Heart Station

The Heart Station, on the second floor of St. Louis Children’s Hospital, is responsible for all inpatient and outpatient non-invasive cardiac testing. These tests are used to diagnose and treat children with congenital and acquired heart disease. The heart station also provides staff and equipment for all the cardiology testing required during satellite clinic visits.

Heart Station procedures

The following example procedures are not intended to be a fully inclusive list of all procedures available.


Transthoracic echocardiography

High frequency sound waves are used to create a two dimensional picture of the heart. The test is performed with a device, called a transducer, that is placed on the chest. The transducer sends out and then collects the high frequency sound waves. The information is stored in a bedside machine that records the images and displays them on a TV monitor.

Transesophageal echocardiography

This test is the same as the transthoracic echocardiogram, but instead of being placed on the chest, the transducer is placed in the esophagus (food pipe). This provides clear images of the heart when adequate images are unable to be seen from the front of the chest in the usual manner. This test is always performed with the patient sedated.

Intracardiac echocardiography

Special catheters can be introduced into the heart. At the tip of the catheter, there are imaging ultrasound elements that direct visualization of the heart. This procedure is already used in interventional manipulations.

Fetal echocardiography

Fetal echocardiography is an echocardiogram performed on a fetus with the transducer placed on the abdomen of the mother. This test is performed if there is concern about the fetus having abnormal cardiac structures on screening obstetric ultrasounds or if there is a family history of congenital heart defects.

Exercise echocardiography

  • Dobutamine stress echocardiography
  • Exercise stress echocardiography

These studies both involve an echocardiogram to evaluate heart function but are conducted while the heart is stimulated to work harder. The heart is stimulated wither with exercise on a treadmill or a bicycle or with a medicine called dobutamine.


12-lead electrocardiogram (EKG or ECG)

This is a test that records heart rate and rhythm and provides additional information about heart chamber size.

24 Hour Holter monitoring

A portable EKG that records rhythm over a 12 to 24 hour period.

Event recording

A small device is provided for outpatient monitoring of heart rate and rhythm. When a child experiences chest pain, dizziness or other symptoms that may be related to abnormalities of rate or rhythm, the device is placed on the chest, and a recording is made for 30 seconds. The information can then be called in to the Heart Station over a telephone.

Cardiovascular stress testing

This test checks the heart rate and rhythm response to exercise. An EKG is connected to your child, who then exercises on a treadmill or bicycle. With increasing levels of exercise, the heart rate and rhythm is continuously monitored for any changes or abnormalities.

Pacemaker testing

  • Pacemaker interrogation
  • Pacemaker programming and reprogramming
  • Implantable defibrillator interrogation and programming

These tests are restricted to those patients who require pacemakers or defibrillators to maintain normal heart rate and rhythm. The Heart Station is closely involved with maintaining the normal function and follow-up of these devices.

Other testing

  • Tilt-table testing (Used to evaluate selected patients with fainting spells)
  • Oxygen saturation monitoring
  • Blood pressure monitoring