Pressure Tracings Flashcards
Identify and describe the parts of an atrial waveform, relationship with cardiac cycle
A wave
X descent
V wave
Y descent
Correlate with ECG
A wave - ____________
V wave - ____________
A wave - represents atrial contraction and follows the electrocardiographic P wave, late diastole
X descent - atrial relaxation and to the descent of the tricuspid annulus in early systole; early ventricular systole
V wave - atrial filling while the tricuspid valve is closed; ventricular systole
Y descent - RA emptying, TV opens; early diastole
A wave - follows peak of P wave
V wave - peaks AT or AFTER End of T wave
Timing of atrial, ventricular and arterial pressures
Atrial - ________
Ventricular - ________
Arterial - _______
Atrial - peaks before ST segment (A wave) and after the ST segment ( V wave)
Ventricular - during ST segment
Arterial - during ST segment
During diastole - ventricular and arterial pressure increases
Pressures are best measured at _____________, at which time, the thoracic pressure is nil.
End expiration
Normally, RA and LA pressures are affected by respiratory changes in intrathoracic pressure and, therefore, decrease in inspiration. The X and Y descents in particular become deeper with inspiration.
Identify the atrial pressure tracings on the ffg conditions:
Constrictive Pericarditis
Cardiac Tamponade
Severe TR and/or RV Failure
Severe TR
Impaird RV compliance
Equally large A and V waves
Deep X and deep Y: constrictive pericarditis
Deep X and flat Y (diastolic flow blunting): tamponade, but also sinus tachycardia (mnemonic: Flat Y Tamponade=FYT)
Flat X (systolic flow blunting) and deep Y: severe TR and/or RV failure
Large V wave: severe TR and/or RV failure
Ventricularized RA pressure: severe TR
Large A wave: impaired RV compliance
Equally large A and V waves: ASD
Normally, ____ on RA tracing and ___ on LA tracing
The A wave correlates inversely with ______ compliance, whereas the V wave correlates inversely with _____ compliance.
A. A>V, V>A
This is because the V wave correlates with the atrial compliance and the atrial ability to distend; the LA, being constrained by the pulmonary veins and having thicker musculature, cannot normally distend as much as the RA.
B.
RV compliance
RA compliance
A-V, V-A
This tracing has the following characteristics
Increases during diastole
Has a rectangular shape during systole
Has an A wave
Ventricular pressure tracing
Vs Arterial pressure tracing
Decreases during diastole
Triangular shape in systole
Has a dicrotic notch
Only in early diastole is there a ________ between RA and RV pressure that drives the rapid filling in early diastole
Gradient
Normally, RV diastolic pressure is equal to RA diastolic pressure during most of diastole. There is normally an RV pressure dip in early diastole that sucks blood from the RA.
Young individuals - suckers
Decompensated RV Failure - pushers; elevated RA pressure; because the loss of RV compliance makes the RV diastolic pressure rise rapidly to a high-level plateau, RV failure is characterized by an early RV diastolic dip followed by a “plateaued” high diastolic pressure (dip and plateau pattern)
Seen also in CP and RCMP, bradycardia
RV is very sensitive to afterload changes and is more likely to fail from __________________ than from volume overload
Pressure Overload
RV is very sensitive to afterload changes and is more likely to fail from pressure overload (such as pulmonary hypertension, pulmonary embolism) than from volume overload (such as ASD, primary TR, or pulmonic regurgitation)
This is because the RV wall is thinner than the LV wall, with afterload inversely correlating with myocardial thickness
Laplace
Wall tension = pressure x radius / 2 x wall thickness
Hemodynamic findings in RV systolic or diastolic failure
Elevated RV EDP > 8 mmHg
Elevated mean RA pressure > 7 mmHg
Large RA ____ wave
Deep ___ and ___ on RA tracing
RV __________ pattern
Elevated RV EDP > 8 mmHg*
Elevated mean RA pressure > 7 mmHg*
Large RA V wave (RV failure ot secondary TR)
Deep X and Y on RA tracing
RV dip and plateau pattern
These 2 features are necessary to define RV failure. An elevated RA pressure suffices to define RV failure in the absence of isolated primary TR, tricuspid stenosis, or constrictive pericarditis.
