CARDIAC LECTURE 2: Endocardial, valvular, myocardial, pericardial & congenital heart disease Flashcards
What are 4 reasons the endocardial or valvular structures may be damaged?
- Inflammation
- Scarring
- Calcification
- Congenital
What is the term for the failure of the valve to open completely?
Stenosis
What is the term for the inability of the valve to close completely?
Regurgitation/insufficiency
What is the term for the sounds of improper flow or leaking of blood?
Murmurs
What is the term for impaired blood flow from the left atrium to the left ventricle during ventricular diastole?
Mitral stenosis
Why does mitral stenosis lead to atrial enlargement/hypertrophy?
The blood cannot leave the left atrium, increasing the pressure in the chamber
Why does mitral stenosis lead to pulmonary hypertension, right ventricular hypertrophy, and right sided heart failure?
The pressure in the pulmonary circuit and right side of the heart is elevated since the blood cannot flow into the left ventricle properly
What is the term for backflow of blood from the left ventricle to the left atrium during ventricular systole?
Mitral regurgitation
Why does mitral regurgitation lead to left sided dilation and hypertrophy?
Due to extra blood volume in the heart
Why does mitral regurgitation lead to left sided heart failure?
Left side of the heart must work harder to pump enough blood out to the body, as blood pumped out of the LV goes back into the LA
What is the term for displacement of the mitral valve leaflets into the left atrium during ventricular systole?
Mitral valve prolapse
What are the signs and symptoms of mitral valve prolapse?
Typically asymptomatic, but patients may eventually develop mitral regurgitation or heart failure
Which valve disorder results in obstruction of aortic outflow from the left ventrciel into the aorta during systole?
Aortic stenosis
What is the predominant cause of aortic stenosis?
Age-related calcium deposits
Why does aortic stenosis result in left ventricular hypertrophy and left sided heart failure?
Pressure builds up in LV, muscle must work harder to pump
What valvular disorder involves blood leaking back from the aorta into the left ventricle during diastole?
Aortic regurgitation
What causes aortic regurgitation?
Aortic valve or root dilation
Why does aortic regurgitation lead to left ventricular dilation and hypertrophy and eventually left sided heart failure?
Left ventricle must accomodate a higher volume of blood
LV works harder to pump blood to the rest of the body
Why would mitral stenosis lead to atrial clots?
Because the blood cannot flow out of the left atrium, causing stasis
What is a unique clinical sign of aortic regurgitation?
Wide pulse pressure
Which cardiac disorder is an acute inflammatory disease that follows infection with group A streptococci, and involves immune attack on individual’s own tissues?
Rheumatic heart disease
What tissues do antibodies target in rheumatic heart disease?
Connective tissue in joints, skin, and heart (especially valves)
Which cardiac disorder involves invasion and colonization of the endocardium/heart valves by microorganisms, and leads to vegetations and tissue destruction?
Infective endocarditis
What are vegetations in infective endocarditis composed of, and why are they significant?
- Platelets, fibrin, cellular debris, pathogens
- Pathogens hide from immune system within vegetations
What is required in contracting infective endocarditis?
Microbes gain access to bloodstream through incision or via GI tract
Which form of infective endocarditis can develop in anyone if the number or virulence of the pathogen is high enough?
Acute infective endocarditis
Which form of infective endocarditis only develops in susceptible hosts with pre-existing conditions?
Subacute infective endocarditis
What are 3 consequences of infective endocarditis?
- Valve stenosis
- Heart failure
- Septic emboli
What are 4 complications that can develop with artificial valves?
- Coagulation
- Intravascular hemolysis due to shear force
- Structrual deterioration
- Infective endocarditis
What is the term for an inflammatory disorder of the myocardium characterized by
damage and necrosis of cardiomyocytes?
Myocarditis
What are 4 causes of myocarditis?
- Infection
- Toxins
- Allergies
- Autoimmune
What are 2 histological characteristics of myocarditis?
- Cytotoxic T cell and macrophage infiltration
- Collagen deposition
What are 2 treatments for myocarditis?
