EP-4™ H403023Recalls & reported problems

Summary

The FDA's MAUDE database contains 42 adverse event reports that list this exact device (DI 05414734030236), received between Jun 15, 2018 and Aug 24, 2026 — classified as 23 injuries, 19 malfunctions.

The most frequently reported specific device problem is “Communication or Transmission Problem” (21 reports).

Reports come from manufacturers, hospitals and patients and are not verified by the FDA. A report does not prove the device caused the event, and counts can't be used to compare devices or estimate failure rates. How this data works · Data updated Oct 13, 2026.

Most reported problems

Recent adverse event reports

The 25 most recent of 42 reports, in the reporter's own words as published by the FDA.

• MalfunctionAug 24, 2026Pacing Problem

  During a supraventricular tachycardia procedure, it was noted that the EP-4 stimulator was not able to stimulate. The System was rebooted, connections were verified and the fiber optics were swapped. The issue was not resolved, and the procedure was cancelled with no adverse patient health consequences.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50408046 ↗
• MalfunctionFeb 26, 2026Pacing Problem

  DURING AN ATRIAL FIBRILLATION PROCEDURE USING NON-ABBOTT PFA (FARAWAVE), THE PROCEDURE WAS ABANDONED DUE TO CONNECTION AND PACING ISSUES. IT WAS NOTED THAT THERE WERE COMMUNICATION ISSUES WITH THE EP-4 TOUCHSCREEN AND THE WORKMATE CLARIS COMPUTER AND PACING WAS UNABLE TO BE COMPLETED. A "CHECK OUTPUT SWITCHES/CABLES" MESSAGE APPEARED. THE CABLES WERE RECONNECTED AND EXCHANGED, AND THE EP-4 CARDIAC STIMULATOR WAS REPLACED, BUT THE ISSUES PERSISTED. IT WAS VERIFIED THAT CABLES WERE CONNECTED, THE CHANNELS WERE TURNED OFF AND ON BOTH PHYSICALLY AND ON THE GUI. THE PROCEDURE WAS UNABLE TO BE COMPLETED SUCCESSFULLY. DURING FURTHER TROUBLESHOOTING, IT WAS OBSERVED THAT THE STIM PORT ON THE WORKMATE CLARIS COMPUTER HAD COLLAPSED AND THIS DAMAGE WAS PREVENTING THE EP-4 TOUCHSCREEN FROM CONNECTING TO THE DEVICE. THE EP-4 HAS NOT BEEN ABLE TO PROPERLY PACE SINCE. IT IS ALLEGED THAT BOTH THE EP-4 AND WORKMATE CLARIS COMPUTER CONTRIBUTED TO THE CANCELATION OF THE PROCEDURE.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 24462330 ↗
• MalfunctionDec 16, 2025Communication or Transmission Problem; Communication or Transmission Problem

  DURING THE SVT PROCEDURE, COMMUNICATION ISSUES WITH THE EP-4 STIMULATOR RESULTED IN THE CANCELLATION OF THE PROCEDURE. THE EP-4 STIMULATOR WAS UNABLE TO CONNECT TO THE WORKMATE CLARIS PC. THE SYSTEM WAS REBOOTED, THE CONNECTIONS WERE CHECKED, AND THE EP-4 RECEIVER BOX AND FIBER OPTIC CABLES WERE REPLACED, BUT THE ISSUE WAS NOT RESOLVED. THE PROCEDURE WAS CANCELLED AS A RESULT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 23822598 ↗
• MalfunctionNov 17, 2025Communication or Transmission Problem; Communication or Transmission Problem

  DURING A SUPRAVENTRICULAR TACHYCARDIA PROCEDURE, COMMUNICATION ISSUES RESULTED IN THE PROCEDURE BEING CANCELLED. THE EP-4 SIMULATOR WAS POWERED ON BUT THE FOLLOWING MESSAGE WAS DISPLAYED ON THE TOUCHSCREEN: "EP-4 IS OFF". THE PROCEDURE WAS CANCELLED. THERE WERE NO ADVERSE CONSEQUENCES TO THE PATIENT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 23571166 ↗
• MalfunctionJun 23, 2025Power Problem; Power Problem

