Klein TTE Q book Flashcards
How can you differentiate linear aortic artifacts (which are caused by reverberation) from aortic dissection?
1) These artifacts typically occur when the aortic diameter is > than the LA diameter
2) Dissection flaps, unlike linear artifacts, have independent motion the posterior aortic wall (artifacts move in parallel to the posterior aortic wall)
3) Dissection flaps, unlike artifacts, have rapid oscillatory movements
4) Artifacts are usually created at the posterior aortic wall interace with the LA, not the anterior aortic wall
What type of artifact does a mechanical valve create?
Reverberation artifact
What type of artifact is a double image aortic valve?
Refraction
What type of artifact is a mitral valve below diaphragm?
Mirror image
What type of artifact is distortion of ball and cage valve?
Propagation speed
How can you tell the difference between a side lobe artifact and a refraction artifact, when both appear adjacent to the original structures?
- Echo Intensity:
Side Lobe Artifact:
The artifact is usually fainter and less well-defined compared to the actual structure since it originates from secondary energy (side lobes).
Refraction Artifact:
The artifact can appear nearly as bright and well-defined as the actual structure because it is part of the primary beam, albeit redirected.
- Behavior with Probe Manipulation:
Side Lobe Artifact:
Does not move significantly with changes in probe angle or position.
Persistently aligns with the original reflective structure producing the side lobe.
Refraction Artifact:
Shifts position depending on the angle of insonation because refraction follows Snell’s Law.
Moving the probe can make the artifact disappear or change its displacement.
When does a mirror image artifact occurs, and how can you reduce it?
It occurs when the doppler gains are set too high and it can be reduced by decreasing the power output or gain and optimising the angle between the ultrasound beam and doppler flow.
How can you differentiate from a LV thrombus and near field clutter?
1) Change from fundamental to harmonic imaging (this also helps with reduce side lobe / grating lobes / reverberation artifacts)
2) Increasing transducer frequency
3) Decreasing the depth
4) Using multiple views
5) Contrast agents (decrease the MI)
What are the artifacts that could mimic LV thrombus?
1) Reverberation (near-field clutter, comet tail)
2) Range ambiguity
3) Attenuation (shadowing)
What is a ghosting artifact
Colour doppler that is distorted beyond anatomic borders due to multiple reflections
What is refraction?
Bending of the ultrasound beam that results in side-to-side images
How can you tell AR on a M-mode tracing of the LV?
Fluttering of the mitral valve leaflets
What, on an M-mode of the LV, suggest high LVEDP?
The “b-bump” which is at the end of the leaflet
What is the formula for relative wall thickness?
(2 x PWTd)/LVIDd
The UL is 0.42
What is the UL for LV mass index
115 g/m2 in men
95 g/m2 in women
Do you need to have a holodiastolic murmur for severe AR?
In acute severe AR, the LV diastolic pressure rises rapidly because the LV is non-compliant (stiff). This can cause early equalization of aortic and LV pressures, truncating the murmur (it may only be early diastolic).
Similarly, in chronic severe AR with very low systemic vascular resistance or hypotension, the aortic diastolic pressure may fall, reducing the pressure gradient and shortening the murmur.
If you put a pulse wave in the RVOT just prior to the pulmonary valve in a patient in NSR with severe PAH, what will you see?
Small or absent A wave (atria cannot contract sufficiently against the high RVEDP seen, therefore v little blood flow so small or absent A wave)
A mid-systolic notch (flying “W” sign)
In an acute PE, are pulmonary pressures significantly raised?
typically not >50 mmHg
What findings do you see on M mode for a subaortic membrane?
Fluttering of the RCC (top) cusp
Abrupt, very early posterior motion of the right cusp of the aortic valve
Talk about chamber collapse assessment in tamponade assessment:
Normal Chamber Dynamics:
The RV and RA naturally collapse during parts of the cardiac cycle due to physiologic variations in pressures.
RA collapse: Occurs briefly during atrial systole (end-diastole).
RV collapse: May occur during early systole due to contraction.
Pathologic Chamber Collapse in Tamponade:
In tamponade, pericardial pressure exceeds the chamber pressures (RA and RV diastolic pressures), leading to prolonged, abnormal chamber collapse.
