Cardio TBL Flashcards

1
Q

Areteriosclerosis =

A

Hardening of Arteries

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2
Q

• Atherosclerosis: large and medium arteries;

A

INTIMAL CHANGES
—Lipid deposition, accumulation of macrophages + myointimal cells —>
plaque formation

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3
Q

• Arteriolosclerosis: Hypertension induced

A

hyperplasia/trophy of smooth muscle cells (Media)

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4
Q

• Endarteritis Obleterans:

A

Response to inflammation (syphilis); INTIMA

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5
Q

Arteritis:

A

• Arteritis: fibrinoid necrosis of arterial wall

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6
Q

Monkeberg’s:

A

Calcification of MEDIA

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7
Q

Areteriosclerosis Emphasis on Progression

A

• Intimal changes are persistent for decade(s), but then sclerosis can progress. Evidence shows lesions in same gross location, but different depth (in vessel wall) as individuals age.

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8
Q

Areteriosclerosis Presentation

A

• Presentation: 50 years of age

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9
Q

Arterial Structure Review Three Parts:

A

Intima:
Media:
Adventitia:

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10
Q

Arterial Intima:

A

Endothelium –> internal elastic lamella; contains myointimal cells in the sub-endothelial space

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11
Q

Arterial Media:

A

smooth muscle cells + Collagen I/III

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12
Q

Arterial Adventitia:

A

type I collagen + fibroblasts Vasa Vasorum not found in abdominal aorta –> more susceptible to athero.

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13
Q

CHRONIC ENDOTHELIAL DYSFUNCTION:

A
  • Platelet Microthrombi

* Fatty Streaks

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14
Q

Platelet Microthrombi -

A

Proposed theory because aggregates of plat are found incommon sites of athero

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15
Q

Fatty Streaks -

A

Subendothelial lipid (cholesterol/esters) + foamy cells

  • –No hemodynamic change
  • –Reversible (Lactating babies +, 4-5 y/o)
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16
Q

Bottom Line: Endothelial injury

A

↑permeability for lipids + ↑adhesions

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17
Q

Endothelial Injury occurs from:

A
• Hyperlipidemia/hypercholesterolemia
• HTN
• Smoking
• Diabetes/Metabolic Syndrome
• Toxins/Viruses
• Homocysteine
Fatty streaks are reversible with lifestyle
change. if not --> Fibrous (Fatty) Plaque
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18
Q

Areteriosclerosis Pathophysiology:

A

• Because Atherosclerosis = chronic endothelial dysfunction; any disease that causes endothelial injury can lead to it.

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19
Q

Three Consequence of endothelial injury:

A
  1. ↑Endothelial adhesion to leukocytes and platelets
  2. Passage of lipids (LDL) into subendothelial space (Fatty streak)
  3. DAMAGE –> endogenous activation macrophages–> ↑cytokines + ↑Macrophage presentation to T-Cells –> ↑T-Cell Inflammation
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20
Q
  1. ↑Endothelial adhesion to leukocytes and platelets leads to?
A

Adhesion Accumulation of macrophages, myointimal cells and monocytes (future foamy cells) in subendothleial space

  • –Platelets on Fatty Streak –> ↑Cytokines –> ↑T Cell Activation
  • **Cytokines–> Smooth muscle proliferation / ECM deposition (smooth muscle from tunica media –> tunica intima)
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21
Q
  1. Passage of lipids (LDL) into subendothelial space (Fatty streak) leads to?
A
  • –LDL must be oxidized –> release inflammatory lipids
  • –Can be modified by homocysteine (MI in Homocysteinuria)
  • –Additional ↑Endothelial adhesion particles
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22
Q
  1. DAMAGE –> endogenous activation macrophages–> ↑cytokines +
    ↑Macrophage presentation to T-Cells –> ↑T-Cell Inflammation leads to?
A

—Inflammation –> ↑IL-6 –> ↑Acute Phase Proteins (SAA, CRP)
***CRP is best indicator of disrupted plaques; thus better than LDL for
predicting cardiovascular events

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23
Q

↑Endothelial adhesions leads to?

A

Macrophages and monocytes migrating: Lumen (L) to subendothelial space.
Once in subendothelial space,monocyte and macrophage ingests lipid –> Foamy Cell

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24
Q

Endothelial injury morphology?

A

• Fatty streaks: yellow streaks on
endothelium
• streaks occur at points of bifurcation
—Turbulent flow, likely place for injury

