CPT® Code 93562

Deleted

1. Indications

Indicator dilution studies, including those for cardiac output measurement, are indicated for various clinical scenarios where assessment of cardiac function is necessary. The following conditions may warrant the performance of this procedure:

• Intracardiac Shunts - These are abnormal connections between the heart chambers that can lead to inefficient blood flow and oxygenation.
• Valvular Regurgitation - This condition occurs when blood leaks backward through a heart valve, which can affect overall cardiac output and efficiency.
• Heart Failure - Patients with heart failure may require evaluation of cardiac output to guide treatment decisions and monitor disease progression.
• Severe Pulmonary Hypertension - Assessment of cardiac output can help in understanding the impact of elevated pressures in the pulmonary circulation on heart function.

2. Procedure

The procedure for indicator dilution studies involves several critical steps, which vary slightly depending on whether dye or thermal dilution is used:

• Dye-Based Indicator Dilution - Initially, venous and arterial catheters are inserted into the patient. A blood sample is drawn, and the densitometer is calibrated using known concentrations of the dye mixed with the patient's blood sample. Once calibrated, dye is injected into the catheterized vein. The dye mixes with the blood as it circulates through the heart and is subsequently pumped into the arteries. A blood sample is then obtained from the catheterized artery, and the densitometer analyzes the sample to measure the concentration of dye present. This data is used to calculate the cardiac output.
• Cold Thermal Dilution - For this method, a Swan-Ganz catheter is inserted through the internal jugular or subclavian vein into the right atrium and ventricle, with the tip advanced into a branch of the pulmonary artery. Cold dextrose is injected through the catheter port located in the right atrium. The cold dextrose mixes with the blood in the right heart chambers and travels into the pulmonary artery, where a thermistor at the catheter tip detects the drop in temperature. Cardiac output is then calculated based on the temperature-time curve generated from this data.
• Warm Thermal Dilution - Similar to the cold method, a Swan-Ganz catheter with a heating coil is placed in the right heart. A series of heat pulses are administered, and the resulting temperature changes are analyzed to determine cardiac output.

3. Post-Procedure

After the completion of the indicator dilution study, patients may be monitored for any immediate complications related to catheter placement or the procedure itself. It is essential to observe for signs of bleeding, infection, or adverse reactions to the dye or injected fluids. The results of the cardiac output measurements will be analyzed and interpreted by the healthcare provider to guide further management and treatment decisions. Patients may be advised on any necessary follow-up appointments or additional testing based on the findings of the study.