Background:

- Currently, heart catheterization procedures are guided by X-rays. Researchers are developing new techniques to perform heart catheterization without the use of X-rays by investigating possible uses of magnetic resonance imaging (MRI) scans. To study these uses, researchers are interested in performing a part of the standard X-ray catheterization procedure using MRI on individuals who are scheduled to have heart catheterization.

Objectives:

- To examine the safety and feasibility of right-heart catheterization using MRI-guided catheters.

Eligibility:

- Individuals at least 21 years of age who are undergoing a medically necessary heart catheterization procedure.

Design:

• The research MRI procedure will be performed either before or after standard X-ray guided heart catheterization.
• Participants will be transferred from an X-ray table onto an MRI table and advanced into the scanner. Under MRI guidance, a MRI-compatible catheter will be used to measure blood pressure and blood oxygen levels in the heart, and MRI scanning will be performed for approximately 30 minutes.

Heart catheterization is a minimally invasive procedure to measure pressure and inject dye into specific heart cavities. Heart catheterization usually uses X-ray guidance, which involves radiation exposure and which fails to visualize soft tissue.

We have developed real-time magnetic resonance imaging (MRI) to guide heart catheterization with tissue visualization but without X-ray radiation. In the first phase of this protocol we showed that comprehensive right-sided heart catheterization is feasible in adult patients, using commercially available MRI-compatible ( passive ) catheters.

In the second phase of the protocol, we began performing systematic right-sided heart catheterization without X-ray whenever possible. We will assess the hearts response to hemodynamic provocation during MRI catheterization tailored to the patient s problem. We will use this protocol to further refine the technique

If successful, this will enable future testing of devices for adult and pediatric MRI-guided catheterization, such as special active wire guides, which may lead to new non-surgical treatments of cardiovascular disease.

• INCLUSION CRITERIA:

Age greater than or equal to 2 years old

Undergoing medically necessary diagnostic or interventional right and/or left cardiovascular catheterization

EXCLUSION CRITERIA :

Cardiovascular instability including ongoing acute myocardial infarction, refractory angina or ischemia, and decompensated congestive heart failure.

Women who are pregnant or nursing

Unable to undergo magnetic resonance imaging:

• Cardiac pacemaker or implantable defibrillator
• Cerebral aneurysm clip
• Neural stimulator (e.g. TENS-Unit)
• Any type of ear implant
• Ocular foreign body (e.g. metal shavings)
• Metal shrapnel or bullet.
• Any implanted device (e.g. insulin pump, drug infusion device), unless it is labeled safe for MRI

EXCLUSION CRITERIA FOR GADOLINIUM-BASED CONTRAST AGENTS FOR ADULTS:

Renal excretory dysfunction, estimated glomerular filtration rate < 30 mL/min/1.73m(2) body surface area according to the Modification of Diet in Renal Disease criteria

Glomerular filtration rate will be estimated using the CKD-EPI equation (33):

eGFR equal 141 x (minimum of (Scr/K, 1)(a) x (maximum of (Scr/K, 1)) (-1.209) x 0.993(Ag x 1.018 (if female) x 1.159 (if black)

Where<TAB>Scr equal serum creatinine

a = -0.329 for females and -0.411 for males

k = 0.7 for females and 0.9 for males

Subjects meeting this exclusion criterion may still be included in the study but may not be exposed to gadolinium-based contrast agents.

EXCLUSION CRITERIA FOR GADOLINIUM-BASED CONTRAST AGENTS FOR CHILDREN

Renal excretory dysfunction, estimated glomerular filtration rate < 30 mL/min/1.73m(2) body surface area according to the Schwartz equation for estimation of GFR in children as recommended by the National Kidney Disease Education Program. The Schwartz equation is commonly used for GFR determination in children at Children s National Medical Center, Washington, DC.

GFR (mL/min/1.73 m2) = (k (SqrRoot) height) / serum creatinine concentration where K = constant defined as

follows:

k = 0.33 in premature infants [Excluded from this protocol]

k = 0.45 in term infants to 1 year of age [Excluded from this protocol]

k = 0.55 in children to 13 years of age

k = 0.70 in adolescent males (not females because of the presumed increase in male muscle mass,

the constant remains 0.55 for females)

• Height in cm
• Serum creatinine in mg/dL