Cardiac Catheterization is a diagnostic option for various cardiovascular conditions. It allows the monitoring and measurement of several determining factors, such as systolic and diastolic pressure, and blood flow. Doctors often perform cardiac catheterization during angioplasty and angiography, and to advance and introduce electrodes onto the cardiac muscle for analysis and examination.
“Cardiac Catheterization (Heart Cath) is a specialized study of the heart during which a catheter, or thin hollow flexible tube, is inserted into the artery of the groin or arm. Under x-ray visualization, the tip of the catheter is guided to the heart. Pressures are measured and an x-ray Angiogram (Angio) movie of the heart and blood vessels are obtained while injecting an iodinated colorless ‘dye’ or contrast material through the catheter. Coronary angios are obtained by injecting the contrast material into the opening or mouth of a coronary artery. The iodinated solution blocks the passage of x-rays. X-ray movie pictures taken during the injection of the contrast material allow the coronary arteries to be visualized. In other words, coronary arteries are not visible on x-ray film. However, they can be made temporarily visible by filling the coronary artery with a contrast solution that blocks x-ray.”1
The Purpose of Cardiac Catheterization
Cardiac catheterization is useful during diagnostic procedures and treatments. Itallows medical professionals to surgically manage some types of cardiac conditions.
“Cardiac catheterization was used for diagnosing structural heart disease (SHD) before the development of modern echocardiography. Despite the development of cardiac computed tomography and magnetic resonance imaging since the early 2000s that has allowed safer and more accurate diagnosis of SHD, cardiac catheterization continues to play an important role in assessing the hemodynamic status of SHD. Recently, because of more advanced therapeutic interventions for SHD and the increased incidence of adult congenital heart disease, the number of cardiac catheterization procedures and associated transcatheter treatments for SHD has increased.”2
Cardiac catheterization has an interesting history. Claude Bernard was a French Physiologist who famously introduced a catheter made of glassware into a horse’s heart in 1844. He was the first to use the term cardiac catheterization.
Many years later in 1929, the German doctor Werner Frossman performed a self-catheterization and became the first human to have a cardiac catheterization procedure. In the absence of catheters specifically made for the heart, Frossman used a 0.125 inch diameter urethral catheter and inserted it into a vein in one of his arms and reached his heart. Frossman photographed this feat with an x-ray machine. In 1956, clinical application and standardization of this procedure were possible thanks to the physiologists Dickinson Richards and Andre Cournand. That same year, Frossman, Richards, and Cournand received a Nobel Prize for their contributions in the surgical field of Medicine.
Incidence of Cardiac Catheterization
“Percutaneous coronary intervention (PCI) and other types of cardiac catheterization (e.g., diagnostic procedures of the heart) are increasingly prevalent in the United States, accounting for over 2 000 000 procedures annually. This increase has been driven by the substitution of cardiac surgeries for less‐invasive catheterization, increased hospital catheterization capacity, and a greater emphasis on evidence‐based care for non-complex lesions.”3
Furthermore, Cardiac Catheterization has popularized along the US in the last two decades. “Catheterization laboratory infrastructure has increased, and, in 2007, an estimated 85% of all United States hospitals provided cardiac catheterization services. Although the volume of catheterization laboratories has decreased in recent years, the variety of catheterization procedures has expanded to include both diagnostic and therapeutic procedures. A diverse mix of procedure types and increasingly complex patients make it difficult to predict patients’ post-procedure care needs. For example, low-risk diagnostic procedures may reveal adverse conditions or trigger an immediate therapeutic intervention that necessitates extended recovery (ie, an inpatient overnight stay). Thus, prior to catheterization, it is often unknown whether a patient’s post-procedure condition will require an inpatient overnight stay”4
Iodinated contrast agents, a type of dye, are injected into vasculature via catheterization and increase the visibility of body structures, facilitating visualization of radiographic images of otherwise concealed anatomy. Iodinated contrast mediums detect the locations of anatomical deformities (aneurysms) identify the cardiac part that requires replacement or transplant.
The application of injected iodinated dye helps determine the severity of atherosclerotic processes or the degree of vascular stenosis. This information the most suitable treatment, such as coronary bypass surgery or balloon angioplasty.
