Congestive heart failure (CHF) is characterized by inadequate pump function that causes _____ build-up in the lungs and/or peripheral tissue (congestion).
_________ (systolic or diastolic) dysfunction is the most common form of CHF, due to progressive deterioration of myocardial contractile function due to IHD or hypertension.
Is CHF is the frequent end-point of many heart conditions like ischemic heart disease, hypertension, pulmonary diseases, and valve diseases?
What happens in CHF with diastolic dysfunction? In which populations is it most common?
Contraction is OK but relaxation (filling) is abnormal. Common in older people, females with hypertension, and people with diabetes mellitus.
What three compensatory responses of the heart are seen in CHF?
- Activation of neurohumoral systems
- Frank-Starling mechanism
- Structural changes (e.g. hypertrophy)
Name three examples of hormones that are released during the “activation of neurohumoral systems” compensatory response to CHF.
- Norepinephrine release from the SNS.
- Activation of renin-angiotensin-aldosterone system.
(both increase cardiac output)
- Atrial natriuretic peptide (ANP) release –> vasodilation and diuresis to alleviate hypertension.
What is meant by “compensated heart failure,” and “decompensated heart failure?”
In compensated heart failure, the dilated ventricle is able to maintain sufficient cardiac output via increased sarcomere stretch (Frank-Starling).
In decompensated failure, the ventricle is dilated too much to generate sufficient force to perfuse the body.
What are the two major types of hypertrophic changes that can occur in CHF? Explain each.
- Concentric hypertrophy: Happens in pressure overload states like hypertension or valve disease. Diameter of muscle fibers increase causing an increase in ventricular wall thickness without an increase in chamber size.
- Eccentric hypertrophy: Happens in volume overload states like valvular regurgitation and abnormal shunts. The length of muscle fibers increases leading to an increase in heart size and wall thickness.
Name four bio-molecules that cause the hypertrophic myocardial response.
- Angiotensin II
- Insulin-like GF 1
Does hypertrophy of the myocardium increase metabolic demand, putting the heart at risk for ischemic injury?
Name five of the most common causes of left-sided heart failure.
- Ischemic heart disease
- Mitral valve disease
- Aortic valve disease
- Primary myocardial diseases
The morphologic and clinical effects of left-sided heart failure are due to the progressive ________ of blood within the pulmonary circulation and the consequences of diminished peripheral _______ _________ and _____.
due to progressive damming of blood in the pulmonary circulation and the consequences of diminished peripheral blood pressure and flow.
What five morphological changes are seen in lungs with pulmonary congestion?
- Lungs are heavy and soggy
- Perivascular and interstitial transudate
- Alveolar septal edema
- Intra-alveolar edema
- Presence of “heart failure cells”
What is a “heart failure cell?”
Macrophages loaded with hemosiderin (from extravasated RBCs) found in lungs with pulmonary congestion - in the intra-alveolar exudate.
What is typically the earliest and most significant complaint/symptom of left-sided heart failure?
What is orthopnea?
Dyspnea in a supine position - happens with advanced left heart failure due to increased pulmonary capillary pressure from increased venous return from the lower extremities.
How can left ventricular failure cause right heart failure?
LV failure causes an increase in pulmonary circulation pressure, putting increased demand on the RV –> hypertrophy, etc.
What is “cor pulmonale?”
A term used to describe purely right-sided heart failure in patients with one of a variety of disorders affecting the lungs that involve pulmonary hypertension.
Explain how right sided heart failure causes engorgement of the systemic and portal venous system, which produces distension of neck veins, nutmeg liver, and congestive splenomegaly.
Inability of the right heart to pump blood backs it up in the systemic and portal systems (increased pressure) and that screws everything up.
Are most cases of CHF characterized by right heart failure, left heart failure, or biventricular failure?
CHF is characterized by various degrees of decreased cardiac output and tissue purfusion (known as _______ failure) and pooling of blood in the venous system (known as _______ failure).
decreased cardiac output and tissue purfusion is forward failure and pooling of blood in the venous system is backward failure.
Are many clinical features and morphologic changes noted in CHF secondary to injuries induced by hypoxia and congestion of tissues distant from the heart?
What is the main cause of hypertensive heart disease?
Hypertension (either pulmonary - causing RV hypertrophy, or systemic - causing LV hypertrophy)
Name five morphological changes of systemic hypertensive heart disease.
- Thickened LV (>2cm)
- Increased heart weight (>500 grams)
- Enlarged myocytes and nuclei
- Diffuse interstitial fibrosis
- Focal myocyte atrophy and degeneration
What is the cause of death in 1/3 of all hypertensive patients?
Congestive heart failure
What is the difference between valvular stenosis vs. insufficiency?
Stenosis: Valve won’t open all the way
Insufficiency: Valve won’t close all the way
What three typical types of adult valve pathologies are common?
- Degeneration and dystrophic calcification
- Rheumatic heart disease
- Infective endocarditis
What is the most common valvular abnormality?
Degenerative calcific aortic stenosis.
How can degenerative calcific aortic stenosis cause LV hypertrophy? Is it typically concentric or eccentric?
Ejection through a narrowed opening is a type of increased functional demand –> hypertrophy. Typically concentric
Name the disease: Enlarged, myxomatous (weakened), floppy mitral valve with occasional ruptured chordae tendinae seen in 20 to 40 year olds. Female:male is 7:1.
Mitral valve myxomatous degeneration (mitral valve prolapse)
What microscopic morphological changes are seen in mitral valve myxomatous degeneration?
Thinning and degeneration of the fibrosa layer of the valve. Mucoid expansion of the middle spongiosa layer with increased proteoglycans.
Mitral valve myxomatous degeneration can increase risks for what four things?
- Infective endocarditis
- Gradual valvular insufficiency leading to congestive heart failure.
- Sudden cardiac death
In what population is Rheumatic heart disease most commonly seen?
5-15 year olds
What causes Rheumatic HD?
Anti-streptococcal antibodies that cross-react with cardiac antigens.
What is the most important complication of Rheumatic heart disease?
Chronic valvular deformities via scarring
What morphological changes occur in valves that have been damaged as a result of Rheumatic heart disease?
Fibrinoid necrosis within the cusps or along the tendinous cords.
What is an Aschoff body?
Found in the acute phase of Rheumatic heart disease. Characterized by a central zone of degenerating, hypereosinophilic ECM infiltrated by lymphocytes (primarily T cells), occasional plasma cells, and plump activated macrophages called Anitschkow cells (capillary cells).
Which heart valves are most often injured from Rheumatic HD?
Mitral and aortic
What causes clinical features of Rheumatic HD?
Symptoms are secondary to valve disease.
What is infective endocarditis?
Colonization of valves by microorganisms leads to the formation of friable (readily crumbled), infective vegetations that can cause valve damage.
Name the disease: Valve infection by Staph. aureus (highly virulent) that produces a rapid development of fever with rigors, malaise, and rigors, large emboli in the heart chambers, and death within days to weeks in more than 50% of patients despite antibiotic treatment.
Acute infective endocarditis.
Can moderate-to-low virulence organisms (Staph. viridans) cause infective endocarditis by infecting a perfectly healthy valve?
Not usually, they often infect previously injured valves.
What is marantic endocarditis and what causes it? Name morphological changes.
AKA nonbacterial thrombotic endocarditis. Occurs due to hypercoagulable states (cancer, prolonged illness, etc.) Morphological changes include masses of fibrin, platelets, and other blood components on heart valves.