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25
FATTY STREAK leads to?
FIBROUS PLAQUE
26
Proliferative lesion:
Monocyte, macrophage, myointimal cells proliferate===Intimal Thickening!
27
Fibrous Plaque =
• Amorpous central core: cholesterol + esters, acellular debris, foamy cells • Fibrous cap: myointimal cells, collagen, glycoproteins, PGs ---Provides stability • Endothelium is intact (Continuous) ---But dysfunctional --> platelets!
28
Pathophysiology: | FATTY STREAK --> FIBROUS PLAQUE
* Untreated fatty streaks allow ↑Lipid deposition + ↑Leukocyte adherence to dysfunctional endothelium * ↑Foamy Cells * ↑Stress --> ↑Smooth muscles changes --> ↑Myointimal cells
29
Veins and Pulmonary Circulation
* VEINS ARE NOT AFFECTED | * Same with pulmonary circulation, EXCEPT IN PULMONARY ATHEROSCLEROSIS (DDx: Pulmonary Hypertension)
30
Morphology: “Fibrofatty Plaque”?
* Gross: elevated lesions at points of turbulent flow * Micro: (image) see foamy cells (F) (in and out of core), fibrous cap, and central core (necrotic material and cholesterol crystals)
31
Complex Atheromatous Lesions
FIBROUS PLAQUE + SOMETHING ELSE
32
Complex Atheromatous Lesions Maintains Components of Fibrous Plaque
* Necrotic debris * Cholesterol deposits * Foamy cells/fibrous cap
33
Complex Atheromatous Lesions + New Process:
``` • Calcification (breaks off with pulse flow) • Hemorrhage (capillary ingrowth) • Ulceration/Fissure (abdominal aorta) • Ruptured Plaque (Coronary Syndrome) • Luminal Thrombosis (platelets) Progression from Fibrous Plaque --> Complex Lesions is NOT mandatory ```
34
Complex Atheromatous Lesions Pathophysiology:
* Again, lack of treatment/intervention allows fatty streak --> fibrous cap --> addition of new process * Recall abdominal aorta is more susceptible to atherosclerosis because lack of vasa vasorum
35
Myocardial Infarction from CAD requires?
100% occlusion
36
Most patients with CAD have?
Multiple plaques along their entire coronaries
37
Because ATHEROsclerosis =
Intima of CA is thickened
38
Effect of Pre-Existing Collaterals:
• Men have ↑↑ collateral circulation • Premenopausal women have ↓collaterals, but ↓atherosclerosis • Immediately post-menopausal women CA occlusion = DEVESTATING ---Enter “accelerated atherosclerosis” and have ↓collateral circulation
39
Coronary Artery Disease Etiology:
• Coronary arteries especially at risk because intimal thickening naturally takes place at points of bifurcation (turbulent flow)
40
Coronary Artery Disease Areas at Risk
• LAD: anterior LV, IV-Septum, Apex • Circumflex A: Wall of LV • RCA: Posterior wall of LV, IV septum, RV, and Right wall of Heart
41
Coronary Artery Disease Pathophysiology:
* 80% of lumen can be narrowed without myocardial necrosis * Recall from acute coronary syndrome that endothelial dysfunction --> atherosclerosis, but damage does not occur until plaque ruptures * Acute episode (plaque rupture, fissure, hemorrhage, thrombosis) ----> dislodge plaque + expose endothelium --> platelets aggregate (thrombus) ---> TXA2 = VASOCONSTRICTION
42
Stary’s Classification of Coronary Artery Disease
* Type 1: Adaptive Thickening * Type 2: Macrophageic Foam Cells * Type 3: Extracellular Lipid = preatheroma * Type 4: Necrotic Core = atheroma * Type 5: Fibrous cap = fibroatheroma * Type 6: Atheroma + addition = complicated lesion
43
Myocardial Infarction =
100% Occlusion of Coronary Artery
44
Myocardial Infarction Area of Risk vs. Area of Necrosis
• Area of risk: area irrigated by coronary artery if occluded for long time • Area of Necrosis: area of actual tissue death Big Point: quicker perfusion occurs --> less area of necrosis
45
Myocardial Infarction: 10 hours:
no gross/micro change
46
Myocardial Infarction: 10-20 hrs:
Dead cells (white) cell surrounded by hypereosinophilic + some edema +/- PMN (Coagulative necrosis)
47
Myocardial Infarction:1-3 days:
↑eosinophilia, pyknosis, karyorrhexis, ↑edema + ↑PMNs
48
Myocardial Infarction: 4-7 days:
Macrophages + PMNS remove dead cells --> risk for rupture; granulation tissue begins to form around necrotic area
49
Myocardial Infarction: 7-10 days:
Gross yellowish color; ↑collagen + granulation tissue
50
Myocardial Infarction: 11-21 days:
Dead cells gone (macro w/ lipofuschin); granulation tissue
51
Myocardial Infarction: 4-10 weeks:
Granulation tissue ---> non-contractile scar
52
Post-MI Complications Reperfusion Injury:
``` • Fibers at edge of MI are hypereosinophilic bands with distortion, pyknosis, and interstitial edema ===Contraction Bands • During MI, ↑Ca++ accumulation. • When reperfused --> massive sustained contraction • Also free radical damage ```
53
Post-MI Complications Pathophysiology:
During reperfusion post MI, lots going on: 1. Mitochondria come back, but not quick enough to stop ROS 2. pH is changing drastically (back up) 3. Ca++ overload 4. Inflammation
54
Myocardial Hypercontracture -->
↑Pores in Mito. Membrane = DAMAGE
55
Reperfusion ↓Infarction size, but do it after cardioprotection to prevent cardiac hypercontracture:
* Rx preventing mitochondrial membrane pore formation | * Rx activating reperfusion injury salvage kinase (RISK) pathway
56
Post-MI Complications Mural Thrombosis
Area over infarct thickens and is | abnormal --> attracts platelets
57
Post-MI Complications Consequences Mural Thrombosis
* Embolism | * Occupy LV volume ---> ↓CO
58
Post-MI Complications Ventricular Aneurysms
