心臟超音波在勞工健檢及心臟疾病之診斷運用

祝年豐 醫師

國防醫學中心 衛生署臺東醫院

Occupational Heart Disease

• Carbon Disulfide• Carbon Monoxide• Environmental Tobacco Smoke• Nitroglycerine• Shiftwork• Stress

Occupational Heart Disease

• Direct effect on the myocardium • CAD• Hypertension• Cardiomyopathy• Arrhythmia

職業性心臟血管疾病因素危害物 病名

二硫化碳 動脈硬化

砷 腎毒性續發冠狀動脈心臟病

鉛、鎘 腎毒性續發冠狀動脈心臟病

鹵化溶劑 心律不整

特定脂肪胺 冠狀動脈痙攣

二氯甲烷 心肌梗塞

硝化甘油 缺血性心臟病

噪音 暫時性高血壓

長期振動 續發性雷諾氏現象

一氧化碳 動脈硬化

轉換工作 冠狀動脈心臟病

工作壓力 心肌梗塞

Echocardiography BasicsUltrasound waves sent from chest wall

Dimensions and Area

• Parasternal short-axis at level of papillary muscles

• Parasternal long-axis• Apical 4-chamber• Apical 2-chamber

健康管理

•健康管理項目

1.健康教育與衛生指導•結合教育訓練•了解自己、認識環境、學習急救…

2.適當配置作業：是否適任•體檢：僱用與否•健檢：醫療、變更場所、更換工作、 縮短工時

3.以健康管理資料實施健康管理

健康管理

•以健康管理資料實施健康管理

1.一般作業勞工•製成健康檢查手冊予以紀錄•實施勞工衛生教育、派工、調職、醫療服務…

2.特別危害健康作業勞工：分級管理•粉塵作業以外•粉塵作業

3.各健檢後之管理

Echocardiography Basics

Echocardiography BasicsOne-dimensional imaging (M-mode)

Echocardiography BasicsTwo-dimensional imaging

Echocardiography BasicsDoppler - Spectral

Pulse Continuous

Bernoulli equation ∆P = 4V2

Echocardiography BasicsDoppler - Colour

Left ventricle - Size

Normal

End-diastole 3.5-5.7cm

End-systole 2.1-4.0cm

Left ventricle - Size

Normal

End-diastole 3.5-5.7cm

End-systole 2.1-4.0cm

Left ventricle - Wall thickness

IVS and PW

0.6 -1.1cm

Left ventricle - Systolic functionFractional Shortening (FS)

FS = EDD-ESD / EDD

Left ventricle - Systolic function

Left ventricle - Systolic function

Ejection fraction (%)

Normal >55

Mild 40-50

Moderate 30-40

Moderate-severe 20-30

Severe <20

Causes of LV Systolic Dysfunction

• CAD• HTN• Cardiomyopathy

– iDCM, HCM, Etoh, Peripartum, Viral, Infiltrative, Toxins, Thyroid Dz., Tachyarrythmias

• Valvular Disease

LV Mass Quantification

• M-mode• Area-length method• Truncated ellipsoid method• Subjective assessment

LV Mass Quantification• 2D M-Mode method using parasternal short axis view

or parasternal long axis view• Assumes that LV is ellipsoid (2:1 long/short axis ratio)• Measurements made at end diastole

• ASE approved cube formula:• LV mass (g) = 1.04 [(LVID + PWT + IVST)3 - (LVID)3]

X 0.8 + 0.6

LV mass index (g/m2) = LV mass / BSA

• Small errors in M-Mode cause large errors in mass values. Can have off axis/tangential cuts due to motion.

LV Mass Quantification

• Penn convention formula (Another form of the cube equation)

• LV mass = 1.04[(IVS + LVID + PWT)3 –(LVID)3] – 13.6 g

NL LV mass index for males: 93 +/- 22 g/m2NL LV mass index for females: 76 +/- 18 g/m2

RWT = 2(PWT/LVID)

LV Volume Measurement With M-Mode

Assuming nl ventricle morphology:V = (LVID)3

If ventricle is dilated (spherical):Teichholz equation

Vdiastole = [7/(2.4 + LVID)] x [LVID]3

LV Systolic Function VariablesLVEDD – LVESD

FS = ------------------------ X 100LVEDD

Percent change in LV dimension with systolic contractionFS approximates EF if there are no significant wall motion abnormalities

SV = EDV - ESV CO = SV x HR

EDV - ESVEF = ------------------ X 100

EDV

How do we quantify LV function?

