EP-4Recalls & reported problems across all models

We found 3 models of EP-4 by St. Jude Medical, Inc. in the FDA's device registry (GUDID). Together they are named in 57 adverse event reports in the FDA's MAUDE database, received between Jun 15, 2018 and Aug 24, 2026 — classified as 30 injuries, 27 malfunctions.

The most frequently reported specific device problem is “Communication or Transmission Problem” (22 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. Widely used products collect more reports, so totals can't be used to compare products or estimate failure rates. Only reports that name a model's exact device identifier are counted. What reports can and can't tell you · How this data works

Most reported EP-4 problems

EP-4 models

3 models, most reported first. Each model has its own page with its reports, recalls and device details.

• EP-4™ H403023

  Generator, pulse, pacemaker, external programmable (for electrophysiological studies only)
  42 reports
• EP-4™ H21911

  GENERATOR, PULSE, PACEMAKER, EXTERNAL PROGRAMMABLE
  12 reports
• EP-4™ Cardiac Stimulator

  GENERATOR, PULSE, PACEMAKER, EXTERNAL PROGRAMMABLE
  3 reports

Recent EP-4 adverse event reports

The 15 most recent reports across all models, 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 ↗
• MalfunctionJul 5, 2023Pacing Problem; Impedance Problem; Pacing Problem; Impedance Problem

  DURING THE SUPRAVENTRICULAR TACHYCARDIA PROCEDURE, PACING AND IMPEDANCE ISSUES RESULTED IN THE PROCEDURE BEING ABANDONED WITH NO REPORTED ADVERSE PATIENT CONSEQUENCES. IT WAS NOTED THAT THE PACING SPIKE WAS NOT BEING DELIVERED PROPERLY TO THE TISSUE. THE PACING SPIKE WAS VISIBLE ON THE NON-ABBOTT SYSTEM (CARDIOLAB), BUT THERE WAS NO RESPONSE FROM THE TISSUE. THE TOUCHSCREEN SHOWED AN IMPEDANCE ERROR AND "CHECK OUTPUTS SWITCHES" ERROR. THE PROCEDURE WAS NOT ABLE TO BE COMPLETED AND THEREFORE ABANDONED. THERE WERE NO ADVERSE CONSEQUENCES TO THE PATIENT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 17256219 ↗
• InjuryMay 17, 2023No Tactile Prompts/Feedback; No Tactile Prompts/Feedback

  DURING AN ATRIAL FLUTTER PROCEDURE, THE STIMULATOR WAS UNRESPONSIVE TO A COMMAND TO STOP PACING RESULTING IN THE PATIENT EXPERIENCING ATRIAL FIBRILLATION WHICH REQUIRED CARDIOVERSION TO RESOLVE THE ATRIAL FIBRILLATION. THE STIMULATOR WAS TURNED OFF AND REBOOTED AND THE ISSUE WAS RESOLVED WITH NO FURTHER PATIENT CONSEQUENCES. THE PHYSICIAN WAS PACING DOWN TO A RATE IN THE 200S, THEN THE STIMULATOR SWITCHED TO PACING ON CHANNEL 3 AT 340 ON ITS OWN. WHEN THE COMMAND TO STOP PACING WAS GIVEN VIA THE KEYBOARD, IT DID NOT STOP PACING. IT WAS ATTEMPTED TO STOP PACING USING THE TOUCHSCREEN BUT THIS WAS ALSO UNSUCCESSFUL. WHILE THIS ISSUE WAS OCCURRING, THE SYSTEM AND TOUCHSCREEN DISPLAYS SHOWED A GREEN STIM BAR, INDICATING THE SYSTEM DID NOT THINK IT WAS PACING, EVEN THOUGH IT WAS. THE CONTINUED PACING CAUSED THE PATIENT TO BE PUT INTO ATRIAL FIBRILLATION. THE STIMULATOR WAS TURNED OFF WHICH STOPPED THE PACING. THE SYSTEM WAS REBOOTED AND THE ISSUE WAS RESOLVED. CARDIOVERSION WAS PERFORMED TO RESOLVE THE ATRIAL FIBRILLATION. THE PROCEDURE WAS COMPLETED WITH NO OTHER CONSEQUENCES.

  Patient problems: Atrial Fibrillation

  MAUDE report 16948120 ↗
• MalfunctionDec 20, 2022No Tactile Prompts/Feedback; No Tactile Prompts/Feedback

  DURING AN ATRIAL FIBRILLATION PROCEDURE, IT WAS NOTED THAT THE EP-4 STIMULATOR WAS SHOWING AS OFF AND NOT RESPONDING TO TOUCHSCREEN INPUTS WHICH CAUSED THE PROCEDURE TO BE CANCELLED. THERE WERE NO ADVERSE CONSEQUENCES TO THE PATIENT.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 16015272 ↗
• 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 ↗

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