- Immunosuppressants
- Supportive therapy
Which term describes a heterogeneous group of diseases involving structural or functional abnormalities of the myocardium?
Cardiomyopathies
How are cardiomyopathies classified by cause?
Primary and secondary
Which type of cardiomyopathy is the most common type, and is characterized by dilation/impaired contraction of one or both ventricles?
Dilated cardiomyopathy
In what manner does the heart enlarge in dilated cardiomyopathy?
Heart can triple in size, but ventricular walls look normal or thinned
Which cardiomyopathy is purely genetic, and is characterized by thickened, hypercontractile ventricular muscle mass?
Hypertrophic cardiomyopathy
What are 2 ways hypertrophic cardiomyopathy impairs cardiac function?
- Impaired diastolic filling
- Aortic stenosis / obstruction
What are 2 treatments for hypertrophic cardiomyopathy?
- CCBs and beta blockers (relaxes ventricles to improve filling)
- Surgical septal myectomy
What is the main difference between dilated and hypertrophic cardiomyopathy?
Dilated=hypocontractility
Hypertrophic=hypercontractility
Which type of cardiomyopathy is the rarest form, and is characterized by a rigid, fibrotic, noncompliant ventricle?
Restrictive cardiomyopathy
How does restrictive cardiomyopathy impair cardiac function?
Ventricles cannot fill
What are 2 reasons for restrictive cardiomyopathy?
- Genetic mutations in genes for sarcomeres and cytoskeleton
- Amyloidosis (protein fragment deposition in heart)
How is restrictive cardiomyopathy treated?
There is no treatment
What is the term for accumulation of fluid in the pericardial sac?
Pericardial effusion
What are 4 types of pericardial effusion?
- Serous
- Serosanguineous
- Purulent
- Chylous
What is the term for exaggerated systolic BP decrease with inspiration, a clinical manifestation of cardiac tamponade?
Pulsus paradoxus
What is the term for 3 clinical manifestations of cardiac tamponade: hypotension, dilated neck veins, and muffled heart sounds?
Beck’s triad
What procedure would be performed to treat cardiac tamponade?
Pericardiocentesis
What is the cause of most cases of acute pericarditis?
Idiopathic, presumed viral
What auscultation finding is characteristic of acute pericarditis?
Pericardial friction rub
What are 2 treatments for acute pericarditis?
- NSAIDs
- Pericardial drainage
Chronic pericarditis can lead to what condition, where the pericardial sac becomes dense, non-elastic, fibrous, and scarred?
Constrictive pericarditis
What are 3 treatments for chronic pericarditis?
- NSAIDs
- Glucocorticoids
- Pericardiectomy
What are the 2 major forms of congenital heart diseases?
- Shunts
- Obstructions
What is the term for a shunt where deoxygenated blood enters the left side of the heart without passing through the lungs?
Cyanotic defect
What is the term for a shunt where oxygenated blood enters the right side to be sent to the lungs again, causing right sided hypertrophy?
Acyanotic defect
What is the term for the fetal heart valve that allows blood to flow from the right atrium straight to the left atrium?
Foramen ovale
What is the term for the channel between the pulmonary artery and the aorta in the fetal heart?
Ductus arteriosus
In cases of atrial and ventricular septal defects, which way will the blood flow?
Left to right (acyanotic), at least at first
Why may a septal defect eventually reverse to become a right-left shunt?
Increase in pulmonary blood flow leads to pulmonary hypertension and right ventricular hypertrophy
What is the most common congenital cardiac defect?
Ventricular septal defects
What are the consequences in patent ductus arteriosus?
Pulmonary hypertension
Right sided heart failure
Which congenital heart defect is characterized by obstruction of blood flow from the right ventricle to the pulmonary circulation, usually due to abnormal fusion of valvular cusps?
Pulmonary stenosis
How can pulmonary stenosis be treated?
Balloon valvuloplasty
What are the 4 features of tetralogy of Fallot?
- Pulmonary stenosis
- Ventricular septal defect
- Overriding aorta
- Right ventricular hypertrophy
What kind of shunting is involved in tetralogy of Fallot?
Right to left (cyanotic)