Ventricular Aneurysms • Common in transmural infarcts Mechanism: • While scarred area has ↑strength, during contraction it remains stationary and healthy myocardium contracts, creating an anuerysm
59
Ventricular Aneurysms
Common in transmural infarcts
60
Ventricular Aneurysms Mechanism:
While scarred area has ↑ strength, during contraction it remains stationary and healthy myocardium contracts, creating an anuerysm
61
Myocardial Rupture Occurs
Days 4-7 (max removal of tissue) | ---60% during this time period; 30% in 24 hr
62
Myocardial Rupture Risk Factors:
* Hypertension * Diabetics * Women in early menopause * Psychiatric Patients
63
Myocardial Rupture Pathophysiology - Two Required Conditions
• Transmural infarct - full thickness of wall must be necrotic --- Makes sense, or else blood would not seep out • ↑↑ intraventricular pressure --- Push blood out, dissecting through the wall Rupture pushes blood into pericardial sac (TAMPONADE) or can rupture a papillary
64
Septal Rupture
Acquired A-V Defect Less common than rupture of the free wall. Free wall > septal > papillary
65
Aneurysm =
Sac formed from dilation of vascular wall (cardiac, arterial, venous) ---Call venous aneurysm “Varicose / Varices”
66
Thoracic aneurysms =
Dissecting unless proven otherwise.
67
Abdominal aneurysms =
Atherosclerotic unless proven otherwise.
68
Aneurysms Morphological Classification:
Fusiform, Saccular, Cylindrical, Fistula
69
Laplace’s Law :
Tension = (Pressure)(Radius)/(2xHeight) | • Dilation --> ↑Radius --> ↓Wall Thickens (↓H) --> -->
70
What causes symptoms of aneurysms?
* Compression of surrounding organs * Ischemia distal to aneurysm * Hemorrhage due to rupture
71
Dissecting (Thoracic) Aneurysm =
Intimal tear in Aorta --> Blood in MEDIA | • Intimal tear ~ 6cm from aortic valve.
72
Dissecting (Thoracic) Aneurysm Etiology:
``` • Poorly controlled hypertension*** • Marfan’s Syndrome (presents early) • Bicuspid Aortic Valve • Familial Thoracic Aortic Aneurysm Syn • Coarctation of Aorta (HTN proximal) • Ehlers Danlos Syndrome (Type IV) • Loey’s Dietz Syndrome (TGF B) • Iatrogenic (catheters, surgery) • Turnuer’s Syndrome (coarctation) Ascending/thoracic aorta has > 30 elastic lamella, it has vasa vasorum blood supply. ```
73
Dissecting (Thoracic) Aneurysm Presentation
Presentation • Age: 50-70; males > females (2:1); >50% mortality • Pain to back b/c adventitia is stretched (has pain receptors)
74
Dissecting (Thoracic) Aneurysm | Fate of Dissection
• Rupture ---> hemorrhage OR false lumen (↑BP) • Re-entry (best prognosis) • No rupture ---> thrombosis of false lumen (note normal BP) • Collapse of Aorta --hemocardium --> cardiac tamponade with retro-grade flow only
75
Dissecting (Thoracic) Aneurysm Morphology:
• Dissection occurs and blood flows to specific location • 80% have Cystic Medial Necrosis ---No cysts; pools of PG (cystic) displacing smooth muscle and elastic lamellae (necrosis) in media (medial) = Creates points of weakness
76
Vasa vasorum penetrates?
Adventitia and divides ~1/3 way into media; at this junction (inner 2/3 from outer 1/3 of media) is least resistance path for blood being forced through intimal tear
77
Atherosclerotic (Abdominal) Aneurysm =
Weakening of Aortic Wall --> Leakage
78
Atherosclerotic (Abdominal) Aneurysm Etiology:
Atherosclerosis***
79
Atherosclerotic (Abdominal) Aneurysm Mechanism:
``` • Atherosclerosis ---> weakening of wall • ↑Dilation --> ↑Pressure (Laplace) • ↑Pressure --> Endo damage (↑ather) • Cycle continues; eventually endothelial damage ---> ↑Thrombus/Platelets • ↑Thrombus --> damage --> leakage ```
80
Atherosclerotic (Abdominal) Aneurysm Presentation:
• 33% die <10 years • Usually asymptomatic until late ∝ size + diagnosis + rate Leakage/Rupture most common COD
81
Atherosclerotic (Abdominal) Aneurysm | Consequence of Dissection
* Narrow/occlude renal and mesenteric arteries * Pressure = ↑Bone Damage + ↑Viscera Damage + ↑Neuron Damage * Rupture --> hemorrhage
82
Atherosclerotic (Abdominal) Aneurysm Morphology:
TONS of atherosclerosis and thrombi (mura/transmural)
83
Pseudoaneurysms (Thrombus)
Trauma induced bleed --> thrombus --> | dilation --> looks like aneurysm
84
Pseudoaneurysms (Thrombus) Presentation:
Knife, bullet wound, Carson Rider post-Wiz concert
85
Pseudoaneurysms (Thrombus) Morphology:
Hemorrhage --> clot --> dense fibrous tissue
86
Mycotic Aneurysm:
Bacterial Arteritis (Septic Emboli) Vessel wall weakening from infection Misnomer, caused more by bacterial rather than from bacteria
87
Mycotic Aneurysm Presentation:
* Thrombosis +/- infarction | * Rupture
88
Most common cause of Sudden Cardiac Death?
Ventricle Fibrillation (1,000 Americans/day)
89
Ventricle Fibrillation most common in patients with?
MI + Heart Disease
90
Ventricle Fibrillation Treat with?
AICD (Automated Implantable | Cardioverter Defibrillator)
91
Ventricle Fibrillation Iatrogenic undetectable cause?
↑potassium
92
Most common cause of stroke?
Atrial Fibrillation (atrial stasis --> thrombus --> stroke)
93
Atrial Fibrillation Prophylaxis with?
Warfarin
94
Atrial Fibrillation interpret ECG?
• HR = 300 / (#Big boxes between peaks) = # total peaks x 6 • LV Hypertrophy: (V1 Depth of S-Wave) + (V5 Depth of R Wave) ---If >35 mm = LV Hypertrophy • Rhythm: look for normal P wave before each complex (normal~60) • Axis: Determined by Lead I and aVF +Lead 1 and +Lead aVF = normal +Lead 1 and -Lead aVF = Left Axis Deviated (opposite is RAD) -Lead 1 and -Lead aVF = Indeterminate Axis
95
Mechanisms Arrhythmia Types?
1. Enhanced Automaticity | 2. Re-Entry
96
