IsoflexRecalls & reported problems across all models

We found 4 models of Isoflex by St. Jude Medical, Inc. in the FDA's device registry (GUDID). Together they are named in 4,644 adverse event reports in the FDA's MAUDE database, received between Jun 11, 2018 and Sep 28, 2026 — classified as 65 deaths, 2,019 injuries, 2,560 malfunctions.

The most frequently reported specific device problem is “Over-Sensing” (1,324 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 Isoflex problems

Isoflex models

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

• Isoflex™ 1948-58

  Permanent defibrillator electrodes
  26 deaths2,015 reports
• Isoflex™ 1944-52

  Permanent defibrillator electrodes
  12 deaths1,647 reports
• Isoflex™ 1948-52

  Permanent defibrillator electrodes
  20 deaths653 reports
• Isoflex™ 1944-46

  Permanent defibrillator electrodes
  7 deaths329 reports

Recent Isoflex adverse event reports

The 15 most recent reports across all models, in the reporter's own words as published by the FDA.

• MalfunctionSep 28, 2026Over-Sensing

  It was reported that the asymptomatic patient presented remotely via Merlin.net. Upon review of transmission, it was found that the Right Ventricular (RV) lead exhibited oversensing noise resulted in pacing inhibition and triggering noise reversion and High Ventricular Rate (HVR) episodes. No intervention was performed. Patient condition was stable.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50916323 ↗
• InjurySep 28, 2026Capturing Problem; Device Sensing Problem

  It was reported that the patient presented to the hospital for a scheduled pacemaker replacement procedure and extraction of the right ventricular (RV) leads. The patient had experienced syncope and dizziness associated with diminishing R-wave amplitudes and elevated capture thresholds related to both the active and previously capped RV leads. Fluoroscopic evaluation confirmed that the active RV lead had become dislodged. During the procedure, the pacemaker and active RV lead were explanted and replaced. The previously capped RV lead was also explanted on (b)(6) 2026. Subsequently, a new leadless pacemaker system was implanted. The patient remained stable throughout the procedure.

  Patient problems: Dizziness; Syncope/Fainting

  MAUDE report 50914704 ↗
• InjurySep 28, 2026Capturing Problem; Device Sensing Problem; Device Dislodged or Dislocated

  It was reported that the patient presented to the hospital for a scheduled pacemaker replacement procedure and extraction of the right ventricular (RV) leads. The patient had experienced syncope and dizziness associated with diminishing R-wave amplitudes and elevated capture thresholds related to both the active and previously capped RV leads. Fluoroscopic evaluation confirmed that the active RV lead had become dislodged. During the procedure, the pacemaker and active RV lead were explanted and replaced. The previously capped RV lead was also explanted on (b)(6) 2026. Subsequently, a new leadless pacemaker system was implanted. The patient remained stable throughout the procedure.

  Patient problems: Dizziness; Syncope/Fainting

  MAUDE report 50914700 ↗
• InjurySep 28, 2026Over-Sensing

  It was reported the patient presented for a follow up in clinic. It was noted that the right ventricular lead exhibited noise over-sensing which resulted in pacing inhibition. The noise was noted to reproduced with shoulder movement. The lead was explanted and replaced with a leadless pacemaker. The patient remained in stable condition.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50910950 ↗
• MalfunctionSep 28, 2026Break

  It was reported that the patient presented to hospital for a generator change procedure. During the procedure, it was noted visually that the right ventricular (RV) lead had an insulation breach. The RV lead was capped and replaced on (b)(6) 2026. The patient was in stable condition.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50910768 ↗
• InjurySep 25, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that the patient presented for a clinical follow up. It was noted that the patient had experienced persistent redness and swelling at the cervical pocket site, along with symptoms of a pocket infection, for the past six months. The entire system, including the Implantable Cardioverter Defibrillator (ICD), right ventricular lead, right atrial lead, and left ventricular lead, was explanted. The patient remained in stable condition.

  Patient problems: Unspecified Infection

  MAUDE report 50893650 ↗
• MalfunctionSep 24, 2026Fracture; Over-Sensing

  During remote follow-up, noise which resulted in oversensing was observed on the atrial lead. The suspected cause of the event is a lead fracture; however this has not been confirmed. No intervention has been performed at this time. The patient was stable and will continue to be monitored.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50884236 ↗
• MalfunctionSep 24, 2026Fracture; Over-Sensing

  During remote follow-up, noise resulting in oversensing and pacing inhibition were observed on the right ventricular (RV) lead. The patient is pacemaker dependent; however, no consequence occurred due to the inhibition. The suspected cause of the event is a lead fracture; however, this has not been confirmed. No intervention has been performed at this time. The patient was stable and will continue to be monitored.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50884211 ↗
• InjurySep 20, 2026Over-Sensing

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50834689 ↗
• MalfunctionSep 18, 2026High impedance; Capturing Problem

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50829144 ↗
• MalfunctionSep 18, 2026Intermittent Capture; Device Sensing Problem

  It was reported that the patient presented to hospital for an implant procedure. During the procedure, it was noted that the right atrial (RA) lead exhibited inconsistent capture issue and inconsistent P wave measurement. The RA lead was not used and replaced. The patient was in stable condition.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50813976 ↗
• MalfunctionSep 17, 2026High impedance

  It was reported that the patient presented remotely via Merlin.net. Review of transmission, it was noted that the right ventricular (RV) lead exhibited gradual increase of pacing impedance. No changes or interventions were reported and will continue to be monitored. There were no patient consequences.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50798313 ↗
• InjurySep 14, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that the patient presented to the hospital and experienced symptoms related to right ventricular (RV) lead pacing. The RV lead was explanted and replaced with a left bundle branch area (LBBA) lead. Multiple repositioning attempts were made on the LBBA lead. The LBBA lead was unsuccessfully implanted during the same procedure and was replaced on (b)(6) 2026. There were no patient consequences.

  Patient problems: Insufficient Information

  MAUDE report 50749636 ↗
• InjurySep 14, 2026Adverse Event Without Identified Device or Use Problem

  It was reported that the patient presented for a scheduled clinic visit due to heart failure. Interrogation revealed that reduced pacing function and low-voltage measurements on the right ventricular (RV) lead associated with cardiomyopathy. An echocardiogram confirmed reduced low voltage function. The RV lead was capped and replaced on (b)(6)2026. The patient condition was not reported.

  Patient problems: Heart Failure/Congestive Heart Failure

  MAUDE report 50748137 ↗
• MalfunctionSep 14, 2026Component Missing

  It was reported that the patient presented for an implant procedure. During the procedure, it was noted that one of the wing-shaped hooks of the passive right atrial (RA) lead was missing. The RA lead was not used and replaced. The patient remained stable throughout the procedure.

  Patient problems: No Clinical Signs, Symptoms or Conditions

  MAUDE report 50748091 ↗

Other St. Jude Medical, Inc. products

• Tendril15 models · 49,498 reports
• Octrode10 models · 36,740 reports
• Proclaim12 models · 35,038 reports · 17 recalls
• Durata28 models · 19,805 reports
• Assurity MRI2 models · 17,838 reports · 1 recall
• Gallant8 models · 12,885 reports · 5 recalls
• Quartet10 models · 11,001 reports
• MitraClip19 models · 9,056 reports · 2 recalls