Ventriculography

Introduction

Cardiac Ventriculography is a medical imaging study used to determine a patient’s cardiac function in the right, or more commonly, the left ventricle. Cardiac ventriculography involves injecting a contrast dye into the heart’s ventricle(s) to measure the volume of blood pumped. Cardiac ventriculography can be performed with an iodine-based contrast in cardiac chamber catheterization or by radionuclide ventriculography.

The 3 important measurements obtained by cardiac ventriculography are:

• Ejection Fraction

• Stroke Volume

• Cardiac Output

Nuclear ventriculography:

This is a test that uses radioactive materials called tracers to show the heart chambers. The procedure is noninvasive as no instruments directly touch the heart.

Procedure:

The health care provider injects a radioactive material called as technetium into patient’s vein. This substance attaches to red blood cells (tags red blood cells) and passes through the heart.

Patient is instructed not to eat or drink anything for several hours before the test.

Special cameras or scanners trace the movements of this substance through the heart area. The red blood cells inside the heart tagged by radioactive material form an image which is seen. The images may be combined with an electrocardiogram. Using computer software, the images can be made to appear as if the heart is moving.

Preparation:

Patient is instructed not to eat or drink anything for several hours before the test.

A brief sting or pinch is felt when the IV is inserted into the vein, usually in the arm. There may be problem in staying still during the test.

Normal results:

Normal results indicate that the heart’s pumping function is normal. The test can check the squeezing strength of the heart (ejection fraction). A normal value is above 55%.

The test also can check the motion of individual chambers of the heart. If one part of the heart is moving poorly while the others move well, it may mean that there is a blockage in the artery supplying blood to that damaged part.

Abnormal results:

They may indicate:

• Coronary artery disease or blockages

• Heart valve disease

• Past heart attack (myocardial infarction)

• Poor pumping function

Other conditions for which the test may be performed are:

• Atrial septal defect

• Heart failure

• Dilated cardiomyopathy

• Idiopathic cardiomyopathy

• Peri-partum cardiomyopathy

• Cardiac amyloidosis

Risks:

Nuclear imaging tests carry a very low risk of complications. The radioisotope delivers a very small amount of radiation. This amount is safe for patients occasionally undergoing nuclear imaging test.

Ventriculography by cardiac chamber catheterization:

Left heart ventriculography is commonly done while coronary angiography. However, right heart ventriculography is an independent imaging study for the right chambers (atrium and ventricle) of the heart.

Procedure:

• A mild sedative is given to the patient 30 minutes before the procedure. A cardiologist cleanses the site and numbs the area with a local anesthetic. Then a catheter (a small tube) is inserted into a vein of neck or groin.

• The catheter is moved forward into the right side of the heart. As the catheter is advanced, the doctor records pressures from the right atrium and right ventricle.

• After this, a contrast material (“dye”) is injected into the right side of the heart. It helps in determination of the size and shape of the heart’s chambers.

• The procedure takes about 1 to 2 hours.

Preparation:

• Patient should not eat or drink anything for 6 – 8 hours before the test. The procedure takes place in the hospital and patient is usually admitted the morning of the procedure.

• The procedure and its risks are explained by the health care provider and a consent form is signed by the patient.

• Local anesthesia is given at the site of catheter insertion. You will not feel the catheter as it is moved through the veins into the right side of the heart.

Indication:

Right heart angiography is used for detecting the cause of abnormal blood flow through the right side of the heart.

Abnormal Results suggest:

• Abnormal connection between the right and left side of the heart

• Rarely a right atrial myxoma

• Abnormalities of the valves on the right side of the heart

• Abnormal pressures or volumes

• Weakened pumping function of the right ventricle

Risks:

1. Cardiac arrhythmias

2. Heart attack

3. Cardiac tamponade

4. Embolism from blood clots at the tip of the catheter

5. Hemorrhage

6. Infection

7. Low blood pressure

8. Reaction or allergy to contrast dye

9. Stroke

10. Trauma to the artery or vein