Enhanced Automaticity Two things can change the slow depolarization?
Increasing rate of depolarization OR raising the threshold potential (less negative)
97
What causes ↑ In Phase 4 Slope?
``` ↑SNS Tone / ↓PS Tone ↑CO2 / ↓O2 ↑Stretch ↑Digoxin ↓Potassium ```
98
Re-entry occurs requiring?
Slow conduction + re-excitable | cell
99
Re-entry causes?
Circular movement produces a rapid series of APs with ↑ Frequency ===TACHYCARDIA ===ARRHYTHMIA
100
Most common cause of SCD (Sudden Cardiac Death)?
Ventricular Fibrillation (1,000 Americans/day)
101
Ventricular Fibrillation ECG Features
* Complete erratic rhythm | * No Identifiable waves
102
AICD - Automated Implantable Cardioverter Defibrillator does what?
* Device is given preset HR | * Monitors rate and rhythm of heart and alters via shock delivery
103
Atrial Fibrillation ECG Features:
* Chaotic baseline = Irregularly irregular = not consistently weird * NO DISCRETE P WAVES
104
Atrial Fibrillation Treatment:
* B-Blocker * Ca++ Channel Blocker * Digoxin
105
Atrial Flutter ECG Features:
* Rapid back-back atrial depolarization waves | * SAW TOOTH PATTERN
106
Ventricular Hypertrophy:
``` Ventricular Hypertrophy • ↑Mass of ventricle • ↑Mass --> Delayed Depolarization • Common with CHF • Common with valvular disease • LV Hypertrophy puts patient at ↑Risk for Coronary Heart disease • Equal risk factor for MI as smoking, etc ```
107
Ventricular Hypertrophy ECG Features:
* ↑QRS Complex Peak ---> steep QRS Segment * S in V1 + R in V5 or V6 (whichever is larger) ≥ 35 mm * May see tall P-wave * T-Wave Reversal
108
Bundle Branch Block:
* Conducting tissues is “blocked” * Delayed activation of ventricle * Always abnormal, but not specific
109
Bundle Branch Block ECG Features:
↑ QRS width --> prolonged QRS Segment
110
P waves -->
Look at for atrial / supraventricular origin
111
QRS -->
Widened in ventricular origin; can be narrowed in atrial
112
Tombstone ST =
STEMI
113
Depressed ST =
Ischemia
114
Automaticity Disease:
Sinus tachycardia, sinus arrest, VPB, etc. | *Both mechanisms can cause most arrhythmias; these are common groupings
115
Re-Entry Disease:
VTAC, PSVT, WPW, AFIB | *Both mechanisms can cause most arrhythmias; these are common groupings
116
Pathogenetic Mechanisms of Vasculitis
1. Immune Complex Deposition in Vessel Wall 2. ANCA-Mediated 3. Ab Directed at Vessel Wall (endothelial, GBM) 4. Cell Mediated Immune Reaction (Granuloma) 5. Component of Other Immune Disorders
117
Vasculitis ANCA-Mediated:
- --Pathogenic from activating PMNs (↑adhesion via B2 integrin, Fcgamma) - --Target Endothelia--> ANCA-PR3 + Endothelia --> lost thromboresistance
118
Vasculitis Ab Directed at Vessel Wall (endothelial, GBM):
- --In anti-endothelial, Ab levels == disease activity | - --Ab usually bind to cytoplasmic components, not surface
119
Immune Complex Pathogenicity Criteria
* Circulating immune complex * Hypocomplementemia * IgG (or other) deposition in vessel wall * Complement deposition in vessel wall
120
Vasculitis has to be diagnosed with?
Biopsy
121
Vasculitis Infectious:
From pathogen directly invading wall. | Recognize that infectious can generate an immune-mediated inflammation.
122
Vasculitis Non-infectious
Non-infectious from immune-mediated inflammation.
123
Variability in Non-Infectious Vasculitis
Disease occurs from complexes; presentation is location-dependent
124
Vasculitis =
Vessel Wall Inflammation with necrosis of vessel walls, narrow/occlusion +/- aneurysms
125
Kawasaki’s Disease
Kawasaki’s Disease Vasculitis • Exact etiology is uknown • Most likely delayed hypersensitivity T cell reaction
126
Kawasaki’s Disease Presentation:
* Asian children < 4 years old * “strawberry tongue” * Lymphadenitis, conjunctivitis * High association with developing coronary aneurysms
127
Buerger’s Disease | Thromboangitis Obliterans
* SMOKING, SMOKING, SMOKING | * Treat: smoking cessation!
128
Buerger’s Disease (Thromboangitis Obliterans) Presentation:
* Heavy smokers * Males < 40 * Intermittent claudication --> gangrene + autoamputation of digits * Radial arteries often affected --> Raynaud’s Phenomenon
129
Temporal (Giant-Cell) Arteritis:
``` • Exact etiology unknown • Most likely T-cell mediated response against vessel antigen • Affects arteries neck and up • Most common vasculitis in elderly people (females) ```
130
Temporal (Giant-Cell) Arteritis Presentation:
* Female patients > 50 y/o * Unilateral headache + jaw claudication * Irreversible blindness (opthalmic artery occlusion) * Associated with polymyalgia rheumatica
131
Temporal (Giant-Cell) Arteritis Morphology
* Affects branches of carotid artery | * Focal granulomatous inflammation
132
Temporal (Giant-Cell) Arteritis Labs
↑ ESR
133
Temporal (Giant-Cell) Arteritis Treatment
High Dose Steroids
134
Fats have two functions:
1. P-lipids + cholesterol = structural part of all cell membranes 2. Triglycerides (TG) and FFA = energy sources of body
135
General Flow of Transport Fats:
1. TG in Liver/Gut ----> Muscle (energy) and Fat (storage) 2. Cholesterol across tissue ---> Liver - --All cells make cholesterol; they have excess; rarely deficient
136
Lipoprotein Functions:
1. Carry p-lipids, free cholesterol, cholesterol esters, TG, and apolipoproteins - --Apo’s have structural, cofactor, and receptor roles 2. Allow easy circulation of fat throughout body
137
Lipoprotein Pathophysiology Disease Overview
1. Genetic disease: think mutation in apo, apo-receptor, or enzymes 2. Environmental disease: think overproduction of certain component