  DURING A SUPRAVENTRICULAR TACHYCARDIA PROCEDURE, POWER ISSUES WITH THE EP-4 STIMULATOR RESULTED IN THE CANCELLATION OF THE PROCEDURE. THE STIMULATOR TURNED OFF AND COULD NOT BE SWITCHED BACK ON, ONLY THE DISPLAY WOULD WORK. THE PROCEDURE WAS STOPPED AND THERE WERE NO CONSEQUENCES TO THE PATIENT AS A RESULT OF THE CANCELLATION. THE PROCEDURE WILL BE RESCHEDULED FOR THE PATIENT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 22307699 ↗
• MalfunctionMay 23, 2025Pacing Problem; Pacing Problem

  DURING A SUPRAVENTRICULAR TACHYCARDIA PROCEDURE, THERE WAS A PACING ISSUE WITH THE EP-4 STIMULATOR RESULTING IN A 30-MINUTE DELAY. A DECAPOLAR CATHETER WAS USED WITH THE WORKMATE CLARIS SYSTEM. WHEN ATTEMPTING TO PACE WITH THE CLARIS EP-4 STIMULATOR, A STIMULATION SPIKE DISPLAYED ON THE SCREEN, BUT THE TISSUE WAS NOT CAPTURED. THE CHANNEL WAS CHANGED, DIFFERENT CATHETERS WERE TRIED IN DIFFERENT PARTS OF THE HEART, ALL CONNECTIONS WERE CHECKED, AND OUTPUT VALUES WERE MODIFIED (20.0 MA), BUT THE ISSUE PERSISTED. STIMULATING WAS DONE THROUGH A TEMPORARY PACEMAKER TO RESOLVE THE ISSUE. THE PROCEDURE WAS SUCCESSFULLY COMPLETED WITH NO ADVERSE CONSEQUENCES TO THE PATIENT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 22075737 ↗
• MalfunctionMar 26, 2025Device Remains Activated; Communication or Transmission Problem; Device Remains Activated; Communication or Transmission Problem

  DURING AN ATRIAL FIBRILLATION PROCEDURE, IT WAS REPORTED THAT THE EP-4 COULD NOT STOP PACING AND THE ERROR MESSAGE "HARDWARE ON RESPONDING" WOULD DISPLAY RESULTING IN CANCELLATION OF THE PROCEDURE. WHEN THE CONNECTION ERROR APPEARED, THE PACING SOUND MADE A BUZZING SOUND, THE STIMULATION SPIKE COULD BE SEEN IN THE SIGNAL LINE, AND THE LIGHT IN THE PACING CHANNEL WAS BLINKING. TROUBLESHOOTING INCLUDED CONNECTING THE EP-4 STRAIGHT TO THE WORKMATE CLARIS DWS, SWAPPING THE MEDIA CONVERTER AND ANALOG CABLE, AND EXCHANGING THE E-4 STIMULATOR TO A NEW UNIT BUT ISSUE PERSISTED. THE PROCEDURE WAS NOT COMPLETED.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 21702499 ↗
• MalfunctionJan 3, 2025Communication or Transmission Problem; Communication or Transmission Problem

  DURING A SUPRAVENTRICULAR TACHYCARDIA/EP STUDY, ELECTRICAL PROPERTY ISSUES WITH THE COMPUTER RESULTED IN A PROCEDURAL DELAY. SHORTLY AFTER CATHETERIZATION, EXTRA-STIMULUS PACING WAS ATTEMPTED, BUT IT WAS NOTED THAT THE EP-4 TOUCH SCREEN AND EP-4 PANEL ON THE WORKMATE CLARIS SCREEN FLASHED WHITE AND RETURNED TO THE MAIN MENU. THE ON/OFF DISPLAY ON THE EP-4 TOUCH SCREEN ALSO SHOWED "EP-4 IS OFF". THE SYSTEM WAS RESTARTED AND THE ISSUE WAS RESOLVED BRIEFLY, BUT THEN THE ISSUE RECURRED. ALL OF THE CONNECTIONS WERE CHECKED BETWEEN THE EP-4 TOUCH SCREEN, THE DWS, THE EP-4 STIMULATOR, AND THE WORKMATE CLARIS AMPLIFIER. ALL CONNECTIONS WERE SECURE BUT THE ISSUE PERSISTED. THE PROCEDURE WAS COMPLETED USING A NON-ABBOTT SYSTEM AND STIMULATOR WITH NO ADVERSE CONSEQUENCES TO THE PATIENT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 21069352 ↗
• MalfunctionSep 16, 2024Communication or Transmission Problem; Communication or Transmission Problem

