Notes on Heart Disorders
Rahul's Noteblog Notes on Pathology Notes on Heart Disorders
Ventricular hypertrophy:
• High-pressures increased wall stress.
• Increased resistance (afterload) causes concentric thickening of ventricular wall.
Causes of concentric Left Ventricular Hypertrophy:
• Essential hypertension; aortic stenosis.
Causes of concentric Right Ventricular Hypertrophy:
• Pulmonary hypertension; pulmonary artery stenosis.
• Volume overload (increased preload) causes dilation and hypertrophy (eccentric hypertrophy) of ventricular wall.
Causes of eccentric Left Ventricular Hypertrophy:
• Mitral or aortic valve regurgitation; VSD.
Causes of eccentric Right Ventricular Hypertrophy:
• Tricuspid or pulmonary valve regurgitation.
Findings in Ventricular hypertrophy:
• Angina, S4 heart sound, L- or R-HF.
• Mitral valve or aortic valve regurgitation, left-to-right shunting of blood cause eccentric hypertrophy of left ventricular wall.
• Tricuspid valve or pulmonary valve regurgitation causes eccentric hypertrophy of right ventricular wall.
Congestive Heart Failure:
Left-sided HF:
• Blood cannot be ejected into aorta.
• Pulmonary edema.
• Caused by concentric LVH.
• Alveolar macrophages contain hemosiderin (heart failure cells).
• Difficulty breathing.
• Left-sided S3 sound.
• Mitral-valve regurgitation.
• Paroxysmal nocturnal dyspnea.
Right-sided HF:
• Blood cannot be pumped into lungs.
• Prominent jugular veins.
• Right-sided S3 sound.
• Tricuspid valve regurgitation.
• Painful hepatomegaly.
• Pitting edema and ascites.
High-output HF:
• Increased CO.
• Increased SV.
• Decreased blood viscosity.
• Vasodilation of arterioles.
• Arteriovenous fistula: increased venous return to heart; trauma from knife wound.
Ischemic heart disease:
• O2 supply and demand imbalance.
• Tachycardia leads to ischemia.
• LAD occlusion most common.
• RCA occlusion, second-most common.
• Left circumflex coronary a. occlusion, third-most common.
• Sudden cardiac death; angina pectoris; MI.
Angina pectoris:
Stable angina:
• Caused by atherosclerotic coronary artery disease.
• Exercise-induced chest pain.
• ST depression.
• Relieved by resting or nitroglycerine.
Prinzmetal angina:
• Coronary artery vasospasm at rest.
• Vasoconstriction.
• ST-elevation.
• Nitroglycerine and Ca-channel blocker.
Unstable angina:
• Severe atherosclerotic disease.
• Chest pain even at rest.
• May progress to MI.
• Balloon angioplasty.
• Stents.
Chronic ischemic heart disease:
• Ischemic damage to myocardial tissue causes CHF.
• Findings: CHF, angina, dilated cardiomyopathy.
Myocardial infarction:
• Disruption of atheromatous plaque; platelet thrombus formation.
• TXA2 plays important role in platelet thrombus formation.
• Causes of MI: cocaine use, vasclitis, embolization, etc.
Transmural / Q-wave:
• Involves full thickness of myocardium.
Subendocardial / non-Q-wave:
• Involves inner third of myocardium.
• Reperfusion used to salvage some injured myocytes.
Gross change:
• 0-24 hours: no changes; coagulation necrosis.
• 1-3 days: pallor; dead cells lysed.
• 3-7 days: red granulation tissue; necrotic debris removed.
• 7-10 days: bright yellow area; well-developed granulation tissue.
• 2 months: white, patchy scar tissue.
Findings:
• Sudden retrosternal pain.
• Not relieved by nitroglycerine; lasts 45 minutes.
• Radiates to left arm and jaw.
• Sweating, anxiety, hypotension.
Complications:
• Arrhythmias, CHF, rupture, mural thrombus, pericarditis, ventricular aneurysm, right ventricular acute MI.
• Increased CK-MB; peaks at 24 hours.
• Troponins: cTnl and cTnT.
• LDH 1-2; "flip."
• Inverted T waves.
• Elevated ST segment.
• New Q waves.
Congenital heart disease:
LH to RH shunts:
• Pulmonary hypertension, RVH, LVH, shunt reversal.
VSD:
• Common in cri du chat syndrome, trisomy 13 and 18.
• Children.
ASD:
• Fetal alcohol syndrome.
• Adults.
PDA:
• Caused by congenital rubella.
• Pink upper body and cyanotic lower body.
• Machine murmur.
Right and left heart shunts:
• Cyanosis.
Complications:
• secondary polycythemia and infective endocarditis of damaged valves.
Tetralogy of Fallot:
• VSD, RVH, pulmonary stenosis, overriding aorta.
• Squatting reverses shunt.
Transposition of great vessels:
• Aorta arises from right ventricle.
• Pulmonary artery arises from left ventricle.
• Cardioprotective shunts: ASD, VSD.
Truncus arteriosus:
• Aorta and pulmonary artery blood is mixed.
Coarctation of aorta:
• Aortic constriction between subclavian artery and ductus arteriosus.
• Turner's syndrome.
Coarctation of aorta in adults:
• Systolic murmur.
• Increased upper body BP.
• Aortic regurgitation.
• Risk for aortic dissection.