138
CM + VLDL =
TG Rich Lipoproteins
139
CM made in?
GI
140
VLDL made in?
Liver
141
CM has?
apoB-48 (no LDL receptor)
142
VLDL has?
apoB-100
143
• TG removed from and via?
CM or VLDL via LPL
144
LPL hydrolyses?
TG --> FFA + Monoglyc.
145
VLDL =
↑TG + ↑Cholesterol
146
Post LPL =
IDL/LDL w/↑Cholesterol
147
ApoE =
Liver, Macrophages, CNS ---Macrophages w/cholesterol secrete apoE with the cholesterol; important b/ c macrophages are involved in athero
148
Hypobetalipoproteinemia =
trunc apoB ↓ApoB Production • Truncated apoB secreted ↓, excreted ↑ by renal tubule
149
Hypobetalipoproteinemia Genetics Heterozygotes:
Heterozygotes: 25-50% of LDL; steatosis
150
Hypobetalipoproteinemia Genetics Homozygotes:
Homozygotes: ↓↓↓LDL and CM - --Fat malabsorption --> ↓Vit A,D,E, K - --Acanthocytosis - --Neuromuscular Degeneration (↓VIt E)
151
Hypobetalipoproteinemia - Physiology
Intestine and liver REQUIRE apoB to export TG • ApoB = hydrophobic; remains in membrane of ER and grabs p-lipids, TG, esters and free cholesterol = forming lipoprotein • Secreted; acquire additional apo-proteins from HDL in blood
152
Hypobetalipoproteinemia Pathophysiology:
• Partial (heterozygotes) or full (homozygote) truncation of apoB --> inability to export TG from gut (48) or liver (100) in CM + VLDL • Expect to see ↓CM and ↓LDL levels (↓Synthesis and ↓Secretion)
153
Abetalipoproteinemia =
Deficient MTP | ↓CM + ↓VLDL production (RECESSIVE)
154
Abetalipoproteinemia Heterozygotes:
No abnormal values.
155
Abetalipoproteinemia Homozygotes:
↓CM + ↓LDL - --Similar sympotoms as hypo-beta - --↓ApoB containing lipoproteins (DDx)
156
Abetalipoproteinemia Physiology:
MTP = Manages Transport & Particle formation • Shuttles TG and cholesterol esters: membranes lipoproteins • Controls lipid particle / droplet formation for apoB to attach
157
Abetalipoproteinemia Pathophysiology
* If apoB does not accumulate lipoprotein components --> degrades * ↓MTP --> ↓Shuttling of TG + ↓Lipoprotein Particle --> apoB degrade
158
Familial Combined Hyperlipidemia (FCHL) =
``` • Some patients have ↑ApoB Production ---B/c one gene cluster causing FCHL also involved in apoB/LDL metabolism • ↑Risk of CVD ---↑## of small dense particles --> ↑atherogenic risk of LDL • Family with varying lipid phenotypes, • Consistent ↑VLDL of NORMAL COMPOSITION ```
159
Familial Combined Hyperlipidemia (FCHL) | Physiology
apoB is key in forming lipoproteins CM and VLDL
160
Familial Combined Hyperlipidemia (FCHL) | Pathophysiology
* ↑ApoB synthesis ---> ↑VLDL synthesis by liver (normal composition) * ↑VLDL ---> ↑LDL
161
Familial Combined Hyperlipidemia (FCHL) | Consequences of ↑LDL
1. ↑VLDL Production + ↓LDL Clearance --> ↑Normal LDL --> ↑Cholesterol (b/c TG is removed via LPL) 2. ↑VLDL Production + ↓Cholesterol Accumulation --> ↑LDL apoB (low TG and low cholesterol) --> HYPERAPOBETA 3. ↑VLDL production + ↑LDL Clearance --> normal/↓LDL apoB and cholesterol
162
Familial Dysbetalipoproteinemia | Type III Hyperlipidemia
``` • ↑Beta-VLDL in plasma = ↑Risk Athero ---Cholesterol rich ---Labs: ↑TG + ↑Cholesterol • Called “Broad-Beta” Disease • E2/E2 genotype ---Normal VLDL, but... ---Post-delipidation, cannot bind to LDL-R ---Accumulates cholesterol via HDL CETP • Analysis will look like ↑VLDL, but these are composed of ↑cholesterol ```
163
Familial Dysbetalipoproteinemia (Type III Hyperlipidemia) Possible Genotypes
``` • E2/E2 = ↓+ charge in ApoE LDL-R binding domain • E2/E2 genotype is 1%, but frequency of this disease ~ 10,000 (rare) ---B/c mutation not inside AA 140-160 • 1-2 E2 alleles = ↓LDL + ↑TG ---Even without Type III HLP • 1-2 E4 alleles = ↑LDL + ↑TG ---↑LDL b/c better IDL--> IDL conversion ```
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Familial Dysbetalipoproteinemia (Type III Hyperlipidemia) Alzheimer’s Risk
* ApoE4 best predictor for Alzheimer’s | * ApoE2 protects against Alzheimer’s
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Familial Dysbetalipoproteinemia (Type III Hyperlipidemia) Physiology:
• AppE clears remnants of TG rich lipoproteins = CM/VLDL remnants • ApoE gets into circulation via HDL or LDL, b/c these come from liver ---CM never has ApoE before plasma b/c ApoE not made in intestine • Reservoir of ApoE is in HDL; new VLDL/CM particles get ApoE when they enter plasma from HDL transfer • Post-lipolysis (TG removal via LPL), the ApoE donation to CM/VLDL allows them to bind to both B-E receptors on liver ---B-E receptors = LDL-R that bind both ApoB (LDL) and ApoE (IDL) ---Remnants are atherogenic; important to remove!
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Familial Dysbetalipoproteinemia (Type III Hyperlipidemia) Pathophysiology
``` • AppE normally binds E-LDL-R via charge interaction (ApoE is ++++) • If + charge is lost --> binding is disrupted ---Note charge mutation has to exist AND it has to be in the LDLReceptor binding region (AA 140-160) • IEF Gel for ApoE Shows ---ApoE-3 = normal charges ---ApoE-2 = ↓+ or ↑- charge ---ApoE-4 = ↑+ or ↓- charge ```
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Why is Beta-VLDL Bad?
Beta-VLDL, like LDL, is taken up by macrophages, but does not need to be oxidized first --> ↑foam cell formation
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Changes in ApoA1 Production Cause:
``` • Mutated ApoA1 --> ↓HDL Levels • Most likely responsible for hypoalphalipoproteinemia (↓HDL) and hyperalphalipoproteinemia (↑HDL) • Most have ↑atherosclerosis Exception • ApoA1 Milano == Rapid RCT • Still have ↓HDL levels ```