RA collapse: Abnormal if it persists for more than one-third of the cardiac cycle.
RV collapse: Significant if it occurs during diastole, when the RV is supposed to be filling.
RA collapse in tamponade occurs in late diastole, when the RA should be filling.
RV collapse in tamponade occurs in early diastole, when the RV is supposed to be filling.
Is hypertension related to dilatation of the sinuses of Valsalva?
No - just the distal aortic segments
When should the aortic annulus be measured?
Mid-systole
When should all the other aortic measurements be made e.g. STJ, Asc aorta
End-diastole
An IVC diameter <1cm with spontaneous collapse indicates
intravascular volume depletion
Is IVC dilation in athletes suggestive of raised RA pressure?
No - they have normal collapsibility
When should IVC diameters be measured?
End-expiration and end diastole using M mode - correlates better with RA pressure
Are 2D methods of RV function i.e. TAPSE, S’ reliable post cardiac surgery?
No, but 3D RVEF is more reliable
What are the abnormal cutoffs for RV size and function
RV base > 41mm
RVEF < 45%
RV FAC <35%
TAPSE <17mm
RV S’ <9.5 cm/s
RV strain >- 20%
RIMP by PW >0.43
RIMP by TDI >0.54
Should you index your RV dimensions to BSA?
According to ASE, only if a patient is at the extremes of BSA
When should the continuity equation not be used when assessing stenosis severity?
If there’s concomitant regurgitation
What are the absolute contraindications to TOE?
- Oesophageal or pharyngeal obstruction
- Oesophageal diverticulum
- GI bleeding from an unknown source
- Perforated viscus
What are the relative contraindications to TOE?
- Oesophageal varicies
- History of radiation to the neck
- Barrett’s oesophagus
- Coagulopathy
Do fibroelastomas have stalks?
Half do, half don’t.
Most commonly found on the aortic valve followed by the mitral.
What is the most reliable visual guide to the presence of hypovolaemia?
Small LVESV
How do you manage acute SAM?
This can occur in aortic (decreased LV cavity size from relief of increased afterload) or mitral valve repair (redundant posterior mitral valve leaflet) or replacement
Avoid catecholamines (beta 1 agonists e.g. dobutamine, norad, isoprenaline, levo), make sure patient is intravascularly replete, and if BP support is needed than use phenylephrine.
How can you differentiate CW of AS versus MR?
By looking at the positive deflection - in AS there’s a gap (lasting about 80 ms) during isovolumetric relaxation that starts immediately at the cessation of the AS signal, at the time of aortic valve closure, and ends at mitral valve opening, the beginning of the mitral valve antegrade flow signal.
This is unlike an MR signal where there is no gap between the MR jet and the EA like signal on top.
What is a high risk atheroma on echo?
If it protrudes into the lumen by 4mm or more, and/or shows mobility, that atheroma is considered severe and associated with increased perioperative mortality (mostly from atheroembolic events that shower cholesterol plaques to the liver, kidneys, brain and skin).
What is the formula for MVA
MVA = 220 / PHT
Alternatively MVA = 759 / DT
What is the formula for PHT (ms)
PHT = 0.29 x deceleration time
What’s the formula for SV
SV = MVA x VTI
What is Qs and Qp in a patient with a PDA?
Unlike an ASD or VSD, Qp represents flow across the LVOT and Qs represents flow across the RVOT.
And the shunt flow is Qp - Qs (of you can do SV LVOT - SV RVOT)
And depending on the Qp Qs you can say which part of the heart will dilate. If the Qp:Qs > 1, then the left sided will dilate first as it’s accommodating more blood
What is normal PADP and how is it calculated?
5 to 16 mmHg
PADP = 4 x [Pulmonary artery end diastolic velocity]squared + RAP
(RAP can be estimated based on IVC size and response to inspiration unless there is significant tricuspid stenosis)
Define severe MR quantitatively
EROA 0.4cm2 or more
RF 50% or more
RV 60ml or more
VC 0.7cm or more
The formula for EROA
EROA = [2πr² x V aliasing]/V max
The formula for instantaneous flow rate [IFR]
=2πr² x V aliasing
Regurgitant volume formula
Rvol = EROA x VTI
Regurgitant fraction formula
Rfrac = Rvol/SV x100
Pulmonary artery wedge pressure (PAWP) formula
PAWP = 4.6 + 5.27 x [E / Vp]
Where E = peak blood flow velocity of the mitral inflow in cm/s
Vp = flow propagation velocity of the mitral inflow (in cm/s) obtained by colour M-mode.
