THE CARDIAC AXIS

-         NORMAL CARDIAC AXIS

-         DEVIATION OF THE CARDIAC AXIS

 

THE NORMAL CARDIAC AXIS

 

Link to Normal Cardiac Axis

 

DEVIATION OF THE CARDIAC AXIS

 

 

Dextrocardia

 

 

 

 

 

Deviation of the cardiac axis due to an
intrinsic cardiac abnormality.

Apex of heart points towards right chest.

Look for structural cardiovascular disease.

 

Dextroposition

Heart pushed from left to right but maintains a normal

Or near normal cardiac axis.

  1. Intrathoracic, extracardiac pathology.
    - Diaphragmatic hernia
    - Congenital lobar emphysema

- Bronchogenic cyst.

      - Pericardial and pulmonary tumors.

      - Cystic adenomatoid malformation of the lung

 2. Lung hypoplasia.

- Agenesis of the right lung

      - Scimitar syndrome.

Left cardiac axis deviation

Cardiac axis of greater than 75° to the left
- 75% are due to cardiac anomalies
- 25% have normal hearts

 

 

 

 

REFERENCES
  1. Smith RS, Comstock CH, Kirk JS et.al. Ultrasonographic left cardiac axis deviation: A marker for fetal anomalies. Obstet Gynecol 1995;85:187-191.
  2. Abdullah MM, Lacro RV, Smallhorn J et.al. Fetal cardiac dextroposition in the absence of an intrathoracic mass: Sign of significant right lung hypoplasia. J Ultrasound Med 2000;19:669-676.