Path 1 - Cardio 1

drraythe's version from 2016-03-03 18:23

HEART: Intro + Post Mortem Changes

Question Answer
**What should the ratio of thickness of the walls be in the heart? What can this thickness be contributed to?Should be 3:1 ratio (LV wall:RV wall) (thickness is proportional to the pressure of that chamber)
From in to out: trabeculae → endocardium → myocardium → fatty connective tissue & coronary artery & vein → serous pericardium (visceral layer, epicardium) → pericardial space → serous pericardium (parietal layer) → fibrous pericardium
Long-term compensation to ↑ work load → This is through hyper_ (plasia or trophy?)TROPHY (cells get bigger, no new cells created! The heart will never get bigger by making new cells, a broken heart can never heal)
**Normal heart has a 3-5 fold reserve capacity, by ↑ heart rate & stroke volume. LONG TERM compensation to ↑ work load can lead to...Myocardial hypertrophy
**If there is a sig. change in weight or shape of the heart, what pathological mechanisms should you suspect?Dilation & hypertrophy
Pathophysiologic Mechanisms of Cardiovascular Dysfxn → PUMP FAILURE can be characterized by what 2 situations?(1) Weak contractility & emptying of chambers
(2) Impaired filling of chambers
Pathophysiologic Mechanisms of Cardiovascular Dysfxn → Obstruction to forward blood flow can happen from what 4 problems?(1) Valvular stenosis (narrowing of the valves)
(2) Vascular narrowing (narrowing of the vessels)
(3) Systemic dz
(4) Pulmonary hypERtension
**Pathophysiologic Mechanisms of Cardiovascular Dysfxn → Regurgitant blood flow happens when?Volume overload of chamber behind failing valve
Pathophysiologic Mechanisms of Cardiovascular Dysfxn → Shunted blood flows from congenital defects...What are 2 examples of defects which can cause this?(1) Septal defects in heart
(2) Shunts btwn blood vessels
Pathophysiologic Mechanisms of Cardiovascular Dysfxn → Rupture of the heart or a major vessel can lead to what 2 problems?(1) Cardiac tamponade
(2) Massive internal hemorrhage
Pathophysiologic Mechanisms of Cardiovascular Dysfxn → Cardiac conduction disorders (arrhythmias) are a failure of What?Failure of synchronized cardiac contraction
Congestive heart failure (CHF) develops slowly from gradual loss of cardiac pumping efficiency associated w/ what 2 things?(1) Pressure or volume overload
(2) Myocardial damage
Where does blood accumulate in congestive heart failure?BEHIND the failing chamber
*Left CHF results in congestion where?Lungs: pulmonary congestion & edema
**Right CHF results in congestion where?Hepatic congestion (Rt side backs up into tissues)
What are the 3 most common czs for LEFT congestive heart failure?(1) Loss of myocardial contractility (myocarditis, myocardial necrosis, cardiomyopathy)
(2) Dysfxn of the mitral or aortic valves
(3) Several congenital heart dzs
Dysfxn of the mitral or aortic valve will lead to which sided CHF?LEFT (& it will back up into the lungs czing pulmonary edema)
**Nutmeg liver is a result of?Rt sided CHF (backs up into tissues)
Which czs MORE severe Na & H2O retention - Lt or Rt sided congestive heart failure?Rt sided
Clinical sign of Rt sided CHF in HORSES/RUMINANTS?Ventral subcutaneous edema
Clinical sign of Rt sided CHF in DOGS?Ascites
Clinical sign of Rt sided CHF in CATS?Hydrothorax
What are 3 common causes of Rt CHF?(1) Pulmonary hypERtension
(2) Cardiomyopathy
(3) Dz of the Tricuspid & Pulmonary valves
Dz of the tricuspid & pulmonary valves will lead to which sided congestive heart failure?RIGHT
How long does it take for rigor mortis to occur? Why does it happen?Fast - about 15-30 min bc of lack of ATP to maintain relaxation of myofibrils, leading to rigid ventricular walls while contracted disallowing the filling of the ventricle w/ blood before clotting sets in
**If there is clotted blood in the left ventricle when you do a post-mortem, what do you know?You know that myocardial dz was present BEFORE death, bc usually rigor mortis czs the LV to become rigid while contracted, not allowing the ventricle to fill before clotting of blood begins
Where will you see blood clots in the heart post mortem & what will it look like?Looks like a "red currant jelly" mass in the atria, RV & large vessels (NOT IN THE Lft VENTRICLE, UNLESS THERE WAS MYOCARDIAL DZ)
If there is a clot in the heart that looks like chicken fat, what does it indicate?Indicates anemia or prolonged agonal period (yellow bc mostly clotted serum/plasma)
If you see Red staining of endocardium & epicardium, what is this? What should it not be confused w/?This is blood imbibition, don't confuse it w/ hemorrhage