Vp measures the rate which red blood cells reach the LV apex from the mitral valve level during early diastole.
The rate of blood flow from the mitral valve to the LV apex is determined by the rate of LV relaxation during early diastole.
Therefore, Vp is an indirect measure of the rate of LV relaxation, the lower the Vp, the slower the LV relaxation and higher the LVEDVP.
The normal PAWP is 12mmHg or less.
What is the pseudonormal filling pattern?
E/A 1-2, E wave deceleration time >160 ms or more
What is a restrictive filling pattern?
E/A >2, E wave decel time <160 ms
What are the normal flow propagation velocity values?
In young individuals, Vp > 55cm/s
In middle aged and elderly individuals, Vp>45 cm/s
What are the criteria for severe AR
Regurgitant orifice ≥ 0.3 cm2
Regurgitant fraction ≥ 50%
Regurgitant volume ≥60 ml
Vena contracta (cm) >0.6
Is the VC strongly influenced by the Nyquist limit?
No
By lowering the colour Doppler Nyquist limit, one lowers the velocity filter allowing for inclusion of lower velocities and an increase in the colour area.
VC contains predominantly high velocities, but PISA radius becomes progressively larger with lower Nyquist limits.
What is E/e’ a sign of?
Left atrial pressure
What does an E/e’ >15 mean?
LAP is elevated
> 12 means LAP is elevated if the lateral e’ is used
> 15 means LAP is elevated if the medial e’ is used
Formula for LAP
LAP = 1.9 + 1.24 x (E/e’)
A simplified version of the above is 4 + (E/e’)
A normal LAP is <12 mmHg
What’s the formula for LVSP
LVSP = Peak systolic gradient of the MR jet (i.e. 4V² + LAP)
What’s the formula for the peak to peak gradient of e.g. AS
P2P = LVSP - SBP
P2P is lower than the peak instantaneous gradient obtained by CW doppler across the aortic valve
What is the formula for pressure gradient
Pressure gradient (4V²) = DBP - LVEDP
where V = end-diastolic velocity of AR
Is the peak LVSP higher or lower than SBP in patients with AS?
Always higher
Does AR affecting calculating the AVA using the continuity equation?
No - both the VTI LVOT and VTI AV are equally affected by AR
What is the continuity equation for AVA
AVA = CSA LVOT x [VTI LVOT/VTI AV]
What’s the formula for PVR
PVR = [MPP - LAP] / Qp
When MPP is mean pulmonary artery pressure = 1/3 [PASP - PADP]
LAP = Left atrial pressure
Qp = pulmonary blood flow (litres/min)
The normal PVR is 1-2 Wood units
ASD closure should not be performed if the PVR is 2/3 or more of the systemic vascular resistance (SVR)
Normal SVR is 11-16 Wood units
A PVR ≥ 9 wood units usually precludes ASD closure
RVSP in a patient with VSD and no LVOTO can be calculated as
RVSP = SBP - Peak systolic VSD gradient (4V²)
Normally PASP = RVSP however in the presence of pulmonic stenosis,
PASP = RVSP - Peak PS gradient
In the presence of a VSD, what is RVEDP
RVEDP = LVEDP - end diastolic VSD gradient (4V²)
What’s the formula for dP/dT
Change in pressure / RTI
Where RTI (in seconds!) is the relative time interval measured in seconds, between MR jet velocities of 1 m/s and 3 m/s.
and change in pressure represents the difference between the LV to LAP gradients at V2 and V1.
The normal dP/dT is >1200 mmHg/s (although the book says 1661 + 323 mmHg/s)
How do you calculate LAP
In the absence of LVOTO or significant AS, SBP = LVSP
and if you know the peak velocity of an MR jet, then you can calculate the pressure gradient between LA and LV by 4V²
then do SBP (i.e. LVSP) - 4V² = LAP
if LAP ≥ 12 mmHg, it’s elevated
In MS, is the peak velocity of the mitral E wave expected to be low, normal or high
High
velocity (V) across an orifice is inversely related to the cross sectional area (CSA) of the orifice
therefore the smaller the CSA or MVA, the higher the peak velocity of the mitral E wave
What assumption does PHT make?
