PathophysiologyBMS 243

Lecture IIIRheumatic Heart DiseaseCardiac Valves Diseases

Dr. Aya M. Serry

2015/2016

What Is Rheumatic Fever?• A rare but potentially life-threatening disease, rheumatic fever is a complication of untreated strep throat caused by bacteria called group A streptococcus (Streptococcus Pyogenes)

• Rheumatic fever results from an inflammatory reaction where the body produces antibodies to fight the bacteria, but instead the antibodies attack a different target: the body's own tissues. The antibodies begin with the joints and often move on to the heart and surrounding tissues.

Rheumatic Fever

What Is Rheumatic Fever?• It primarily affects children between the ages of 6 and 16, About 5% of those with untreated strep infection will develop rheumatic fever.

•Within 2-4 weeks after an acute attack of Streptococcus Pyogenes, anti-streptococcal antibodies are formed and attack the heart valves and the extra-cardiac sites. 

Rheumatic Fever

Strep throat

Antibody production

Antibody cross-reaction with heart

vegetations Aschoff body pericarditis

The disease passes into two phases;

A. Acute phase:

acute rheumatic pancarditis (inflammation of endocardium,

myocardium and pericardium)

1. Myocarditis : the heart muscle itself .

2. Pericarditis: the pericardial, or exterior, heart surface.

3. Endocarditis: endocardial, or interior, heart surface.

Rheumatic Heart Disease

B.Chronic phase:Acute changes may resolve completely or progress to scarring and development of chronic valvular deformities many years after the acute disease.

Rheumatic Scarring of heart valve

Rheumatic Heart Disease

Chronic scarring of the valves constitutes the most important long-term problem of rheumatic fever, and usually becomes clinically manifest decades after the acute process.

Other cardiac complications:1. Bacterial endocarditis.2. Arrhythmia.3. Chronic heart failure.

Cardiac ValvesDiseases

Stenosis Regurgitation(Insufficiency)

Cardiac Valves Diseases

Cardiac Valves Diseases are classified into:

A) Valve Stenosis

A) Valve Stenosis

•This occurs when a heart valve doesn't fully open due to stiff or fused leaflets. The narrowed opening may make the heart work very hard to pump blood through it.

•All four valves can develop stenosis; the conditions are called tricuspid stenosis, pulmonic stenosis, mitral stenosis, or aortic stenosis

A) Valve Stenosis

Cardiac Valves Diseases

• Definition: Aortic stenosis occurs when the heart's aortic valve narrows. This narrowing prevents the valve from opening fully, which obstructs blood flow from your heart into your aorta and onward to the rest of your body.

• Normal Aortic Valve Area: 3-4 cm2

• Symptoms: Occurs when valve area is 1/4th of normal area.

1. Aortic Stenosis

• Congenital• Rheumatic• DegenerativePatients under 70: >50% have a congenital causePatients over 70: 50% degenerative

Causes of Aortic Stenosis

• A pressure gradient develops between the left ventricle and the aorta.• LV function initially maintained by compensatory pressure hypertrophy• When compensatory mechanisms exhausted, LV function failure.

This will lead to (Symptoms) :1.Syncope2.Angina: (increased myocardial oxygen demand; demand/supply mismatch)3.Dyspnea: on exertion due to heart failure (systolic and diastolic)4.Sudden death

Pathophysiology of Aortic Stenosis

2. Mitral Stenosis

Definition:

Obstruction of LV inflow that prevents proper filling during diastole.

Normal MV Area: 4-6 cm2

•symptoms begin at areas less than 2 cm2

•Rheumatic carditis is the predominant cause

Prevalence and incidence: decreasing due to a reduction of rheumatic heart disease.

• Rheumatic heart disease: 77-99% of all cases• Infective endocarditis: 3.3%• Mitral annular calcification: 2.7%

• Symptoms:1. Shortness of breath2. Fatigue3. Swollen feet or legs4. Heart palpitations5. Dizziness or fainting6. Heavy coughing, sometimes with blood-tinged sputum7. Chest discomfort or chest pain

Causes of Mitral Stenosis

PATHOPHYSIOLOGY OF MS

Narrowing of mitral valve

O2/CO2 exchange(fatigue, dyspnea)

Left ventricular atrophy

pulmonary congestion

pulmonary pressure

left atrial pressure blood flow to left ventricle

Right-sided failure

Fatigue

CO

•Also called insufficiency or "leaky valve", this occurs when a valve does not close tightly. If the valves do not seal, some blood will leak backwards across the valve. As the leak worsens, the heart has to work harder to make up for the leaky valve, and less blood may flow to the rest of the body.

