ABCs of Heart Disease

The ABC’s ofThe ABC’s of

Heart DiseaseHeart Disease

With AcknowledgementFor Its Creation toBernard J. Ostrum, M.D.

What It Is

An approach

For congenital or acquired heartdisease in adults

Asking systematic set of questions

Answers based on certainfundamental observations

Visible on frontal chest x-ray alone

Cardio-thoracicRatioCardio-thoracicRatio

<50%

One of the easiestobservations to make issomething you alreadyknow: the cardio-thoracicratio which is the widestdiameter of the heartcompared to the widestinternal diameter of the ribcage

Sometimes, CTR is more than 50%But Heart is Normal

Extracardiac causes of cardiacenlargement

Portable AP films

Obesity

Pregnant

Ascites

Straight back syndrome

Pectus excavatum

>50%

Here is a heart that is larger than 50% of the cardiothoracic ratio, but it is still a normal heart.This is because there is an extracardiac cause for the apparent cardiomegaly. On the lateralfilm, the arrows point to the inward displacement of the lower sternum in a pectus excavatumdeformity.

Obstruction to outflow of the ventricles

Ventricular hypertrophy

Must look at cardiac contours

Sometimes, CTR is less than 50%But Heart is Abnormal

<50%

Here is an example of a heart which is less than 50% of the CTRin which the heart is still abnormal. This is recognizable becausethere is an abnormal contour to the heart (yellow arrows).

Ascending Aorta

“Double density”of LA enlargement

Right atrium

Left ventricle

Indentation forLA

Main pulmonaryartery

Aortic knob

The Cardiac Contours

There are 7 contours to the heart in the frontal projection in this system.

Ascending Aorta

“Double density”of LA enlargement

Right atrium

Left ventricle

Indentation forLA

Main pulmonaryartery

Aortic knob

The Cardiac Contours

But only the top five are really importantin making a diagnosis.

Low density,almost straightedgerepresents sizeof ascendingaorta

Ascending Aorta

Small

Prominent

Ascending Aorta

Indentationwhere “doubledensity” of leftatrialenlargement willappear

Double density of left atrialenlargement

Left atriumLeft atrium

sits in middle ofheartposteriorlysits in middle ofheartposteriorly

Left atriumLeft atrium

sits in middle ofheartposteriorlysits in middle ofheartposteriorly

Left atriumLeft atrium

forms no borderof normal heartin PA viewforms no borderof normal heartin PA view

Left atriumLeft atrium

forms no borderof normal heartin PA viewforms no borderof normal heartin PA view

Even though we are on the right side of the heart, we cansee left atrial enlargement. Normally the left atrium sitsright in the middle of the heart posteriorly and does notform a normal border on the frontal film.

This inset from a CT scan of the chestshows how RA and LV obscure LA fromforming a heart border on the frontal film.

“DoubleDensity”of left atrialenlargement“DoubleDensity”of left atrialenlargement

When the LA enlarges, it will do something on the leftside of the heart we’ll talk about in a minute. And it mayproduce a “double-density” on the right side of the heart.

LALA

Two shadows,the yellowarrow pointingto the LA andthe red arrowto the RAoverlap eachother wheretheindentationbetween theascendingaorta and rightheart bordermeet

Right atrium–not importantcontour inadults

The last bump on the right side is the right atrium. Sincethere is no disease in an adult that causes isolatedenlargement of the RA, we’ll consider the RA togetherwith the RV later.The last bump on the right side is the right atrium. Sincethere is no disease in an adult that causes isolatedenlargement of the RA, we’ll consider the RA togetherwith the RV later.

Aortic knobshouldmeasure< 35mm

Aortic Knob

The first bump onthe left-side is theaortic arch. We canmeasure the knobfrom the lateralborder of air in thetrachea to theedge of the aorticknob.

42mm

Enlarged with:

 Increased pressure

 Increased flow

 Changes in aortic wall

Aortic Knob

ImportantImportant

MainPulmonaryArtery

The next bump down is themain pulmonary artery and isthe keystone of this system.

Finding theMainPulmonaryArtery

Adjacent to leftpulmonary artery

Finding theMainPulmonaryArtery

We can measure the main pulmonary artery . . .

