Pathophysiology BMS 243 Rheumatic Heart Disease Lecture III Rheumatic Heart Disease Cardiac Valves Diseases Dr. Aya M. Serry 2016

Rheumatic Fever 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.  

Antibody cross-reaction Strep throat Antibody production Antibody cross-reaction with heart pericarditis vegetations Aschoff body

Rheumatic Heart Disease The disease passes into two phases; A. Acute phase:  acute rheumatic pancarditis (inflammation of endocardium, myocardium and pericardium) Myocarditis : the heart muscle itself . Pericarditis: the pericardial, or exterior, heart surface. Endocarditis: endocardial, or interior, heart surface.

Rheumatic Scarring of heart valve 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. 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: Bacterial endocarditis. Arrhythmia. Chronic heart failure. Rheumatic Scarring of heart valve

Cardiac Valves Diseases

Cardiac Valves Diseases Cardiac Valves Diseases are classified into: Stenosis Regurgitation (Insufficiency)

A) Valve Stenosis

A) Valve Stenosis

Cardiac Valves Diseases 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

1. Aortic Stenosis 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.

Causes of Aortic Stenosis Congenital Rheumatic Degenerative Patients under 70: >50% have a congenital cause Patients over 70: 50% degenerative

Pathophysiology 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.Syncope 2.Angina: (increased myocardial oxygen demand; demand/supply mismatch) 3.Dyspnea: on exertion due to heart failure (systolic and diastolic) 4.Sudden death

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.

Causes of Mitral Stenosis Rheumatic heart disease: 77-99% of all cases Infective endocarditis: 3.3% Mitral annular calcification: 2.7% Symptoms: Shortness of breath Fatigue Swollen feet or legs Heart palpitations Dizziness or fainting Heavy coughing, sometimes with blood-tinged sputum Chest discomfort or chest pain

Pathophysiology of MS Narrowing of mitral valve  left atrial pressure  blood flow to left ventricle  pulmonary pressure CO pulmonary congestion Fatigue Left ventricular atrophy O2/CO2 exchange (fatigue, dyspnea) Right-sided failure

B) Valve Regurgitation Cardiac Valves Diseases B) Valve Regurgitation 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

B) Valve Regurgitation

1. Aortic 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

Treatment of Aortic Regurgitation Surgery -Your aortic valve may need surgical repair or replacement 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) Medications that control Blood Pressure

2. Mitral Regurgitation (MR) 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 Blood flowing turbulently through your heart (heart murmur) Shortness of breath (dyspnea), especially with exertion or when you lie down Fatigue, especially during times of increased activity Heart palpitations

Treatment of 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.

Pathophysiology of MR Right-sided heart failure Incomplete closure of mitral valve Backflow of blood to the left atrium  vol. of blood ejected by left ventriclee  Left atrial pressure  CO Left atrial hypertrophy  Pulmonary pressure Right-sided heart failure  Right ventricular pressure

Aortic Mitral . Treatment: Stenosis Regurgitation 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: Syncope Angina Dyspnea 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 Shortness of breath Fatigue Swollen feet or legs Heart palpitations Dizziness or fainting Heavy coughing 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 need surgical repair or replacement . Medications that control Blood Pressure . Anticoagulants Definition: 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 .The most common Cause of MR include MV prolapse ,rheumatic heart disease &endocarditis Surgery -Your Mitral valve may need surgical repair or replacement Medications such as : . Diuretics . Medications that control Blood pressure Symptoms of MR Heart murmur Dyspnea) **MR is the most common form of  Cardiac valves diseases Stenosis Regurgitation