Cardio Flashcards
the three types of injectable selenium supplement in order of greatest selenium content
Mu-Se (5 mg/mL) -
labeled for weanling calves and mid-gestation beef cows
E-Se (2.5 mg/mL) - labeled for horses
Bo-Se (1 mg/mL) - labeled for calves, lambs, ewes, sows, piglets
differentials/mechanisms for ascites
heart failure (septal defect, valve failure, endocarditis, pericarditis, traumatic reticulo-pericarditis) with backup into Caudal vena cava -> leakage into abdomen. Liver dysfunction -> low oncotic pressure. May not be true ascites - hydrops,
differentials for muffled heart sounds
Pneumonia, plueropneumonia. pericardial effusion. pleural effusion. diaphragmatic hernia. abscess, mass, or air in mediastinum. pneumothorax. emphysema. fat.
typical signs/manifestations of CV disease
Edema, pleural effusion, ascites. Arrhythmias. Murmurs. Muffled heart sounds. exercise intolerance, weakness. syncope (fainting) Venous distension +/- pulsation. Painful peripheral swelling. Lymphadenomegaly.
Mechanisms of edema, and which are the most common in ruminants?
increased vascular permeability.
increased hydrostatic pressure in the vasculature
decreased oncotic pressure in vasculature
edema of lymph drainage.
increased oncotic pressure (doesn’t cause problems often)
signs that edema may be due to increased vascular permeability
Evidence of systemic inflammation/infection -
PE: pale MM, injected MM/sclera, petechiation, fever, tachycardia, tachypnea or dyspnea,
signs that edema may be due to increased hydrostatic pressure
venous distension/pulsation, tachycardia (if decreased cardiac output), murmur, arrhythmia, ascites, distal limb edema, …
DfDx: CHF, Tricuspid (RAV) valve insufficiency, Venous thrombosis, liver dz, portal v. obstruction…
edema due to decreased oncotic pressure occurs when:
Total Protein is below ___ and albumin is below ___
TP <5g/dL
albumin < 1.5 g/dL
three ways to get hypoproteinemia/hypoalbuminemia?
Don’t make it: starvation/inadequate protein in diet, liver dz
Lose it:
protein losing enteropathy, PL nephropathy, 3rd space loss (e.g. burns, uncommonly seen)
YOU screwed up (iatrogenic):
hemodilution
differentials for causes of lymphedema
tumor obstructing a lymph vessel or node.
trauma - damage to lymph vessels?
increased central venous pressure.
benign arrhythmias (sinus arrhythmia, sinus bradycardia) are typically due to ___
decreased feed intake/anorexia –> hypocalcemia!
pathologic arrhythmias most commonly seen in ruminants?
Atrial fibrillation, premature depolarization
pathologic arrhythmias are typically secondary to ___
GIT disease –> electrolyte disturbance, acid-base imbalance
the best way to treat pathologic arrhythmias in ruminants?
correct the electorlyte/acid base abnormality, usually the arrhythmia will resolve.
AV blocks occur when there is a delay between ___ & ___.
p wave & QRS complex
what are the types of AV block?
1st degree: increased time between P wave and QRS (prolonged P-R interval)
2nd degree: prolonged P-R interval with occasional dropped beats (2 normal for every 1 dropped?)
3rd degree: prolonged P-R interval with fewer than 2 beats for every dropped beat.
atrial standstill ECG findings?
NO P waves!
atrial standstill most commonly seen in what signalment and disorder?
calves with metabolic acidosis.
describe what happens to potassium during metabolic acidosis
the H+ gradient between intracellular and extracellular compartments gets messed up, causes K+ to move out of the cells –> hyperkalemia
describe the pathophysiology of atrial standstill
hyperkalemia -> myocardium membrane depolarization -> Opens Na+ channels, they become inactivated -> hyperkalemia causes repeated depolarization, but the Na+ channels have not been able to reset themselves (membrane repolarizaiton not taking place) -> cells are refractory to the depolarization signal -> atrial standstill –> can quickly progress to V-fib , asystole, and death
treatment for hyperkalemia/atrial standstill?
you need to do something FAST - Ca2+ IV is the best way to quickly treat these animals –> causes the membrane depolarization threshold to shift so that the electical conductivity of the heart can go back to normal. THEN you need to fix the hyperkalemia - bicarbonate will re-establish the acid balance, drive K+ back into cells. Insulin will also work.
causes of arrhythmias in ruminants
electrolyte abnormalities. pericarditis. valvular disease. myocardial disease. toxemia. Cor Pulmonale. Lymphosarcoma. Fever.
