How to Write a Cardiology Case Report

Cardiology reviewers read the tracing before the text. A case report stands or falls on whether its ECGs, biomarkers, imaging and device data can be checked.

Guide · 10 min read · Directive Publications Editorial Team

What makes a cardiology case report different

A general case report is judged mostly on its narrative. A cardiology case report is judged on its evidence. Reviewers in this specialty look at the 12-lead ECG, the troponin curve, the echo clip or the angiogram first, and then read the text to see whether it matches.

That changes where the work goes. A case can have a genuine lesson and still be returned because the ECG is cropped to three leads, the troponin has no assay or reference limit, or a valve lesion is called "severe" without the measurements behind it.

The general framework still applies. The CARE checklist sets out what any case report needs, and our guide to writing a medical case report with CARE covers the timeline, the patient perspective and the discussion in detail. This post covers what cardiology adds on top: the tracings, the assays, the imaging, the devices and the journals.

Step 1: Name the lesson and the guideline it tests

Write one sentence that starts "After reading this case, a cardiologist should..." If you cannot finish it, the case is not ready.

Cardiology is unusually guideline-dense, so the strongest lessons usually sit at the edge of a guideline or a definition:

• a presentation the diagnostic criteria do not handle well
• a recognised complication of a procedure or device that was missed or managed in a new way
• a drug interaction or adverse effect relevant to common cardiac therapy
• an imaging finding that changed management when the standard workup did not

Identify the specific guideline or consensus document your case relates to before you write anything. Journals ask for this explicitly: JACC: Case Reports wants the discussion to address "current guidelines/position papers/current practice," and European Heart Journal - Case Reports asks authors to refer to relevant ESC guidelines where appropriate.

Step 2: Pick the journal before you draft

Cardiology case report journals differ enough that drafting first and choosing later usually means rewriting. The dedicated options include European Heart Journal - Case Reports (ESC), JACC: Case Reports (American College of Cardiology), HeartRhythm Case Reports (Heart Rhythm Society, for rhythm disorders and electrophysiology), and CASE (American Society of Echocardiography, for cases where cardiovascular ultrasound is central). Two examples show how far the formats diverge:

These figures come from each journal's instructions for authors when we checked; limits change, so confirm them on the journal's own site before you start. Two further details catch authors out. JACC: Case Reports asks that the first author be an early-career practitioner or trainee, or that the authors explain why not, and it requires an Equipment List figure for cases describing investigations or procedures. EHJ - Case Reports asks for a CARE checklist and a short lead author biography with a photograph.

For a single striking ECG or image, consider a short format instead. The JACC: Case Reports instructions include a Diagnostic Challenge Corner for a de-identified image or ECG tracing followed by a multiple-choice question. For the wider comparison of journal types, fees and indexing, see where to publish a case report.

Step 3: Secure consent and de-identify tracings, clips and device data

Cardiology journals generally require written patient consent for case reports. JACC: Case Reports, for example, states that individual case reports do not require institutional review board approval but do require consent, and that consent must be obtained before initial submission. Use the target journal's own consent form where it has one; EHJ - Case Reports recommends its own.

Consent does not replace de-identification, and cardiology material carries identifiers in places authors overlook:

• ECG printouts and scans usually print the patient's name, date of birth, record number, recording date and time, and the hospital or device name in the header and footer.
• Echo, CMR, CT and angiography clips often have the name, date and institution burned into the image overlay, not just stored in the file metadata. Exporting to MP4 does not remove burned-in text.
• Device interrogation reports for pacemakers, ICDs and loop recorders show the device serial number. The HIPAA Safe Harbor standard (45 CFR 164.514) lists device identifiers and serial numbers among the identifiers to remove.
• Pedigrees in inherited cardiomyopathies and channelopathies identify relatives as well as the patient.

Crop or mask identifiers on every frame, and replace calendar dates with time relative to presentation. The ICMJE guidance on protecting research participants says consent should be obtained if there is any doubt that anonymity can be maintained, and that if identifying characteristics are altered, authors should give assurance that the changes do not distort scientific meaning. That last point matters for pedigrees: altering a pedigree to protect a family can change its inheritance pattern.

Two cardiology situations need extra care. After sudden cardiac death, JACC: Case Reports, for example, expects consent from the next of kin or legal representative in line with applicable law. And when relatives underwent cascade screening, describing their results may need their consent too. Our post on patient consent for case reports and images covers proxies and deceased patients in more detail.

