deck_diastology1 Flashcards
What are the normal limits for E/A Ratio
1.31 +/- 0.42
What are the four stages of Diastolic Filling?
1) IVRT2) Rapid Passive Filling3) Diastasis4) Atrial Contraction ( a-kick)
Define Diastole by Echo
Begins with Closure of the Aortic Valve and ends with Closure of the Mitral Valve.
Define Diastole by EKG
Begins with the end of the T wave and Ends with the beginning of the QRS.
Define Diastole by Pressure
When pressure in the Aorta is greater than the LV, the Aortic valve closes. Pressure rapidly drops in the LV until it drops below the LA pressure, at which time the Mitral valve opens and Rapid Passive Filling ensues. The Mitral leaflets drift toward closing as the pressure gradient between the LV and LA equalize. The Atrium contracts and increases its pressure and contributes the last mLs of diastolic filling. The now higher pressure in the LV closes the Mitral valve just as ventricular contraction begins. The beginning of IVCT is the end of diastole and the beginning of systole.
What happens to IVRT if disease causes changes in the ventricles ability to relax?
IVRT becomes prolonged and results in a reduction of the early peak filling rate.Normal IVRT = 63ms (+/- 11ms)
Is Ventricular Relaxation Passive or Active?
LV relaxation and early diastolic filling is an active process and utilizes energy by the myocardium. Internal conditions, extrinsic conditions, non-uniformity in spatial and temporal conditions can all affect myocardial relaxation and inhibit efficient filling of the ventricle.
How does disease affect E Velocity and Deceleration Time.
Disease is reflected by a prolongation in IVRT, a decrease in E velocity an increase in deceleration time.
What is Compliance?
The property of altering size and shape in response to force. -Myocardial: the ease with which the heart muscle relaxes as it fills with blood. Physically, Compliance is the ratio of ∆Volume/∆ Pressure ( ∆V/∆P ). Compliance it the inverse of Stiffness ( ∆P/∆V ) Less Compliance is More Stiffness and More Compliance = Less Stiffness.
How are Myocardial Characteristics related to Compliance?
Myofibril health affects compliance; their ability to reset is directly related to relaxation, from the Fibrils themselves to the myocardial cells ability to exchange ions.Muscle Thickness as in hypertrophy adversely affect compliance.Medications can affect compliance.
How are Chamber Characteristics related to Compliance?
Size, Shape, Normal, Fibrotic, Aneurysmic, Necrotic, Hypertrophied, Hypotrophied….Anything that affects the stiffness of the walls will adversely affect compliance and therefore diastolic filling.
How does the Aging Process affect Compliance and diastolic filling?
Age naturally causes the ventricular walls to become more stiff/less compliant, so it’s natural to see a decrease in E velocity and and increase in Decel time with older patients. To compensate the A component will increase to make up the difference. Also, Pulm. V flow with mirror these changes and Ar velocity will increase too.
What are the parameters evaluated by doppler in diastology?
1) MV Flow2) Pulmonary Vein Flow3) Tissue Doppler (TDI)4) MV Decel Time5) Ar-A Time
Early Peak Rapid Passive Filling is affected by what parameters?
1) Change in Preload2) Change in the flow rate across the AV Valve.3)Change in Atrial Pressure
Late Diastolic Filling is affected by what Parameters?
Late Diastole is affected by the Atrial contraction, so…1) Stenosis/Valvular disease2) Atrial Dilation3) Atrial Fibrillation or conduction defects4) LA Size, Volume, Pressures, Compliance (age)