Reynolds’ number is calculated by the ratio of ___ to ___
velocity: viscosity
turbulence of blood flow occurs when Reynolds’ number is greater than
2000
animals are predisposed to murmurs if there is an (increase or decrease?) in velocity or (increase or decrease?) in viscosity of blood?
increased velocity
decreased viscosity
typically, murmurs can be heard after PCV falls below ___
25% (but not all animals with PCV<25 have a murmur)
PMI for murmurs: Pulmonic valve Aortic valve Mitral (LAV) valve Tricuspid (RAV) valve
PV: left, basilar, 3-4th ICS
AoV: left, basilar, 4-5th ICS, radiates up aorta
MV: left, apical, 5-6th ICS (near elbow)
TV: right, apical, 3-4th ICS (between shoulder & elbow)
systolic ejection murmur occurs between which heart sounds? describe the sound.
S1 & S2
increases in volume and then decreases <>
Holosystolic regurgitation murmur occurs between which heart sounds? describe the sound
S1 & S2
flat sound, same volume throughout systole.
diastolic decrescendo murmur occurs during which heart sounds? describe the sound
S4 & S1, S2 & S3
starts loud and then volume decreases
causes of ejection murmurs
innocent murmur (no clinical signs or lesion associated)
anemia, fever
Aortic or Pulmonic valve stenosis
Atrial or Ventricular Septal Defect, Tetrology of Fallot
causes of regurgitant murmurs
Mitral or Tricuspid valve insufficiency (regurg)
VSD, tetrology of Fallot
normal jugular pulse/distension may be seen in what portion of the neck / how far away from the base of the heart (with animal’s head up)
caudal 1/3 of neck / about a hands-breadth from the base of the heart.
mechanism of jugular distension/pulsation
decreased right ventricular filling (there is an increase in resistance to filling)
typical causes of jugular distension/pulsation
RH failure
constrictive pericarditis
cardiomyopathy
If prominent pulsations:
Tricuspid regurg
Arrhythmia assoc. w/ atrial contraction against a closed AV valve
most common reported congenital disease
Ventricular septal defect
describe VSD murmur
Bilateral, harsh, plateau, pansystolic.
PMI: Right apex (tricuspid area) initially, because L to R shunt > left base (pulmonic area) later
palpable thrill
what is Eisenmenger’s complex?
L -> R shunt is converted to a R-> L shunt d/t increased pressure in pulmonary artery and results in reversal of blood flow, severe hypoxia, pulmonary hypertension.
https://emedicine.medscape.com/article/154555-overview
describe the ductus arteriosis in a normal calf
Ductus arteriosis should close prior to birth in calves (foals - closes within 96 hr of birth). DA is closed d/t decreased pulmonary vascular resistance and increased systemic vascular resistance.
describe the murmur associated with PDA
continuous, high pitched, “machinery”
PMI: lounder on left, audible on both sides, 3-4th ICS
May be no murmur if large hole.
what are the defects involved with tetrology of fallot?
Overriding aorta,
VSD,
RV hypertrophy,
obstruction of pulmonary artery flow.
describe murmur of tetrology of fallot
loud pansystolic murmur with thrill, Left 3-4th ICS.
common presentation of Tetrology of Fallot?
Cyanotic calf/lamb/kid
major rule-outs for tetrology of fallot?
respiratory distress (TF has murmur) CNS distress (TF has no neuro issues)
pathologic effects of tetrology of fallot?
VSD: ventricular shunting of blood (L –> R),
partial stenosis of pulmonary artery and pulmonic valve,
increased outflow from aorta,
RV hypertrophy
atrial septal defect is commonly associated with which other congenital defect?
PDA
describe the murmur associated with ASD
holosystolic ejection murmur, L heart base
ASD shunt is typically which direction?
L–> R
T/F? ASD murmur is always pathologic
False. may be innocent, calves are frequently asymptomatic
other congenital heart defects seen in ruminants?