“Cardiac catheterizations are performed in the Cardiac Catheterization Laboratory. Catheterizations are performed by a specially-trained cardiovascular invasive physician and a cardiovascular team of cardiology fellows, nurses, and technicians.”5
Right and Left Catheterization
“If catheters are introduced through the femoral (pronounced fem-rull) or groin artery, the procedure is known as “left heart” catheterization, because the catheter goes from the femoral artery to the aorta, coronary arteries, and the Left Ventricle (LV). This accounts for the majority of procedures. Left heart cath can also be performed by using the artery in the arm. If a catheter is also placed in the right femoral vein to measure pressures within the right side of the heart, the procedure is called “right heart” catheterization. This is used in patients with congenital heart disease, diseases of the heart valve, or certain conditions involving the pericardium (pronounced perry-card-e-yum), or sac, of the heart. This may also be used in certain diseases of the heart muscle, heart failure, shock, or when measurements of heart output or lung pressures are needed. Right and left heart catheterization is a combination of both.”6
Indications for Catheterization Procedures
“As with any procedure, the decision to recommend cardiac catheterization is based on an appropriate risk/benefit ratio. In general, diagnostic cardiac catheterization is recommended whenever it is clinically important to define the presence or severity of a suspected cardiac lesion that cannot be evaluated adequately by noninvasive techniques. Because the risk of a major complication from cardiac catheterization is less than 1% with a mortality of less than 0.08%, there are few patients who cannot be studied safely in an active laboratory.”7
Doctors prescribe catheterizations in case of:
- “Acute coronary syndrome
- STEMI, NSTEMI, unstable angina
- Pre-operative coronary assessment
- Aortic stenosis, mitral valve regurgitation, high-risk vascular surgery
- Coronary/hemodynamic evaluation in CHF or valve disease
- Pulmonary hypertension
- Peripheral arterial disease including claudication, acute limb ischemia, and critical limb ischemia
- Gangrene, nonhealing lower extremity wounds
- Cardiac tamponade
- Cardiogenic shock requiring hemodynamic support
- Heart block/Bradycardia”8
Patients with a variety of diseases may require catheterization as a diagnostic procedure. “Cardiac catheterization should be considered a diagnostic test used in combination with complementary noninvasive tests. For example, cardiac catheterization in patients with valvular or congenital heart disease is best performed with full prior knowledge of noninvasive imaging and functional information. This allows catheterization to be directed and simplified without obtaining redundant anatomic information that is reliably available through echocardiography, cardiac magnetic resonance, or CT.”9
Preparation of Patient History
“Preparation for the cardiac catheterization procedure starts with a thorough history of the patient along with a detailed examination. After defining the clinical question, the performing interventional cardiologist will decide on the access for the procedure. These procedures may need either arterial or venous access or both. Physical examination should specifically focus on assessing the suitability of the patient for the planned procedure. Special attention has to be paid in reviewing drug allergies of the patient and routine lab work. Basic workup includes a complete blood count (CBC), basic metabolic panel (BMP), prothrombin time, electrocardiogram and chest x-ray.”10
Contraindications and Potential Complications
The contraindications will depend on the general health state of the patient. “There are no absolute definitive contraindications for cardiac catheterization procedures. Most of the contraindications are relative depending on the indication for the procedure and the associated comorbidities of the patient. When the risk of complications is expected to be more than what is considered acceptable for the procedure, alternative modes of imaging and assessment can be used to answer the clinical question. Experienced operators will modify the technique of the procedure in a way as to get the best possible outcomes for the patient with the least amount of risk. Before planning for this procedure, the clinician should have a clear understanding of the clinical question that needs to be answered.”11
If the doctor does not consider all the potential contraindications, complications could arise. “The risk of major complications during diagnostic cardiac catheterization procedure is usually less than 1%, and the risk and the risk of mortality of 0.05% for diagnostic procedures. For any patient, the complication rate is dependent on multiple factors and is dependent on the demographics of the patient, vascular anatomy, comorbid conditions, clinical presentation, the procedure being performed, and the experience of the operator. The complications can be minor as discomfort at the site of catheterization to major ones like death.”12
Recent advancements and improvements have emerged. Current techniques include placing a small ultrasound on the tip of a cardiac catheter to send images of the inner walls of coronary arteries.
“Currently, the use of cardiac catheterization in SHD (structural heart disease) is increasing and becoming more complex; this could cause complications despite the preventive efforts. Careful patient selection for therapeutic catheterization and improved technique and management during the peri-procedural period are required to reduce complications.”13
Catheterization is a moderately safe procedure and is conducted on an outpatient basis throughout the world. Consult with your doctor if you have questions about the procedure or its potential risks.
(1, 9) Cardiac Catheterization. Davidson, C., & Bonow, R. Indications for Diagnostic Cardiac Catheterization. 2010. https://www.abe.pl/html/files/Bonow_Chapter%2020_main.pdf
(2, 13) Complications of Cardiac Catheterization in Structural Heart Disease. Lee, K., Seo, Y., Kim, G., An, H., Song, Y., Kwon, B., Bae, E., & Noh, C. Korean Circulation Journal. 2016. https://e-kcj.org/DOIx.php?id=10.4070/kcj.2016.46.2.246
(3) Incidence and In‐Hospital Mortality of Acute Kidney Injury (AKI) and Dialysis‐Requiring AKI (AKI‐D) After Cardiac Catheterization in the National Inpatient Sample. Brown, J., Rezaee, M., Nichols, E., Marshall, E., Siew, E., & Matheny, M. Journal of the American Heart Association. 2016. https://www.ahajournals.org/doi/10.1161/JAHA.115.002739
(4) Cardiac catheterization laboratory inpatient forecast tool: a prospective evaluation. Toerper, M., Flanagan, E., Siddiqui, S., Appelbaum, J., Kasper, E., & Levin, S. Journal of the American Medical Informatic Association. 2016. https://www.researchgate.net/publication/281510035_Cardiac_catheterization_laboratory_inpatient_forecast_tool_A_prospective_evaluation
(5) Cardiac Catheterization. Cleveland Clinic. 2019. https://my.clevelandclinic.org/health/diagnostics/16832-cardiac-catheterization
(6) Care of the Patient Following Cardiac Catheterization. Kaushal, R. Cardiovascular Nursing Symposium. 2015. https://california.providence.org/~/media/Files/Providence%20CA/Torrance/care_of_the_patient_following_cardiac_catheterization.pdf
(7, 8) Cardiac Catheterization. Marshall Medical Center. 2011. https://www.mmcenters.com/pdf/MMC-cardiac-cath-cardiac-catheterization.pdf
(10, 11, 12) Cardiac Catheterization, Risks and Complications. Manda, Y., & Baradhi, K. StatPearls. 2018. https://www.ncbi.nlm.nih.gov/books/NBK531461/