Lecture 6 Cardiac Disorders

Question 1

Valvular Stenosis

Answer 1

Failure of the valve to open completely Results in extra pressure work for the heart.

Question 2

Valvular Regurgitation (Insufficiency)

Answer 2

Inability of a valve to close completely Results in extra volume work for the heart.

Question 3

Mitral Stenosis

Answer 3

Impaired blood flow from left atrium to left ventricle during ventricular diastole. Leads to increased pressure and enlargement of the left atrium.

Question 4

Mitral Valve Prolapse

Answer 4

Displacement (ballooning) of mitral valve leaflets into the left atrium during ventricular systole. Often asymptomatic.

Question 5

Mitral Regurgitation

Answer 5

Backflow of blood from left ventricle to left atrium during ventricular systole. Left atrium and ventricle dilate and hypertrophy due to extra volume.

Question 6

Aortic Stenosis

Answer 6

Obstruction of aortic outflow from left ventricle into aorta during systole. Predominant cause is age-related calcium deposits.

Question 7

Aortic Regurgitation

Answer 7

Incompetent aortic valve allows blood to leak back from aorta into left ventricle during diastole. Leads to left ventricular hypertrophy and dilation.

Question 8

Mural Thrombi

Answer 8

Thrombi that form on the endocardium. Causes include endocardial damage, stasis/turbulence, or a hypercoagulable state.

Question 9

Rheumatic Heart Disease

Answer 9

Acute inflammatory disease following infection with group A streptococci. Damage due to immune attack on connective tissue in the heart (especially valves), joints, skin.

Question 10

Infective Endocarditis

Answer 10

Invasion and colonization of endocardium/valves by microorganisms. Forms vegetations (platelets, fibrin, cellular debris, pathogens). Commonly due to staphylococci, streptococci, enterococci.

Question 11

Myocarditis

Answer 11

Inflammatory disorder of the myocardium. Caused by viruses (common), other infectious agents, toxins, immune reactions. Characterized by damage and necrosis of cardiomyocytes.

Question 12

Cardiomyopathy

Answer 12

Heterogeneous group of diseases involving structural or functional abnormality of the myocardium. Can be primary (heart) or secondary (systemic disorder).

Question 13

Dilated Cardiomyopathy

Answer 13

Most common cardiomyopathy. Dilation and impaired contraction of one or both ventricles. Heart can triple in size. Estimated prevalence is 1:250.

Question 14

Hypertrophic Cardiomyopathy

Answer 14

Thickened, hypercontractile ventricular muscle mass. Often affects the left ventricle and septum. Can cause sudden cardiac death, especially during exertion.

Question 15

Restrictive Cardiomyopathy

Answer 15

Rarest cardiomyopathy. Characterized by a rigid, noncompliant ventricle. Impairs diastolic filling.

Question 16

Pericardial Effusion

Answer 16

Accumulation of fluid in the pericardial sac. Consequences depend on volume and stretch. Types include serous, serosanguineous, purulent, chylous.

Question 17

Cardiac Tamponade

Answer 17

Large or sudden fluid accumulation in pericardial sac causing external compression of heart chambers. Impairs diastolic filling due to increased intracardiac pressure.

Question 18

Acute Pericarditis

Answer 18

Acute inflammation of the pericardium. Most cases are idiopathic, presumed viral. Clinical signs include chest pain, pericardial friction rub.

Question 19

Chronic Pericarditis

Answer 19

Recurrent pericarditis leading to chronic pericardial dysfunction. Can lead to constrictive pericarditis (dense, non-elastic sac).

Question 20

Congenital Heart Disease

Answer 20

Heart abnormality present from birth. Two major forms: Shunts (abnormal blood flow) and Obstructions (narrow openings).

Question 21

Shunt (Congenital Heart Disease)

Answer 21

Abnormal path of blood flow. Right to left shunt = cyanotic (deoxygenated blood enters left side). Left to right shunt = acyanotic (oxygenated blood enters right side).

Question 22

Atrial Septal Defect (ASD)

Answer 22

A hole, majority at the foramen ovale location. Allows blood flow between the atria. Large defects can lead to pulmonary hypertension, right heart failure.

Question 23

Ventricular Septal Defect (VSD)

Answer 23

A hole, typically in the membranous septum. Most common congenital cardiac anomaly. Allows blood flow between the ventricles.