  DURING DEVICE PREPARATION FOR AN ATRIAL FIBRILLATION PROCEDURE WITH A PATIENT INVOLVED, THERE WAS A COMMUNICATION ISSUE WITH THE EP-4 STIMULATOR CABLE, RESULTING IN CANCELLATION OF THE PROCEDURE.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 20226936 ↗
• MalfunctionOct 3, 2023Output Problem; Output Problem

  DURING A SUPRAVENTRICULAR TACHYCARDIA PROCEDURE, THE STIMULATOR TOUCHSCREEN SHOWED AN "EP-4 IS OFF" ERROR AND SWITCHED BACK TO THE MENU SCREEN INSTEAD OF A SCREEN TO PACE FROM. THE ISSUE WAS TEMPORARILY RESOLVED BY RESTARTING THE RECORDING SYSTEM, STIMULATOR AND TOUCHSCREEN, HOWEVER THE ISSUE RECURRED. THE STIMULATOR WAS REPLACED, AND THE ISSUE WAS RESOLVED. THERE WERE NO ADVERSE CONSEQUENCES TO THE PATIENT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 17860243 ↗
• InjuryAug 21, 2023Pacing Problem; Pacing Problem

  DURING A PROCEDURE, THE PACING INTERVAL DROPPED FROM 500MS TO 100MS ON ITS OWN, AND THE PATIENT HAD TO BE DEFIBBED. THE DECREASE OCCURRED INCREMENTALLY OVER APPROXIMATELY 10 SECONDS. F5 STRAIGHT PACING PROTOCOL WAS BEING USED. IT WAS ADVISED THAT THE DOWN ARROW KEY ON THE KEYBOARD MAY BE STUCK.

  Patient problems: Arrhythmia

  MAUDE report 17581563 ↗
• MalfunctionDec 20, 2022Failure of Device to Self-Test; Failure of Device to Self-Test

  DURING AN ATRIAL FIBRILLATION PROCEDURE, IT WAS REPORTED THE EP-4 DID NOT PASS THE SELF-TEST AND THE PROCEDURE WAS CANCELLED. THE ISSUE WAS NOT RESOLVED, THE PATIENT TAKEN OFF THE TABLE, AND THE PROCEDURE WAS CANCELLED.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 16013505 ↗
• MalfunctionSep 2, 2022Communication or Transmission Problem; Communication or Transmission Problem

  DURING PREPARATION FOR A PEDIATRIC SUPRAVENTRICULAR TACHYCARDIA PROCEDURE, WITH THE PATIENT ON THE TABLE, THE STIMULATOR DID NOT FUNCTION AS INTENDED (DATA COULD NOT BE SENT FORWARD) AND THE CASE WAS CANCELLED. THE SYSTEM WAS SHUTDOWN AND RESTARTED, THE FIBER OPTIC CABLES WERE REPLACED, THE CONNECTIONS WERE CHECKED AND THE MEDIA CONVERTERS WERE TURNED OFF AND ON WHICH DID NOT RESOLVE THE ISSUE AND THE CASE WAS CANCELLED WITH NO CONSEQUENCES TO THE PATIENT. THE PROCEDURE HAS BEEN RESCHEDULED. ANOTHER EP-4 UNIT WAS OBTAINED FROM ANOTHER LAB WHICH RESOLVED THE ISSUE.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 15347805 ↗
• InjuryMay 10, 2022Pacing Problem; Pacing Problem

  DURING AN ATRIOVENTRICULAR NODAL ABLATION, EMERGENCY STIMULATION FUNCTION OF THE EP-4 WAS USED. WITH THE USE OF ELECTROCAUTERY, VENTRICULAR SALVOS COULD BE INDUCED, WHICH DEGENERATED INTO VF. A CARDIOVERSION WAS PERFORMED TO STOP THE TACHYCARDIA. THE PROTOCOL WAS CHANGED TO A FIXED STIMULATION PROTOCOL VIA F5 ON EP4 AND COMPLETED THE PROCEDURE WITHOUT ANY FURTHER COMPLICATIONS TO THE PATIENT.