That LV pressure and compliance are normal, and therefore that the deceleration slope of the mitral E wave on spectral Doppler tracings in diastole is the function of the MVA alone
The reason why PHT is unreliable immediately post BMV is because with the increase in valve area, as LV compliance cannot change acutely, LVEDP increases, the diastolic LA/LV gradient decreases, and the mitral PHT shortens above and beyond what would be expected by an increase in MVA alone after BMV.
How can you calculate AVA
AVA = [CSA LVOT (πr²) x TVI LVOT]/TVI Aortic valve
OR
AVA = [CSA LVOT (πr²) x Peak LVOT velocity]/Peak aortic valve velocity
What is the dimensionless index?
Peak LVOT velocity / peak Aortic valve velocity
In AS, is the SBP higher or lower than the LVSP?
Lower
To calculate pressure gradients the formula is
4V²
Don’t confuse with πr² !!!!
How can you calculate the mean aortic valve gradient form a peak aortic velocity and LVOT diameter?
Mean gradient = 0.6 x the peak gradient
Peak gradient = 4V²
Can pregnancy / high cardiac output or severe AR be responsible for a peak LVOT 1 m/s but peak AV of 5 m/s?
No, both conditions would result in a significant increase in both velocities not just one.
Can the subvalvular LVOT velocity i.e. by PW be normal in obstructive HCM with a significant gradient at rest?
No
In an uncomplicated PDA, what do you expect to see on the CW trace?
Antegrade flow in both systole and diastole
In severe PR, will the PASP be higher than RVSP?
No. RVSP will be higher as regurg leads to reduced pressure in the PA in systole (less volume!)
Does regurg lead to increase forward flow velocities?
Yes. velocity = Q/PVA
Where Q is the volumetric flow across the pulmonic valve in systole
(Q = SV x HR)
When PVA remains constant, any increase in stroke volume leads to increase transvalvular velocity
What does a lack of measurable of end-diastolic gradient mean on e.g. PR CW Trace suggestive of severe PR?
It means that there is a large regurgitant orifice which results in the pressure gradient between the pulmonary artery and the RV equalising rapidly, being achieved by mid-diastole.
What effect does Valsalva have on the mitral E wave velocity?
Valsalva reduces preload, leading to a lower early diastolic pressure gradient between the LA and LV. This leads to a lower peak velocity of the mitral E wave and a lower mitral E/A ratio.
A peak of AR velocity ≥ 35 ms indicates
elevated LVEDVP
AR is the atrial reversal wave seen on PV CW doppler (the negative deflection reflecting blood going back into the PVs during systole / QRS complex on ECG)
Also if the duration of the AR wave is ≥ 30 m/s more than the duration of the mitral inflow A wave, this suggest an elevated LVEDP
As LAP increases, what do you expect of the ratio of the S wave (systolic) to D (diastolic) wave in the PV CW doppler tracings to be?
The higher the LAP, the lower the S/D ratio is (i.e. the S wave decreases more than the D wave)
Explain interventricular dependence
Normal Mechanism: Inspiration and Intrathoracic Pressure
During inspiration, the intrathoracic pressure drops (becomes more negative), which:
Increases venous return to the right side of the heart (right atrium and right ventricle).
Reduces the pressure inside the pulmonary veins (the vessels bringing oxygenated blood from the lungs to the left atrium).
Why the Drop in Intrathoracic Pressure Decreases LA and LV Filling
Pulmonary Veins Are Also in the Thoracic Cavity:
The pulmonary veins are exposed to the same intrathoracic pressure changes as the lungs and other thoracic structures.
When intrathoracic pressure decreases (during inspiration), it reduces the pressure in the pulmonary veins.
Pressure Gradient Between Pulmonary Veins and LA:
Blood flows from the pulmonary veins into the left atrium due to a pressure gradient.
Normally, the pressure in the pulmonary veins is slightly higher than the pressure in the left atrium, which drives blood flow into the LA.
