DIASTOLIC FUNCTION DR. LE HUU DUNG HUE UNIVERSITY OF MEDICINE AND PHARMACY
DIASTOLIC FUNCTION
Isovolumic relaxation
The early rapid
diastolic filling phase
Diastasis
Late diastolic filling
due to atrial
contraction
Isovolumic relaxation
The early rapid diastolic
filling phase
Diastasis
Late diastolic filling due
to atrial contraction
DIASTOLIC FUNCTION
Factors influence
Ventricular systolic function
AV valve function
Rate of ventricular relaxation (compliance or
stiffness)
Atrial and ventricular muscle
Atrial systolic function
Loading or volume conditions of the two chambers
Intrathoracic pressure changes with respiration
Heart rate and rhythm
DIASTOLIC FUNCTION
PARAMETERS OF DIASTOLIC FUNCTION
1. Ventricular relaxation
2. Myocardial compliance and Chamber Compliance
3. Left Ventricular end diastolic pressure (LV-EDP)
4. Ventricular Diastolic filling
5. Atrial Pressures and Filling
Occurs during IVR and early diastolic filling
Active process involving utilization of energy of the
myocardium.
The measure of Ventricular Relaxation include the
following:
1. Isovolumic relaxation time (IVRT)
2. The maximum rate of pressure decline (- dP/dt)
PARAMETERS OF DIASTOLIC FUNCTION
VENTRICULAR RELAXATION
Impaired LV relaxation
Reduced dP/dt
prolonged time
constant of relaxation.
The Doppler:
Prolonged (IVRT)
Reduced E velocity
Increased A velocity.
PARAMETERS OF DIASTOLIC FUNCTION
VENTRICULAR RELAXATION
Compliance: Ratio of change in volume to change in
pressure (dV/dP).
Stiffness: Inverse of compliance: the ratio of change in
pressure to change in volume (dP/dV)
Myocardial: myocardium
Compliance
Chamber: Entire chamber
PARAMETERS OF DIASTOLIC FUNCTION
VENTRICULAR COMPLIANCE
Reduced diastolic compliance:
Pressure-volume relationship of the LV.
LV volume increases in diastole, pressure rises rapidly, resulting in an initial high LA-LV pressure gradient with a rapid decrease in the filling gradient during diastole.
Doppler
Decreased IVRT,
Steep deceleration slope
Reduced A velocity.
PARAMETERS OF DIASTOLIC FUNCTION
VENTRICULAR COMPLIANCE
Chamber compliance is influenced by:
1. Ventricular size and shape
2. Characteristics of the myocardium
3. Extrinsic factors:
a. pericardium
b. right ventricular volume
c. pleural pressure
PARAMETERS OF DIASTOLIC FUNCTION
VENTRICULAR COMPLIANCE
Used in patient management.
LV end-diastolic pressure (LV EDP): ventricular
pressure after filling is complete
Mean left atrial pressure (LAP): average pressure in
the LA during diastole
Clinically LAP is estimated by the pulmonary capillary
wedge pressure (PCWP)
Single time point in the cardiac catheterization
laboratory
Many time points with Swan-Ganz catheter
PARAMETERS OF DIASTOLIC FUNCTION
VENTRICULAR DIASTOLIC PRESSURES
Clinically available measure related to diastolic function
is the time course of ventricular filling.
Can be measured using
1. Angiography
2. Computed tomography (Cat Scab)
3. Magnetic Resonance Imaging (MRI)
4. Doppler Echocardiaography
PARAMETERS OF DIASTOLIC FUNCTION
VENTRICULAR DIASTOLIC FILLING (VOLUME) CURVES
Factors that affect Diastolic filling
Early filling
• Ventricular Diastolic Function
• Changes in the pressure difference between the ventricle
and atrium due to changes in preload.
• Changes in Transmitral volume flow rate (increased in
mitral regurgitation).
• Change in left atrial pressure.
PARAMETERS OF DIASTOLIC FUNCTION
VENTRICULAR DIASTOLIC FILLING (VOLUME) CURVES
Factors that affect Diastolic filling
Late filling
• Ventricular Diastolic function
• Cardiac rhythm
• Atrial contractile function
• Ventricular end-diastolic pressure
• Heart rate
• Time of atrial Contraction
The utility of ventricular diastolic filling patterns forassessing diastolic function is valid only in the absence ofobstruction at the atrioventricular valve level (mitralstenosis).
PARAMETERS OF DIASTOLIC FUNCTION
VENTRICULAR DIASTOLIC FILLING (VOLUME) CURVES
Right atrial filling
Small reversal of flow following atrial contraction (a
wave)
Systolic phase (which is effectively “diastole” for the
atrium) when blood flows from the superior and
inferior vena cava into the atrium
Small reversal of flow at end-systole (v wave)
Diastolic filling phase when the atrium serves as a
conduit for flow from the systemic venous return to
the RV
PARAMETERS OF DIASTOLIC FUNCTION
ATRIAL PRESSURES AND FILLING CURVES
LA filling:
Small reversal of flow following atrial contraction (a
wave)
Systolic filling phase
Blunting of flow or brief reversal at end-systole (v
wave)
Diastolic filling phase
PARAMETERS OF DIASTOLIC FUNCTION
ATRIAL PRESSURES AND FILLING CURVES
EVALUATION OF LV DIASTOLIC FUNCTION
Mitral Inflow +/- Valsalva
Pulmonary Venous Flow
Tissue Doppler
Color M-mode
cm/s
E velocity
A velocity
IVRT
A dur
Deceleration time
EVALUATION OF LV DIASTOLIC FUNCTION
MITRAL VALVE INFLOW
cm/s
D velocity
S velocity
AR velocity
AR dur
EVALUATION OF LV DIASTOLIC FUNCTION
PULMONARY VENOUS FLOW
EVALUATION OF LV DIASTOLIC FUNCTION
FACTORS THAT EFFECT
Atrial arrhythmia showing the effect of a shorter
diastolic interval on the E/A pattern
EVALUATION OF LV DIASTOLIC FUNCTION
FACTORS THAT EFFECT
Nondiastolic physiolgic factors
Preload
Volume flow rate
LV systolic function
Atrial contractile function
DIASTOLIC DYSFUNCTION
STAGE II VERSUS NORMAL
1.0 < E/A < 2.0
• AR < 0.35
• AR dur < A dur
• No E/A reversal
• AR > 0.35
• ARdur > A dur + 30 ms
• E/A reversal
Valsalva
PV inflow
Valsalva
PV inflow
Normal Stage II