Why Cardiologists Get Sued: The Missed MI, the Aortic Dissection, and Ablation Gone Wrong

By John Mahoney · June 2026 · 8 min read

Cardiology is one of the few specialties that lives on both sides of the master malpractice axis. Most of its claims are cognitive — the missed or delayed diagnosis — but a meaningful slice are procedural, driven by electrophysiology, ablation, and device-implant complications. Reported data puts the annual claim rate around 8.2%, above the all-physician average and in the mid-to-upper tier of non-surgical specialties; invasive and EP cardiology skew higher than general cardiology. The severity is what makes these cases consequential: reported mean indemnity sits around $375,000 to $394,000, and roughly two-thirds of claims involve high-severity injury, frequently death or permanent harm.

This guide is for plaintiff and defense med-mal attorneys screening cardiology and EP matters. It covers the frequency and severity reality, the split between diagnostic and procedural allegations, the cannot-miss conditions and the device-specific injuries, the contributing factors that drive payment, and what separates a strong case from a weak one.

Disclaimer: This article is for informational purposes only and does not constitute legal advice. Malpractice standards, claim data, and verdicts vary by jurisdiction and over time. Figures cited here are drawn from closed-claims and insurer reports and should be independently verified before use in any matter.

The Frequency and Severity Reality

Cardiology claim frequency has drifted down and leveled off over the past two decades, by reported insurer data — from a peak above 11% in 2008 to a low around 6% in the mid-2010s. But the per-claim economics stay meaningful. Reported mean indemnity is in the high-$300-thousands, with average defense expense reportedly $79,000 to $139,000 even on claims that are ultimately dropped. About a third of cardiology claims close with a payment; the rest close without one. The reason the paid claims are expensive is simple: cardiac injury is frequently catastrophic, so the high-severity end of the distribution is heavily populated.

For an attorney, the practical signal is that cardiology is a defensible-but-expensive specialty. Two-thirds of claims are non-paid, which tells you the defense bar wins most contests — but the third that pay carry serious indemnity, so the screening question is which bucket a given case falls into.

The Two Allegation Tracks

Cardiology claims divide along the cognitive/procedural axis:

• Diagnosis-related (failure, delay, or wrong diagnosis) — reported at roughly 33–36%, the single largest driver.
• Improper management of medical treatment — reported around 36% in a 2026 analysis, effectively tied as the largest category.
• Improper medication management — reported around 13%.
• Improper performance of a treatment or procedure — reported around 7% for surgical-treatment allegations, the bucket that captures EP, ablation, and device-implant claims.
• Incorrect or unnecessary treatment or procedure — informed-consent and indication disputes.

This matters for case theory. A diagnostic cardiology case is screened like internal medicine — was the workup adequate, was the differential documented, was the abnormal result acted on. An EP or device case is screened like a procedural specialty — was the realized complication a known, disclosed risk or a negligent technical error, and was the post-procedure deterioration recognized and managed in time.

The Cannot-Miss Diagnoses

On the cognitive side, the reported missed and failed conditions cluster tightly:

• Acute MI and cardiac arrest — the archetypal cardiology claim, reported as roughly 13% of diagnosis-related claims. Losses cluster in patients with typical chest pain and known coronary risk factors, and in the failure to do a serial workup — serial troponins and ECGs.
• Aortic aneurysm and dissection — reported as the top diagnosis-related condition, around 15%. The catastrophic miss: a dissection presenting atypically, attributed to something benign, until it is too late.
• Atherosclerosis of the native coronary artery — reported around 11%; endocarditis — reported around 8%.
• Cardiac dysrhythmia, congestive heart failure, pulmonary embolism, and cerebral artery thrombosis — each reported in the low single digits.

The missed MI and the missed aortic dissection are the two fact patterns that should immediately elevate merit and exposure. Both are in the "Big Three" vascular-event category that drives serious misdiagnosis harm across cognitive specialties, and both produce the death or permanent-disability outcomes that supply the damages.

