Echocardiography

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Contents 1 More Specific Terms 2 Introduction 3 Methods 4 Notes 5 More General Terms 6 References

More Specific Terms

• pocket mobile echocardiography; mobile-device echocardiography
• stress echocardiography
• transesophageal echocardiography (TEE)
• transthoracic echocardiogram (TTE)

Introduction

• Use of high-frequency ultrasound (2-10 MHz) in the investigation of the heart & great vessels. Sound waves are generated from a piezoelectric crystal.

• Purpose:

• to detect & record intracardiac structures & their motion
• to measure cardiac chamber size, shape, & wall thickness
• these measurements are used in the diagnosis of cardiovascular lesions.

• Limitations:

• accoustic windows may be limiting in:

• obese patients
• patients with COPD or restrictive lung disease

• operator-dependent
• pericardial thickening generally requires CT or MRI for confirmation
• inaccurate for measuring pulmonary artery pressure in patients with suspected pulmonary hypertension [4]

Methods

• M-mode:
• single cursor beam
• single dimensional information
• identification of characteristic borders

• endocardium
• epicardium
• aortic root (< 40 mm)
• atria, left atrium (< 40 mm)
• valve leaflets

• heart motion
• Two-dimensional:
• provides beat to beat tomogram of heart
• left ventricular volume: end- diastolic & end- systolic

• stroke volume
• ejection fraction
• muscle mass

• regional wall motion abnormalities can be assessed
• morphology of cardiac valves

• pliability
• degree of calcification
• morphologic abnormalities

• assessment of intracardiac & pericardial structures
• may be used in conjunction with exercise or dobutamine stress

• assess regional wall motion at rest & during stress for the assessment of coronary artery disease
• requires highly skilled interpretation

• mobile equipment
• Doppler:
• allows direct measurement of blood flow velocities

• across valves
• along conduits

• left ventricular outflow tract
• vessels

• stroke volume
• cardiac output
• valve gradients
• severity of regurgitant lesions
• semiquantitation of intracardiac & extracardiac shunts

Notes

• hand-held echocardiographic devices may be helpful for triage (training & experience required) [3]

More General Terms

• ultrasound (US, UTZ)

References

1. Stedman's Medical Dictionary 27th ed, Williams & Wilkins, Baltimore, 1999.
2. Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed) Lippincott-Raven, Philadelphia, 1998, pg 57-58
3. Medical Knowledge Self Assessment Program (MKSAP) 11, 15 American College of Physicians, Philadelphia 1998, 2009
4. Rich JD et al. Inaccuracy of Doppler echocardiographic estimates of pulmonary artery pressures in patients with pulmonary hypertension: Implications for clinical practice. Chest 2011 May; 139:988 PMID: [1]

echocardiography