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A team of cardiologists shared tips and tricks for clinicians to address the pitfalls they may encounter when conducting cardiac catheterization.
A team of cardiologists from the United Kingdom shared guidance for clinicians on optimizing right heart catheterization (RHC) procedures to diagnose and treat pulmonary arterial hypertension (PAH).
“Despite major advances in imaging and other non-invasive diagnostic modalities over recent decades, cardiac catheterization has several indications in contemporary clinical practice,” wrote Konstantinos Dimopoulos, MD, MSc, PhD, and colleagues in the International Journal of Cardiology Congenital Heart Disease. “In this paper, we provide a detailed overview of diagnostic cardiac catheterization…with an emphasis on fundamental concepts, tips and tricks, and potential pitfalls.”
Following a Standard Protocol
Some patients with pulmonary hypertension may require left heart catheterization if:
- Clinicians cannot establish a reliable pulmonary arterial wedge pressure or need to obtain left ventricular end-diastolic pressure.
- The patient has left-sided congenital or other obstructive lesions for which invasive hemodynamics assessment is needed.
- The patient requires coronary angiography, although most patients with low risk who have suspected coronary artery disease undergo CT coronary angiography.
However, most patients only require RHC. The authors advocated for a standardized RHC protocol, reviewing pre-, peri-, and post-procedure guidance.
Before RHC, clinicians should review the indications and explain to the patient the procedure’s goals, steps, alternative investigations, possible complications, and management. The authors wrote that clinicians should also manage the patient’s medications, noting that management for patients receiving anticoagulation depends on whether clinicians may need arterial access.
As part of peri-procedure management, clinicians should review the patient’s recent blood test results, follow the WHO safety checklist, and tailor sedation, pain management, discomfort prevention, choice of access route, and need for oxygen to the individual.
After RHC, clinicians can re-establish anticoagulation, monitor the access site, conduct discharge planning, and watch for complications, especially in patients who are frail, older, or have significant comorbidities.
Ensuring Catheter Reaches Pulmonary Structures
The authors discussed several difficulties clinicians may encounter when advancing a catheter toward pulmonary circulation.
Femoral Insertion
Catheters inserted via femoral access often enter collateral veins, particularly in the pelvic region. Clinicians should proceed cautiously to avoid vessel injury (from excessive force or balloon inflation in smaller vessels) or catheter kinking, which can lead to the formation of large loops that are challenging to untangle. Clinicians can straighten small loops in the right atrium using a guidewire to prevent knot formation.
“A looped catheter should not be pulled back to the sheath without fluoroscopy to avoid kinks that may make catheter removal difficult or traumatic,” the authors noted.
The most difficult step when accessing pulmonary arteries through femoral insertion is advancing the catheter from the right ventricular (RV) inlet toward the RV outflow tract. The authors recommended 1) inflating the balloon and gently rotating the catheter clockwise to align with the RV outflow tract, or 2) carefully creating a loop in the right atrium such that the catheter points toward the RV outflow tract as soon as it enters the ventricle.
“In both instances, a guidewire can be used to either provide more support (‘body’) and straighten the tip of the catheter or be carefully advanced ahead of the catheter, avoiding injury to the tricuspid valve or RV and monitoring for ventricular arrhythmia,” Dr. Dimopoulos and colleagues wrote.
Arm Insertion
Catheters inserted from the arm may become obstructed at the shoulder. Additionally, the catheter may veer towards the head instead of the heart. Clinicians can use fluoroscopy and a hydrophilic guidewire to resolve these issues and inject a small amount of contrast to clarify the patient’s anatomy.
IVC Access
An upper body approach can make accessing the inferior vena cava challenging. The review authors recommended advancing a guidewire while keeping the catheter in the superior vena cava (SVC).
SVC Access
By accessing the SVC, clinicians can obtain reliable mixed venous oxygen saturation measurements and rule out shunts. The authors cautioned that clinicians must carefully manipulate balloon-tipped catheters inserted via the femoral artery in the right atrium. Typically, clinicians use anticlockwise rotation to align with the SVC; however, clockwise rotation may be necessary to advance toward the RV.
Left Pulmonary Artery Access
Balloon-tipped catheters inserted into the upper body tend to enter the right pulmonary artery. If clinicians need to access the left pulmonary artery for measurements such as PA wedge pressure, they should position the catheter in the RV outflow tract or proximal pulmonary artery, and a guidewire can help direct it towards the left pulmonary artery.
“Femoral access usually results in left pulmonary artery access,” the authors said.
Additional Considerations
The authors discussed the interpretation of various measurements, considerations for patients with suspected pulmonary hypertension associated with congenital heart disease, and the prognostic value of invasive hemodynamics.
“Despite its invasive nature and major improvements in imaging, cardiac catheterization remains fundamental to cardiology,” Dr. Dimopoulos and colleagues said. “It is the gold standard for the assessment of intracardiac and pulmonary pressures, detection and quantification of shunts and other hemodynamic lesions, and is integral in the diagnosis and classification of pulmonary hypertension.”