Question 24

Patent Ductus Arteriosus (PDA)

Answer 24

Failure of the ductus arteriosus to close after birth. Allows blood flow between the aorta and pulmonary artery. Normally closed by increased O2 and decreased prostaglandins.

Question 25

Pulmonary Stenosis (Congenital)

Answer 25

Obstruction of blood flow from right ventricle to pulmonary circulation. Usually due to abnormal fusion of valvular cusps. Can lead to right ventricular hypertrophy, heart failure.

Question 26

Tetralogy of Fallot

Answer 26

Complex congenital defect with four features: 1. Pulmonary stenosis 2. Ventricular septal defect 3. Overriding aorta 4. Right ventricular hypertrophy Most common cause of cyanosis in newborns.

Question 27

Clinical manifestations of Mitral Stenosis

Answer 27

Opening snap, low-pitched diastolic rumble Exertional dyspnea, hemoptysis, chest pain, fatigue, atrial clots, A fib

Question 28

Clinical manifestations of mitral valve prolapse

Answer 28

Mid-systolic click and late-systolic murmur Exertional dyspnea, dizziness, fatigue, palpitations, arrhythmias, chest pain, anxiety

Question 29

Clinical manifestations of mitral regurgitation

Answer 29

High-pitched, pansystolic murmur Exertional dyspnea, chronic weakness and fatigue

Question 30

Clinical manifestations of aortic stenosis

Answer 30

Systolic ejection murmur Exertional dyspnea, dizziness, angina

Question 31

Clinical manifestations of aortic regurgitation

Answer 31

Diastolic murmur, widened pulse pressure, Exertional dyspnea, angina, palpitations

Question 32

Clinical manifestations of mural thrombi

Answer 32

Can be asymptomatic Embolization -> ischemia

Question 33

Clinical manifestations of rheumatic heart disease

Answer 33

Valve dysfunction - dyspnea, dizziness, fatigue, chest pain

Question 34

Clinical manifestations of ineffective endocarditis

Answer 34

Fever, malaise, myalgia, arthralgia Majority of vegetation form on mitral or aortic valve: leads to valvular stenosis, heart failure, and death Vegetation can grow several centimetres: tend to form septic emboli Treatment is antibiotics

Question 35

How does microbes gain access to bloodstream

Answer 35

IV drug use, invasive surgery, cardiovascular devices, dental work

Question 36

Artificial valves

Answer 36

Used to treat valvular disorders Complications: - may require chronic anticoagulation - intravascular hemolysis due to shear force - structural deterioration - increase risk of infective endocarditis

Question 37

Clinical manifestations of myocarditis

Answer 37

• Highly variable, from asymptomatic to sudden death • Fatigue, dyspnea, chest pain, myalgia • Thrombi and emboli • Arrhythmias • Left ventricular failure, dilation of heart chambers → heart failure

Question 38

Treatment of myocarditis

Answer 38

Immunosuppressants, Supportive therapy for heart failure if required

Question 39

Treatment of hypertrophic cardiomyopathy

Answer 39

• Calcium channel blockers and β-adrenergic blockers • Reduce contractility, relax ventricular wall for better diastolic filling • Surgical septal myectomy

Question 40

Clinical manifestations of restrictive cardiomyopathy

Answer 40

Impaired diastolic filling exercise intolerance, dyspnea, peripheral edema, weakness and fatigue No specific treatment Cooked within 10 years

Question 41

Serous pericardial effusion

Answer 41

transudate, secondary to heart failure or hypoproteinemia

Question 42

Serosanguineous pericardial effusion

Answer 42

mix of serous fluid and blood, secondary to blunt force trauma, malignancy, ruptured MI, aortic dissection

Question 43

Purulent pericardial effusion

Answer 43

exudate, secondary to infection

Question 44

Chylous pericardial effusion

Answer 44

exudate, secondary to infection

Question 45

Clinical manifestations of cardiac tamponade

Answer 45

• Compensatory tachycardia • Chest pain • Dyspnea • Beck’s triad – hypotension, increased jugular venous pressure, muffled heart sounds

Question 46

Clinical manifestations of acute pericarditis

Answer 46

• Fever, leukocytosis, malaise • Chest pain • Pericardial friction rub • Pericardial effusion