Diastolic Dysfunction Flashcards
diastolic suction
A ventricular negative pressure when the ventricle is
allowed to relax completely in the absence of filling. It has not been
extensively studied in the human heart in vivo.
Loading factors
By plotting ventricular load as tension time index
against stroke volume, one obtains a valid pump function curve for one beat which is insensitive to changes in heart rate but remains sensitive to changes in end-diastolic volume and contractility
phases of diastolic function
- IVRT: LV relaxes after AV closes
- rapid filling: E wave
- atrial contraction: A wave
what is normal diastolic function
-the ability of the left ventricle to fill in a competent fashion
• This implies that the filling of the LV will not cause a significant increase in LV pressure
what is diastolic dysfunction
- impaired LV relaxation and increased LV chamber stiffness, which increase cardiac filling pressures
- LV pressure will increase rapidly
- ecreased compliance, decreased relaxation or both
assessing for diastolic function
- mitral inflow
- tissue doppler
- color m mode
- pulmonary inflow
- left atrial volume index
what 2 places do you perform tissue doppler
mitral annulus on the lateral and septal walls
what measurements do you get at the PW of the mitral inflow
- E and A filling peaks
- deceleration time
- IVRT
mitral inflow PW normal findings E & A
biphasic, separate E & A peaks;
E > A; E/A ratio between 0.8 and 2.0
E/A > 1 for children and adults < age 50 E increases and A decreases with age
normal deceleration time
160-240 msec
increases with age
normal IVRT
60-100 msec
reflects the rate of the relaxation of the myocardium
values age sensitive
IVRT is longer in patients with…
imparied relaxation
ivrt is shorter in patients with
restrictive filling
what is IVRT
the time interval between aortic valve closure and mitral valve opening
IVRT is also prolonged in patients with…
CAD, advanced age, hypertrophy due to relaxation abnormalities
pitfalls of measuring diastolic function
- cardiac arrhythmias: changes inflow patterns
- tachycardia: fuses E and A together
- A fib : produces no A wave
normal TD medial E prime velocity
11.5 cm/s
normal lateral E prime velocity
13.3 cm/s
TDI velocities less than 8 cm/s indicates what?
diastolic dysfunction and relaxation
what is the annular velocity associated with restrictive filling
5 cm/s