Bullet Points of Heart Disease and Failure

Donald E Thrall, DVM, PhD

Ross University

School of Veterinary Medicine

Basseterre, St. Kitts

Body Condition Affects Cardiac Appearance

A123287 Pericardial Fat

M153669 Pericardial Fat

Body Stature (Breed) Affects Cardiac Appearance

A127812

A128326

A127894

A128313

Radiographic Projection Affects Cardiac Appearance

VD DV •Shape of heart different

•Position of heart different

•Shape of thorax different

A59806

Radiographs Are Not Sensitive for Detecting

Ventricular Hypertrophy

Normal

Dilation Hypertrophy

Hypertrophy occurs at expense of lumen volume

Radiographs Are Not Specific for Detecting Ventricular

Dilation

M121369

Heart appears big

Is this cardiomegaly?

Is this ventricular

dilation?

Is this hypertrophy?

This could be normal

No failure!

Need echo if indicated

Measurement Techniques are Generally Not Helpful

Measurement Techniques

Vertebral Heart Score

(L + W) normalized to vertebrae

Mean = 9.7 ± 0.5; n=100

Thus, normal = 8.7-10.7 (x ± 2s.d.)

Can do this well qualitatively

VHS method can’t assess hypertrophy

(neither can visual examination)

Buchanan et al, JAVMA, 206:194, 1995

Radiographs are Relatively Sensitive and Specific for

Detecting LA Dilation

Image by K. Spaulding

Left Atrial Dilation

Best seen in lateral view

Elevation of carina

Splitting of principle bronchi (VD)

Compression of bronchi (Lat) if dilation severe

A127519

Moderate L.A. Dilation

Huge LA Dilation

A122860

A82455

Double Wall Sign

Normal: Note angle of branching bronchi Large L.A.

causes

splaying of

main stem

bronchi

‘Bowlegged

Cowboy’

Sign

Pulmonary Vessels Should be Assessed in a Left Lateral

View (vs. R)

A61370

L

R

Conspicuity of

cranial lobe

vessels is better in

L lateral

L

R

Left and right side

vessels are

superimposed in R

lateral

Left and right side

vessels seen

distinctly in L

lateral

Rib 9 a Useful Reference For Vessel Size in VD View

Pulmonary Vessels Vessels should be same size as R 9th rib at point of intersection

A80639 13

11

12

10

9

9 Veins

medial to

Arteries

Relative Vessel Size is a Tipoff to Underlying

Physiology

Pulmonary Vessels

V > A

Venous Hypertension

Mitral Valve

A > V

Arterial Hypertension

Heartworms

Fibrosis

A & V increased

L to R Shunt

Fluid Overload

Fluid Retention

A & V Decreased

Dehydration

Dec. RV Output

Venous Enlargement

A76551 A104636

L DV

Arterial Enlargement

A84024

DV L

A & V Enlarged

Can be hard to

conclude from

lateral views

Mostly a

subjective

assessment in

lateral views

L

A107712 L

A & V Enlarged

DV A107712

12

11

10

9

Radiographs Valuable for Assessing Left Heart Failure

(Pulmonary Edema)

Pulmonary Edema Interstitial Disease in transition

Difficult to diagnose

Alveolar Expected pattern

Often patchy

Air bronchograms may not be visible Especially in cats

Veins may not be enlarged Prior diuretic therapy

Perihilar?

A53025

Lungs will always

look more opaque

in lateral

radiographs

Pulmonary Edema?

Unremarkable

veins; patient

received diuretic

A53025

Patient has

pulmonary edema

Pulmonary Edema can Look Inflammatory

M153049

Cats

A47816

Dogs with DCM

112206 M112206

Sometimes The Kidneys Work Against Us

Enlarged arteries and veins

http://commons.wikimedia.org/wiki/File:Renin-angiotensin-aldosterone_system.png

A125258

Summary

Radiographs are limited in evaluation of the

heart

Normal and breed variations

Extremely valuable for evaluation of

vessels and left heart failure

Echocardiography is the gold standard for

assessing cardiac function