Devices › Automated external defibrillators (non-wearable)
Device brand name · Defibrillator/pacemaker
X Series: medical device reports filed with FDA
13,983 reports name it, 2012–2026. Manufacturer given most often on reports: Zoll Medical. Product code MKJ.
- 13,983
- device reports naming the brand
- 0.1% of all MAUDE reports · about 987 a year
- 1,692
- reports, 12 months to August 2026
- 1,668 in the 12 months before
- 97.1%
- classified as malfunction
- 96.8% across the product code
- 2.7%
- classified as death, as reported
- 381 reports · not verified by FDA
FDA's MAUDE database holds 13,983 reports that name the brand "X Series" (defibrillator/pacemaker), received between May 2012 and August 2026; the manufacturer given most often on reports is Zoll Medical. Spellings of one product vary from report to report.
1,692 reports arrived in the 12 months to August 2026, close to the 1,668 of the 12 months before. FDA releases MAUDE data monthly; reports can arrive months after an event, so the newest months grow in later releases. The event types recorded are malfunction (97.1%), death (2.7%) and injury (0.1%); across all automated external defibrillators (non-wearable) reports (product code MKJ) death is recorded in 1.7% and malfunction in 96.8%. Event type is the reporter's classification of the report, not a verified outcome.
The device problems coded most often are failure to power up (19.9%), unable to obtain readings (16.3%) and no display/image (14.7%). The patient problems coded most often are no patient involvement, cardiac arrest and death. FDA states that "MDR data alone cannot be used to establish rates of events, evaluate a change in event rates over time or compare event rates between devices. The number of reports cannot be interpreted or used in isolation to reach conclusions about the existence, severity, or frequency of problems associated with devices." It adds that the reporting system "has limitations, including the potential submission of incomplete, inaccurate, untimely, unverified, or biased data."
Reports by month, five years
Reports by the month FDA received them. FDA releases MAUDE data monthly; reports can arrive months after an event, so the newest months grow in later releases.
By year received
Event type and report source
Event type, as classified on the report
Who filed the report
Grey bar: all 269,686 reports carrying product code MKJ. Event type is the filer's classification and is not verified by FDA.
Device problems coded
| Device problem (FDA code) | Reports | Share | Share across product code |
|---|---|---|---|
| Failure to power up | 2,786 | 19.9% | 13% |
| Unable to obtain readings | 2,276 | 16.3% | 4.4% |
| No display/image | 2,050 | 14.7% | 4.2% |
| Failure of device to self-test | 1,898 | 13.6% | 8.9% |
| Unexpected shutdown | 744 | 5.3% | 1.8% |
| Defibrillation/stimulation problem | 743 | 5.3% | 3.2% |
| Pacing problem | 578 | 4.1% | 1.2% |
| Reset problem | 555 | 4% | 0.3% |
| Failure to deliver shock/stimulation | 543 | 3.9% | 1.8% |
| Device displays incorrect message | 433 | 3.1% | 11.6% |
| Failure to charge | 362 | 2.6% | 2.5% |
| Loss of powerthe device lost power | 246 | 1.8% | 1.6% |
| Device operates differently than expectedthe device behaved unexpectedly | 214 | 1.5% | 11.8% |
| Incorrect interpretation of signal | 153 | 1.1% | 0.4% |
| Activation problem | 140 | 1% | 0.1% |
| Failure to discharge | 127 | 0.9% | 1.6% |
| Failure to analyze signal | 107 | 0.8% | 0.5% |
| Output problem | 100 | 0.7% | 0.5% |
| Electrical shorting | 82 | 0.6% | 0.1% |
| Device operational issue | 68 | 0.5% | 0.1% |
FDA's device problem codes as entered on the report; one report can carry several. Generic codes such as "no apparent adverse event" are left out.
Patient problems coded
| Patient problem (FDA code) | Reports | Share |
|---|---|---|
| No patient involvement | 2,792 | 20% |
| Cardiac arrestthe heart stopped | 221 | 1.6% |
| Deaththe patient died; cause not stated by this term | 178 | 1.3% |
| Necrosisdeath of tissue | 112 | 0.8% |
| Ventricular fibrillationa chaotic rhythm from the lower heart chambers | 22 | 0.2% |
| Intraoperative cardiac valve injury | 13 | 0.1% |
| Bradycardiaslow heart rate | 9 | 0.1% |
| Burn(s)a burn | 7 | 0.1% |
| Chest painchest pain | 7 | 0.1% |
| Electric shockan electric shock | 7 | 0.1% |
| Administration site reaction | 5 | 0% |
| Asystole | 5 | 0% |
| Tachycardiafast heart rate | 4 | 0% |
| Atrial fibrillationan irregular heart rhythm | 3 | 0% |
| Inadequate osseointegration | 3 | 0% |
Patient problem codes are present mainly in reports filed since 2019 and are often blank.