• Depending on which valve is affected, the condition is called tricuspid regurgitation, pulmonary regurgitation, mitral regurgitation, or aortic regurgitation

B) Valve Regurgitation

Cardiac Valves Diseases

B) Valve Regurgitation

B) Valve Regurgitation

Definition:is the leaking of the aortic valve of the heart that causes blood to flow in the reverse direction during ventricular diastole, from the aorta into the left ventricle.

Endocarditis is the main cause

1. Aortic Regurgitation

1. Aortic Regurgitation

1. Surgery -Your aortic valve may need surgical repair or replacement

2. Because mechanical valves are made from metal, they are durable, but carry the risk of blood clots forming. (you'll need to take an anticoagulant medication, such as warfarin (Coumadin), for life to prevent blood clots)

3. Medications that control Blood Pressure

Treatment of Aortic Regurgitation

Definition:

• It is the abnormal leaking of blood from the left ventricle, through the mitral valve, and into the left atrium, when the left ventricle contracts, i.e. there is back flow of blood into the left atrium during systole.

• MR is the most common form of Cardiac valves diseases

• The most common Cause of MR include MV prolapse (MVP), rheumatic heart disease and infective endocarditis

2. Mitral Regurgitation (MR)

Symptoms of MR

1. Blood flowing turbulently through your heart (heart murmur)

2. Shortness of breath (dyspnea), especially with exertion or when you lie down

3. Fatigue, especially during times of increased activity

4. Heart palpitations

2. Mitral Regurgitation (MR)

Surgery -Your Mitral valve may need surgical repair or replacement

Medications can't correct a mitral valve deformity. But some medications can be used such as :

• Diuretics can relieve fluid accumulation in your lungs or legs.

• Anticoagulants, which can help prevent blood clots

• High blood pressure makes mitral valve regurgitation worse, so if you have high blood pressure, your doctor may prescribe medication to help lower it.

Treatment of Mitral Regurgitation (MR)

PATHOPHYSIOLOGY OF MR

Incomplete closure of mitral valve

vol. of blood ejected by left ventriclee Left atrial pressure

Right-sided heart failure

Left atrial hypertrophy CO

Pulmonary pressure

Backflow of blood to the left atrium

Right ventricular pressure

Sten

osis

Regu

rgita

tion

Aortic Mitral•Definition: Aortic stenosis occurs when the heart's aortic valve narrows

•Occurs when valve area is 1/4th of normal area•Causes: Congenital, Rheumatic, Degenerative•Symptoms: 1. Syncope2. Angina3. Dyspnea4. Sudden death

•Definition: Obstruction of LV inflow that prevents proper filling during diastole

• symptoms begin at areas less than 2 cm2

•Main Cause: Rheumatic Carditis•Symptoms:1. Shortness of breath2. Fatigue3. Swollen feet or legs4. Heart palpitations5. Dizziness or fainting6. Heavy coughing7. Chest discomfort or chest pain

•Definition: is the leaking of the aortic valve of the heart that causes blood to flow in the reverse direction during ventricular diastole, from the aorta into the left ventricle.

•main cause : Endocarditis

. Treatment:

. Surgery -Your aortic valve may needsurgical repair or replacement

. Medications that control Blood Pressure. Anticoagulants

Definition: The abnormal leaking of bloodfrom the left ventricle, through the mitral valve, and into the left atrium, when the left ventricle contracts, i.e. there is back flow of blood into the left atrium during systole

.The most common Cause of MR include MV prolapse ,rheumatic heart disease &endocarditis

. Treatment:

Surgery -Your Mitral valve may need surgical repair or replacement

Medications such as :. Diuretics . Anticoagulants . Medications that control Blood pressure

Symptoms of MR1. Heart murmur2. Dyspnea)3. Fatigue4. Heart palpitations

**MR is the most common form of Cardiac valves diseases