PA systolic pressure = _____ systolic pressure
PA diastolic pressure = _______
________ > RVEDP
RVEDP = _______ pressure
PA systolic pressure = RV systolic pressure
PA diastolic pressure = PCWP
PCWP > RVEDP
RVEDP = RA pressure
Identify the ffg pressure tracing:
Has 2 dominant waves for every QRS
V wave peaks after the T wave
Has an A wave
Horizontal shape in diastole
Atrial Pressure Tracing
Mean PCWP is equal to ________ pressure. However, PCWP is delayed approximately 50 to 150 milliseconds in comparison with LA pressure
Therefore, PCWP _____ and _____ waves peak later than LA
Peak of PCWP V wave? _______
Characteristic of PCWP wave
1.
2.
Mean PCWP is equal to mean LA pressure.
This is due to delay in pressure transmission retrogradely from the LA through the pulmonary vasculature to the PA occluded by the balloon; therefore, PCWP A and V waves peak later than LA A and V waves.
While LA V wave peaks at or immediately after the end of T wave, PCWP V wave peaks well after the end of T wave
- Smooth contour
- Less deep X and Y descents
In pulmonary venous hypertension related to left HF (postcapillary pulmonary hypertension), PCWP _____ diastolic PA pressure
In pulmonary arterial hypertension related to arterial and arteriolar remodeling, PCWP is _______ than diastolic PA pressure by more than ___________
Normally, mean PCWP is equal to or is up to 5 mmHg lower than diastolic PA pressure
Pulmonary venous hypertension related to left HF (postcapillary pulmonary hypertension), PCWP ~ diastolic PA pressure
Pulmonary arterial hypertension related to arterial and arteriolar remodeling, PCWP is lower than diastolic PA pressure by more than 5 mmHg.
PA catheter should be wedged in __________ of the lung, that is, the dependent lung area.
Zone 3
Mean PCWP greater than diastolic PA represents either a damped PA pressure tracing or the catheter’s being wedged in zone 1 or 2
In zone 1 or 2, the alveolar pressure is higher than the capillary pressure and therefore collapses the pulmonary capillaries — PCWP reflects alveolar pressure (larger PCWP, large respiratory variations, smoother appearance, no A or V waves)
Issues of PCWP waveform with severe PH:
- Severe PH makes it difficult for the catheter to occlude the PA resulting in a __________ PA pressure and ______________ the true PCWP
- Phasic PCWP depends on appropriate retrograde transmission of LA pressure through the pulmonary vasculature without any anatomical barrier, hence producing a ________ and __________ PCWP.
- Dampened PA pressure and overestimate true PCWP
- Damped and flattened PCWP; waveform is flat and featureless and falsely creates or overestimates a transmitral gradient
PCWP tracing may simulate the PA pressure tracing in 3 situations:
A _________________ may resemble PA systolic pressure.
In __________________________, the PCWP obtained may represent a damped PA pressure or a PCWP contaminated with PA pressure rather than a true PCWP.
If the ________________________, for example, the catheter is too proximal in the PA, the PCWP obtained will also represent a damped PA pressure.
A. Large V wave
B. Severe pulmonary arterial hypertension
C. Catheter not wedged properly
The most important determinant of V wave height ________________
LA Compliance
The height of the V wave inversely correlates with LA compliance, the latter being the most important determinant of V wave height.
Abnormalities in PCWP tracing
1. Severe acute or decompensated MR - V wave >/= 10 mmHg larger than mean PCWP or a V wave larger than twice the mean PCWP or V wave 3x the mean PCWP
2. Other disease conditions with large V wave:
-Decompensated LV systolic or diastolic failure with impaired LA compliance
-VSD
-MS
-Diastolic HF, postop. RHD with atrial dysfunction/fibrosis
-AF where V is dominant V wave
LV Diastolic Pressure and Evaluation of LV Pressure
The most commonly used surrogate of LV dysfunction is ______________________
Findings seen in patients with HFpEF with reduced LV compliance and normal LA compliance:
1. LA V wave is ______________________
2. Systolic LA pressure ______________
3. Mean LA pressure ________________
4. LVEDP ___________
5. End diastolic LA pressure ________
6. LA A wave ________________________
An elevated LVEDP (>16 mmHg) usually signifies LV dysfunction and is the most commonly used surrogate of LV dysfunction (systolic or diastolic dysfunction)
LA V wave, systolic LA pressure and mean LA pressure - NOT SIGNIFICANTLY ELEVATED
LVEDP, end-diastolic LA pressure and LA A wave are ELEVATED
Findings in decompensated or acute LV failure (systolic or diastolic):
1. LV pressure is increased _________________
2. LA pressure _____________________
3. LA A and V waves are ____________________
3. _________ early diastolic LA-LV gradient
S4 - loss of LV compliance with elevated LVEDP but _________ mean LV diastolic pressure
