Cardiac catheterization (cath) labs, electrophysiology (EP) labs, and the broader family of fixed-imaging interventional procedure rooms — interventional radiology (IR), neuro-interventional/biplane, and structural-heart rooms — are the hospital's image-guided, minimally-invasive procedural platform. They share the DNA of an operating room (sterile field, anesthesia capability, code-compliant power) but are organized around a permanently installed C-arm fluoroscopy system and a control-room/equipment-room triad that fundamentally shapes their architecture, shielding, power, and HVAC design.

What This Article Covers (and What It Does Not)

This Article is the canonical home for fixed-imaging interventional procedure rooms whose defining asset is a floor- or ceiling-mounted angiographic C-arm and its supporting control and equipment rooms. That family includes:

• Cardiac cath labs — diagnostic coronary angiography and percutaneous coronary intervention (PCI), including primary PCI for STEMI.
• EP labs — diagnostic electrophysiology studies, catheter ablation (RF and cryo), and cardiac implantable electronic device (CIED) implants (pacemakers, ICDs); often equipped with 3-D electroanatomic mapping and, increasingly, intracardiac imaging.
• Structural-heart rooms — TAVR, mitral/tricuspid repair, LAAO; frequently a single-plane or biplane lab with enhanced anesthesia and echo (TEE) support, and sometimes overlapping with hybrid-OR territory.
• Interventional radiology (IR) / neuro-interventional rooms — angiography, embolization, drainage, vascular and oncologic interventions; neuro/stroke rooms typically use a biplane imaging system.

The room types sit on a spectrum. At one end is a single-plane diagnostic cath lab; at the other is a biplane neuro suite or a structural-heart room that approaches a hybrid OR in capability. The hybrid OR — a fully restricted operating room with fixed imaging governed by surgical (Class C / Group 2) requirements — is treated as its own Article and is not duplicated here. Likewise, the standard OR and the endoscopy suite with scope reprocessing are separate siblings. This Article stays in the lane of the cath/EP/IR interventional platform: its rooms, supporting spaces, shielding, power, air, and code classification.

Classification: Procedure Room vs. Operating Room

The single most consequential design decision for any interventional room is its clinical classification, because classification drives ventilation, air change rate, finishes, and code pathway. The Facility Guidelines Institute (FGI) Guidelines for Design and Construction of Hospitals defines three relevant room types:

A diagnostic cath lab or EP lab is most commonly classified as a procedure room in current FGI/ASHRAE 170 terms. The moment a program intends to perform open surgery, planned surgical conversion, or implant of permanent devices under conditions demanding an OR-grade environment, the room must be designed as an operating room — with the higher air change rate, surgical finishes, and code classification that follow. Structural-heart programs frequently push a room across this line, which is why TAVR/mitral rooms are often built as hybrid ORs rather than enhanced cath labs.

Owners must lock classification at programming, with cardiology, anesthesia, infection prevention, the AHJ, and the accreditor (TJC or DNV) aligned. Misclassifying a room — building it as a procedure room when the clinical service intends OR-grade work — is among the most expensive and disruptive errors to discover during commissioning or survey, because remediation can mean re-doing the air handling and finishes.

Room Configuration: The Lab Triad

Unlike a standard OR, an interventional lab is rarely a single room. It is a coordinated set:

• Procedure room — houses the patient table, the imaging gantry (floor- or ceiling-mounted C-arm), ceiling-suspended monitor booms, surgical/procedure lights, anesthesia and hemodynamic equipment, and the sterile field. Generous clear floor area is required so the gantry can travel and rotate without collision; biplane systems consume substantially more floor area than single-plane.
• Control room — an adjacent, glass-walled space where the physiologic monitoring/hemodynamic recording system, imaging acquisition workstation, and staff console sit behind leaded glass. The control room is the radiation-safe operating position for technologists and the recording nurse.
• Equipment room — a dedicated, conditioned room for the imaging system's generator, computing cabinets, UPS, and isolation/power equipment. Imaging-equipment rooms generate significant heat and have their own cooling, access, and clearance requirements set by the vendor.

This triad must be planned together; the control and equipment rooms are not afterthoughts. Sightlines from the control room into the procedure room, cable-pathway lengths between equipment room and gantry (vendor-limited), and staff circulation among the three are all early architectural drivers.

Typical Sizing (Rule-of-Thumb)