Model note · Defibrillator
Philips HeartStart MRx monitor/defibrillator
The HeartStart MRx is a portable biphasic monitor and defibrillator offering AED, manual defibrillation, synchronised cardioversion and pacing, with optional SpO2, NBP, EtCO2, invasive pressure, temperature, 12 lead ECG and Q-CPR feedback. It is no longer sold new but remains widely installed in hospitals and ambulances, and its long recall history makes field action tracking a core part of looking after it.
The model
Maker, model and type.
- Maker
- Philips Medical Systems
- Model
- HeartStart MRx monitor/defibrillator (M3535A hospital, M3536A pre hospital)
- Device type
- Defibrillator
- Main document
- Open the public document
Key specifications
What the public record says.
| Item | Value | Source |
|---|---|---|
| Waveform | Biphasic truncated exponential, parameters adjusted for patient impedance | Source |
| Manual energy settings | 1 to 10, 15, 20, 30, 50, 70, 100, 120, 150, 170, 200 J; limited to 50 J with internal paddles | Source |
| Delivered energy accuracy | Plus or minus 2 J up to 10 J, plus or minus 15% from 15 J upwards | Source |
| Charge time to 200 J | Under 5 s with a new full battery at 25 degrees C; under 15 s on the M3539A AC module alone | Source |
| Patient impedance range | 25 ohm minimum external, 15 ohm minimum internal, 180 ohm maximum | Source |
| Battery (M3538A lithium ion) | Under 0.82 kg, about 3 h to full charge (2 h to 80%), at least 50 charge and shock cycles at 200 J | Source |
| Battery run time | At least 5 h full monitoring with 20 shocks at 200 J; at least 9 h ECG only | Source |
| Size and weight | 31.5 x 21.0 x 29.5 cm with pads; 13.9 lb or less with pads, cable, battery and paper | Source |
| Network connectivity | IntelliVue Network connection added under K062233 | Source |
Recalls
Known FDA recalls.
- Z-2794-20202020-07-16
Therapy switch failure could block the selected function or deliver a different energy.
FDA record - Z-1499-20202020-02-26
Dropped units could have hidden internal damage and fail to deliver therapy.
FDA record - Z-1923-20192019-06-07
M3539A AC power module failing at higher than expected rate.
FDA record - Z-0603-20192018-11-23
M3538A batteries with a defective thermal cut off could stop charging or supplying power.
FDA record - Z-2035-20182018-05-03
Wrong component on therapy PCB could cause failure to charge.
FDA record - Z-2842-20162016-08-26
Handle could separate from the housing after rear case mount breakage.
FDA record - Z-1797-20132013-06-19
Possible unsynchronised cardioversion shock.
FDA record - Z-2347-20122012-06-20
Therapy cable connection wear affecting pads and paddles cable detection.
FDA record
Safety
Safety warnings from the record.
- Only qualified service personnel should service or repair the device; detailed repair data is in the separate service manual. Source
- A 2013 recall found the MRx could deliver an unsynchronised cardioversion shock, which may induce VF, so software must be at the corrected level. Source
- Units on battery only may shut down without warning under strong RF interference unless corrected. Source
- Wrong wiring of the vehicle wall mount DC power module during installation can cause smoke or fire. Source
Sources
Where this note comes from.
- Philips HeartStart MRx Instructions for Use
- FDA 510(k) K062233, HeartStart MRx network connectivity
- openFDA recall search, HeartStart MRx
- openFDA MAUDE problem counts, brand HEARTSTART MRX
Not covered: Specs and messages come from one public edition of the IFU; earlier software versions may behave differently. The MRx service manual was not read, so service codes, Operational Check failure codes and part numbers are not given. There are over 50 recall records; only the most relevant are listed, and many were driven by a 2017 consent decree period. The manufacturerUrl points to the public IFU rather than a product page, as the MRx is discontinued. MAUDE counts include bulk reporting and are not failure rates.
BMEssentia knowledge drafted from public information, reviewed by Hasan Khaled Ismail on 2026-10-24. Always follow the manufacturer's instructions for use and service manual.
Defibrillator