinal haemorrhage).
Vasculitis: Causes
Bacterial infection
Irradiation
Necrotising vasculitides.