Effect of the Pressure Drop:
During inspiration, the pressure in the pulmonary veins decreases due to the drop in intrathoracic pressure.
If the pressure in the pulmonary veins decreases, the pressure gradient between the pulmonary veins and the left atrium also decreases.
A smaller pressure gradient means less blood flows into the left atrium during diastole, reducing LA filling and, consequently, LV filling.
Analogy to Understand This
Think of blood flow as water flowing downhill due to gravity:
The steepness of the hill represents the pressure gradient.
A larger gradient (steeper hill) means faster flow.
When the hill flattens (smaller gradient), the flow slows down.
During inspiration:
The drop in intrathoracic pressure flattens the “hill” (reduces the pulmonary vein-to-LA pressure gradient), leading to reduced flow into the left atrium.
Additional Factors in Constrictive Pericarditis
In constrictive pericarditis, the effect is exaggerated because:
The rigid pericardium prevents the left atrium and ventricle from expanding fully to compensate for this reduced pressure gradient.
This further impairs LV filling during inspiration.
The SVC and IVC are veins that carry systemic venous blood back to the right atrium.
These veins are located primarily in the thoracic cavity but originate from outside the thorax. During inspiration:
The intra-abdominal pressure increases (due to diaphragmatic contraction).
The intrathoracic pressure decreases.
This combination creates a favorable pressure gradient for blood flow from the IVC (abdomen) and SVC (upper body) into the right atrium.
Thus:
Blood flow in the SVC and IVC increases during inspiration, and pressures in these vessels do not drop significantly because the increase in flow offsets any reduction in intrathoracic pressure.
- Overview of Expiration
During expiration, the intrathoracic pressure increases (becomes less negative or even slightly positive in some conditions).
This rise in intrathoracic pressure affects the flow dynamics of:
Systemic veins (SVC/IVC): Blood returning to the right atrium (RA).
Pulmonary veins: Blood returning to the left atrium (LA).
Expiration reverses many of the changes seen during inspiration. - Systemic Venous Return (SVC/IVC)
Key Effect: Reduced systemic venous return.
During expiration:
The rise in intrathoracic pressure compresses the SVC and IVC, increasing their internal pressure and partially reducing the pressure gradient driving blood into the right atrium.
At the same time, intra-abdominal pressure decreases (as the diaphragm relaxes), further reducing venous return through the IVC.
This results in less blood flow into the right atrium and a subsequent reduction in right ventricular (RV) filling. - Pulmonary Venous Return
Key Effect: Increased pulmonary venous return.
During expiration:
The increased intrathoracic pressure is transmitted to the pulmonary veins, which slightly increases their pressure.
The pressure in the left atrium also increases (because it’s in the thoracic cavity), but the rise in pulmonary venous pressure is greater than the rise in left atrial pressure, improving the pressure gradient.
This leads to improved left atrial (LA) filling and subsequent left ventricular (LV) filling. - Interventricular Dynamics
Inspiration vs. Expiration:
During inspiration, the right ventricle (RV) fills at the expense of the left ventricle (LV) (due to septal shift and ventricular interdependence).
During expiration, the opposite happens: LV filling improves at the expense of the RV.
In conditions like constrictive pericarditis, this interplay is exaggerated:
The interventricular septum shifts toward the RV during expiration (because RV filling is reduced), allowing more space for the LV to fill. - Hepatic Vein Flow
During expiration, when RV diastolic pressure rises (due to reduced RV filling), there may be retrograde flow into the hepatic veins. This is a hallmark finding in conditions like constrictive pericarditis, where RV filling is severely restricted.
During inspiration, hepatic vein anterograde flow significantly increases.
What does aortic coarctation look like on PW doppler?
Anterograde flow throughout the cardiac cycle i.e. including diastole, with a large peak systolic gradient (this indicates severe coarctation)
What does a normal PW look like in the descending aorta
There is systolic anterograde flow but no diastolic anterograde flow.
There is a small amount and duration of flow reversal in early diastole but it’s not throughout diastole which is what’s seen in severe AR
If you see a significant peak systolic gradient on PW in the desc aorta, why is this not significant AS?
