Catheterization of the heart is an invasive but commonly employed procedure for visualization of the heart's coronary arteries,
chambers, valves, and/or great vessels. Basic catheterization techniques involve inserting a long, flexible, radio-opaque catheter
into a peripheral vein (for right heart catheterization) or a peripheral artery (for the left heart) under fluoroscopy (continuous
X-ray observation). Commonly, during this invasive procedure, a radio-opaque contrast medium is injected into a cardiac vessel or
chamber. The procedure may specifically be used to visualize the anatomical features of the coronary arteries, coronary veins,
aorta, pulmonary blood vessels, and/or ventricles. Such investigations may provide pertinent clinical information about structural
abnormalities in blood vessels that restrict flow (such as those caused by atherosclerotic plaque), abnormal ventricular blood
volumes, inappropriate myocardial wall thicknesses, and/or altered wall motion. A sample venogram from an isolated heart preparation
can be seen to the right/left; the catheter was inserted into the coronary sinus to block off antegrade flow, and then contrast was
injected retrograde such that the coronary venous tree was more easily observable.
To date, coronary angiography has been the primary visualization modality used clinically. However, multiple contrast injections
can potentially be acutely deleterious to patients such as those with compromised cardiac output.(1) Left coronary angiography(1-3) or
intracardiac ultrasound(1) can be employed to aid in locating the coronary sinus ostium for coronary venous system procedures. More
recently, digital subtraction angiography has been observed to allow examination of venous occlusions and anatomical variants. (4)
Movie showing a venogram in an isolated heart. The movie shows a catheter cannulating the coronary sinus ostium, then switches to a fluoroscopic
view of the heart, where the coronary veins become opaque as a contrast agent is injected.
In the future, improving the quality of cardiac visualization will allow for better planning of cardiac interventional procedures and, therefore, decreased patient risk.(5) For example, in coronary artery bypass surgery, planning where sutures should be fixed is essential to avoid suturing to a rigid calcified arterial wall.(6) Several visualization modalities have recently been used and developed to enhance visualization of the coronary system. For instance, prior to lead implantation, tissue Doppler imaging can be utilized to identify the target implant region for a transvenous pacing lead.(7, 8)
Several other visualization methodologies are worth mentioning. First, electron beam computed tomographic angiography allows minimally invasive, detailed visualization of the coronary system.(9) Second, multislice computed tomography uses a 4-dimensional functional imaging computed tomography scanner to obtain structural and functional features. High quality, virtual images show details such that transvenous lead implantation, for instance, can be planned to reduce procedure time and patient risk.(5) It is likely that future innovation in imagery technologies, including 4-dimensional intracardiac ultrasound, will further increase efficiency of assessing the presence of coronary plaques and stenoses, coronary sinus cannulation, and/or venous paths for subselection.
Leon AR. Cardiac resynchronization therapy devices: Patient management and follow-up strategies. Rev Cardiovasc Med 2003;4 Suppl 2: S38-46.
Macias A, Gavira JJ, Alegria E, Azcarate PM, Barba J, Garcia-Bolao I. Effect of the left ventricular pacing site on echocardiographic parameters of ventricular dyssynchrony in patients receiving cardiac resynchronization therapy. Rev Esp Cardiol 2004;57:138-45.
Walker S, Levy T, Rex S, Brant S, Paul V. Initial United Kingdom experience with the use of permanent, biventricular pacemakers: Implantation procedure and technical considerations. Europace 2000;2:233-9.
Oginosawa Y, Abe H, Nakashima Y. Prevalence of venous anatomic variants and occlusion among patients undergoing implantation of transvenous leads. Pacing Clin Electrophysiol 2005;28:425-8.
Coatrieux JL, Hernandez AI, Mabo P, Garreau M, Haigron P. Transvenous path finding in cardiac resynchronization therapy. Functional Imaging and Modeling of Heart, Proceedings, 2005:236-45.
von Ludinghausen M. The clinical anatomy of coronary arteries. Adv Anat Embryol Cell Biol 2003;167:III-VIII, 1-111.
Ansalone G, Giannantoni P, Ricci R, Trambaiolo P, Fedele F, Santini M. Doppler myocardial imaging to evaluate the effectiveness of pacing sites in patients receiving biventricular pacing. J Am Coll Cardiol 2002;39:489-99.
Cazeau S, Leclercq C, Lavergne T, et al. Effects of multisite biventricular pacing in patients with heart failure and intraventricular conduction delay. N Engl J Med 2001;344:873-80.
Shinbane JS, Girsky MJ, Mao S, Budoff MJ. Thebesian valve imaging with electron beam CT angiography: implications for resynchronization therapy. Pacing Clin Electrophysiol 2004;27:1566-7.
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