Faculty of allied medical sciences Histopathology and cytology (MLHC-201)

PATHOLOGY OF THE CARDIOVASCULAR SYSTEM DISEASES OF THE HEART Supervision: Prof.Dr. Noha Ragab

Outcomes: By the end of this lecture, the student will be able to know: 1-Definition, types and diagnosis of rheumatic fever. 2-Type and causes of heart failure.

Normal Heart Anatomy

Rheumatic Fever (RF) Definition: Rheumatic fever (RF) is an autoimmune disease affecting the heart and extra- cardiac sites (joints, brain, skin and others)

The incidence of RF has been lowered in the developed countries but is still high in poor communities The disease affects children and young adults (5-15years) The disease follows upper respiratory infection (tonsillitis) with Group A Beta hemolytic streptococci

Theories of Pathogenesis: Toxic products of streptococci Sensitized T-lymphocytes may lead to cardiac injury

JONES' CRITERIA FOR DIAGNOSIS OF RF: Major Manifestations Carditis (friction rub, murmur, cardiomegaly, Chronic Heart Failure (CHF) Arthritis (migratory polyarthritis, swollen, red, tender) Chorea Subcutaneous nodules Erythema marginatum Minor Manifestations Clinical Fever Arthralgia History of rheumatic fever or rheumatic heart disease Laboratory Acute phase reactants (ESR, C-reactive protein, leukocytosis) Prolonged P-R interval on ECG

PATHOLOGY OF RHEUMATIC FEVER Cardiac Disease (Rheumatic heart disease) Extra-Cardiac Disease

RHEUMATIC HEART DISEASE Rheumatic heart disease: all the heart layers are affected (pancarditis) Rheumatic myocarditis Rheumatic pericarditis Rheumatic endocarditis

1- Rheumatic myocarditis: Acute phase: it is characterized by the development of pathognomonic lesions called Aschoff’s Bodies within the myocardium. Gross features: Aschoff bodies are multiple tiny nodules (1-2 mm in diameter) Microscopic features: Aschoff body is a lesion composed of: Fibrinoid necrosis ( destroyed fragmented collagen) Surrounded by lymphocytes and histiocytes & Aschoff cells (large mononuclear or multinuclear macrophages)

Aschoff’s body Blood vessel fibrinoid degeneration Aschoff cells

Chronic phase: Over years or decades the Aschoff bodies undergo fibrous scarring

2- Rheumatic Pericarditis: Acute phase: Aschoff bodies are formed accompanied by serofibrinous inflammation. Chronic phase: Fibrosis and adhesions may occur between the visceral and the parietal layers of the pericardium

3- Rheumatic Endocarditis: It affects both mural and valvular endocardium Mural Endocardium: i- Acute phase: Aschoff bodies develop in the endocardium ii- Chronic phase: healing results in a white patch

Valvular Endocardium Vegetations (thrombi) develop at the lines of contact of the cusps causing friction of the swollen cusps.

Rheumatic Mitral Valve Small vegetations are formed at injured parts

CHRONIC RHEUMATIC VALVULAR DISEASE Mitral & Aortic Valves Pathology: Thickening of valve leaflet, especially along the lines of closure Fusion of commissures Result is mitral or aortic stenosis, insufficiency, or both

Rheumatic Mitral Stenosis Fusion of commisures Thick valve leaflet

EXTRACARDIAC LESIONS OF RHEUMATIC FEVER Joints: Rheumatic arthritis affect the large joints in a fleeting way i.e joint inflammation is followed by joint resolution, then another joint become inflamed followed by resolution and so on. The affected joint is painful, tender, hot & swollen. Microscopically: it shows congestion, oedema, lymphocytes, plasma cells and macrophages. Brain: Rheumatic chorea (rapid involuntary purposeless movements); it is due to inflammation of the basal ganglia. The condition is reversible Skin: Rheumatic subcutaneous nodules occur over bony prominences and their structure is similar to the Aschoff bodies. Rheumatic arteritis: affecting the coronaries, renal, mesenteric and cerebral arteries Pleurisy and peritonitis: serofibrinous type

PERICARDIAL DISEASES I. PERICARDITIS Inflammation of the pericardium Causes Myocardial Infarction (MI), Staphylococcus, tumor, TB, uremia

II. PERICARDIAL EFFUSION Serous fluid in pericardial sac Usual cause: Chronic Heart Failure

III. HEMOPERICARDIUM Myocardial rupture from MI Trauma Bleeding from infection, tumor, etc. Haemorrhage from aorta

Hemopericardium

IHD-Ischaemic Heart Disease:

Coronary Arteries Left Coronary A. L.A.Descending Left Circumflex LCx LAD Left Coronary A. L.A.Descending Left Circumflex Right Coronary A.

Ischaemic Heart Disease Common Health problem. High Mortality & Morbidity. Etiology – common Atherosclerosis Two major types Angina & MI. Risk factors – Hypertension Hypercholesterolemia Diabetes Smoking, Life style, Diet, Genetic.

Patterns of Coronary Heart Disease: Angina Pectoris Acute Myocardial Infarction Sudden cardiac death

Pathogenesis: Obstruction to blood flow. Atheroma, Thrombosis, Embolism Diminished coronary blood flow. Ischemia leads to Angina Pectoris Infarction leads to Coagulative Necrosis Inflammation Granulation tissue Fibrous scarring.

Myocardial Infarction-MI “Death of heart tissue due to lack of blood supply” Atherosclerosis is the common cause. Coagulative necrosis – intact tissue shape. Characterized by Severe chest pain, breathlessness & sweating Complications: Shock, Death or Cardiac failure.

Normal Myocardium:

MI 18-24 hr loss of nucleus, coagulative necrosis.

Laboratory Diagnosis LDH Creatinine Kinase- Isoenzymes Troponins

Management: Aims at preventing complications. Rest & sedation Supportive measures Thrombolytic agents - Streptokinase

HEART FAILURE

Definition: Failure of the ventricles to pump enough blood to meet the body needs Types of heart failure: Acute heart failure Chronic heart failure

ACUTE HEART FAILURE Eitiology: Acute myocardial infarction or myocarditis Massive pulmonary embolism hemopericardium  heart compression Complications: Acute congestion and edema

CHRONIC HEART FAILURE Pathogenesis: I-Stage of compensation: The heart maintains adequate cardiac output by: 1-slight dilatation  stretch of myocardial fibers  stronger contraction 2-compensatory hypertrophy  stronger contraction 3-increased heart rate

II- Stage of decompensation: Marked dilatation of the affected chamber & cardiac fatigue dilatation  overstretching of muscle fibers  weak contraction of heart

CAUSES OF CHRONIC HEART FAILURE: hypertension coronary disease valve diseases as aortic stenosis, aortic incompetence or mitral incompetence congenital heart diseases as ASD &VSD

Questions Complete: 1-Rheumatic fever (RF) is ……………………….. 2-Complications of myocardial infarction are…………… 3-Rheumatic arteritis affecting ……………… 4-Risk factors for Ischaemic Heart Disease are………. 5- Stages of compensation in CHRONIC HEART FAILURE are……………….

Assignments Myocardial infarction احمد محمد احمد اسراء محمد عبد الوكيل اسماء حسن احمد Heart failure اسماء محمد عبد الوهاب الزهيري عاطف امال عرابي الكردي