What is a cardiac Left Heart Catheterization (LHC)?

Left Heart Catheterization (LHC): A Comprehensive Overview

Left heart catheterization (LHC) is an invasive diagnostic procedure that involves inserting a catheter into the left side of the heart to assess cardiac function, measure pressures, evaluate blood flow, and visualize coronary arteries through angiography. 1

Procedure Components and Purpose

• LHC allows direct assessment of left heart hemodynamics, including measurement of left ventricular pressure, left atrial pressure (via pulmonary capillary wedge pressure), and evaluation of the aortic root and valve function 1

• The procedure typically includes selective coronary angiography, which provides detailed images of coronary arteries through the injection of radiographic contrast material 1

• Left ventricular angiography may be performed during LHC to evaluate ventricular function, wall motion, and ejection fraction 1

• LHC is often combined with right heart catheterization (RHC) in specific clinical scenarios to provide comprehensive hemodynamic assessment, known as bilateral heart catheterization (BHC) 2

Clinical Indications

• LHC is indicated when therapeutic interventions such as coronary bypass surgery or percutaneous coronary intervention (PCI) are being considered 3

• The procedure is essential for definitive diagnosis when non-invasive imaging techniques provide insufficient or conflicting information about cardiac anatomy or function 1

• LHC is recommended for assessment of coronary circulation in suspected coronary artery anomalies or in cases of Kawasaki disease with suspected coronary involvement 1

• It serves as the "gold standard" for determining true peak-to-peak pressure gradients in cases of valvular stenosis, particularly when Doppler echocardiography results are inconclusive 1

Technical Aspects

• Access for LHC is typically obtained through the femoral artery, though radial artery access has become increasingly common and is associated with fewer access site complications, particularly in anticoagulated patients 4

• For transseptal LHC (accessing the left atrium from the right atrium), a specialized technique is used to puncture the interatrial septum when direct access to the left atrium is required 1

• The procedure requires fluoroscopic guidance to navigate the catheter through the vascular system and into the heart chambers 1

• Pressure measurements, blood sampling, and angiographic imaging are performed according to standardized protocols to ensure reliable and reproducible results 1

Risks and Complications

• Cardiac arrhythmias are among the most common complications during catheterization, with ventricular arrhythmias occurring in approximately 0.1-1.1% of diagnostic LHCs 5

• The risk of ventricular tachycardia or fibrillation is higher during interventional procedures (1.1%) and significantly elevated during procedures for acute myocardial infarction (4.1-4.3%) 5

• Other potential complications include vascular injury, cardiac perforation, stroke, allergic reactions to contrast material, renal insufficiency, and rarely, death (0.1-0.2% in elective cases) 1

• Complication rates are higher in patients with severe left ventricular dysfunction, neonates, elderly patients, and those with severe arterial hypoxemia or pulmonary hypertension 1

Combined Right and Left Heart Catheterization

• Bilateral heart catheterization provides comprehensive hemodynamic assessment and is particularly valuable in evaluating pulmonary hypertension associated with left heart disease 6

• In a study of Veterans Affairs hospitals, 61.3% of patients undergoing bilateral heart catheterization had abnormal right heart catheterization values, suggesting appropriate clinical indications for the combined procedure 2

• Combined right and left heart catheterization is essential for accurate assessment of pulmonary vascular resistance and transpulmonary gradient in patients being evaluated for heart transplantation 1

Quality Considerations

• LHC should be performed in specialized centers by experienced operators following strict protocols to ensure reliable results and minimize complications 1

• The rate of concurrent right heart catheterization in patients undergoing LHC for coronary artery disease indications is considered a quality marker for catheterization laboratories, with inappropriately high rates suggesting overutilization 2

• Cardiac catheterization should never be viewed as a routine technical service but rather as a specialized consultation requiring sophisticated techniques and experienced personnel 1

• A prospective registry of complications should be maintained by each catheterization laboratory to monitor performance and ensure high standards 1

Special Considerations

• In anticoagulated patients, LHC can be safely performed using radial artery access without interruption of anticoagulation, reducing the risk of thromboembolism while avoiding major access site complications 4

• For pediatric patients and those with complex congenital heart disease, specialized protocols and equipment are necessary, and the procedures should be performed in centers with appropriate expertise 1

• The timing of catheterization is critical; when possible, it should be performed when problems such as arrhythmias, heart failure, or azotemia are stable or improving to obtain accurate physiological data and minimize risks 1