Heart Disease in Xray.

We can diagnose various types of heart disease in the Xray. The disease will be discussed with the following questions.

We can diagnose various types of heart disease in the Xray. The disease will be discussed with the following questions.

Evaluating for Cardiomegaly

Cardiomegaly is diagnosed when the size of the heart is more than ½ of the thoracic diameter. It is measured as follows

  • A vertical line is made joining the spinous processes is drawn.
  • The maximal distance from the vertical line to the right heart border is given as ‘ A’.
  • The maximal distance from the vertical line to the left heart border is given as ‘ B’.
  • The size of the heart is estimated as A+B.
  • The maximal thoracic diameter is given as ‘C’.
  • Cardiomegaly is given as A+B/ C if more than 50% in adults and 60% in children. 

Features of particular Chamber Enlargement-

After seeing the enlargement of the heart, we should look for the particular chamber enlargement. The features of particular chamber enlargement are as follows –

a. Left ventricular enlargement-

The apex of the heart is shifted downwards and outwards.​

The cardiac apex shifted downwards in left ventricular enlargement.

b. Rght ventricular enlargement –

 Apex of the heart is shifted outwards and upwards.

Cardiac apex shifted upwards and outwards in right ventricular enlargement.

c. Right atrial enlargement-

In normal patients, 1/3rd of the heart lies to the right of midline, and 2/3 of the heart lies to the left of midline. In right atrial enlargement, more than 1/3rd lies to the right of midline. Also, we can see the increased vertical length of the right half of the heart ( which is more than ½ of the thoracic length ( from apex till diaphragm).

d. Left atrial enlargement-

The left atrium is the most posterior chamber of the heart and lies just below the carinal angle.

So, in left atrial enlargement, the following features will be seen-

I. Widening of the carinal angle- Normally carinal angles is less than 90 degrees. In the left atrial enlargement, there is a widening of the carinal angle.

II. Double density- In left atrial enlargement, since the left atrium is the posterior chamber of the heart when enlarged, it will form an additional density within the heart.

III. Since the carina angle is increased and the left main bronchus becomes more vertical than horizontal ( figure/ animation), there will be an increased distance from the right border of the heart to the left main bronchus, which will be more than 7 cm.

Look at the chest Xray. Can you appreciate the features of left atrial enlargement?

Take some time to identify all features, and then look at the Xray Below.

In this case, note the carina is widened ( shown by outlining the carina ). Also, note the double density superimposed to the heart ( small dots and arrow). These are the features of left atrial enlargement. Also when we measure the distance from the right heart border to the left main bronchus, it will be more than 7 cm ( blue line).

Now, with these features of chamber enlargement, we will be able to predict the nature of heart disease. Just to give you some examples,

  • If there is left atrium enlargement only, probably it is from mitral stenosis.
  • If there is left atrium and ventricular enlargement, probably it will be from mitral regurgitation.

Similarly, we will be able to estimate the type of heart disease by viewing Chest Xray. But in Modern times, this has already been replaced by Echocardiography.

 

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