Evaluation of Left Ventricular Function and Hypertrophy Gerard P. Aurigemma MD

Transcription

1 Evaluation of Left Ventricular Function and Hypertrophy Gerard P. Aurigemma MD Board Review Course year old health assistant Severe resistant HTN LT BSA 2 Height 64 1

2 Here is the M mode echocardiogram LVIDd 4.2 cm IVSTd 1.4 cm PWTd 1.4 cm RWTd 0.64 LV mass 239 g LVMi 119 g/m2 3 What phrase best describes the LV in LT? 1. Normal 2. Concentric hypertrophy 3. Eccentric, dilated hypertrophy 4. Concentric remodeling 5. Eccentric hypertrophy 4 2

3 M-mode evaluation of the LV RWT=(2*PWTd)/LVIDd What can be said about M mode calculations of calculating LV mass? 1. The M mode cube formula takes into account shape distortions caused by valvular disease, such as AR, but not those caused by AS 2. There are as much data accumulated with 2D mass measurements as there are for M mode measurements 3. The method produces results which are similar to MRI 4. The formula used is called the cube formula because linear dimensions are cubed 5. The formula is called the cube formula because you need a stiff drink with ice cubes to settle down after using it 6 3

4 Assumes prolate ellipsoid shape LV volume = /3 (LVIDd) 3 assumes D 1 = D 2 = L/2 Concept: subtract inner shell volume from outer shell volume Outer shell= (5 +1+1) 3 Inner shell= 5 3 Shell volume= =118 ml Shell volume*1.04 g/ml=122 g 4

5 9 LV Remodeling Otto, Clinical Echocardiography, 4 th edition Descriptors: LV volume LV mass index RWT Sphericity 10 5

6 11 Which statement concerning indexation of LV mass is most accurate? 1. Indexation to BSA allows you to separate concentric from eccentric LVH 2. BSA indexation be insensitive to obesity related LVH compared to height indexation 3. There is consensus that height indexation better predicts outcome than BSA indexation 4. BSA indexation is inferior to BMI indexation for predicting outcome 12 6

7 Off axis preferred 13 Figure 4. LV mass (y axis) was reduced more in patients randomized to losartan than atenolol. 32% reduction in LV Mass Richard B. Devereux et al. Circulation. 2004;110: Copyright American Heart Association, Inc. All rights reserved. 7

8 ASE Best Practices: Modified Biplane Simpson s Rule ( Diastole Systole a i b i Single plane ok if no WMA 20 i=1 V = /4 a i b i L/20 Which statement concerning indexation of LV volume is the most accurate? 1. Papillary muscles should be included with the cavity volume 2. Diastolic volumes should be computed at the peak of the R wave 3. Biplane Simpsons method is the echo method which best correlates with cmri 4. Volumes computed by biplane Simpson s method take into account shape distortions caused by MI 16 8

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10 19 Pressure and Volume Load and Cardiac Remodeling 2:1 L:D L to D ratio decreases with increasingly shperical LV AR MR Increased CO 1:1 L:D 2:1 L:D Hypertension AS 10

11 How does the LV remodel with aging? 94 year old Hypertension 1. BSA indexed systolic and diastolic volumes both increase with age 2. BSA indexed systolic and diastolic volumes both decrease with age 3. BSA indexed systolic volume increases and and diastolic volumes decrease with age 4. BSA indexed systolic volume decreases and end diastolic volumes increase with age

12 What can be said about this patient with severe hypertension (Systolic BP 240)? 1. LVMI 155 g/m2 2. PWTd 1.5 cm 3. RWT LV Volume index 55 ml/m2 1. Eccentric LVH is present 2. Concentric remodeling is present 3. Concentric LVH is present 4. EF is preserved primarily because of increased contractility 5. EF is preserved primarily because of increased preload 23 Afterload = Wall stress Meridional Circumferential Radial Afterload proportional to heart size and pressure and inversely to wall thickness s = p x r / th 12

13 LV Systolic Function Anatomic Considerations 13

14 EF: Pro and Con Pro 1. Internally normalized for size 2. Outcome data 3. Universally used and understood Con 1. Dependent on load 2. Not equivalent to stroke volume or cardiac output 3. Normal EF does not mean normal regional function Partition values for EF 28 14

15 Aortic Stenosis Prototype afterload excess lesion no bad myocytes only bad loading conditions Contractility preserved even with markedly reduced EF Afterload reduction and EF AVR=afterload reduction Carabello et al Circulation

16 47 year old man S aureus BE LVIDd 7 cm LV EF 48% 31 What best describes this situation? 1. LV dysfunction is due to reduced preload 2. LV dysfunction is due to reduced contractility 3. LV dysfunction is due to decreased afterload 4. LV dysfunction is due to increased afterload 32 16

17 In Normal Sized Adult Patients with Heart Disase, Stroke Volume is closely correlated with Ejection Fraction 1.True 2.False How Cardiac Output is Preserved CO = SV x HR EF (%) LV EDV (ml) SV (ml) HR (ml) NL CO (L/min) DCM

18 EF does not equal SV LVIDd EF SV normal LVH DCM Paradoxical Low Flow AS Pibarot and Dumesnil, JACC Imaging

19 Other measures of LV systolic function that do not rely on endocardial border delineation Isovolumic indices dp / dt Ejection phase indices Time interval (Doppler) Tei index Doppler stroke volume dp/dt Mean Rate Method Record MR velocity using CW Select 2 points at 1m/s and 3m/s ( P = 36mmHg - 4mmHg) Measure the time between the two points ( T) dp/dt = 32 /0.055=581 < 600 poorer outcome in HF patients 19

20 Measuring mean dp/dt CW Doppler of MR Measure time interval for velocity to increase from 1 m/s to 3 m/s dp/dt = 32/t Kolias, et al. JACC 2000;36:1594 Low dp/dt Normal dp/dt 40 20

21 Improved dp/dt after CRT Fan et al, JASE 2004:17:

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