Tracy Exam #2 Flashcards
Diastolic Dysfunction, Pericardial Dz, Pregnancy related cardiac problems
There is an increasing number of patients with heart failure but have a preserved
EF!
Diastolic heart failure (HF) accounts for what percentage of all HF patients
50%
Why is assessing diastolic function important? (general)
it is an early sign of cardiac dz (HTN)… it shows up before systolic dysfunction
What little measurement can assess diastolic function?
IVRT
isovolumic relaxation time
it is important… it can elongate…
clinical definition of diastole
the interval from aortic valve closure (end systole) to mitral valve closure (end diastole)
IVCT is or is not included in diastole
IS NOT…
isovolumic contraction period is the time from the closure of the mitral valve to the opening of the aortic valve
4 phases of diastole
- isovolumic relaxation
- early rapid diastolic filling
- diastases
- late diastolic filling due to atrial contraction
what is diastasis?
the space between early and late diastolic filling… those with higher heart rates diastasis starts to disappear…
in those with higher heart rates what phase of diastole starts to disappear?
diastasis… you’ll just have one spike because there is no break in-between
Fill in the blanks
what is the IVRT exactly?
it is the time it takes the ventricle to relax (pressure) low enough so that the mitral valve can open… any issues in relaxation is going to delay that time
during IVRT (as long as there is no MR or AI) the LV pressure is
decreasing while its volume is unchanged
sequence of events for IVRT (4)
- closure of aortic valve
- LV ventricular pressure falls rapidly
- LV pressure falls below LA pressure
- Mitral valve opens
what event in the sequence of events triggers the end of IVRT?
mitral valve opens
In very simplistic terms (8 words) the IVRT is
time the AoV closes and the MV opens
think… diastole sounds like another “dia” word
“dilate”… the heart is literally dilating
what happens in early rapid diastolic filling?
blood flows from LA to LV
the rate of flow during early rapid diastolic filling depends on (3) things
- pressure difference along flow path
- ventricular relaxation
- compliance of both chambers
the rate of decline in early diastole is related to
LV stiffness… the higher LV stiffness leads to faster deceleration of LV filling
In the majority of normal patients… most of LV ventricular filling happens during
early diastole
Remember late diastolic filling is the what wave? (on EKG)
p wave
E-A reversal is normal in older patients (65 yo and up) true or false
TRUE
very stiff, non compliant LV can lead to very high what and rapid what
very high E waves and rapid deceleration
diastasis in a more detailed description (4)
- results because pressure difference in LA and LV equalize
- There is little blood movement
- Mitral leaflets remain in semi open position (drift back toward one another, don’t completely close) **then atrial systole pops them back open - this part is not part of diastasis but is late diastolic filling (on another slide)
- duration of this phase depends on heart rate (long in slow HR, absent in rapid HR)
late diastolic filling more detailed description (4)
- LA pressure exceeds LV pressure
- MV opens
- Second pulse of LV filling occurs
- This is responsible for only about 20% of ventricular filling
what happens with the right ventricle in diastole? is it similar to the LV? what will you see? Any change in velocities? Are the annulus sizes the same? Is the duration of diastole shorter or longer?
- similar to left ventricle, yes
- will see reciprocal respiratory variation with RV filling
- Lower velocities in TV
- TV annulus is larger
- Total duration of diastole is shorter - this is bc there is a longer RV systolic ejection period
Why will an A wave be higher in a patient that doesn’t have an LV that relaxes
that initial opening during early diastole isn’t going to get as much blood out so when the atria contracts there is more blood left in the LA so that’s why your A wave will be higher…. there is more toothpaste in the the tube to squeeze out
Anything higher than ______cm/s at the TV starts to get iffy…
70 cm/sec… shouldn’t be that high…
Respiratory variation normal for a TV but not for a MV because
IVC goes into the right side of heart, not the left side.. and IVC - RA inflow is affected by inspiration
Parameters of diastolic fx
- ventricular relaxation (happens at IVRT and early diastole)
- myocardial compliance (ability of myocardial cells themself to relax, like some infiltrative diseases)
- chamber compliance (ability of chamber to relax)
what is the definition of compliance
the measure of a hollow organ to resist recoil towards its original dimensions upon removal of a distending or compressing force.
