Basic Veterinary Echocardiography

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Basic Veterinary EchocardiographyThe Subject for a Radiologist?

Daniel A. Feeney DVM, MS

Professor of Veterinary Radiology

College of Veterinary Medicine

University of Minnesota

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Transducer Configuration

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What is Echocardiography?

• High Hz Sound– TRANSMITTED– REFLECTED– TRANSLATED into time-associated image

(graphic 2-D)

Goals of Current Discussion• COMPARE Echocardiography to Survey &

Contrast Radiography• Introduce BASIC Technical Aspects of

Echocardiography• Introduce ELEMENTARY Interpretive Principles

of Echocardiography• Focus on Diagnoses for the GENERALIST

• Radiologist doing echocardiography = plumber doing neurosurgery?

Justification for Echocardiography

• Shortcomings of Survey Radiography– hypertrophy vs. dilation– no information cardiac function– no information on valves– no information on internal cardiac anatomy– miss masses (pericardial sac or heart)– pleural fluid problems

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• Shortcomings of Contrast Radiography(particularly angiography)– contrast media risk– nonselective angiography +/- for shunts– selective angiography

invasiveanesthesia riskspecialized equipment


• Shortcomings of Contrast Radiography(particularly angiography)– pericardial sac procedures (e.g.

pneumopericardiogram)invasiveanesthesia riskembolism & hemorrhage risk

Justification for Echocardiography• noninvasive• no contrast media risk• sector scanners applicable for general abdomen, etc.• hypertrophy vs. dilation• quantitate cardiac function • find masses in the pericardial sac or heart (not

100%)• no pleural fluid problems• information on internal cardiac anatomy

& valves

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Applications of Echocardiography• determine size and quantitate function of cardiac

chambers• identify intracardiac or pericardial sac masses (or

vegetations)• non-invasively reevaluate indices of cardiac function

after Rx• clarify origin of pleural fluid

Technical Considerations

• Windows– [R, 4-5] parasternal intercostal (M-mode standard)– [L, 3-4] cranial parasternal intercostal– [L, 5-6] caudal parasternal intercostal (apical)


• Transducer Configuration/Frequency (Hz)– “inline” configuration

– Use Hz that will put area of interest in focal zoneof transducer

horses/cattle 2.25-3.5 MHzmedium/large dogs 3.5-5.0 MHzsmall dogs/cats 5.0-7.5 MHz

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Cardiac Notch

From:Boon J, Wingfield WE &

Miller Cw:

Echocardiographic Indices

in the Normal Dog.

Vet Radiol 24:214-221,

1983.

Technical Considerations• Cardiac Anatomy vs. Ultrasound Display Modes/Views

M-mode Real-time, sector, 2D** Two-dimensional Views

R parasternal long axisR parasternal short axisL (cranial parasternal long axisL (caudal) [apical] parasternal long axisL parasternal short axis

Technical Considerations• Cardiac Anatomy vs. Ultrasound Display

Modes/Views– “M-mode easiest method by which to obtain

cardiac dimension.”– “The 2-D is generally superior in identification of

cardiac masses, atrioventricular septal defects, regional wall disorders and heartworms.”

(Bonagura, O’Grady & Herring: VCNA(SA) 15:1177, 1985)

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Anatomy

Anatomy

Basics of Interpretation

• What Parts Have You Identified (is the study complete)?– Valves

aortic semilunar (M-mode & 2-D)mitral (M-mode & 2-D)pulmonic (2-D)tricuspid (M-mode & 2-D) [BEST-LCrP/S L-Aor LCrP/S S-A]

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• What Parts Have You Identified (is the study complete)?– Chambers

left atrium (M-mode & 2-D)left ventricle (M-mode & 2-D)right ventricle (M-mode & 2-D)right atrium (2-D) [BEST-LCaP/S L-A (apical) view]


• What Parts Have You Identified (is the study complete)?– Miscellaneous Structures

chordae tendinae (M-mode & 2-D)pericardium (M-mode & 2-D)papillary muscles (M-mode & 2-D)endocardium (M-mode & 2-D)


• Contrast Echocardiography– Use of saline, green dyes, aggregated albumen, etc.

to create echogenic fluid or bubbles which will flow with the blood and identify its course

– Use for identifying shunts

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Making Sense of M-mode

From:Feigenbaum H:

Echocardiography (3rd

edition)

Lea & Febiger,

Philadelphia, 1981.

Long-axis, R L

From:Thomas WP:

Two-dimensional, Real-

time Echocardiography

in the Dog – Technique

& Anatomic Validation.


