Module 7: LV diastolic function Flashcards
What is diastole?
Phase of the heart cycle where the chambers relax and fill with blood
What is the time interval for diastole?
Interval from AV closure to MV closure
What does relaxation mean?
Relaxation of the ventricule
What does relaxation mean? Including IVRT and early phase of ventricular filling
Relaxation of the ventricular filling
What does compliance mean for Diastole?
Change in volume/ change in pressure (DV/DP) in the LV during diastole
What is the inverse to stiffness?
Compliance
A complaint ventricle is able to do what?
Increase its volume without increasing its pressure significantly
Think of the balloon - easily stretch
What is the inverse of compliance?
Stiffness
What is stiffness?
Change in pressure/ Change in volume in the LV during diastole
A stiff ventricle has a disproportionate increase in what?
Pressure for a relatively small increase in volume
What is filling pressure? What does it include?
Includes LV EDP (LV end diastolic pressure) and mean LA pressure
What is LV EDP? 2
- Left ventricular end diastolic pressure
- Reflects LV pressure after filling is complete
Where is LV EDP located on the MV doppler wave?
After the MV doppler “A” wave
What is Mean LAP?
Average pressure during the LV filling period
What does LV filling pressures include? 2
- LV end diastolic pressure (LVEDP)
- Mean LA pressure (LAP)
What does this image represent?
LV filling pressures
What is normal diastolic function?
Means that the LV can fill to an adequate volume to ensure forward stroke volume at low filling pressures during rest or exercise
What is diastolic dysfunction (DDfxn)?
Increasing stiffness of the LV means that the LV can fill to ensure a normal forward volume, but only when the filling pressures increase to abnormal levels
What causes Diastolic dysfunctions? 5
- Aging
- Hypertension
- DM
- Renal dysfunction
- Infiltrative diseases
How does aging affect diastolic dysfunction?
As we age, our stiffness increases and compliance decreases
How does hypertension affect diastolic dysfunction?
Causes high afterload which may lead to Left ventricle LVH, which leads to decrease in compliance
What is the only treatment for diastolic dysfunction?
Exercise is the only treatment which directly alters diastolic function
What other s/s of diastolic dysfunction might be treated with exercise? 4
- Hypertension
- Obesity
- Sodium intake
- Smoking may also be treated
A program of aerobic ______ training can __________ the ___________ function of the heart and can be very helpful in _________ _____________. In fact, an ________ program is the only treatment that has been demonstrated to improve the quality of life in patients with Diastolic dysfunction
- Exercise
- Improve
- Diastolic
- Diastolic dysfunction
- Exercise
Diastolic dysfunction has been previously described as an increased filling pressures, are they the same thing?
No
Elevated filling pressure is a consequence of what?
Diastolic dysfunction
Why is elevated filling pressure a consequence of diastolic dysfunction?
When the LV loses its ability to relax and becomes more stiff, then the filling pressures rise to maintain flow
What is Normal LV filling?
LV fills at low pressures because the myocardium is compliant
In a normal filling LV what would happen if the LV was stiff what would happen to the filling pressure?
It would rise above normal
What does this image demonstrate?
LV normal filling.
What are some factors that affect filling? 2
- Chamber compliance
- Extrinsic factors
What are some chamber compliance factors that affect filling in the LV? 3
- Hypertrophy/ infiltrative disease
- LV muscle remodeling (post Myocardial infarction scar tissue)
- Normal change with aging (fibrotic changes in the LV stiffness as we age)
What are some extrinsic factors that affect filling?
Pericardial stiffness
What are some factors that specifically affect early diastolic filling? 3
- Volume load (preload)
- Hyper/Hypovolemia
- Excessive mitral regurgitation (increases the volume of blood moving past the MV)
What are some conditions that specifically affect late diastolic filling? 5
- Cardiac rhythm
- Atrial contractile function
- Increased LV EDP
- HR
- Ventricular diastolic function
As we get older (_____) or if we are under _____ with diseases stated on the previous slide, the LV muscle becomes _____ __________ during diastole
- > 60 years
- 60
- Less compliant
During impaired LV filling what happens in the early filling stage? 3
- LV does not expand as quickly
- LV/LA pressure gradient is reduced which reduces the E wave peak velocity
- Leads to lower velocity E wave and relatively higher velocity A wave
What are the four phases of diastole?
- IVRT
- Early phase
- Diastasis
- Late phase
During the IVRT phase of Diastole: There is no change in ventricle volume but pressure in ventricle is __________
Falling
During the early phase of diastole: ________ filling of the LV
Rapid
During diastasis of diastole: Pressure ___________ between LV and LA
Equalize
What happens during the late phase of diastole?
Atria contract and push the rest through “atrial kick”
During IVRT what happens to the valves?
They are all closed
During IVRT what is the pressure?
Rapidly falling
What is IVRT?
Period between AV closure and MV opening
What is the volume like during IVRT?
Constant
What is IVRT influenced by?
- conduction abnormalities or conduction mechanics
- Loading conditions (preload and LAP)
- Age
What is Normal IVRT?
50-100ms
What is the timing of Early/ rapid filling?
Period between V opening and diastasis
What is the valves like during early/ rapid filling?
AV valves open
What is the pressure during Early/ rapid filling? 3
- LV pressure low
- Ventricle has “elastic recoil”
- Blood is effectively “sucked” from LA to LV
What is the volume during the early filling phase?
Increasing
During the early- rapid filling stage LA/LV PG begins to fall resulting in what? what is this called?
- Slowdown of blood entering the LV
- Deceleration time
Rapid filling is influenced by what? 3
- Rate of LV relaxation
- Chamber compliance
- LAP
How much filling is done during the early/ rapid filling phase?
70%
What is the normal DT for the early filling phase?
160- 220ms
What is the time for diastasis?
Between early and late filling
What is the valves like during diastasis?
MV hovering barely open
What is the pressure like during diastasis?
- LV/LA pressure almost equal, LV pressure increasing as it fills
- LAP decreasing as it empties
What is the LV volume during diastasis?
Small amount of blood may flow due to inertia
What is the diastasis length determined by? 2
HR
1. Slow = long diastasis
2. Fast: Short/ absent diastasis
What is the time of atrial contraction? ( on ecg)
After P wave on ECG
What is the valves like during atrial contraction?
MV opens more again due to atrial contraction