Which invasive procedure threads a catheter into a vein or artery to reach the heart and measures blood flow, oxygen, and pressures?

• A. Bronchoscopy
• B. Cardiac catheterization
• C. Colonoscopy
• D. Bone scan

Answer: (B)

Cardiac catheterization is an invasive procedure where a catheter is threaded from a peripheral vein or artery into the heart. This setup allows direct measurement of intracardiac pressures (such as right atrial, right ventricular, and pulmonary artery pressures, and the left-sided pressures estimated by the wedge technique), as well as sampling blood to determine oxygen content in different chambers. From these data, clinicians can calculate blood flow or cardiac output and assess overall heart function and abnormal hemodynamics. It’s often combined with coronary angiography to visualize coronary arteries.

The other procedures don’t involve threading a catheter to the heart or measuring its pressures and oxygenation. Bronchoscopy examines the airways, colonoscopy examines the colon, and a bone scan images bones using a radioactive tracer.