S3 - LV decompensation with volume overload of _____, ______, ______________________, and a push from LA to LV in early diastole
- Increased LV pressure throughout diastole
- The LA volume also increases beyond LA compliance, which increases LA pressure (pusher)
- High early diastolic LA-LV gradient
S4 - elevated LVEDP but normal mean LV diastolic pressure
S3 - volume overload of LA, LV, and pulmonary capillaries; mean PCWP = LVEDP
** Only compensated severe MR may have a high LA pressure in early diastole, a high early LA-LV pressure gradient, and S3 with normal mean LA pressure and LVEDP
Identify the aortic pressure tracings:
- Sharp downslope of the diastolic pressure, widened pulse pressure, attenuated dicrotic notch __________________________
- Pulsus parvus et tardus/late peaking ______________________
- Double peaking _______________
- Double peaking with spike and dome ______________________
- Loss of dicrotic notch ______________, ________________
- Accentuated dicrotic notch ________________, _______________
- Aortic insufficiency
- Aortic stenosis
- Aortic insufficiency (PULSUS BISFERIENS)
- HOCM
- Severe AI, Poor arterial compliance (elderly, hypertensive, diabetic patients or patients with diffuse peripheral atherosclerosis)
- Vasoconstriction, good arterial compliance
- Gradual reduction of the systolic pressure by more than 10 mmHg during normal quiet inspiration
- Narrow pulse pressure (<30% of systolic arterial pressure), narrow-base arterial pressure, plateaued diastole, and prominent dicrotic wave
- Every-other-beat alternation in systolic pressure
- Pulsus Paradoxus
- Low stroke volume, HF, tamponade, hypovole ia
- Pulsus Alternans - severe reduction in CO; often initiated by a premature beat. The strong beat leaves a small residual end-systolic volume that reduces inotropism of the next beat. The end-systolic volume is increased after the weak beat (because of decreased ejection), which leads to more force development in the next beat.
Factors determining systolic, diastolic, and pulse aortic pressure
- Effect of high SV and low arterial compliance in systolic pressure?
- Effect of low arterial resistance, low arterial compliance and bradycardia in diastolic pressure?
- Effect of low cardiac output, low systolic pressure and increase diastolic pressure in pulse pressure?
- High systolic pressure
- Low diastolic pressure
- Low pulse pressure
- The systolic pressure increases in the peripheral arteries (femoral, radial) as a result of _______________
- After the age of 60 years, the reflected waves not only amplify the peripheral arterial pressure but also return to the central aorta quickly as a result of heightened arterial stiffness __________________
- Reflected waves and systolic amplification
The systolic pressure increases in the peripheral arteries (femoral, radial) as a result of the pressure waves that are reflected from arterial bifurcation points and small peripheral vessels.
The arterial waveform base narrows in the peripheral arteries; therefore, the mean arterial pressure is unchanged; the diastolic pressure is reduced
Peripheral systolic amplification can be as high as 20 to 50 mmHg and is particularly marked in case of AI, poorly compliant arteries (elderly), peripheral arterial disease, aortoiliac or femoral stenoses, tachycardia, or hyperdynamic circulation
- Increased pulse wave velocity
Waves arrive to the aortic root in late systole, which leads to augmentation of the central aortic pressure in conjunction with the peripheral pressure. This explains that the systolic aortic pressure is closer to the peripheral systolic pressure in the elderly.
Young patient - reflected waves return in early diastole which increases diastolic pressure and potentially coronary filling.
PCWP or LVEDP is not an adequate preload measure as it depends on _______________/_________________ but also the ___________________
PCWP or LVEDP is not an adequate preload measure as it depends on preload (=LV end-diastolic volume) but also the LV compliance curve
Pressure Damping and sources of Pressure artifact
________________ pressure tracing is too smooth, has no swiggles/spikes, and peaks and troughs are effaced
________________ accentuation of reflected waves within the catheter systems; seen in hyperdynamic state or from the use of stiff tubing; overshooting of the early diastolic dip and excessive peaking of the systolic pressure
________________ catheter is hit by a structure, which creates transient pressure peaks; this is particularly seen when a hyperdynamic LV hits the LV catheter in systole, simulating an intracardiac gradient
_______________ seen in case of excessive motion of the tip of the catheter within the measured chamber
- Damped/Overdamping
- Underdamped/Excessive catheter ringing
- Catheter impact artifact
- Catheter whip artifact