1984

Long-axis, R L

From:Thomas WP:

Two-dimensional, Real-

time Echocardiography

in the Dog – Technique

& Anatomic Validation.


1984

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Long-axis, R L

R L Long Axis (loop)

Doppler: Duplex/Color-flow

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Short-axis, R L

From:Thomas WP:

Two-dimensional, Real-time Echocardio

in the Dog – Technique & Anatomic

Validation. Vet Radiol 25:50-64, 198

Short-axis, R L

From:Thomas WP:

Two-dimensional, Real-time Echocardiog



Short-axis, R L

From:Thomas WP:

Two-dimensional, Real-time Echocardiogra



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Short-axis, R L

4-chamber, L R/M-mode, R L

4-chamber, L R

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• Are These Structures Basically Normal?– ? chambers conspicuously dilated or compromised– ? contractility = 30%, rate & rhythm– ? any percardial fluid [vs. pleural fluid]– ? any masses or vegetations– ? CVC persistently dilated, 4-5 level hepatic vein

branches seen– ? obvious spontaneous contrast in the

chambers


• On Further Practical Scrutiny, Are They Sill Normal?– ? is ECG normal– ? is mitral valve motion normal [AMV = “M”]– ? paradoxical septal motion


• On Further Practical Scrutiny, Are They Sill Normal?– Relevant Generalities

• right ventricular free wall = 1/3-1/2 as thick as ventricular free wall in small animals (Bonagura, Herring: VCNA(SA) 15:1195, 1985)

• excessive “E-point” [1st hump of AMV’s “M”] to septal separation consider left ventricular dilation or failure (Bonagura, O’Grady & Herring: VCNA(SA) 15:1208, 1985)

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• Relevant Referenced Normal Parameters By Species– Dog-many dimensions proportional to body size1

– Cat-only weak relationship between dimensions & body size2

– Horse-most dimensions not specified as varying with breed/size3

1 Bonagura, O’Grady & Herring: VCNA(SA) 15:1208, 1985Boon, Wingfield & Miller: Vet Radiol 24:214, 1983O’Grady, Bonagura, Powers & Herring: Vet Radiol 27:34, 1986

2 Bonagura, O’Grady & Herring: VCNA(SA) 15:1208, 19853 Bonagura, Herring & Welker: VCNA(SA) 2:311, 1985


• Relevant Referenced Normal Parameters By Species– “There is good agreement between 2-D & M’moade

indices of heart size except for the left atrial side, whick is measurably larger within 2/d.”4

4 Bonagura, Herring: VCNA(SA) 15:1995, 1985


• Measurement Standardization ≈ that used for humans:

Sahn DJ, DeMaria A, Kisslo J, et.al.: Circulation 58:1072-1083, 1978. [M-mode Echocardiography]

Henery WL, DeMaria A, Gramiak R, et.al.: Circulation 62:212-217, 1980 [2-D Echocardiography]

– Leading edge method– Systolic measurements “nadir of septal motion”– Diastolic measurements “onset of the QRS

complex”

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Canine Measurement Scheme

Boon J, Wingfild WE & Miller CW:Echocardiographic Indices in the Normal DogVet Radiol 24:214-221, 1983

Canine Measurement Scheme

Bonagura JD, O’Grady MR & Herring DS:Echocardiography – Principles of InterpretationVet Clin North Am (SA) 15:1177-1194, 1985

Canine Dilatory Cardiomyopathy

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Canine Dilatory Cardiomyopathy

Canine Dilatory Cardiomyopathy &L Atrial Clot

Feline Hypertrophic Cardiomyopathy

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Feline Hypertrophic Cardiomyopathy

Feline Dilatory Cardiomyopathy

Feline Dilatory Cardiomyopathy

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Pericardial Infusion Bullet

Pericardial Infusion Bullet

Pericardial Fluid + Masses (clots)Endocarditis (cow)

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Heartbase Mass

Heartbase Mass

Mitral Endocardiosis

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FLOW

BASELINE0

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2 Venous Flow

Respiratory/Cardiac Periodicity

Arterial FlowHigh-resistance Low-resistance

fD =2v (cos ) f

cT

Doppler Principle

4-Chamber, Mitral Regurgitation

Long Axis, Mitral Regurgitation

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Mitral Regurgitation

Endocarditis (aortic valve)

Aortic Stenosis Valvular/Subvalvular

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VSD (foal)

Invasive Retroperitoneal Mass

Sublumbar Lymphadenopathy

Basic Veterinary Echocardiography

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