ventricular relaxation occurs during _________ relaxation and _________.
isovolumic relaxation (IVRT) and early diastolic filling
ventricular relaxation is what kind of process?
an active process - myocardium uses energy
what factors can affect LV relaxation (specific)
- load
- inactivation of myocardial contraction (metabolic, neurohumoral, pharmacologic)
- asynchrony
how can load affect lv relaxation? does it affect directly or indirectly? Does it affect internally or externally?
can affect LV relaxation directly AND indirectly because it can aggravate dyssynchrony..
affects internal AND external
Internal loading forces (cardiac fiber length)
External loading conditions - wall stress, arterial impedance, increased after load (LV end systolic wall stress) leads to delayed and slow relaxation
when talking about wall stress (an external factor that can affect LV relaxation) what causes wall stress or wall tension
tension of the LV wall determined by LV pressure, radius of the LV and wall thickness
abnormal relaxation is going to prolong your (4)
IVRT… measurement of it will be longer because ventricle is not dropping its pressure quick enough. can come from a multitude of factors. 1) prolongs the IVRT 2) ventricular pressure has a slower rate of decline 3) results in reduction in early peak filling rate 4) pressure difference between LA and LV is not as great when AV valve opens
reduction in E wave… increase in A wave
reduction in E wave… increase in A wave means
an increased A wave means more blood left over at atrial contraction… more than there should be
________ / Impaired Relaxation
Amyloidosis
LV relaxation time can be measured how (3)
- using IVRT
- maximum rate of pressure decline
(-dP / dt) negative change in pressure over change in time
IVRT acquisition from what window? multiple or one?
apical long axis or 5-chamber
******Describe IVRT Acquisition in echo exam
use apical long axis or 5 chamber
1. use CW and place sample volume in LVOT to get aortic and mitral flow (position it in between mitral inflow and left ventricular outflow) - can do it from PW too bc ur not measuring a velocity but the book says CW
2. Put sweep speed at 100 mm/sec
3. normal is less than or equal to 70 msec
4. impaired relaxation with normal LV filling pressure (IVRT is prolonged)
5. Increased LAP - IVRT shortens and is inversely related to LV filling pressure in pts with cardiac dz
Two things to consider when talking about ventricular compliance
- compliance: ratio of change in volume to change in pressure (dV/dP)
- stiffness - inverse of compliance, ratio of change in pressure to change in volume (dP/dV)
When talking about the components of compliance specifically, it could be ________ compliance or it could be __________ compliance or it could be both.
myocardial compliance: characteristics of isolated myocardium
chamber compliance: characteristics of the entire chamber
compliance defined
a property of a heart ventricle in its resting state that determines the relation between the filling of the ventricle and its diastolic pressure
what factors affect chamber compliance / stiffness? (general) (3)
- LV geometry (ventricle size + shape)
- myocardial stiffness
- extrinsic factors outside LV - ex. pericardium, rv interactions with LV, Pleural pressure
outside the heart, talk about extrinsic factors outside the LV that can affect the chamber compliance/stiffness
pericardium
pericardial dz that results in impaired cardiac filling due to extrinsic compression of heart such as
- pericardial tamponade
- pericardial constriction
RV interactions with LV (RVVO - causes RV to be a bully and pushes on the LV)
Pleural pressure (affects hearts ability to move too - don’t usu go into tamponade from pleural effusion but it can affect heart mobility)
in any situation where there is decreased SV, heart will compensate with increased HR
some invasive methods for assessing diastolic function.. what parameters are evaluated invasively?
left heart cath (cath lab)
parameters evaluated invasively?
- Tau (time constant): relation between LV pressure and time
- IVRT
- End diastolic pressure
- Compliance of LV chamber stiffness using dP/dT
diastolic function assessment NONINVASIVE
2D / m-mode evaluation!!!!!!
it’s limited but some indicators can be seen… a patient with heart failure, normal wall thickness, normal chamber size, and normal systolic function
What are some 2D / M-mode indicators of diastolicdysfunction (7)
- could be present with systolic dysfunction
- motion of the posterior wall on m-mode
- pericardial thickening
- septal motion w /respiration (sign of tamponade)
- dilated IVC and hepatic veins (sign of elevated R sided pressures) can happen with congestive heart failure… plumbing backs up all the way to the right side of heart
- tissue characterization of myocardium
- LA maximum volume index is the most useful 2D measurement method
LA remodeling: changes in adaptive to maladaptive range often occurring as a result of pressure or volume overload… this can happen from (4)
- diastolic dysfunction
- tachycardia
- ischemia
- valve disease (MS or AS)
In LA remodeling due to diastolic dysfunction, LA pressure ______ to maintain adequate LV filling. Would be associated with increased _______ and decreased _________.
