CV monitoring Flashcards
Diagnosis of right atrial hypertrophy
Initial component of P larger in V1
Height > 2.5mm in any limb lead
Precordial limb lead placement
V1 4th intercostal space, right of sternum
V2 4th intercostal space, left of the sternum
V3 between V4 and V2
V4 5th intercostal space, left of sternum- mid clavicular line
V5 5th intercostal space, left of sternum- anterior axillary line
V6 5th intercostal space, left of sternum- mid axillary line
dx Left atrial hypertrophy
Terminal portion of diphasic P in V1 larger
Occurs with mitral stenosis, systemic HTN
Right ventricular hypertrophy dx
Right ventricular wall very thick; more depolarization toward V1
QRS in V1 positive, R waves get smaller
Left ventricular hypertrophy dx
Large S wave V1; larger R wave V5
Depth of V1 and height of V5= 35mm
Myocardial ischemia
Reduced supply of O2 from the coronary arteries
Inverted, symmetrical T wave
Myocardial injury
st elevation
Myocardial infarct (transmural) dx
Q indicated necrosis and makes diagnosis of “old” infarction
Must be significant…1mm wide or 1/3 QRS tall and 2 related leads
energy source and electrical circuits
Generator
Components of a pacemeaker
pulse generator and electrode leads
Reasons to have a pacemaker
Elderly….SSS
Anti-bradycardic treatment
insulated wire from generator to electrode
Lead
exposed metal end in contact with endocardium
Or epicardial leads
Electrode
neg electrode in chamber; positive electrode (grounding)
More sensitive to EMI
Unipolar
both electrodes in chamber being paced
Common; uses less energy
Bipolar
multiple electrodes within 1 lead but multiple chambers
Multipolar
Generic Code for Pacemaker Function
1 = chamber paced
2 = chamber sensing
3= Response to sensing
4= Rate modulation
5= multisite backing
Requirement for Bi-V pacing
Moderate/severe heart failure
EF 30-35%
Intraventricular conduction delays (BBB)
History of cardiac arrest
What is Bi V pacing
3 chambers; Ra, LV, RV.
2 Lead with two electrodes, one in Ra and one in RV and then a 3rd wire to the septum to the LV, risk of tamponade and bleeding because going through septum.
if intrinsic activity is perceived, chamber is not paced
inhibited
What is the purpose of Bi V Pacing
“cardiac resynchronization” (CRT)
Improves RV-LV activation time
Increases EF%
Very sick pts.
Done for bad conduction and the ventricles stop working together. Goal is to resynchronize = improve
what is CVP dependent on
Highly dependent on blood volume and vascular tone
Where is CVP measured
Pressure measured at the junction of vena cava and right atrium
pacemaker discharges if intrinsic activity IS sensed; used currently only for testing of devices
Triggered
Normal CVP for awake/ spont breathing
1-7 mmHg
Rate modulation occurs with: (4)
Vibration
Motion
Minute ventilation/ respiratory artifact
Right ventricular pressure
Indications for CVP lines
CVP monitoring
PA catheter placement
Transvenous cardiac pacing
Temporary hemodialysis
Drug administration
Rapid infusion of fluids/blood
Aspiration of air emboli
Inadequate peripheral access
Repeated blood testing
Multisite pacing is used for what pts
Atrial fib or dilated cardiomyopathies?
CVP A wave
Atrial contraction
Occurs after “P” wave
Increases atrial pressure
Provides “atrial kick”
Perioperative care for PM
Turn on pacmaker mode on monitor
move grounding pags away from PM
Interrogation pre/post op
CVP C wave
Interrupts the decreasing atrial pressure
Isovolumetric contraction of the ventricle
Tricuspid valve closed and ventricle bulges toward the atria
Follows “R” wave
Monopolar bovies and PM
EMI interference a Monopolar; bovie -> grounding to pad will cause more emi
CVP x descent
Decrease in atrial pressure from a wave through ventricular systole
Called systolic collapse
Sometimes called X and X1
CVP V wave
Venous filling of the atrium
During late systole…tricuspid valve remains closed
Peaks just after the “T”
CVP Y descent
Tricuspid valve opens; initial blood flow into ventricle
Called diastolic collapse
afibs affect on cvp
Absence of a wave
Larger c wave (more volume)
Tricuspid regurg affect on CVP
No x descent…valve is incompetent
Tricuspit stenosis affect on CVP
Tall a wave
Lose Y descent becuase it continues to leak for awhile
Lumens of pulmonary artery catheter
Most distal; Monitors PAP
30 cm proximal; monitors CVP
3rd Lumen; Leads to a balloon near the tip, fills baloon
4th Lumen; Lies just proximal to balloon
Houses temperature thermistor
Preferred site for PAC
Preferred site: Right IJ
RA length with PAC
20-25 cm
balloon deflated until reaching RA
RV length
30-35 cm
Pulmonary artery length with PAC
40-45 cm
wedge length with PAC
45- 55cm
AICD
implanted carioverter defibrillators
capable of terminating VF or VT
What do ICD measure?