Because significant AS would be above the baseline if the PW was in the asc aorta.
Also severe AS is not characterised by an antegrade diastolic gradient across the aortic valve
Is BP higher in the legs or arms in coarctation?
Coarctation usually occurs distal to the origin of the neck arteries
BP in the arms is higher that that in the legs
How can I differentiate between a TR and AS jet on CW?
AS flow does not occur during the short period of isovolumetric contraction straight after the QRS onset. It only occurs in the subsequent ejection period.
In contrast, the TR jet extends throughout systole.
The AS flow is therefore of a shorter duration and has a later onset compared to the TR jet.
What’s the difference between the EA pattern in tamponade and constrictive pericarditis?
In tamponade, LV filling is impaired from the onset of diastole therefore the peak velocity of the mitral E wave is lower than that of the A wave (i.e. impaired relaxation pattern), and the deceleration time is prolonged.
In constrictive pericarditis, early diastolic filling is rapid and then abruptly decreases in late diastole when the expanding myocardium reaches the rigid pericardium. Therefore there is a restrictive filling pattern (E/A>2, deceleration time of E wave <160 ms)
What is the formula for calculating respiratory variation to identify tamponade?
E expiration - E inspiration / E expiration
(this is measured from the EA trace taken at the tips of the mitral valve leaflets)
≥25% inspiratory drop is suggestive of tamponade, constrictive pericarditis
However, marked respiratory variations also occur with laboured breathing, asthma, COPD, PE and obesity
How can you differentiate restrictive cardiomyopathy vs constrictive pericarditis?
There are no significant respiratory variations in mitral inflow in patients with restrictive cardiomyopathy
e’ velocity is also significantly decreased in restrictive cardiomyopathy but normal or raised in constrictive pericarditis
How can you tell if TR is severe based on CW?
There will be a sharp upstroke of the TR jet, followed by a rapid deceleration slope.
The sharp upstroke also indicates a normal dP/dT and thus normal RV function.
When the TR orifice is large, there is ventricularisation of the RAPs, which results in a very rapid pressure equilibration between RVP and RAP.
The rapid rise in RAP results in a rapid deceleration slope.
The peak velocity in very severe TR is often low, and just because its low, doesn’t mean there isn’t significant pulmonary hypertension.
In severe TR, the jet peaks in early systole, but if there was a midcavitary RV gradient, the peak would be in late systole.
In an uncomplicated VSD, to calculate the LVEDP what is the formula
In the absence of TS or AS,
LVEDP = VSD end-diastolic gradient + RA end-diastolic pressure
and RV peak systolic pressure
= SBP - VSD peak systolic gradient
What are the signs of constrictive pericarditis on mitral annular tissue doppler tracings?
Annulus reversus
Peak E’ velocity is normally higher in the lateral compared to the medial annulus i.e. E’ lateral / E’ medial > 1
Eventhough E’ values are reduced in restrictive cardiomyopathies, this ratio is maintained
unlike in constrictive pericarditis where the lateral E’ is significantly reduced compared to the medial E’ which is often normal or increased
How do you measure LA pressure in someone with an ASD?
Peak LA pressure = peak trans-ASD gradient + RA pressure
What’s the formula for regurgitant volume?
R volume = EROA x VTI
How can you calculate SBP knowing the Vmax of a MR jet and LA pressure
Peak LV to LA gradient is 4Vmax²
Peak LVSP = 4Vmax² + LA pressure
In the absence of AS
Peak LVSP = SBP
Is MR typically holosytolic?
Yes and in these cases both EROA and regurgitant volume are accurate measures of MR severity
However when MR is only late systolic (e.g often in MVP), the VTI is often small, therefore the calculated regurgitant volume will be small as R vol = EROA x VTI
he EROA isn’t a good measure and you should use other measures i.e. regurgitant volume, fraction
What’s the formula for regurgitant fraction
RF = R vol / R vol + forward stroke volume
What does Cor triatriatum look like on CW doppler?
Clinically, it presents like MS
On doppler, unlike MS (supra, valvular or subvalvular), it has a triphasic flow which consists of a systolic (S) wave and two diastolic waves: early diastolic (E) wave and late diastolic (A) wave.
