Drug Infusion Study

A drug (medication) infusion study is used to try and help an electrophysiologist determine if a patient has certain kinds of cardiac (heart) genetic syndromes or channelopathies. It can help diagnose patients who have been thoroughly evaluated but still don’t have a confirmed diagnosis that explains their symptoms.

Drug infusion studies can be helpful in diagnosing patients with certain channelopathies, such as Long QT Syndrome or Brugada Syndrome. However, since these can often be diagnosed through other noninvasive (or less invasive) testing, such as electrocardiograms, exercise studies, or genetic testing, drug infusion studies are usually only performed after a thorough evaluation has already been performed.

Before the procedure begins, an IV is placed for medication administration and an electrocardiogram is placed for continuous rhythm strip monitoring for the duration of the test.

The medication and dosing that will be infused during the procedure is chosen based on the specific channelopathy and the patient’s body weight. During the infusion, your doctor will watch closely for specific changes in the electrocardiogram.

If your doctor sees the specific changes they are looking for during the infusion, they will stop the infusion and the test will be "positive", meaning a diagnosis has been established.

If your doctor does not see the specific changes they are looking for before the infusion finishes, they will continue monitoring you for a set amount of time afterwards to make sure there are no delayed changes. If they still see no changes after that waiting period, the result is "negative".

A positive drug infusion study can confirm a suspected diagnosis, which is very helpful in providing you with appropriate care. However, not everyone with a specific channelopathy will have a positive drug infusion study. This means that a negative drug infusion study does not exclude a diagnosis.

Depending on the results of the procedure, or on your doctor’s personal practice, you will either go home the same day or spend the night in the hospital.