diagnosis for cardiac diseases Flashcards
what are the risk factors for cardiac diseases ?
family history age male sex hyper and dyslipidemia diabetes hemostatic disorders - hyperhomocystinurea , hyperfibrinogenima fctor 5 leiden arterial hypertension overwieght stress smokin
when do the early markers for myocardial infraction rise ?
1-3 hours after symptoms appear -myoglobin , glycogenphsophorilase BB , ischemia modified albumin
CK-MB
when do the medium early markers arise ?
4-6 hour after symtoms ?
TROPONIN T AND I
ASAT
CK
what are the late markers ?
LDH , troponin
where is myoglobin found ?
heme binding protein found in skeletal muscles and myocardial muscles
why is myoglobin and early marker and why isn’t it very reliable ?
in cytoplasm - comes out easy due to damage
has a short plasma half life
its levels can easily change
low diagnostic specificity - also in muscle damage ,renal elimination can also arise in renal failure
what are the methods to detect myoglobin ?
immunoturbidmetric
immunonephelometric
antibodies coated with polystyrene is used
myoglobin is also used to detect what ?
effectiveness of thrombolytic therapy
succesful reperfusion rises quickly due to washout
marker comes to normal value in 10-20 hours with thrombolysis
without 24-36 hours
how can we better myoglobin specificity ?
myoglobin tother with carbohydrase 3 /low molecular weight protein placed in muscles
ratio between these markers
what are the isoenzymes of glycogenphosphorlase
bb- brain and myocardial muscle
mm - skeletal mucle
ll- heptic cells
what methods are used to obtain Glycogenphosproliase bb in blood ?
ELSA
glycogen phosprylase BB only comes normal after how much time ?
2-3 days
what is the use of glycogen phosphorylase bb
used in bypass surgery
problem of glycogen phsoprylase bb ?
too sensitive - reacts even to ischemia in stable angina
how is TROPONIN obtained ?
ELISA - first determination
3rd way
ECLIA (Electro chemiluminescence Assay). specific for the cardiac isoform with high sensitivity
troponin max levels are ?
16-36th hour and stay high 10-12 days.
troponin other than to diagnose Mi what else is it used for ?
also used to monitor the reperfusion
if successful there is a rise in troponin
High sensitivity troponins have a number of significant advantages
allow for earlier identification of MI,
negative predictive value,. are a better “rule-out” test than former assays.
predict the risk for the next myocardial infarction and death in a group of patients previously undetected by former Tn assays.
they speed up chest pain triage to 4 hours
Serial samples demonstrating rising or falling levels of hsTn differentiate acute from chronic cardiomyocyte necrosis
what rules out MI by high sensitivity troponin ?
initial normal hsTn level in a patient with a reliable history of chest pain onset more than 6 hours prior to sampling
how should the serial sample of troponin be taken
the timing of the 2nd serial sample should be no sooner than 3 hours after the first.
The percentage change (rise or fall) in hsTn levels in 2 samples 3 hours apart, is used to establish a diagnosis of MI when the Tn level is below the WHO cut-off
the value of troponin depends on ?
size of the affected zone
the blood flow to the area
where the infraction is located
from Hs troponin levels, how can that be used to differentiate if it is acute or chronic myocardial infraction ?
serial samples of high sensitivity troponin rising and falling
for TnI how much change should there be between serial samples for it to be diagnostic indication for myocardial infraction ?
50 percent change from the initial value
what is algorithm for troponin 1 investigation for myocardial infraction
first sample of troponin 1
less than 99 percent – pain is more than 6 hours discharge after stress test
pain less that 6 hours ?– second sample of troponin after 3 hours
in first sample of troponin if it is a 99 percent rise in troponin I
second sample taken after 3 hours
if the change of troponin I is less than 50 percent - discharge
if the change of troponin I is more than 50 percent admit the patient
if the first sample of troponin is more than 99 percent which WHO assizes as a definite Mi - admit the patient , invasive management