• Leg claudication.
• Collateral circulation develops.
• Rib notching.
Rheumatic fever:
• Immune disease that follows group A streptococcal pharyngitis infection.
• Pericarditis.
• Myocarditis.
• Endocarditis.
• Sterile, verrucoid-appearing vegetations near valve.
• Mitral and aortic valve regurgitation.
• Infection.
• Migratory polyarthritis.
• Sydenham's chorea.
• Antistreptolysin O (ASO) titers; throat culture; leukocytosis; increased PR interval; CRP.
Mitral stenosis:
• Caused due to recurrent rheumatic fever.
• Opening snap and mid-systolic rumble.
• Problem with opening the valve.
• Dyspnea, hemoptysis with rust-colored cells.
• Atrial fibrillation.
• Pulmonary venous hypertension.
• Dysphagia for solids.
Mitral regurgitation:
• Mitral valve prolapse.
• Left-sided HF.
• Blood flows back into left atrium.
Mitral valve prolapse:
• Associated with Marfan and Ehlers-Danlos syndrome.
• Excess production of dermatan sulfate.
• Asymptomatic.
• Heart murmur.
• Mid-systolic click.
• Preload decreased; murmur close to S1.
• Preload increased; murmur close to S2.
Aortic stenosis:
• Calcification of aortic or bicuspid valve.
• Rheumatic fever.
• Left ventricular obstruction.
• Systolic ejection murmur.
• Problem of opening the valve.
• Angina, syncope.
Aortic regurgitation:
• Aortic valve dialation.
• Infective endocarditis.
• Rheumatic fever.
• Blood flows back into left ventricle.
• Diastolic murmur.
• Problem with closing aortic valve.
• Bounding pulses, pulsating uvula, head nodding; Austin Flint murmur.
Tricuspid regurgitation:
• Right-sided HF.
• Infective endocarditis.
• Blood flows back into right atrium.
• Pansystolic murmur; pulsating liver.
Carcinoid heart disease:
• Due to liver metastasis from a carcinoid tumor of SI.
• Tricuspid valve regurgitation and pulmonary valve stenosis.
Infective endocarditis:
• S. viridans; S. aureus; S. epidermidis ; S. bovis.
• Mitral, tricuspid, and aortic valves involved.
• Vegetations and infarctions in distant organs.
• Splinter hemorrhages in nail beds; glomerulonephritis; fever; splenomegaly.
Libman-Sacks endocarditis:
• Seen in SLE.
Nonbacterial thrombotic endocarditis:
• Procoagulant effect from mucin.
Myocarditis:
• Microbial infection by Coxsackievirus; Trypanosoma cruzi.
• Acute rheumatic fever; diphtheria toxin.
• Fever, chest pain, CHF, CK-MB, troponins.
Pericarditis:
• Coxsackievirus infection.
• Pain relieved by leaning forward.
• Muffled heart sounds; hypotension.
• Neck vein distention.
• Chest graph: water bottle configuration.
• Constrictive: incomplete filling of heart chambers.
Cardiomyopathy:
• Myocardial dysfunction.
Dilated:
• Most common.
• Decreased contractility; all chambers dilated; biventricular CHF.
Hypertropic:
• Sudden death in young due to conduction disturbances; AD disease.
• Myocardial hypertrophy.
• Systolic ejection murmur; increased preload = decreased murmur; decreased preload = increased murmur.
Restrictive:
• Endomyocardial fibrosis.
• Eg., Pompe's glycogenosis, amyloidosis, hemochromatosis.
• Decreased ventricular compliance.
• Arrhythmias, CHF.
Heart tumors:
Cardiac myxoma:
• Adults.
• Fatigue, fever, malaise, anemia.
• Transesophageal ultrasound.
Rhabdomyoma:
• Chindren.
• Association with tuberous sclerosis.
Additional Reading:
Basic Pathology
1. Cell Injury
2. Inflammation and Repair
3. Immunopathology
4. Water, Electrolyte, Acid-Base, Hemodynamic Disorders
5. Genetic and Developmental Disorders
6. Environmental Pathology
7. Nutritional Disorders
8. Neoplasia
9. Vascular Disorders
10. Heart Disorders
11. Red Blood Cell Disorders
12. White Blood Cell Disorders
13. Lymphoid Tissue Disorders
14. Hemostasis Disorders
15. Blood Banking and Transfusion Disorders
16. Upper and Lower Respiratory Disorders
17. Gastrointestinal Disorders
18. Hepatobiliary and Pancreatic Disorders
19. Kidney Disorders
20. Lower Urinary Tract and Male Reproductive Disorders
21. Female Reproductive and Breast Disorders
22. Endocrine Disorders
23. Musculoskeletal Disorders
24. Skin Disorders
25. Nervous System Disorders
26. Notes on Tissue Regeneration
27. A Table of Bleeding Disorders
28. FAQ on Structure and Function of Red Blood Cells
29. FAQ on Components of Blood
30. Notes on Hemostatic Mechanisms
31. What is Fever?
32. What is Edema?
33. FAQ on Blood Pressure
34. FAQ on principles of fluid and flow dynamics of Blood
35. Causes of Thrombocytopenia
36. Squamous cell carcinoma of head and neck mucosa
37. Four tumors which never metastasize to the brain
38. What is caustic injury?
39. What causes Peripheral Edema?
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