心臓カテーテル検査 III: 左心カテーテル検査

Left heart catheterization evaluates the aortic arch and its major branches, left ventricle function, mitral and aortic valve competency, and coronary artery patency. The procedure uses retrograde catheterization, where a catheter is inserted through a radial, femoral, or brachial artery and advanced into the aorta and left ventricle to assess cardiac structure and function.

Coronary angiography positions the catheter in a coronary artery and injects contrast to visualize arterial anatomy and detect blockages. Ventriculography evaluates the left ventricle's size and function by injecting contrast to enhance its visibility on imaging. Both techniques use contrast agents but target different cardiac structures for diagnostic assessment.

Fluoroscopy is a continuous X-ray imaging technique that allows physicians to visualize catheter movement and placement in real-time. It ensures accurate navigation through the arterial system into the aorta and left ventricle, guides contrast injection, and enables identification of blockages or structural abnormalities. Fluoroscopic guidance also supports interventional procedures like angioplasty or stent placement.

Catheter manipulation and contrast injection can cause myocardial ischemia and arrhythmias, requiring vigilant monitoring. Post-procedure complications include bleeding, hematoma, perforation of the left heart or great vessels, and systemic embolization. Patients must be monitored closely after the procedure to detect and manage these potential adverse events promptly.

Pre-procedure preparations include discontinuing oral anticoagulants 24 hours prior, obtaining thorough history with emphasis on contrast allergy, examining access sites and documenting peripheral pulses, and checking hemoglobin, platelets, creatinine, and coagulation profile. IV normal saline is administered to prevent contrast-induced renal dysfunction, especially in patients with renal impairment.

A fine needle is inserted into the selected artery, and a flexible guide wire is threaded through it. A sheath is placed over the guide wire to facilitate catheter access. The catheter is then introduced through the sheath and navigated to the heart using fluoroscopic imaging, ensuring accurate placement in the aorta, left ventricle, or coronary arteries depending on the procedure's diagnostic or therapeutic purpose.

Left heart catheterization assesses coronary artery bypass grafts, evaluates coronary artery disease in patients with chest pain, determines severity of myocardial or valvular disorders such as aortic stenosis and mitral stenosis, and assesses cardiac arrhythmias. Therapeutically, it treats valvular heart diseases through procedures like valvuloplasty and can perform interventional procedures when blockages are detected.