The Procedural Track: EP, Ablation, and Devices

The electrophysiology and device-implant subset is a distinct world. The reported EP- and device-specific adverse events include:

• Arterial laceration during pacemaker implant or EP study.
• AV-node damage during ablation requiring a pacemaker.
• Pulmonary vein stenosis after atrial-fibrillation ablation.
• Lead malposition or perforation, cardiac tamponade, and pneumothorax.
• Device infection.
• Failure to recognize and escalate a post-procedure complication.

The merit analysis here turns on the consent-versus-negligence question. Tamponade and PV stenosis are recognized risks of these procedures; if the chart shows the risk was disclosed and the complication was recognized and managed appropriately, the case is defensible. If the complication went unrecognized, or the consent did not disclose it, the same event becomes payable. The reported technical-skill contributing factor — around 13% — is concentrated in exactly these EP, ablation, and device claims.

The Contributing Factors That Drive Payouts

The reported cardiology contributing factors are unusually well quantified, and they tell a clear story about what drives payment:

• Clinical-judgment deficiencies — reported around 69%, with inadequate patient assessment cited in roughly 76% of diagnosis-related claims. The reported mean payment on these is near $398,000.
• Communication failures — reported around 41% overall (provider-to-provider near 26%, patient-to-provider near 17%), with reported mean payment near $384,000.
• Behavior and patient-related factors — reported around 28%, including patient non-adherence near 21%; notably, these carry the highest reported mean indemnity, near $429,000.
• Documentation — reported around 22%, with insufficient documentation cited in roughly 14% of diagnosis claims.
• Technical skill — reported around 13%, concentrated in EP, ablation, and device-implant claims.

The reported data also makes one point that should shape strategy: delayed-diagnosis claims lose far more often than misdiagnosis claims. A case where the cardiologist eventually reached the right diagnosis but too late is harder to defend than one where the diagnosis was simply wrong. And the closed-loop failure — an abnormal test or post-procedure symptom that was never tracked or escalated — is a recurring driver across both tracks.

What Separates a Strong Case From a Weak One

The strong plaintiff case

• A missed MI or missed aortic dissection in a patient with typical symptoms and known risk factors, where the serial workup was not done or the abnormal result was not acted on.
• A delayed diagnosis — the right answer reached too late — which the reported data shows loses more often for the defense.
• An EP or device complication that was either undisclosed in the consent or went unrecognized post-procedure.
• A high-severity outcome supplying the damages, plus a closed-loop failure as the systemic merit signal.

The strong defense case

• A documented serial workup and differential, showing a reasonable process even where the outcome was bad.
• An EP or device complication that was a disclosed, known risk and was recognized and managed appropriately — the consent and the post-procedure management are the defense.
• Patient non-adherence — missed follow-up, declined testing, medication non-compliance — that breaks causation; note this factor carries the highest reported mean indemnity when it cuts the other way.
• Causation: even a timely diagnosis or intervention would not have changed the catastrophic outcome.

The weak case on either side ignores the track it is on. A plaintiff theory that treats an ablation tamponade as automatic negligence, without addressing consent and management, will lose on the known-risk defense. A defense that leans on "medicine is hard" while the chart shows a delayed diagnosis with an unacted-on troponin will not survive.

Bottom Line

Cardiology is a two-track specialty: diagnostic misses of MI and aortic dissection on the cognitive side, and EP, ablation, and device complications on the procedural side. Most claims close without payment, but the paid third is high-severity and expensive. Diagnostic cases turn on the serial workup and the closed loop, with delayed diagnoses the hardest to defend; procedural cases turn on consent disclosure and post-procedure recognition. Screen for the track first, weight the severity, and confirm the expert match early.

For how cardiac-injury damages exposure varies across jurisdictions, see our medical malpractice damages-by-state tool, and if a pre-suit expert filing is required, run the certificate of merit readiness checker before drafting.

Questions? Contact us at [email protected] or (856) 979-6525

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