increases… associated with increased LV stiffness and decreased LV compliance
Diastolic dysfunction can affect the LA size… (3)
increases filling pressures and causes LAE
the severity of diastolic function correlates well with LA volume
longstanding effects of LA dilatation is a decrease in LA function
In addition to the 3 main reasons for diastolic dysfunction, LA enlargement can ALSO be from… (7) - CLUES: type of regurg, type of fistula, high out states like _______, special type of heart that is healthy, slow heart rhythm, enlargement of how many chambers, and an irregular heart rhythm
- volume overload from MR
- arteriovenous fistula (ex. coronary fistula)
- high output states like anemia
- athletes heart w/ no cardiovascular dz
- bradycardia
- 4 chamber enlargement (could be part of a cardiomyopathy ex. dilated cardiomyopathy)
- fib or flutter
the bigger the LA, the worse the
diastolic dysfunction
LA volumes are a good predictor of outcomes in a number of different conditions (7)
- hypertensive heart dz
- a-fib
- cardioversion success
- dilated cardiomyopathy
- hypertrophic cardiomyopathy
- ischemic stroke
- coronary events
LA volumes reflect immediate or cumulative effects of filling pressure?
cumulative effects
For LA volumes, 2D and m-mode measurement are
no longer standard
LA volume measurements are preferred over linear measurements due to asymmetric remodeling of the chamber… they correlate well with
CT and MRI methods
2 methods of assessment for LA volumes
- biplane area-length method
- simpsons biplane method
normal LA volume indexed by dividing it by
Body surface area
abnormal is > 34 ml/m2
how do you measure area LA? from what to what?
annulus to annulus during systole… its biggest volume
measure 1-2 frames before MV opening
Make sure view maximizes LA length and transverse diameter
Do not include the LAA or pulmonary veins in the trace from the apical 4 and 2 chamber view
Parameters to measure diastolic function
Peak E and A velocity of MV
MV A duration
MV E/A ratio
MV DT
TDI e’ velocity
Mitral e/e’
Vein S, D, and A wave velocity
Vein A wave duration
Vein S/D ratio
CW TR peak velocity
Color propagation m-mode
Valsalva (reverses E/A velocity)
Secondary measurements (color m-mode, propagation velocity, TE - e’)
Measure what for mitral inflow method
E wave, A wave, E/A ratio, Decel time, Duration of A wave, IVRT
CW or PW for mitral inflow velocities?
PW preferred; inflow will be ABOVE THE baseline at apical measurement… just a mental note - mitral stenosis will always be above the baseline then**
Using diastolic filling patterns to assess diastolic function is only appropriate when
no valvular obstruction is present such as mitral stenosis; arrhythmias also make evaluation limited
mitral inflow… normal diastolic dysfunction with older? what things change?
E and A wave become appx equal during the 6th and 7th decade of life
Common to see E to A reversal in patients after 70 years of age
DT and IVRT become longer with age
Atrial contraction contributes more to LV filling with age
What is a normal E to A in children and young adults
majority of filling occurs in early diastole so E wave is much more prominent than the A wave
Random question… increased after load would be increased with what issues… name a few
aortic stenosis, high blood pressure, sign of increased afterload is thickened ventricles as a result
what is after load (review)
the load or resistance against which the left ventricle must eject its volume of blood during contraction
in terms of diastolic dysfunction, what would be some results of increased preload
- increased E velocity
- Shortened IVRT (due to the quick increase in LA pressure)
- Steeper deceleration slope in early diastolic filling
- Small A velocity (LV pressure is higher so gradient between LA and LV is not as high
MR would be a good cause of increased preload
What does this image show
Shows an inflow pattern on a patient with severe MR. This is therefore a case where there is increased preload. Note the increased E velocity from increased volume across the valve. There will also be an increase in LA pressure with severe MR.