Measure R-R intervals
Too short??? = HR is too high
10% inappropriate….SVT most common
Onset abrupt or gradual
R-R interval consistent or variable
QRS width normal or wide
PAC length and markings
110 cm length; marked at 10 cm intervals
Using a PA catheter for a long period of time can cause what?
Transient RBBB or complete heart block, endocarditis
Relative contraindications for PAC is a RBBB
Treatment for PA rupture
oxygen and intubate
PEEP
reverse anticoagulation
Pulmonary artery wedge pressure (PAWP) is indicative of what? What else can be used to measure? and where does it sit?
Indirect measurement of left atrial pressure
PAD pressure often used as alternative
PAC tip should be in “zone 3”
LVEDP can be influenced by (5)
aortic regurg
PEEP
VSD
Mitral stenosis/ regurg
compliance
use as an estimate not absolute
Mitral regurgitation PAC waveform
Tall V wave
C wave fused with V wave
No X descent
No specificity/sensitivity to severity of MR d/t:
LA compliance
LA volume
Mitral stenosis PAC waveforms
Slurred, early y descent
A wave may be absent d/t frequent assoc. with a-fib
Acute LV myocardial MI PAC waveforms
Tall a waves due to non-compliant LV
LV systolic dysfunction increases LVEDV and LVEDP
PAWP increases
Mixed Venous Oximetry equation
SvO2 = SaO2 - VO2
Q x 1.34 x Hgb
WHen to use SVO2
If Hgb, arterial saturation, and oxygen consumption stay the same then
Mixed venous oximetry is an indirect indicator of CO
so If CO falls, mixed venous saturation decreases
Then Low venous saturation may signal anemia/blood transfusion need
normal CO
4-6.5
normal stroke volume
60-90
Normal SVR
800-1600
Normal PVR
4-180 dynes/sec/cm5
Normal Mixed venous O2 sat
70-80
Bolus Thermodilution
Cold injected (10ml)and a change in temperature measured downstream
Injected RA lumen, measured PA blood by thermister
CO inversely proportionate to degree of change
Thermodilution inaccuracies (5)
Intra-cardiac shunts
Tricuspid/pulmonic regurgitation
Mishandling of the injectate (don’t have steady injection)
Fluctuations in temperature Following bypass
Rapid fluid infusion (cold blood)
What is more accurate during PPV?
continuous CO monitor
Pulse contour devices use ______ arterial pressure tractings to estimate ___,___,______
Use Area Under Curve arterial pressure tracings
Estimate CO, pulse pressure and SVV
What does pulse contour devices indicate?
Indicates whether hypotension is likely to respond to fluid
If SVV is > 10%
Rely on algorithm
From end diastole to end systole
Calculates ventricular compliance
+/- 0.5 L/min compared to thermodilution
less invasive
Pulse contour inaccuracies (5)
Atrial fibrillation
Site of arterial puncture; femoral more accurate than radial
Quality of arterial trace (vasopressors)
Requires frequent re-calibration
Ideally calibrated initially with a known CO
m mode echocardiography
Narrow beams to measure tissue planes
ie. Ventricular wall mass
2D echocardiography
Real time motion
Shows function
Doppler echocardiography
Can determine speed and direction (flow)
Color
TTE views
5 views, Comprehensive exam: 28 views)
*Anterior structures closest to transducer…..at the top of image
TTE 5 views
Parasternal Long Axis
Parasternal Short Axis
Apical Four Chamber
Subcostal Four Chamber
Subcostal IVC
TTE Windows
Parasternal: 3-5 ICS
Apical: @PMI
Subcostal: just below xiphoid
Parasternal Long Axis views
Great overall view
Measures LA, LV, and Ao root
Parasternal short axis view
LV function
LV volume assessment
Apical Four chamber view
RV vs LV size
TV and MV function
Descending Ao
Subcostal Four Chamber view
4 chambers
Pericardial effusion often next
to right heart
Subcostal IVC view
Diameter, collapsibility esp. in
spontaneous respiration
Roles of TEE
Intraoperative monitor
Rescue tool
Assessment of valvular function
Decision making
*posterior structures are closer to transducer…at top of image