There is elevated transmitral pressure gradient in systole and diasotle. MS (whatever form) only has an elevated transmitral gradient in diastole.
In Cor triatriatum you have a perforated membrane that divides the LA into two: the posterior LA which receives the PVs, and the anterior LA which is connected to the LA appendage and is bound by the MV.
What’s the formula for PAWP
PAWP = 1.24 x (E/e’) + 1.9
Septal e’ is often used
Normal PAWP is 6-12 mmHg
Is the pulmonary artery system a higher pressure system than the aorta in the presence of an uncomplicated PDA?
No
with a PDA, more blood flows through the pulmonary valve than the aortic valve because of the recirculation of blood from the systemic circulation into the pulmonary circulation.
However, this does not mean pulmonary pressures immediately increase; the pulmonary vascular system absorbs this extra flow efficiently, at least initially.
Therefore to calculate pulmonary artery pressure (systolic or diastolic), subtract the systolic or diastolic pressure of the PDA from the systolic or diastolic blood pressure and you will get the pulmonary artery systolic or diastolic blood pressure
Which nyquist limit should you use when calculating EROA
the one in the direction of the flow
When does diastolic MR occur?
It may occur in severe LVSD or CHB
How is LAVI calculated?
LAV = 0.85 x [(A1 x A2)/L] and then divide the result by BSA
How do you differentiate normal from pseudonormal diastolic function pattern
pseudonormal e’ <8 cm/s, normal e’ >8 cm/s
Or PW doppler of PV will show systolic wave blunting / S <D
How does the septum move in LBBB
Septum moves posteriorly in the preejection period and then moves anteriorly (away from the posterior LV wall) during the ejection phase of systole
In cardiac surgery, the IVS moves towards the RV rather than the LV in systole, with normal thickening
E>A in …?
Constrictive pericarditis !
in tamponade, E < A !
Does standard doppler exclude high velocities?
No
Standard doppler excludes low velocities and
tissue doppler (as tissue moves at a slower velocity) excludes high velocities
Strain rate can be defined as
the change in velocity between two points divided by their distance
What is the most powerful diastolic predictor of mortality post MI?
E/e’
What is the best strain predictor of cardiac events in a patient with acute HF?
Global circumferential strain
What is a contraindication to Optison contrast?
Allergy to blood products
Contraindication to all contrast agents except Optison is?
Right to left shunt (except in a PFO)
This is because although contrast agents normally pass into the LV - when they pass through the normal route of the lungs, they lose energy and are diluted.
When they pass directly into the LA from the RA, the bubbles are undiluted, and of a higher concentration, increasing the likelihood of microvascular obstruction.
This is not the case with saline bubbles, which are bigger, air filled and therefore less stable / quickly reabsorbed.
Are contrast agents (not saline) used for the detection of intracardiac shunts including PDA?
No
Delay in replenishment on myocardial perfusion imaging (beyond 3 seconds during stress imaging) should be considered abnormal and can be confined to just the subendocardial layers?
During rest 4-5 seconds
During stress within 2 seconds
What will be seen in an unroofed coronary sinus with a left sided injection?
LA then RA enhancement
What is a low MI
<0.3
What is a very low MI
<0.2
should be combined with pulse sequences to get the nonlinear responses from microbubbles
What’s the formula for LVM
=1.04[(LVDD + IVS + PW)³ - LVDD³] - 13.6
the diameters are in cm
The answer can be indexed to BSA
what GLS is associated with an EF of 35%
about -13%
Ischaemic MR tends to occur in which part of the cardiac cycle
Early systole (mainly)
What is definitive of constrictive pericaridits?
Hepatic vein end diastolic flow reversal velocity / forward flow velocity >0.8
What medial e’ velocity suggests constriction as opposed to restrictive cardiomyopathy
≥ 8 cm/s
What other findings suggest restrictive cardiomyopathy?
LAVI > 48 ml/m2
E/e’ >15
How do you estimate LV filling pressures in patients with Afib
Peak acceleration rate of mitral E velocity ≥1900 cm/s2
IVRT less than or equal to 65 ms
DT of pulmonary venous diastolic velocity less than or equal to 220 ms
E/Vp ratio ≥ 1.4
Septal E/e’ ratio ≥ 11