jugular and right atrial pressure Flashcards
in atrial pressure what do a wave, c wave, x descent, v wave and y descent represent?
a wave: atrial contraction c wave: isovolumetric contraction x descent: atrial relaxation, valve descends v wave: atrial filling y wave: filling of ventricle
AV first degree block
PR interval is greater than 0.20 seconds
AV second degree block
two types
type 1 Mobitz 1 or Wenkeback - progressive prolongation of PR
type 2 Mobitz II - PR remains unchanged but suddenly fails to conduct to ventricles
AV third degree block
no association between P and QRS
Simple ST segment elevation means
Acute ischemia
ST elevation; decreased R wave, Q wave begins
Hours of ischemia
T wave inversion and deeper Q wave
days 1-2 of ischemia
ST normalizes, T wave inverted
days later past inschemia
ST ans T normal, Q wave persists means
weeks after ischemia
EKG: ST elevation II, III, aVF
ST depression V1, V2, V3 or I, aVL
auction MI inferior
determining heart rate
R-R interval, count large boxes and divide into three hundred
three main signs of infarct or injury
T wave reversals
ST segment elevation
Q waves significant
Heart circle: top and bottom degreews, left and right
top: -90
bottom: 90
left = 180
right = 0
what is in right upper quadrant of circle?
-90 to 0 degrees quadrant
-60
-30
at -30 aVL (left, makes sense)
at 0 lead I
what is in right lower quadrant of circle
0 to 90 degrees 30 60 90 at 60 lead II at 90 aVF (foot, botom)
what is left lower quadrant of circle
90 degrees to 180 degrees 120 150 180 at 120 lead III
what is left upper quadrant of cricle
180 to -90 degrees
- 150
- 120
- 90
- 150 I have aVR
how does baroreceptor reflex affect pressure
via medulla, pns or sns, CO and systemic peripheral resistance
six steps for EKG evaluation
Rate Rhythm Interval Axis Hypertrophy Infarct
How do you determine rate
R R segment, no of large boxes divided into 300
Rhythm determination 4 steps
- are there P waves
- is QRS wide or narrow
- is rhythm regular
- who’s married to whom; P related to QRS
How do you determine normalcy of PR interval?
PR too short if less than 3 little boxes
PR too long is larger than 1 large box
normaly of QRS interval?
less than 0.10 seconds normal
> 0.10 seconds wide (more than 1/2 large box)
normalcy of QT inverval
prolonged if > half of RR interval
Axis determination
the sharpest QRS will tell you direction of heart on circle
which leads have upside down QRS
V2 and V3
ecg criteria for hypertrophy
increase of wave amplitude
increase of wave duration
electric axis deviation
four types of arrhythmias
conductional abnormalities
sinus arrhythmia
supraventricular arrhythmia
ventricular arrhythmia
types of altered conduction
sinus node block
AV block
bundle branch block
Ion channels involved in ventricular action potential
phase 4 = Ik1 -= leak channels phase 0 - I Na TTx sensitive Phase 1 ITO, K+ transient Phase 2, IK (delayed rectifier) Ltype Ca channels Pahse 3, Ik and Ik1
what ion channels involved in pacemaker cell action potential
Na, so If or funny channels
Ca, T type
Ca, L Type
K, Ik, delayed rectifier
Ivabradine
IF channel blocker
EKG hyperkalemia
tall peaked T wave
EKG severe hyperkalemia
flattened Pm widened QRS
EGC hypokalemia
ST depression, flattened/ prominent U wave
MAP formulas
MAP= CO x TPR MAP = diastolic + (systolic - diastolic)/3
compliance formula
C = deltaV / deltaP
distensibility
D = deltaV/ deltaP x Vi
pulse pressure formulas
deltaP = SV/C
Systolic pressure - diastolic pressure
cardiac index formula
CO/BSA
venous return is always equal to
cardiac output
cathether pressure right auricle
5/0
catheter pressure right ventricle
25/0
catheter pressure pulmonary artery
25/10
cat pressure pulmonary capillaries
10/5
cat prerssure pulmonary vein
8/2
cat pressure left auricle
12/0
ekg corresponds with cardiac cycle how
P: right before atrial systole
QRS: right before rise in ventricular pressure
T right at dicrotic notch
epi and NE receptors
epi, alpha 1 and 2, beta 1 and 2
ne all but beta 2
3 effects of histamine
capillary permeability up
arteriolar dilation
bronchial constriction
see “opposite direction” think
action potential in ventricle
copd sign in ekg
large upright waves in lead III and aVG
positive pressure in hyperventilation slows pressure. why
higher thoracic pressure impedes venous return
which calcium channels make depolarization happen faster?
t channels
law of laplace
tension: pressure x radius
what will happen to pressure of heart during cardiac tamponade
rise
poiuseuiile
delta P = 8nLQ/ pir^4