  Patient problems: Arrhythmia

  MAUDE report 14349090 ↗
• MalfunctionOct 15, 2021Signal Artifact/Noise; Mechanical Problem; Signal Artifact/Noise; Mechanical Problem

  PRIOR TO THE PROCEDURE WITH THE PATIENT PREPPED AND ON THE TABLE, HIGH FREQUENCY SIGNALS WERE NOTED AND THE PROCEDURE WAS CANCELLED. THE SIGNAL ISSUE COULD NOT BE EXPLAINED AND THE SETUPS COULD NO LONGER BE SAVED. A DOUBLE POTENTIAL WAS ALSO CREATED DURING STIMULATION. THE PROCEDURE WAS CANCELLED WITH NO CONSEQUENCES TO THE PATIENT. THE PROCEDURE HAS BEEN RESCHEDULED.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 12642362 ↗
• MalfunctionSep 29, 2021Communication or Transmission Problem; Communication or Transmission Problem

  DURING THE PROCEDURE, THE EP-4 WOULD NOT COMMUNICATE WITH THE SYSTEM AND THE PROCEDURE HAD TO BE CANCELLED. THERE WERE NO ADVERSE CONSEQUENCES TO THE PATIENT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 12551040 ↗
• MalfunctionSep 17, 2021Communication or Transmission Problem; Communication or Transmission Problem

  MANUFACTURER REPORT NUMBERS: 2184149-2021-00287, 2184149-2021-00286. DURING THE PROCEDURE, AFTER BOOTING ON THE SYSTEM, PACING WAS PERFORMED AND SUCCESSFUL MEASUREMENT AND PATIENT DIAGNOSIS WAS DONE. AFTER PRESSING THE ABLATION BUTTON, A HARDWARE MALFUNCTION MESSAGE APPEARED ON THE SYSTEM MONITORING SCREEN: "NMI: PARITY CHECK / MEMORY PARITY ERROR. THE SYSTEM HAS HALTED" AND THE SYSTEM COULD NOT OPERATE AS INTENDED. THE DWS AND THE CPU WERE RESTARTED, BUT THE ISSUE PERSISTED. AFTER OVERALL PATIENT CONDITION ASSESSMENT, IT WAS DECIDED TO STOP THE PROCEDURE. THERE WERE NO ADVERSE PATIENT CONSEQUENCES TO THE PATIENT DUE TO THESE ISSUES. PRODUCT REPLACEMENT IS NOT POSSIBLE FOR THIS CUSTOMER, SO NO EQUIPMENT WILL BE RETURNING FOR INVESTIGATION.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 12490787 ↗
• MalfunctionAug 20, 2021Loss of Threshold; Loss of Threshold

  DURING THE PROCEDURE, THE EP-4 WAS INTERMITTENTLY STOPPED PACING WHILE ATTEMPTING TO PACE THE PHRENIC NERVE. WHILE INTERMITTENT PACING OCCURRED THE SCREEN OF THE STIMULATOR WAS SHOW THAT THE UNIT WAS STILL ON. AFTER PACING RETURNED, THE SYSTEM WOULD RETURN TO THE HOME SCREEN IN THE MIDDLE OF THE PROCEDURE. WHEN PACING RETURNED, THE PROCEDURE WAS ABLE TO BE COMPLETED WITH NO ADVERSE PATIENT CONSEQUENCES.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 12347765 ↗
• MalfunctionFeb 22, 2021Communication or Transmission Problem; Communication or Transmission Problem

  DURING A SUPRAVENTRICULAR TACHYCARDIA ABLATION PROCEDURE, THE EP-4 SHOWED AS "OFF OR DISCONNECTED" ON THE SYSTEM AND THE PROCEDURE WAS NOT ABLE TO BE COMPLETED. THE DEVICE WAS BYPASSED WITHOUT THE TOUCHSCREEN AND THE ISSUE REMAINED. THERE WERE NO ADVERSE CONSEQUENCES TO THE PATIENT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 11359125 ↗
• MalfunctionFeb 12, 2021Communication or Transmission Problem; Communication or Transmission Problem

