Diastolic function

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)


VENTRICULAR RELAXATION

Impaired LV relaxation

Reduced dP/dt

prolonged time

constant of relaxation.

The Doppler:

Prolonged (IVRT)

Reduced E velocity

Increased A velocity.



-dP

dt





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


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.



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





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


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


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.



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).



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


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



EVALUATION OF LV DIASTOLIC FUNCTION

Mitral Inflow +/- Valsalva

Pulmonary Venous Flow

Tissue Doppler

Color M-mode

apical 4-chamber view


MITRAL VALVE INFLOW

cm/s

E velocity


MITRAL VALVE INFLOW

cm/sA velocity


MITRAL VALVE INFLOW

cm/s

IVRT


MITRAL VALVE INFLOW

cm/s

A dur


MITRAL VALVE INFLOW

cm/s

Deceleration time


MITRAL VALVE INFLOW

cm/s

E velocity

A velocity

IVRT

A dur

Deceleration time


MITRAL VALVE INFLOW


MITRAL VALVE INFLOW


PULMONARY VENOUS FLOW

cm/s S velocity



cm/s

D velocity



cm/s

AR velocity



cm/s

AR dur



cm/s

D velocity

S velocity

AR velocity

AR dur






FACTORS THAT EFFECT

Respiration

Heart rate

Age

PR interval


FACTORS THAT EFFECT


FACTORS THAT EFFECT


FACTORS THAT EFFECT


FACTORS THAT EFFECT


FACTORS THAT EFFECT

Atrial arrhythmia showing the effect of a shorter

diastolic interval on the E/A pattern


FACTORS THAT EFFECT

Nondiastolic physiolgic factors

Preload

Volume flow rate

LV systolic function

Atrial contractile function


FACTORS THAT EFFECT


FACTORS THAT EFFECT

MR

Af or AF


FACTORS THAT EFFECT

DIASTOLIC DYSFUNCTION


STAGE I

E/A < 1.0

Stage

I


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


STAGE III VERSUS STAGE IV

E/A > 2.0

• E/A reversal

Valsalva Valsalva

Stage III Stage IV

• No E/A reversal

Date post:	16-Jul-2015
Category:	Documents
Upload:	dung-le-huu
View:	99 times
Download:	7 times

Diastolic function

Documents