Where it fits
Rhythmia HDx is Boston Scientific’s 3D mapping platform, distinguished by the IntellaMap Orion mini-basket catheter and a workflow built around ultra-high-density automated acquisition. Compared with Carto and EnSite X — both capable of high-density mapping with the right catheter — Rhythmia pushes density further by default: a single Orion sweep typically returns tens of thousands of points, with automated annotation through Lumipoint.
In practice, labs use Rhythmia where map detail is the priority — complex atypical flutter, post-ablation atrial tachycardia, scar-related VT, and AF cases where substrate clarity matters. It pairs cleanly with Boston Scientific’s ablation ecosystem (IntellaNav, Farapulse for PFA) but is also compatible with non-BSC ablation catheters via impedance localization.
Localization technology
Rhythmia HDx uses hybrid impedance + magnetic localization.
- Magnetic localization — a magnetic field generator under the table; the Orion basket carries a magnetic sensor in its shaft, giving the basket and its 64 electrodes high-accuracy reference.
- Impedance localization — body-surface patches drive currents across the thorax; non-magnetic catheters in the field are localized by voltage measurement.
- The system fuses both: magnetic anchors the geometry, impedance fills in other catheters.
- Beat acceptance is the defining workflow detail — every potential point is checked against cycle length, respiration, catheter motion, signal-to-noise, and stability. Beats that fail any criterion are silently rejected. This is the source of Rhythmia’s clean maps and also of its “why are no points landing” frustration when a criterion is misconfigured.
Compatible catheters & accessories
- IntellaMap Orion — the platform-defining catheter. Mini-basket configuration, eight splines, eight electrodes per spline = 64 electrodes total at 2.5 mm spacing. Magnetic sensor in the shaft. Deploys to roughly 18 mm diameter when fully expanded; collapses for navigation.
- IntellaNav MiFi OI and IntellaNav Stablepoint — ablation catheters with impedance and (Stablepoint) contact force.
- Farapulse FARAWAVE — Boston Scientific’s PFA catheter; visualizes in Rhythmia for combined mapping + PFA workflows.
- Standard diagnostic catheters (CS, His) visualize via impedance.
Lab setup
Pre-case prep:
- Boot the Rhythmia workstation early; the system is software-heavy and patient registration takes time.
- Confirm the magnetic field generator is positioned under the table at the level of the heart before the patient is on.
- Patch placement with patient supine, arms in final case position:
- Surface impedance patches per the system diagram (anterior, posterior, lateral pairs).
- Surface ECG patches for recording integration.
- Dispersive / RF return patch for ablation.
- Skin prep: clip, alcohol, dry.
- Confirm patch impedance and magnetic field detection on a still patient before drape.
- Pre-test the Orion deploy / collapse mechanism on the bench — the basket should expand smoothly and retract fully.
- Connect catheter inputs and bridge to the recording system.
- Load case profile; review beat acceptance criteria for the planned rhythm (criteria for AF are very different from criteria for atypical flutter or sinus rhythm).
Workflow during the case
Typical atypical flutter or post-ablation AT case:
- Access, CS catheter placement, transseptal under ICE if left-sided.
- Orion advanced into the chamber, basket deployed against the wall.
- Operator sweeps the chamber slowly; the system streams accepted points based on beat criteria. Map density builds rapidly — a thorough LA sweep can yield 20,000–40,000 points in 5–10 minutes.
- Lumipoint runs on the acquired data: automated annotation of activation timing, identification of regions of interest (slow conduction zones, late activation, fractionation), and visualization of conduction channels.
- Tag landmarks; review activation map for the tachycardia circuit or substrate.
- Switch to IntellaNav (or Farapulse for PFA) for ablation; the system tracks lesions on the map.
- Re-map after ablation — Rhythmia’s strength is in showing the post-ablation activation change in detail.
For AF: PVI workflow is similar to other platforms, with Orion providing pre- and post-ablation maps of the LA.
What’s distinctive
- Map density. No other routine clinical platform delivers as many points per unit time in standard practice. Substrate detail and activation circuit clarity are the payoff.
- Lumipoint post-acquisition annotation — automated highlighting of conduction channels, fractionation, late activation, and other regions of interest reduces manual annotation time.
- Orion basket geometry also functions as anatomy acquisition — the deployed basket presses against the wall and the 64 electrodes report position simultaneously.
- Strict beat acceptance keeps maps clean — at the cost of slower acquisition in noisy rhythms or with an unstable catheter.
- Trade-off: the Orion basket has a minimum deployed size; very small chambers, tight PVs, and pediatric anatomy are not its strength.
Common pitfalls
- Basket deployment in small chambers. Orion needs room to expand fully. Forcing the basket into a tight PV ostium or a small RA can damage tissue or fail to deploy. Recognize on fluoro and ICE; collapse and reposition rather than push.
- Signal averaging on noisy beats. Beat acceptance is strict by default. In ectopy-heavy rhythms, AF with rate variability, or when the catheter is moving, very few points land. Recognize as “map not building” and check acceptance criteria — loosen cycle-length or stability tolerances if the clinical rhythm justifies it.
- Basket contact non-uniform. The 64 electrodes are only useful where they touch tissue. Partial deployment or a basket floating in the middle of the chamber returns far-field signals that contaminate the map. Confirm wall contact on ICE.
- Catheter motion under respiration. Long apneic ventilation or jet ventilation helps in chambers where respiratory excursion is degrading the map.
- Magnetic field interference. Metal objects near the field — a forgotten instrument, an unshielded cable — distort localization. Sweep the field if geometry looks off.
- Patch lift through long cases — same problem as on every impedance-using platform; watch the impedance display and replace patches that drift out of range.
Staff role
- Before the case — patch placement, magnetic field generator position confirmed, Orion bench-tested for deploy / collapse, system boot, patient registration, case profile and beat acceptance criteria reviewed.
- During the case — mapping tech drives acquisition, watches the point count and acceptance rate, calls out basket deployment status to the operator, and adjusts criteria if the rhythm warrants.
- Operator and tech together — confirm basket contact on ICE before committing to a sweep; do not chase points on a non-contact basket.
- Lumipoint review — tech can pre-run automated annotation and present regions of interest to the operator for review before the ablation plan is finalized.
- End of case — save final maps, export to archive, power down per lab protocol.