In context
| Measure | X Series | Product code MKJ | All MAUDE reports |
|---|---|---|---|
| Reports | 13,983 | 269,686 | 26,136,888 |
| Share of that pool | — | 5.2% | 0.1% |
| Classified as death, per 1,000 reports | 27 | 17 | 9 |
| Classified as injury | 0.1% | 0.7% | 36.2% |
| Classified as malfunction | 97.1% | 96.8% | 62.3% |
| Filed by the manufacturer | 99.9% | 99.3% | 94.9% |
Shares are of reports, not of devices in use. FDA states that "MDR data alone cannot be used to establish rates of events, evaluate a change in event rates over time or compare event rates between devices. The number of reports cannot be interpreted or used in isolation to reach conclusions about the existence, severity, or frequency of problems associated with devices." It adds that the reporting system "has limitations, including the potential submission of incomplete, inaccurate, untimely, unverified, or biased data."
Other brands with product code MKJ
| Brand | Reports | Latest 12 months | Classified as death |
|---|---|---|---|
| M Series | 27,112 | 4 | 2.3% |
| Heartstart Mrx | 18,592 | 0 | 0.7% |
| HeartStart MRx -EMS Defibrillator | 16,166 | 33 | 0.8% |
| Heart Start XL | 15,944 | 95 | 0.9% |
| R Series Defibrillator | 15,393 | 0 | 0.9% |
| HeartStart XL+ Defibrillator/Monitor | 13,188 | 210 | 0.4% |
| Heartstart Onsite | 10,964 | 0 | 0.8% |
| Aed Plus | 9,225 | 423 | 2.2% |
| Heartsine Samaritan 300p And Pad Pak | 8,197 | 0 | 0.3% |
| E Series Defibrillator | 8,052 | 0 | 1.5% |
| Lifepak R 15 Monitor/Defibrillator | 6,117 | 463 | 1.4% |
| Heartstart Frx | 5,978 | 2 | 1.3% |
| Efficia Dfm100 | 5,076 | 0 | 0.6% |
| LIFEPAK 15 defibrillator/monitor | 4,716 | 369 | 1% |
| Lifeline | 4,877 | 2,117 | 0.4% |
Ordered by report count for navigation only. FDA states that "MDR data alone cannot be used to establish rates of events, evaluate a change in event rates over time or compare event rates between devices. The number of reports cannot be interpreted or used in isolation to reach conclusions about the existence, severity, or frequency of problems associated with devices." It adds that the reporting system "has limitations, including the potential submission of incomplete, inaccurate, untimely, unverified, or biased data." FDA also states that "common products may have a higher number of adverse events due to the higher total number of people using the product."
Questions about X Series reports
How many FDA reports name X Series?
13,983 medical device reports in the openFDA MAUDE release of 28 Sep 2026, covering reports received through August 2026; 1,692 in the latest 12 months.
What kinds of events are reported?
malfunction (97.1%), death (2.7%) and injury (0.1%). "Event type" is how the report was classified when filed: death, injury, malfunction or other.
What device problems are coded?
failure to power up (19.9%), unable to obtain readings (16.3%), no display/image (14.7%), failure of device to self-test (13.6%) and unexpected shutdown (5.3%). These are FDA's device problem codes as entered on the report.
Who files these reports?
manufacturer reports (99.9%) and voluntary reports (0%). Manufacturers and user facilities are required to report; voluntary reports come from health professionals and the public.
Do these reports show that X Series was at fault?
No. FDA states that "MDR data alone cannot be used to establish rates of events, evaluate a change in event rates over time or compare event rates between devices. The number of reports cannot be interpreted or used in isolation to reach conclusions about the existence, severity, or frequency of problems associated with devices." It adds that the reporting system "has limitations, including the potential submission of incomplete, inaccurate, untimely, unverified, or biased data." FDA adds that "a causal relationship cannot be established between product and reactions listed in a report."
How do I report a problem with a medical device?
Through FDA MedWatch (Form FDA 3500 for health professionals and consumers), or to the manufacturer. See the guide on how to report.
Where this comes from. Counts are built from the openFDA Device Adverse Event (MAUDE) bulk export released 28 Sep 2026, which holds reports FDA received through 31 Aug 2026. Brand, generic and manufacturer names are as written on the reports; product code names come from FDA's device classification. A report counts here when any device it lists carries this brand name after punctuation and capitalisation are normalised. No report narrative, lot number, patient detail or reporter identity is published. See the methodology and sources; FDA's record is authoritative, and corrections are handled within five working days.
Drug data (FAERS) through 30 Jun 2026; device data (MAUDE) through 31 Aug 2026. Not medical advice.