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LCAT Deficiency / Fish Eye Disease =
``` ↓HDL Cholesterol • No LCAT = no FC --> CE in pre-HDL • HDL particles don’t acquire spherical shape b/c no hydrophobic ester • +/- Poor RCT; could be fine or terrible ```
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LPL Deficiency Causes
``` ↓ HDL Cholesterol • LPL genetic defect, ↓ApoC2, ↑ApoC3, ↓Insulin (DKA) • LPL delipidizes VLDL and gives extra superficial material to the growing HDL3 particle --> HDL2 • Ability to grow HDL3 w/CE is important for ccn-gradient transfer into liver via SR-B1 ```
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Abnormal ↑Hepatic Lipase Activity Causes:
``` ↑HDL Clearance = ↓HDL Cholesterol • HL can ↑HDL uptake in liver, but does not recycle HDL/ApoA1 ↑HL From: • Hyperinsulinemia • Hyperthyroidism • Hyperandrogenism ↓HL From: • Estradiol • Adiponectin (cytokine in thin people) ```
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Physiology - Reverse Cholesterol Transport (RCT)
0. ApoA1 from liver/GI --> adds to disc-shaped nascent pre-beta HDL 1. Cholesterol Efflux from Cells 2. Free Cholesterol --> Cholesterol Esters (FC-->CE) 3. HDL2 Uptake from Liver 4. Cholesterol Ester Transfer Protein (CETP) CETP levels don’t determine activity; CETP-Inhibitor levels do!
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CETP Deficiency Yields:
↑CETP-I / ↑LTIP === (6-Fold)↑HDL2 Cholesterol
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The real goal of cholesterol should be LDL
LDL<70 in those with other risk factors-not on test…
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Stenosis:
Narrowing of orifice --> valve doesn’t open correctly
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Regurgitation (=insufficiency):
Leakage in opposite direction --> valve doesn’t | close correctly
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Cardiac Adaptation | Concentric Hypertrophy:
Pressure Overload = STENOSIS (+HTN) | ---↑Thickness (thick walls) but normal volume - “LV Hypertrophy”
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Cardiac Adaptation | Eccentric Hypertrophy:
Volume Overload = REGURGITATION | ---↑Dilation of Chamber (more volume + thin walls) ---> ↑Output (Starling’s Law)
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Valvular Heart Disease Acute
In acute scenarios, there is no time to adapt; pt presents severely ill. Murmur heard, but no concentric/eccentric hypertrophy • Thus, expect to see ↑↑ΔP in acute scenarios with ↓structural heart changes.
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Valvular Heart Disease Chronic
↓↓ΔP with ↑structural heart changes in chronic
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Diseased Aortic Valve Rheumatic:
Micro-vegetation (not as much as infective endocarditis) + FUSION of COMMISURES
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Diseased Aortic Valve Calcification/Bicuspid:
Sinus of Valsalva calcification + NO FUSION
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Symptoms of Stenosis
Syncope, Angina, Heart Failure, Arrhythmias
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Types of Stenosis
Supravalvular Stenosis Valvular Stenosis Subvalvular
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Supravalvular Stenosis:
Above the valve; congenital (ex: narrowing of aorta).
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Valvular Stenosis:
At the valve; congenital or acquired.
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Subvalvular:
Below the valve, congenital or acquired ex: IV septum pushing into one ventricle.
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When is stenosis TOO severe?
Valve area depends on two things: 1. Gradient - pressure drop across LV and Aorta in systole (normally 0) 2. Flow Across Stenosed Valve approximated by CO
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Stenosis Evaluation:
ECHO -- view diseased valves, hypertrophy and blood flow.
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Stenosis Pathology Basics:
Valves = AVASCULAR endothelial-lined (endocardium) | ---Core of PG, GP, Collagen (Type 1) Fibers, and Fibroblasts
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Post-Streptococcal Molecular Mimicry?
2-3 weeks post strept infection form Ab: | cross react with cytoskeletal proteins
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What valve is affected?
Mitral > Aortic > Tricuspid > Pulmonary ---Mitral valve experiences the most pressure in the entire heart.
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Possible exam topic? | Fusion of commisures?
Occurs in RF, but not in calcified aortic stenosis.
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Rheumatic Fever Presentation:
• 2-3 Weeks Post-Streptococcal Infection • “Dog that licks the joint, but bites the heart” === TRANSIENT (except long term pericarditis effects)
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Mitral Valve Stenosis | Rheumatic Fever
↑P behind the mitral (stenosed) valve ---Concentric hypertrophy + dilation of the LA ---Pulmonary Hypertension-> Atherosclerosis ---Concentric hypertrophy of RV! ---Thrombi (stasis) from damaged + dilated LA --> Ball/Valve + Emboli
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Mitral Valve Stenosis Rheumatic Fever Presentation:
* SOB (pulmonary HTN --> ↑Pressure in Pulmonary Capillaries --> Capillary Congestion --> ↑fluid in alveolar space) * Alveolar Fluid w/fibrinous material, RBC (+macrophages if chronic) * Hemoptysis (if chronic) * Right Heart Failure * Atrial Fibrillation --> Brain emboli --> Stroke * Dysphagia (atria compresses back on esophagus)
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Mitral Valve Regurgitation Causes:
1. MITRAL VALVE PROLAPSE 2. Left Ventricular Dilation - --Left sided heart failure dilates ring of MV 3. Rheumatic Fever
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Mitral Prolapse Leaflets replaced by?
Myxomatous (spongy) tissue
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Mitral Valve Regurgitation Presentation:
* Can be asymptomatic with murmur * Sudden rise in Atrial pressure * ↑Preload (from atrium) + ↓Afterload (from venting) = ↑↑SV
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Mitral Valve Regurgitation Acute vs. Chronic: EXAM QUESTION • Acute =
No change in RA volume (adaptation), ↑Pulmonary Capillary Wedge Pressure (large pressure build up)
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Murmur For MV Regurgitation
Systolic murmur= pansystolic: S1------S2
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Aortic Valve Stenosis Causes:
1. Age-Related Calcification - --Calcified aortic stenosis from wear/tear - --Calcification in Sinuses of Valsalvas - --”Arthritis of the aortic valve” 2. Bicuspid Aortic Valve - --Congenital Failure of Apoptosis - --Prone to calcification --> stenosis
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Aortic Valve Stenosis Pathophysiology:
In both, ↑P in LV ---> LV Concentric | Hypertrophy --> HTN, Angina, Syncope
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Aortic Valve Stenosis Presentation:
* Pt > 60 = Calcified * Pt ~ 35-40 = Bicuspid Aortic Valve * Delayed/Absent Arterial Pulse * Heart Failure * Angina = O2 demands from ↑work * Syncope = ↓supply (fixed CO) * Arrhythmia * Sudden death
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Aortic Valve Stenosis Murmur:
Systolic diamond shape murmur S1 --<>-- S2
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Mitral Valve Stenosis Murmur
Diastolic murmur: S1------S2 OS⤷S1
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Aortic Valve Regurgitation Disease of?
Aorta/Aortic Cusps
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Disease of Aorta/Aortic Cusps Pathophysiology:
* ↑LV Volume == ↑Preload + ↑Eccentric Hypertrophy (dilation) == ↑SV (Starling) * ↑SV + aortic venting = ↑pulse pressure
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Infective Endocarditis Two Requirements:
1. BUGS in BLOOD - --Any pathogen (virus, bacteria, fungi) 2. Abnormal Heart Valve
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Infective Endocarditis Pathology:
• ↑Velocity blood across abnormal valve • Platelets adhere --> thrombus formation • Bacteria bind to injured endothelium (direct contact / fibronectin mediated)
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Infective Endocarditis Consequences
``` • Valve vegetation, regurge, destruction • Metastatic infection (Osteomyelitis) • Immune Reaction (Arthritis, nephritis) • Local spread (myocarditis, pericarditis) • Septic Embolus (Mycotic Aneurysm) ---Coronary vessels (MI), kidney, hand ```
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Bacteremia =
Living bacteria in blood.
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Septicemia =
↑invasion + replication in blood stream.
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Infective Endocarditis Source of Infection
- --IVDU (polymicrobial); Prosthetic Valves (PVE) - --Dental procedures involving gingiva/gums - --Catheters/iatrogenic.
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Infective Endocarditis Treatment:
* Recall --> VALVES = AVASCULAR * Fibrin verruca forms colonies of bacteria; because avascular valves high dose of abx needed to kill bacteria via passive diffusion.
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Infective Endocarditis Microbiology:
``` Gram + is most common EXAM* • Acute IE = Staph Aureus • Subactue = Strep Viridans • Non-enterococcal Group D (S.Bovis -- look for GI disease) Gram - in Key Patient Profiles • Pseudomonas Aeruginosa in IVDU and PVE Fungal • Also in IVDU and immuno-deficient Culture Negative? • Prior ABX most common cause ```
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Infective Endocarditis Presentation:
* IV Drug abusers (polymicrobial) * Immune compromised (Fungal) * Age: 30 (pre-antibiotic, more women); 50% >50 (last decade, men) * Subacute = nonspecific symptoms; ACute = ill + stroke/arthritis * Splinter Hemorr -- embolization ≠ 100% diagnostic septic emboli * Roth Spots (eye) * Janeway Lesions (septic emboli in palms of hands) * Osler Nodes (immune complexes in fat pads)
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Infective Endocarditis Morphology:
* Note large friable vurruca (vegetation) on mitral valve * Valves often erode and perforate * Fungal vegetations larger than bacterial, though less common * Tricuspid valve commonly infected in Drug users.
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Infective Endocarditis Tests:
* CULTURE, CULTURE, CULUTRE | * TEE - closer to the heart
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Non-Infective Endocarditis (NBTE) | “Marantic"
``` Non-Infective Thrombotic Endocarditis • Aseptic vegetations = thrombotic deposits on endocardium • Often in Libman-Sacks Disease (SLE), DIC, Paraneoplastic ```
