acquired valvular disease in LA Flashcards
what does a diastolic murmur usually mean and characteristics
- aortic regurgitation
- grade 1-6/6, decresdcendo, often musical
- > 10 yrs, usually older
- bounding peripheral pulse (not grade)
when does AR need further evaluation (echo)
- when aterial pulses bounding
- when horse is young
- when horse has other signs of heart dx (excersize intolerance, HR, RR effort, ventricular arrhythmias, mitral regurgitation murmur, VSD murmur, atrial fibrilation)
- when horse has unknown fever
- prepurchase exam
- athlete
what does AR need if its moderate or severe
excercising ECG
what is arrhythmogenesis in AR & exercise
- ventricular enlargemenet & remodeling
- decreased coronary perfusion
- shortened diastole cause by high HR
- increased oxygen demand
- increased sympathetic tone caused by the exercise
what is the clinical relevance of AR
- clinically irrelevant
- excercise intolerance
- safety concerns
- heart failure
- endocarditis
- echo
- exercise ECG
what is pulmonic valve dx
- often clinically insignificant
- except: endocarditis and severe pulmonic stenosis
what is mitral regurgitation
- a loud L sided systolic murmur is MR until proven otherwise
- grade 1-6/6 - no correlation with severity
- often incidental but also most common cause of CHF
what are the signs of MR
- exercise intolerance
- increase HR
- increase RR and effort
- cough
- edema
- arrhythmias (AF)
what is the predisposing factor to AF in MR and equine CHF
atrial enlargement
development of AF can tilt into CHF in severe MR due to:
loss of atrial contraction
when does AF in MR and quine CHF occur
increased rate = needs rate contool
why is cardioversion contraindicated
due to tx complications while in CHF & almost certain recurrence
ruptured chord is a marker of ____
severity
when do horses with a L sided murmur need an echo
all cases unless physiologic murmur or retired horse in which owner understands all monitoring
what is tricuspid regurgitation (TR)
- most common cause of R sided systolic murmur
- frequent in standardbred
- grade and severity correlated
- rarely causes performance problems or heart failure
what are exceptions to TR
- very severe TR or atrial enlargement that predisposes to atrial fibrillation
- endocarditis
- secondary to MR and PH
what are the most common causes of jugular pulses in horses
ventricular tachycardia and TR
TR needs further evaluation (echo) if…
- 4-6/6 holo or pansystolic
- other signs of heart dx (exercise intolerance, HR, atrial fibrilation, jugular pulses)
- FUO or thrombophlebitis
- secondary to MR and PH
what is the clinical relevance of TR
- clinically irrelevant most of the time
- rarely causes performance problems, safety concerns or HF
- echo
what is severe TR in horses with CHF
- often secondary to L side disease (MR & AR)
- right sided CHF
- venous distention, jugular pulsations, ventral edema
- pleural effusion, hepatic congestion, ascites (rare)
- AF and tachycardia (>60/min) often present
continuous murmurs
what is aortocardiac fistula
- connection from aortic root-RV, RA or LV
- signs may be distress, arrhymia or colic
- associated with ventricular arrhythmias
- unsafe to ride/risk of sudden death
- life expectancy days-months
continuous murmurs
what is patent ductus arteriosus (PDA)
- murmur may be present physiologically < 72-96 hrs
- very rare in “non-neonate”
treatment of CHF
- diuretics: furosemide - torsemide
- ACEI: benazepril
- rate control: digoxin mainly in AF
- pimobendan: little info and expensive
- inotropes (dubutamine), sedation for dyspnea, oxygen, sildenafil, brochodilators, spironolactone, nitroglycerine
what to watch for with horses with CHF
tolerance to exercise, HR, RR and effort
how to monitor horses with valvular disease
- mild - moderate: recheck every 6-24 months
- physical exam
- echo
- exercising ECG if moderate or severe disease progression, AF or premature arrhythmias
what is endocarditis
- mitral or aortic valve more common in horses and carries a grave prognosis
- tricuspid or pulmonic valve more common in ruminants and guarded prognosis
what are the signs of bacterial endocarditis
- horses: fever, tachycardia, shifting lameness, synovial effusion
- cow: anorexia, tachycardia, decreased rumen contractions, decreased milk production
- murmur or no murmur
what is the clin path of bacterial endocarditis
- increase in acute phase proteins (fibrinogen and SAA)
- hyperglobulinemia
- leukocytosis
- neutrophilia
- anemia
blood cultures with bacterial endocarditis
bacteremia can be intermitten - 3 cultures at least one hour as an option
how to tx bacterial endocarditis
antimicrobial therapy
- based on culture & sensitivity
- bactericidal IV antibiotic
- broad spectrum antibiotics should be initated prompty (penicillin and gentamicin)
- platelet aggregation inhibitors
- aprin
