How to Read a Pacemaker or ICD Interrogation Report for a Lawsuit (Free Tool)
You get one thing from a device interrogation report that no other document in a cardiac case provides: a timestamped log of what the heart did, recorded by the device itself, that can be laid next to the clinical chart to see what the clinicians knew and when. The report is dense and written for electrophysiology staff, which is why it so often sits in the file unread. This post explains what each section contains, which values matter in a sudden-death, syncope or device-malpractice case, how to line the episode log up against the chart, and what to request from the clinic and the manufacturer.
What the report contains
- Device and leads. Manufacturer, model and serial number for the generator and each lead, implant dates, and lead position. This is what you check against FDA advisories and recalls.
- Battery. Voltage, estimated longevity, and whether the device has reached its elective replacement indicator.
- Lead measurements. Impedance, sensing amplitude and capture threshold for each lead, often with a trend from prior checks. Values outside the expected range suggest lead fracture, dislodgement or insulation failure, which are questions for an expert.
- Programmed parameters. Pacing mode, lower and upper rates, detection zones and therapy sequences for an ICD, and any features turned on or off.
- Pacing and sensing statistics. Percentage of time paced in each chamber, and arrhythmia burden such as atrial fibrillation hours.
- Episode log. Each stored arrhythmia episode with date, time, duration, rate, the device's classification, and any therapy delivered: anti-tachycardia pacing, shock, or none. Stored electrograms for each episode usually exist but are not in the summary PDF.
- Alerts. Conditions the device flagged, and in remote-monitoring reports, when the transmission was received.
What to look for
1. The episode timeline against the chart
Sort every episode by date and time. Then place the clinic visits, the emergency department presentations, the remote transmissions and the phone calls on the same line. The question in most device cases is the same: was there an episode or an alert before a clinical decision that the decision did not account for? The 2023 HRS/EHRA/APHRS/LAHRS expert consensus statement on practical management of the remote device clinic (Heart Rhythm Society summary; full text at PMC10264760) describes remote monitoring as the standard of care for patients with these devices and addresses alert management and workflows, which is the framework an expert will use to evaluate how transmissions and alerts were handled.
2. Therapy delivered or withheld
For an ICD, note each shock and each anti-tachycardia pacing attempt, whether the device classified the rhythm as treatable, and whether therapy was successful. An episode in a monitor-only zone, or a detection rate programmed above the rate the patient's arrhythmia reached, is a programming question for the expert.
3. Lead and battery trends
A single out-of-range impedance is a prompt to request the trend across prior interrogations. A battery at or past the elective replacement indicator, with a replacement not scheduled, is a dated fact the chart must explain.
4. Programming changes
Compare the programmed settings in this report with the prior one. Any change should match an order or a note authorizing it.
5. The clock
Device clocks drift and can be set to another time zone. Before a device time is compared with a hospital time, find out who confirmed the clock and when.
Decode the report in a minute
Paste the text of a pacemaker, ICD, CRT or loop-recorder interrogation or remote-monitoring report. The decoder returns the device and lead table, battery status, programming, a dated episode timeline, alerts, case-relevant flags and a records-to-request list, with unknowns left blank and inferences labelled. Free, no login.
Open the Interrogation Report Decoder →A worked example (hypothetical)
The facts below are invented for illustration. No real patient, clinic, physician or manufacturer event is described.
A 66-year-old man with a dual-chamber ICD is found unresponsive at home and cannot be resuscitated. The family obtains the clinic records and the final interrogation performed by the coroner's request. The report shows a battery voltage at the elective replacement indicator with "ERI reached" dated nine weeks before death; a right-ventricular lead impedance trend that jumped sharply at the prior remote transmission four months earlier; and an episode log with three ventricular tachycardia episodes in the final month, two with anti-tachycardia pacing recorded as unsuccessful and no shock delivered. The clinic chart has one remote-transmission entry in the period, marked "reviewed, no action," two days after the impedance jump.
Pasted into the decoder, the output's device table lists the generator and lead models for an advisory check. The lead section flags the impedance value with a prompt to request the trend. The battery row shows the ERI date. The episode timeline places the three episodes by date and shows "ATP: unsuccessful; shock: none" on two of them, with the quote marks confirming the sentences exist in the pasted text. The clinical flags section lists three items for the expert: ERI without a documented replacement plan, an impedance change followed by a "no action" review, and ventricular episodes with therapy that did not terminate the rhythm. The records-to-request list begins with the full remote-transmission log in native format and the alert acknowledgement records.
For plaintiff counsel, the timeline is the case in three dated facts, each of which needs an electrophysiologist to say what should have followed. For defense counsel, it identifies the documents that will show what the clinic actually saw on the transmission, and whether the device clock matches the clinic's.
What to request next
- Every prior in-clinic interrogation and the full remote-transmission log for the life of the device, in native vendor format, not only the summary PDFs.
- Alert and notification records with the time each alert was generated, received, viewed and acknowledged, and by whom.
- Programming change history with parameter printouts before and after each change, and the orders or notes authorizing them.
- Stored electrograms and marker channels for every episode, including non-sustained and noise episodes.
- Device clock settings and any time-zone or correction entries.
- Manufacturer technical-services notes, any advisories or recalls for the device and lead models named, and the returned-product analysis if the device was explanted.
What the tool does not do
The decoder adds nothing that is not in the report. Unknowns stay blank, inferences are labelled, and the quote-found marks show that the supporting sentence exists in the pasted text, not that the decoder read it correctly. It does not interpret electrograms or decide whether a programming choice or a review met the standard of care. Check every value against the original report page before it goes into a chronology or an expert's file.
Next step: the whole cardiac record with the device episodes already placed on it
Upload the full chart and get a Bates-cited chronology where each stored episode sits next to the clinic note, the call to the office and the discharge it preceded or followed.
Upload the chart →Frequently asked questions
What is in a pacemaker or ICD interrogation report?
The device and lead models and serial numbers, battery voltage and estimated longevity, lead impedance, sensing and capture thresholds, the programmed mode and settings, pacing percentages, and a log of stored arrhythmia episodes and therapies (anti-tachycardia pacing and shocks) with dates and times, plus any alerts the device generated.
Why does the episode timeline matter in a lawsuit?
Because the device records events with a timestamp independent of the clinical chart. An episode that occurred before a clinic visit, a discharge or a remote transmission that was not reviewed is the comparison the case usually turns on.
Can I rely on the time stamps in the report?
Not without checking. Device clocks can drift and may be set to a different time zone from the hospital. Ask who confirmed the device clock and when, and request the clock settings and any correction entries.
What does the free decoder add that reading the PDF does not?
It turns a long vendor printout into a device table, a programming summary, a dated episode timeline sorted by date, an alert list and a records-to-request list, each value with a quote-found mark. Anything it infers is labelled Inferred. It does not interpret the electrograms.
Related: Turning lab results into a chronology and the medical chronology guide.