Step 4: Build a timeline around serial investigations

Cardiac cases are usually told through change: an evolving ST segment, a rising and falling troponin, an ejection fraction that recovers or does not. A narrative that mentions these in passing is hard to follow. Lay them out in a table first, using time from presentation:

Include relevant baseline data from before the event, such as a previous ECG or echo, because comparison is often the point. This table can become the timeline figure both journals above accept as their summary graphic.

Step 5: Report each investigation so it can be checked

Reviewers in cardiology check numbers against methods. Give them what they need:

ECGs. Show the full 12-lead tracing, not a three-lead crop, unless the journal format calls for an excerpt. Keep the calibration signal visible and state the paper speed and gain. The conventional settings are 25 mm/s and 10 mm/mV; if you used anything else, such as 50 mm/s or half gain in the precordial leads, say so in the legend. For arrhythmias, show onset and termination where you have them, and label every channel and the sweep speed on intracardiac electrograms.

Troponin and other biomarkers. Name the assay (for example, high-sensitivity troponin T or I), the units, the assay's upper reference limit, and the timing of each sample relative to symptom onset. Without these, a reviewer cannot judge whether the values meet a definition of myocardial injury.

Echocardiography. Name the views and the method behind each key measurement, for example how left ventricular ejection fraction was calculated. Name the reference document for normal ranges, such as the ASE and EACVI chamber quantification recommendations, and the guideline used to grade any valve lesion. For gradients, say whether a value is a Doppler mean, a Doppler peak or a catheter peak-to-peak measurement, because they are not interchangeable.

Cardiac MRI and CT. State the sequences or protocol used, describe late gadolinium enhancement by pattern and location, and say where mapping reference values came from, since these depend on scanner and site.

Catheterisation and procedures. Report pressures, the method behind any physiological index, and the vessel and segment involved. List the devices and equipment used; JACC: Case Reports turns this into the Equipment List figure and asks authors to reduce brand names in the text.

Devices. Give the device type, pacing mode and the programmed settings relevant to the case, and the lead positions, but leave out the serial number.

Genetics. Give the gene, the variant in standard HGVS nomenclature, and its classification under the ACMG/AMP framework, along with the laboratory's classification date if it may change.

Step 6: Prepare figures and videos that carry the case

Treat the figures as the primary evidence and the text as the commentary. Label every arrow, asterisk and abbreviation in the legend, and keep the original tracing alongside any annotated copy if you add markings.

Supply video whenever the finding moves. JACC: Case Reports states that videos are crucial for imaging modalities with video sequences, naming echocardiography, cardiac magnetic resonance and fluoroscopy, and that submissions without them "may be returned to the authors or rejected." EHJ - Case Reports asks for MP4 files and for the first three videos to be uploaded as inline videos. Choose the clip that shows the finding most clearly, trim it to the relevant loops, and check that it is de-identified frame by frame.

Apply any brightness or contrast adjustment to the whole image, and do not combine frames or tracings from different times into one panel without saying so in the legend. Journals screen figures for manipulation, and a spliced tracing is hard to explain after the fact.

Step 7: Write a discussion against current definitions and guidelines

The discussion should answer three questions: how this case compares with prior reports, where it sits relative to the current guideline, and what a reader should change as a result. Keep the conclusions within what one patient can show; one good outcome is not evidence that a strategy works.

Definitions need particular care right now. The Fifth Universal Definition of Myocardial Infarction, published on 28 August 2026 by the ESC, ACC, AHA and World Heart Federation, replaces the numbered types with three clinical categories (primary, secondary and procedure-related) and incorporates sex-specific troponin thresholds. A case managed and classified under the Fourth Universal Definition is still reportable, but say which definition you applied and do not mix the terminology of both. The same principle applies to heart failure categories, valve severity grades and arrhythmia classifications: name the source and version.

End with the learning points or take-home messages in the journal's required form. Make each one an action, not a restatement of the case.

Before you submit

1. One-sentence lesson written, and the guideline or definition it relates to identified
2. Format, word limit, figure and author limits checked against the journal's current instructions
3. Written consent on the journal's form, including next of kin or relatives where needed
4. Names, dates, record numbers and device serial numbers removed from every tracing, clip and report
5. Full 12-lead ECGs with calibration visible and settings stated
6. Troponin assay, units and upper reference limit given, with sample timing
7. Imaging methods, reference ranges and grading guidelines named
8. Videos supplied for echo, cardiac MRI or fluoroscopy findings
9. Definitions and their versions named, with consistent terminology
10. CARE checklist completed if the journal asks for it

Once the evidence is in order, the writing is the easy part. When the draft is ready, check the author guidance at Directive Publications and submit your manuscript.