Congenital Anomalies (by species)

Question Answer
What are the 3 classifications of congenital anomalies?(1) Anomalies from failure of closure of fetal cardiovascular shunts
(2) Anomalies from failure of normal valvular development
(3) Anomalies from malpositioning of great vessels
What are the 4 anomalies from failure of closure of fetal CV shunts?(1) Patent Ductus Arteriosus (PDA) – dogs
(2) Atrial Septal Defect (ASD)
(3) Ventricular Septal Defect (VSD)
(4) Tetralogy of Fallot (conotruncal septal defects in Keeshonds)
Which failure of closure of fetal CV shunts happens in DOGS specifically?Patent Ductus Arteriosus (PDA)
Which failure of closure of fetal CV shunts happens in KEESHOND DOGS specifically?Tetralogy of Fallot
What are the 4 anomalies from failure of normal valvular development?(1) Pulmonic stenosis - dogs
(2) Subaortic stenosis - pigs, dogs
(3) Valvular hematomas (hematocysts) - young ruminants
(4) Others (endocardial cushion defects in pigs & cats, mitral malformation in cats, tricuspid dysplasia in cats)
Pulmonic stenosis happens in who?Dogs
Subaortic stenosis happens in who?Pigs & dogs
Valvular hematomas happens in who?Young rumis
Endocardial Cushion Defects happens in who?Pigs & cats
What the heck is a Endocardial Cushion Defect?Aka: Atrio-Ventricular Septal Defects (AVSD). The walls separating all 4 chambers of the heart are poorly formed or absent. It is a congenital heart dz
Tricuspid dysplasia happens in who?Cats
Mitral malformation happens in who?Cats
What are the 2 anomalies from malpositioning of great vessels?(1) Persistent Rt Aortic Arch (PRAA) - dogs
(2) Transposition of the aorta & pulmonary artery
Who does Persistent Rt Aortic Arch (PRAA) occur in?Dogs
What are 3 cardiac abnormalities which don't fit into any of the 3 classifications of congenital anomalies?(1) Ectopiacordis
(2) Endocardial fibroelastosism
(3) Heterotopic epithelial rests
What are the 3 possible sequelae to a congenital anomaly of the heart?(1) Neonatal death
(2) Gradual cardiac decompensation (stunted, cyanosis, poor exercise tolerance, murmurs) → CHF
(3) No clinical dz
What should you know about a Patent Ductus Arteriosus in calves?Have delayed morphologic closure but have fxnal closure
What is happening in a Patent Ductus Arteriosus?Duct btwn the pulmonary artery & the aorta fails to close. So deoxygenated blood is getting shunted into the aorta to go to the body
Where do Ventricular Septal Defects (VSDs) usually occur? Who does it usually occur in?(Hole in the wall (septum) btwn the R & L side of the heat). They are usually subaortic in location & are most common in dogs
What are Atrial Septal Defects (ASD) czd by? Who do they occur in most often?Failure of the foramen ovale to close. Common in dogs
What are the 4 lesions of the Tetralogy of Fallot? Who is this inherited in?(1) Ventricular Septal Defects (VSD)
(2) Pulmonic stenosis
(3) Dextroposed aorta
(4) 2⁰ RV hypertrophy
((inherited in Keeshonds)
What are the 3 types of pulmonic stenosis & what is a resulting pathology?May be supravalvular, valvular, or subvalvular. Pulmonic stenosis leads to 2⁰ compensatory RV hypertrophy
Aortic stenosis (AS) occurs in who? What is a result of this stenosis?Dogs, there will be 2⁰ compensatory LV hypertrophy
What is the most common cardiac anomaly in cats?Malformation of the Mitral valve
Malformation of the mitral valve happens in who & what does it look like?CATS (most common cardiac anomaly in cats), it is characterized by short, thick leaflets & chordae tendinae & an enlarged orifice
Persistent Rt Aortic Arch (PRAA) → happens in who? Explain what is happening to cz this problem & what might happen bc of this?Common in dogs, the ligamentum arteriosum forms a vascular ring over the esophagus → may produce obstruction & megaesophagus
What is Ectopia cordis & where is it usually?A congenital malformation in which the heart is abnormally located either partially or totally outside of the thorax. Can be in the NECK
Valvular hematomas (hematocysts) occur in who & what is happening? Sequale?Common in young ruminants. They will undergo spontaneous regression (w/in a few months of birth) & have no fxnal significance
5 most common CV anomalies in the dog?(1) Patent Ductus Arteriosus (PDA)
(2) Persistent Rt Aortic Arch (PRAA)
(3) Subaorticstenosis
(4) Pulmonic stenosis
(5) Ventricular Septal Defect (VSD)
5 most common CV anomalies in the cat?(1) Endocardial Cushion Defects (aka AV Septal Defects - AVSD)
(2) Mitral valve malformation (MOST COMMON)
(3) Ventricular Septal Defect (VSD)
(4) Endocardial fibroelastosis
(5) Patent Ductus Arteriosus (PDA)
3 most common CV anomalies in the horse?(1) Ventricular Septal Defect (VSD)
(2) Patent Ductus Arteriosus (PDA)
(3) Persistent Truncus Arteriosus(PTA)
(I went to my horse's PTA meeting but I kept getting VSDs on my PDA & disrupting the heart of the issue)
4 most common CV anomalies in the cow?(1) Valvular hematomas
(2) Atrial Septal Defect (ASD)
(3) Ventricular Septal Defect (VSD)
(4) Transposition of aorta & pulmonary artery
What is happening in the transposition of aorta & pulmonary artery?The aorta is coming from the RV & the pulmonary artery is coming from the LV
2 most common CV anomalies in the pig?(1) Subaortic stenosis
(2) Endocardial Cushion Defects (AVSD)