  DURING AN ATRIAL FIBRILLATION ABLATION PROCEDURE, THE MESSAGE "EP-4 HARDWARE IS NOT RESPONDING" WAS DISPLAYED AND BECAUSE OF SUCH, PACING COULD NOT BE APPLIED AS PLANED AND THE PROCEDURE WAS ONLY COMPLETED TO THE MINIMUM STANDARD. MULTIPLE TROUBLESHOOTING STEPS WERE ATTEMPTED TO RESOLVE THE ISSUE, BUT THE ISSUE REMAINED. THE PROCEDURE WAS STILL ABLE TO BE COMPLETED WITH AN EMERGENCY STIMULATION BOX WITH NO ADVERSE CONSEQUENCES TO THE PATIENT, BUT WITHOUT PACING OR POST PACING AS PLANNED. DURING FURTHER TROUBLESHOOTING, THE MEDIA CONVERTER WAS EXCHANGED AND THE ISSUE WAS RESOLVED.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 11324312 ↗
• InjuryJan 20, 2021Communication or Transmission Problem; Communication or Transmission Problem

  DURING THE PROCEDURE, THE EP-4 WOULD NOT ESTABLISH CONNECTION WITH THE CLARIS AND THE PROCEDURE WAS CANCELLED. THERE WERE NO ADVERSE CONSEQUENCES TO THE PATIENT DUE TO THE CANCELLATION. THE MONITOR WAS REPLACED AND THE ISSUE WAS RESOLVED.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 11204869 ↗
• InjuryJan 10, 2021Communication or Transmission Problem; Communication or Transmission Problem

  DURING A PVI ABLATION PROCEDURE, IT WAS UNABLE TO ESTABLISH CONNECTION TO THE SIMULATOR. THE POWER SUPPLY AND CONNECTED CABLES WERE CHECKED BUT THE ISSUE PERSISTED. THE PROCEDURE WAS CANCELLED DUE TO THESE ISSUES. THERE WERE NO ADVERSE PATIENT CONSEQUENCES.

  Patient problems: No Clinical Signs, Symptoms or Conditions; No Consequences Or Impact To Patient

  MAUDE report 11144323 ↗
• InjuryJul 20, 2020Failure of Device to Self-Test; Failure of Device to Self-Test

  DURING PROCEDURE SETUP, THE EP4 WOULD NOT GO THROUGH SELF TEST, AND STATES THAT IT IS ON BUT NOT RESPONDING. THE SYSTEM WAS POWER CYCLED, TRIED MULTIPLE SELF TEST, HAD CHANNELS PRESSED IN TO SEE IF IT WOULD PROMPT TO TURN OFF CHANNEL BEFORE SELF TEST, BUT IT STILL SAYS EP4 IS ON BUT NOT RESPONDING. THE PROCEDURE WAS CANCELLED. THERE WERE NO ADVERSE PATIENT CONSEQUENCES.

  Patient problems: No Consequences Or Impact To Patient

  MAUDE report 10295973 ↗
• InjuryJun 26, 2020Communication or Transmission Problem; Communication or Transmission Problem

  DURING THE PROCEDURE, THE EP4 STIMULATOR WAS NOT COMMUNICATING WITH THE DWS AND THE CASE WAS CANCELLED. REMOTE TROUBLESHOOTING WAS DONE BUT THE PROBLEM PERSISTED. THE PATIENT WAS PUNCTURED, BUT THE PROCEDURE COULD NOT BE COMPLETED AND THE CASE WAS ABANDONED. THERE WERE NO CONSEQUENCES TO THE PATIENT.

  Patient problems: No Consequences Or Impact To Patient

  MAUDE report 10202937 ↗
• InjuryMay 21, 2020Environmental Compatibility Problem; Environmental Compatibility Problem

  RELATED MANUFACTURER REFERENCE: 2184149-2020-00056, 2184149-2020-00057. DURING A PROCEDURE, A SALINE BAG RUPTURED CAUSING WATER DAMAGE TO DEVICES. THE PROCEDURE WAS CANCELLED. THE CLARIS EP4 STIMULATOR HAD EVIDENCE OF SALINE FLUID DAMAGE AND HAD FLUID INSIDE THE UNIT. THE SIGNALS WERE INTERMITTENT AND COULD NOT BE REPAIRED. THE DB9 SERIAL TO FIBER MEDIA CONVERTER AND THE CATHETER INPUT MODULE 1¿CM1 PIN BOX BOTH HAD WATER DAMAGE. THERE WAS NO HARM TO THE PATIENT OR THE STAFF.

  Patient problems: No Consequences Or Impact To Patient

  MAUDE report 10080860 ↗