• M-Mode • Modified Simpson’s Method • Single plane area-length method• Velocity of Circumferential Shortening• Mitral Annular Excursion• E-point to septal separation• Rate of rise of MR jet• Index of myocardial performance• Subjective assessment

M-Mode Quantification

• Use Parasternal Short-Axis (Mayo) or Long-Axis (ASE) views to measure LVEDD and LVESD

• May take several measurements at different levels and calculate average

• Assumes no significant regional wall motion abnormalities present….

M-Mode Quantification

• Uncorrected (LVEDD)2 - (LVESD)2 LVEF = ------------------------------ X 100

(LVEDD)2

If apical contractility is normal (Quinones group):

Corrected LVEF = Unc LVEF + ((100 – Unc LVEF) X 15%)

5% hypokinetic, 0% akinetic, -5% dyskinetic, -10% aneurysm

Modified Simpson’s Method (Disc Summation Method)

• Use apical 4 chamber and apical 2 chamber views to measure dimension and area

• Trace borders manually or by acoustic quantification

• Divides area into 20 cylinders of equal height

Acoustic Quantification

• Automatic detection of blood-tissue border based on integrated backscatter analysis

• This is the difference in amplitude of backscatter between the myocardial wall and blood

• Blood-tissue border is recognized by echo machine, and marked with dots

Acoustic Quantification• Area of study is quantified continuously in real

time throughout cardiac cycle• Therefore, the change in LV cavity area or

volume with systolic contraction is calculated instantaneously, thereby providing LVEF.

• AQ limited by its dependency on echocardiographic gain and image quality

• Echo gain: Amplification of the returning RF signal which weakens with distance; i.e. an increased echodensity is seen as “tissue,” thereby decreasing accuracy……Lateral wall is especially subject to error…….

Derivation of 3.14(R)2 X D

Modified Simpson’s Method

EDV – ESVLVEF = ------------------ X 100

EDV

Single plane area-length method

Assessment of Regional Function

• Based on grading wall motion divided into the 16 (17) segment model as proposed by the American Society of Echocardiography

• Each segment can be viewed in multiple tomographic planes

Assessment of Regional Function• 1 = normal• 2 = hypokinesis• 3 = akinesis• 4 = dyskinesis• 5 = aneurysmal

• WMSI = Sum of scores / Number of visualized segments

• WMSI > 1.7 may suggest perfusion defect > 20%

Assessment of Regional Function

Qualitative estimation errors due to:• Underestimation of EF due to endocardial

echo dropout and seeing mostly epicardial motion

• Underestimation of EF with enlarged LV cavity; a large LV can eject more blood with less endocardial motion

• Overestimation of EF with a small LV cavity• Significant segmental wall motion

abnormalities

Summary• LV Mass Quantification: M-mode, Area-length

method, Truncated ellipsoid method, and Subjective assessment.

• LV Volume Quantification: M-mode, Subjective assessment

• LV Function Quantification: Modified Simpson’s and Subjective Assessment by region………….Also by M-mode, Single plane area length method, Velocity of Circumferential Shortening, Mitral Annular Excursion, EPSS, Rate of Rise of MR jet, Index of myocardial performance, etc……..

Summary

• Modalities limited by quality of echo windows, accurate measurements are based on the ability to identify and capture ideal axis (recognize misleading off axis/tangential slices), and of course, echocardiographer experience……..

Right ventricle - Size & function

Estimation of Pulmonary PressurePA Systolic Pressure

• Tricuspid regurgitation jet velocity

Estimation of Pulmonary PressureRA pressure

• IVC size

Doppler Ultrasound Imaging and Arterial Wall

PLAQUE•GRADE %•ECHOGENICITY

INTIMA-MEDIATHICKNESS (IMT)

IMT and Atherosclerosis

E= IMT D = DIAMETER Nb = NB OF Points 212/1cm

Normal Values IMT

•0,36 mm TO 0, 90mm = NORMAL VALUE IMT FOR ADULTS

•AT THE SAME AGE : IMT > MEN / WOMEN

•LINEARLY WITH AGE :0,08 mm/year

•(SALONEN AND SALONEN ATHEROSCLEROSIS 1990 )

• 1/ CAROTID ARTERY• DISTAL COMMON CAROTID = 99% > BIFURCATION AND INTERNAL CAROTID

Feasibility of Measure IMT

Thank You for

Your Attention!