T/F: Routine labwork is generally useful for the diagnosis of cardiac disease
What is routine labwork useful for?
To screen for concurrent diseases that can affect the CV system or complicate tx of the disease
What are some concurrent diseases that can be seen on routine labwork?
Hyper/hypothyroidism, CKD, hyper/hypoadrenocorticism, anemia/polycythemia, hyperaldosteronism, SIRS/sepsis
Routine labs are useful to monitor for _____ of cardiac meds.
What are the routine labs?
CBC, chem, U/A, T4
What common CV meds are concerning and why?
Furosemide, enalapril, benazepril, spironolactone;
We are dehydrating our patients on purpose, i.e. causing increased renal values and electrolyte abnormalities
What does furosemide alter?
Increases BUN/crea and bicarb
Decreases Cl, K, Mg, Na
What does enelapril/benazepril and spironolactone alter?
Increases BUN/crea and K+
What test cannot be used to monitor renal function in patients receiving diuretics?
USG - we already know the pet is isosthenuric
What is cTnI?
Protein attached to actin/tropomyosin in the cardiac sarcomere
cTnI is a _____ protein and is released when myocytes are _____.
What is cTnI sensitive and specific for?
What can cTnI NOT specify?
What caused the injury
What is the normal range for cTnI?
< 0.2 ng/ml (check with lab)
Should not see free range in blood; if see this it means there is myocyte damage
What cardiac conditions may cause an increase in cTnI?
Myocarditis, thoracic/cardiac trauma, cardiotoxicity, cardiac HSA in dogs, occult DCM in Dobermans, severe heart disease/CHF in dogs and cats
What are some non-cardiac decreases with which we may see increased cTnI?
CKD (decreased GFR), GDV, IMHA, anemia
When might you use a cTnI test (in general)?
Patients with a clinical suspicion of myocarditis
When might you use the cTnI test in dogs?
Pericardial effusion (when no mass is seen on echo);
When might you use the cTnI test in cats?
Dyspneic cats (CHF vs. resp disease), HCM
What is NT-proBNP?
(B-type natriuretic peptide)
Hormone synthesized and released from the ventricles in response to myocardial stretch
What does NT-proBNP cause?
Diuresis, natriuresis, vasodilation
NT-proBNP is naturally anti-_____.
NT-proBNP is the inactive form of _____.
What value does Idexx use?
What value does Antech use?
What cardiac diseases can cause an increase in NT-proBNP?
DMVD, DCM, HCM
Magnitude of NT-proBNP increase correlates with _____ of heart disease.
What non-cardiac diseases cause NT-proBNP elevation?
Day-to-day variation, CKD (decreased GFR), critical illness, PHT
When might you use a NT-proBNP test in cats?
Asymptomatic cats with murmurs, dyspneic cats
What type of NT-proBNP test has a higher cutoff value and when might you use it?
Bedside SNAP test (~220 pmol/L);
used in dyspneic cats to determine CHF vs. respiratory disease