Pulmonic stenosis Tricuspid atresia Mitral chordae rupture Ventricular hypoplasia Truncus or pseudotruncus arteriosus Aortic anomalies Ectopia chordis cervicallis (heart outside of the thoracic inlet, in neck)
Etiologies of Acquired Valvular diseases are typically __? (4)
degeneration, infection/inflammation, trauma, or unknown
describe the murmur associated with acquired valvular diseases
systolic, regurgitant, left apex (5-6th ICS) if mitral, right apex (3-4th ICS) if tricuspid
Valvular disease may occur secondary to chronic active infections such as ____ (at least 3 you should think of)
footrot
abscesses
rumenitis
other septic processes
Common bacteria that cause valvular disease
Trueparella pyogenes, Strep. spp.
Neoplastic process that may (rarely) cause valvular disease
lymphosarcoma (HULA - heart, uterus, lymph nodes, abomasal wall)
how can you determine if a murmur is occurring between S1 & S2 (lub-sh-dup), or S2 & S1 (lub-dup-sh-lub-dup)?
palpate the carpal pulse while asculting –> if weak pulses then it is systolic murmur (i think?)
prognosis for valvular disease
depends on etiology, onset, duration, severity; generally guarded to poor
treatment for bacterial endocarditis
long term cidal abx (culture & sensitivity), aspirin, low-dose heparin, furosemide, digoxin
what is cor pulmonale
aka brisket disease, pulmonary hypertension, high mountain disease.
Def: Heart disease secondary to lung dysfunction
pathophys of cor pulmonale
Lung Dysfunction 2’ to [Low O2 tension/high altitude, BRD, lungworm, other infection, or toxins (locoweed)] –>
hypoxia –>
vasoconstriction of pulonary arterioles –>
Pulmonary hypertension –>
RV hypertrophy –>
RV dilation –> RV failure
signs of cor pulmonale
brisket edema jug distension/pulse dyspnea, tachypnea tachycardia split S2 sound (Ao and Pul valves closing at different times) Tricuspid or Pul valve insufficiency
rule outs for cor pulmonale
endocarditis CHF cardiomyopathy cardiac neoplasia (LSA) pericarditis pleuritis pleural effusion etc
in addition to cor pulmonale, what other heart pathology may occur with locoweed poisoning?
myocardial damage
treatment for cor pulmonale
move to lower elevation
treat whatever primary lung disease is occurring, if any
diuretics, digoxin.
Px guarded if showing signs of RH fail.
prevention of cor pulmonale
genetic selection: bulls with good Pulmonary Arterial Pressures at >5000 ft
remove susceptible cattle from herd (if altitude related)
prevent locoweed ingestion
vaccinate for BRD complex, prevent pulmonary dz
myocarditis typically caused by ___?
infectious agents:
bacteria (S. aureus, C. chauvoei, Mycobacterium spp.)
viruses (FMD)
parasites (strongyles, toxoplasma, sarcocysts, Borrelia [Lyme])
what’s the difference between myocarditis and cardiomyopathy?
Myocarditis = inflammation of mycardium (typically caused by infectious agents) Cardiomyopathy = subacute/chronic dz of ventricular myocardium, WITHOUT dz of valves, vessels, or lungs.
Causes of cardiomyopathy
inherited (red holsteins, polled Herefords)
toxins (monensin, lasalocid, gossypol, Phalaris grass.
** Most common etiology: Mineral imbalances (Cu, Se deficiency; Mo, sulfates high)
lymphosarcoma
treatment of cardiomyopathy, myocarditis
treat underlying dz
supportive care
may be too late/guarded Px
definition of pericarditis
inflammation or pericardium resultiing in accumulation of fluid/exudate between visceral and parietal pericardium
etiologies of pericarditis
trauma (most common) TRP
hematogenous
extension from lungs or pleura
neoplasia
Hallmark signs of pericarditis
Muffled heart sounds
Pericardial friction rub “washing machine murmur”
Signs of RH fail
treatment for pericarditis
usually salvage, poor Px: drainage (pericardectomy), 5th rib resection
prevention of pericarditis
magnets
management: don’t leave scrap lying around to be eaten, etc.
Afib in cattle typically caused by
acid-base & electolyte disturbances secondary to GIT dz
- hypocalcemia, hypokalemia, hypochloremia, metaboic alkalosis
describe the sound of afib on ascultation
irregularly irregular rhythm
ECG findings indicative of afib
irregular RR interval, no P waves, f wave, irregular QT intervals
treatment for afib
**treat underlying cause - GIT dz, correct the electrolyte and acid-base abnormalities
can do quinidine conversion, in cattle
can do elecro conversion in small ruminants
