A patient with the Straight Back Syndrome (SBS) may have a pseudo-disease or a significant underlying valve disorder. Only an echocardiographist knows for sure.


The "straight back" refers to a lack of the normal kyphosis seen in the thoracic spine. This can be demonstrated in a lateral chest X-ray by:

(1) Draw a vertical line from the middle of the anterior surface of the T4 vertebra to the middle of the anterior surface of the T12 vertebra.

(2) Draw a horizontal line from the middle of the anterior surface of the T8 vertebra to this line.

(3) The distance along this horizontal line will be less than 1.2 cm in a patient with a straight back.


A patient with a straight back tends to have a narrow chest from anterior to posterior (sagittal axis). The heart may be compressed between the sternum and vertebrae.


Clinical features:

(1) variable chest pain

(2) variable palpitations

(3) often a family history with an autosomal dominant inheritance

(4) systolic heart murmur

(5) physiologic splitting of the second heart sound


Changes seen in the ECG may include:

(1) incomplete right bundle branch block

(2) vertical QRS axis


The murmur may be a benign flow murmur or it may be due to an underlying valve disorder. The most common valve disorders are:

(1) mitral valve prolapse

(2) bicuspid aortic valve


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