Abnormal Pericardial Cavity Content

Question Answer
What is blood in the pericardium called?Hemopericardium
4 big czs of hemopericardium?(1) Iatrogenic puncture
(2) FB (nail, wire, bullet)
(3) Ruptured vessel (aorta in horse) or chamber (post-infarction aneurysm, spontaneous atrial rupture in dogs)
(4) Rupture of neoplasm (hemangiosarcoma, heart base tumor)
What are the lesions associated w/ hemopericardium? The sequale?There is blood in the pericardial sac which czs compression of the heart → CARDIAC TAMPONADE. The sequale is CARDIAC FAILURE (cardiogenic shock) from compression of atria & an inability to fill the chambers
What is it called when there is edemous fluid in the pericardium?Hydropericardium
What are 3 possible czs of hydropericardium?(1) Serous Pericarditis (Uremia, NaCl poisoning in chickens) (These ↑ permeability of vessels)
(2) Right heart failure (backs up into coronary aa which then push fluid into pericardium)
(3) Obstruction at base of heart
Explain the pathogenesis of hydropericardium (remind me of basic causes)(Serous pericarditis, heart base obstruction, RHF) These problems cause ↑ vascular permeability, ↑ hydraulic pressure & Hypervolemia of congestive failure
What are the lesions & sequelae to Hydropericardium?LESION: Clear to yellow watery fluid distending pericardial sac
SEQUELAE: Death from 1⁰ dz, OR recovery accompanied by removal of fluid
Hemorrhagic Pericardial Effusions - who does this happen in? What two things might cause this?Usually happens in large breed dogs, 2 possible czs are IATROGENIC or 2⁰ TO HEMANGIOSARCOMA (sac is also quite thickened)
What's the difference btwn a Hemopericardium & Hemorrhagic Pericardial Effusions?In a Hemorrhagic Pericardial Effusion, the blood wont clot bc it is mixed w/ other fluids as well
In a Hemopericardium, the blood will clot
When/in whom would you see urates in the pericardium?Gout in reptiles & birds
Abnormal pigmentation → If you see melanosis (hyperpigmentation associated w/ ↑ melanin) what are you thinking?Melanosis is actually normal in aortic intima (innermost tunic of aa/vv) of dark-skinned animals
If you see dark pigmentation in the inner layer of the aorta of a dark skinned animal, what is this?Melanosis
Brown atrophy is aka? When do you see this & how does it look histologically?Aka Lipofuscinosis. This may be present in cachectic animals, or inherited in Ayrshire cattle. Histologically, you will see yellowish-brown granules adjacent to nuclei in cardiac muscle cells

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