If we draw atangent linefrom the apexof the leftventricle to theaortic knob(red line) andmeasure alongaperpendicularto that tangentline (yellowline)

The distancebetween thetangent andthe mainpulmonaryartery (betweentwo smallgreen arrows)falls in a rangebetween 0 mm(touching thetangent line) toas much as 15mm away fromthe tangent line

0 mm0 mm

MainPulmonaryArteryMainPulmonaryArtery

AoAo

15 mm15 mm

MainPulmonaryArteryMainPulmonaryArtery

AoAo

LVLV

Main pulmonaryartery ranges from0 mm–15mmfrom tangent line

Two Major Classifications

The main pulmonary artery (MPA)projects beyond the tangent line

The main pulmonary artery is morethan 15 mm away from the tangent line

Because the MPA is small or absent

Because the tangent line is being pushed awayfrom the MPA

Increasedpressure

Increased flow

Mainpulmonaryarteryprojectsbeyondtangent

Small pulmonaryartery

Truncus arteriosus

Tetralogy of Fallot

Main pulmonaryartery is morethan 15 mmfrom tangent

Left ventricleand/or aorticknob push thetangent away

Common

Main pulmonaryartery is morethan 15 mmfrom tangent

0 - 15 mm0 - 15 mm

Torecapitulate:

Concavity where Latrium will appear onleft side whenenlarged

Left atrial enlargement

“Straightening of theleft heart border”

Left atriummay enlargewithoutproducingdoubledensityLeft atriummay enlargewithoutproducingdoubledensity

Left atrial enlargement

MainPulmonaryArteryMainPulmonaryArtery

LeftAtrialAppendageLeftAtrialAppendage

In the example on theright, not only is theleft atrium enlarged,but the left atrialappendage is too. Sothere is a convexityoutward where thereis normally aconcavity inward.

Left Ventricle

Left ventricle

Which Ventricle is Enlarged?

The best way to determine whichventricle is enlarged is to look atthe corresponding outflow tract foreach ventricle

If Heart Is Enlarged,And Main PulmonaryArtery is Big

>50%

Which Ventricle is Enlarged?

Then Right Ventricle isEnlarged

If Heart Is Enlarged,And Aorta is Big

>50%

Which Ventricle is Enlarged?

Then Left Ventricleis Enlarged

Which ventricle is enlarged?

The best way to determine whichventricle is enlarged is to look atthe corresponding outflow tractfor each ventricle

Aorta for the LV

MPA for the RV

Once one ventricle is enlarged,it’s impossible to tell if other ventricleis also enlarged

Which Ventricle is Enlarged?

Ascending Aorta

“Double density”of LA enlargement

Right atrium

Left ventricle

Indentation forLA

Main pulmonaryartery

Aortic knob

The Cardiac Contours

Ascending Aorta

“Double density”of LA enlargement

Right atrium

Left ventricle

Indentation forLA

Main pulmonaryartery

Aortic knob

The Cardiac Contours

The PulmonaryVasculatureThe PulmonaryVasculature

Five States of the PulmonaryVasculature

Normal

Pulmonary venous hypertension

Pulmonary arterial hypertension

Increased flow

Decreased flow

What We’re Going to Evaluate

Right Descending Pulmonary Artery

Distribution of flow in the lungs

Upper versus lower lobes

Central versus peripheral

What to EvaluateWhat to Evaluate

RightDescendingPulmonaryArtery

Serves rightmiddle andlower lobes

1. Right Descending Pulmonary Artery1. Right Descending Pulmonary Artery

Diameter canbe measured(beforebifurcation)

RDPA< 17 mm

1. Right Descending Pulmonary Artery1. Right Descending Pulmonary Artery

Normally, therightdescendingpulmonaryartery shouldnot be morethan 17mm indiameter

