ECG and pulmonary tests Flashcards
what does prolonged PR interval show
1st degree heart block
what does taking a calcium channel blocker do
reduced transmission at AVN > associated with 1st degree heart block
in 1st degree heart block is the T wave biphasic
not biphasic
T and P waves are close together (very small gap between T waves)
how to work out HR from an ECG
300/ number of big squares between 2 identical points
what lead do we look at in an ECG
2
elevated ST wave
STEMI
no p wave is indicative of
atrial fibrillation
what effects does cocaine have on ECG
noradrenaline/adrenaline
activates sympathetic NS
tachycardia
what is regular tachycardia called
sinus tachycardia
directions of heart for lead 1
9-3
directions of the heart for lead 2
11-5
directions of the heart for lead 3
1-7
how do you work out FVC from that graph (volume time)
the biggest volume = FVC
how do you work out FEV1 from the graph
read off volume at 1 seconds
to get the ratio including FVC and FEV1 you do
FEV1/FVC
how do you work out peak expiratory flow rate (L/min)
measure in smallest possible increment for eg in 0.1 s = 1 L volume to work out 1 sec divide by 0.1 so 1/0.1 then to get 60s x 60 10 x 60 = 600
how to understand flow rate graphs - where is FVC
FVC is like the furthest right hand measurement? idk how to explain it sorry just remember it
x intercept (courtesy of hemanshugh and his big brain)
HIGHEST OBSERVED X VALUE ON EXPIRATORY CURVE
how do you get FEV1
FEV1 = usually marked on the graph i think lol
how to work out peak expiratory flow rate from flow rate graph
highest point on graph read off y axis
then as it is per second x 60 for L/min
what are the major 2 types of respiratory disorders
restrictive disorders
obstructive disorders
what do restrictive disorders mean
- extra airway diseases
- disorders that restrict the ability for the lungs to fill
what are obstructive disorders
airway diseases
disorders associated with obstructed airflow
narrowing of lumen > more resistant
emphysema removes elastic properties and recoiling
does COPD increase lung capacity
yes and also increases residual volume
what is the definition for FVC
forced vital capacity (the max amount of air in a single breath - forced exhale)
what is the definition of FEV1
forced expired volume in 1 sec - air out in 1st second of expiration
what is the protocol for measuring flow rate
1) patient wears nose clip
2) patient inhales steady to TLC
3) patient wraps lips around mouthpiece
4) patient exhales as hard and fast as possible
5) exhalation continues until RV is reached
6) visually inspect performance and volume time curve and repeat if necessary :
- inconsistencies with clinical picture
- interrupted flow data
what is affected by the height of an individual
the height of the plateau
FVC is affected
how does the FVC differ in someone with an obstructive disorder
less steep as ability to eject air quickly decreases
how does the FVC differ in someone who has a restrictive disorder
steep - ability to eject air as much as possible
FEV1/FVC ratio normal
84%
FEV1/FVC ratio obstructive
53%
FEV1/FVC ratio restrictive
100%
reduced FVC and indented exhalation curve shows..
an indent called coving is present in mild obstructive disease
reduced FVC, indented exhalation curve and reduced PEFR shows..
severe obstructive disease
what does a reduced FVC and narrower curve show
restrictive disease
NO COVING
PEFR slightly lower
blunted inspiratory curve otherwise normal shows
variable extrathoracic obstruction
blunted expiratory curve otherwise normal shows
variable intrathoracic obstruction
what does a blunted inspiratory and expiratory and otherwise normal flow rate show
fixed airway obstruction