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Non-Infective Endocarditis (NBTE) “Marantic" Morphology:
• Like infective, there are vegetations on valves, CT, and mural endocardium; unlike infective, there are vegetations on papillaries (no septal defects here) • NO INFLAMMATION = STERILE
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Pericardial Disease is?
• Disease of fluid accum., inflammation, fibrous constriction of pericardium • Disease of DIASTOLE ---Prevents heart from relaxing (expanding)
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Pericardial Disease Characteristic Findings:
1. Gets better when they lean forward | 2. Friction rub from serous/parietal layers rubbing together.
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Pericardial Response to Injury Acute:
Congestion, Transudate, Exudate (fibrin, inflammation).
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Pericardial Response to Injury Chronic:
Exudate --> Fibrosis (adhesions + calcifications)
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Pericarditis + Pericardial Effusion?
Go hand in hand.
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Pericardial effusion:
Abnormal accum of serosal fluid in pericardial sac---If chronic accumulation (even though large) --> sac dilates --> asymptomatic but w/↑Halo on Chest Xray
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Cardiac Tamponade:
``` MEDICAL EMERGENCY (rapid accumulation) --> pulsus paradoxus ---Volume is less important than RATE (heart can accumulate 600 ml/mo without tamponade, but not 300 ml/min) ```
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Pulsus Paradoxus
• Loss of heart beat on inspiration • Inspiration --> ↓Intrathoracic Pressure --> ↑Blood to RA (but cannot expand b/c of pericardial disease/effusion) --> ↑Volume distorts IV septum into LV --> ↓Preload (↓LVEDV) --> ↓SV --> HYPOTENSION • Starling Curve (Pressure/Volume) --> Results in ↑ΔP for small ΔLVEDV, but overall ↓Pressure
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Pericarditis Etiology (more often secondary than primary):
• Infectious: viral (primary), bacterial (lung infection), fungal, protozoal • Immune Mediated: secondary to systemic inflammatory disease (SLE, RF, Scleroderma, PAN, RA) ---Often see polyserositis (serosa attacked) • Other: MI (Dresslers), Renal Failure (Uremia - metabolites from urine damage pericardium), Trauma, Pancreatitis
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Pericarditis Key to DDx:
``` Pericardial Fluid • Heart/Kidney Failure = Serous (clear/ straw colored) • Viral Infection = Sero-sanguinous • Bacterial Infection = Purulent + Serosanguinous • Mycoardial Rupture = Sanguinous • Trauma = sero-sanguinous • Drugs = serous ```
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Pericarditis: Acute Pericarditis:
• Serous: mild inflammation + exudate • Fibrinous: inflammation + fibrin strands in pericardial fluid ---”Shaggy” or “Bread and Butter” = PMN, Fibrin, RBC ---MOST COMMON • Purulent: INFLAMMATION + PMNs ---Bacterial --> extension of nearby lung infection ---Often organizes --> granulation tissue w/capillaries and myofibro’s ---Gran tissue can lead to pericardial layer adhesion that may develop into constrictive endocarditis ---Exudate --> Fibrosis = adhesions, restrictions • Caseous: TB • Hemorrhage: inflammatory exudate with RBC
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Pericarditis: Chronic Pericarditis:
* Adhesions: chronic infections, repeated acute pericarditis (fibrosis) * Constriction: fibrosis + calcification fuse the pericardial layers.
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Pericarditis Labs/Tests:
* Silhouette/halo on CX-Ray | * Friction rub (fibrinous pericarditis especially)
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Pericardial Effusion | Acute and Chronic Fluid Accumulation
• Acute vs. Chronic: recall that rate of ↑volume > amount of volume • Mesothelial cells don’t offer passage to fluid --> effusion during pericardial injury
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Acute Pericardial Effusions
Ruptured MI, trauma, etc.
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Chronic Pericardial Effusions
1. Heart Failure, Myocarditis, RF 2. Collagen Vascular Diseases 3. Chronic Infections 4. Chronic Renal Disease 5. Neoplasms - --Breast and lung seen the most (common) - --Melanoma and lymphoma (preference) 6. Radiotherapy
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Pericardial Effusions Presentation:
* If chronic, can be asymptomatic | * If acute (hemopericardium) --> pulses paradoxus --> EMERGENCY
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Pericardial Effusions Types:
1. Hydropericardium (Transudate) 2. Hemopericardium (Blood) 3. Chylopericardium (Lymph)
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Chylopericardium (Lymph)
= Rare | ---Lymph from thoracic duct
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Hydropericardium (Transudate):
- --Associated with anasarca | - --NO INFLAMMATION
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Hemopericardium (Blood):
---Blood accumulates over wks/months --> ↑intrapericardial P --> ↓SV and ↓CO ---Ruptured MI (Req. transmural, ↑ventricular Pressure) ---Ruptured dissecting hematoma ---Aortic dissection ---Trauma ---Iatrogenic
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Pericardial Effusions Labs/Tests
Silhouette/halo on CX-Ray