2. Normal Distribution of FlowUpper Versus Lower Lobes

In erect position,blood flow tobases > than flowto apices

Size ofvessels atbases isnormally> than sizeof vesselsat apex

You can’t measure size ofvessels at the left basebecause the heart obscuresthem

Normaltapering ofvesselsfromcentral toperipheral

Central vesselsgive rise toprogressivelysmaller peripheralbranches

3. Normal Distribution of FlowCentral versus peripheral

Normal Vasculature - review

RDPA< 17 mm indiameter

Lower lobevesselslarger thanupper lobevessels

Gradualtapering ofvesselsfrom centraltoperipheral

RDPA usually > 17 mm

Upper lobevessels equalto or largerthan size oflower lobevessels =Cephalization

Venous Hypertension

Pulmonary Arterial Hypertension

RDPA usually> 17 mm

MainPulmonaryArteryprojectsbeyondtangent line

Rapidcutoff insize ofperipheralvesselsrelative tosize ofcentralvessels

Central vesselsappear toolarge for size ofperipheralvessels whichcome fromthem =

Pruning

Pulmonary Arterial Hypertension

Increased Flow

RDPA usually> 17 mm

All of blood vessels everywhere inlung are bigger than normal

Increased Flow

Distribution offlow ismaintained asin normal

Lower lobevessels biggerthan upperlobe

Gradualtapering fromcentral toperipheral

Increased Flow

Normal

PAH

Increased Flow

Unrecognizablemost of thetime

Small hila

Fewer thannormal bloodvessels

Decreased Flow

The Pulmonary Vasculature

Normal

Pulmonary venous hypertension

Pulmonary arterial hypertension

Increased flow

Decreased flow - mostlyunrecognizable even when it ispresent

Is the Left

Atrium

Enlarged?

If yes,

then

If no,

then

Look at the

Pulmonary

Vasculature

Normal

Increased

Pulmonary

venous

hypertension

Is the Main

Pulmonary

Artery Big

Bulbous?

If yes,

then

If no,

then

Look at the

Pulmonary

Vasculature

Is the Main

Pulmonary

Artery

Segment

Concave?

If yes,

then

If no,

then

Is the

Heart

Dilated or

Delta-

Shaped?

If yes,

then

Don't Look at

Pulmonary

Vasculature.

Look at Aorta

Normal

Increased

Pulmonary

hypertension

Cardiomyopathy

Pericardial

Effusion

Molt. valve dz

Mitralregurg

Mitral

Stenosis

L Myxoma

VSD, PDA

Plum.

stenosis

ASD

(VSD)

Idiopathic

(1°)

Normal

Ascending

dilated

Whole Ao

Dilated

Cardiomyopathy

Stenosis

Ao regurg

HBP

The ABC’s

The System

Those were all of the answers

Now here are the questions

The system is successful only if youask the questions in this order

The answers are the fundamentalobservations you make on the frontalfilm alone

Is The Left AtriumEnlarged ?

Straight orconvex atsite ofnormalconcavity

“Doubledensity” atsite of normalindentation

To answer that question

If Answer To Question “A” Is YES

Look At Pulmonary Vasculature

If Answer To Question “A” Is NO

Then...

Is The Main PulmonaryArtery Big ?

Mainpulmonaryartery projectsbeyondtangent line

To answer that question

If Answer To Question “B” Is YES

Look At Pulmonary Vasculature

If Answer To Question “B” Is NO

Then...

Is The Main PulmonaryArtery Concave ?

Mainpulmonaryartery is >15mmaway fromtangentline

To answer that question

If Answer To Question “C” Is YES

Look At Configuration of Aorta

If Answer To Question “C” Is NO

Then...

Is The Heart a Dilated OrDelta-Shaped Heart ?

Cardio-thoracic ratio > 65%

1. Pericardial effusion2. Cardiomyopathy1. Pericardial effusion2. Cardiomyopathy

Is the Left

Atrium

Enlarged?

If yes,

then

If no,

then

Look at the

Pulmonary

Vasculature

Normal

Increased

Pulmonary

venous

hypertension

Is the Main

Pulmonary

Artery Big

Bulbous?

If yes,

then

If no,

then

Look at the

Pulmonary

Vasculature

Is the Main

Pulmonary

Artery

Segment

Concave?

If yes,

then

If no,

then

Is the

Heart

Dilated or

Delta-

Shaped?

If yes,

then

Don't Look at

Pulmonary

Vasculature.

Look at Aorta

Normal

Increased

Pulmonary

hypertension

Cardiomyopathy

Pericardial

Effusion

Multiple valve dz

Mitralregurgitation

Mitral

Stenosis

L Myxoma

VSD, PDA

Pulmonic

stenosis

ASD

(VSD)

Idiopathic

2° to lung dz

Normal

Ascending

dilated

Whole Aorta

Dilated

Cardiomyopathy

Aortic

Stenosis

Aorticregurgitation

HBP

The End