A patient who smoked PCP-laced cannabis developed ECG changes mimicking a dangerous heart condition | Research

The takeaway

A case report described a patient who presented with chest pain and electrocardiogram changes resembling Wellens' syndrome (which signals critical coronary artery blockage) after smoking phencyclidine-laced cannabis, but coronary angiography showed no actual artery disease.

Emergency medicine physicians; cardiologists evaluating chest pain in young substance users; harm-reduction educators.

ECG changes mimicking imminent heart attack resolved once drug effects wore off

What the researchers found

A patient arrived with atypical left chest pain and dizziness that started 6 hours after smoking phencyclidine (PCP)-laced cannabis.

The ECG showed new deep biphasic T-wave inversions in anterolateral leads, a pattern characteristic of Wellens' syndrome, which typically indicates critical blockage of the left anterior descending artery and imminent heart attack risk.

However, troponin levels were normal and coronary angiography revealed no coronary artery disease. The ECG changes resolved as the chest pain subsided, consistent with a drug-induced mimic rather than true coronary pathology.

The authors diagnosed pseudo-Wellens' syndrome caused by acute PCP and cannabis intoxication.

Why it matters

Emergency physicians encountering Wellens' syndrome ECG patterns need to consider drug intoxication as a cause, particularly in younger patients. Misdiagnosis could lead to unnecessary invasive cardiac procedures, while missing true Wellens' syndrome could be fatal.

The numbers in context

Troponin T levels were normal. ECG showed sinus rhythm with new deep biphasic T-wave inversions in anterolateral leads. Coronary angiography showed no pathological processes. Symptoms and ECG changes resolved within 6 hours of onset.

How the study worked

Single case report with ECG documentation, cardiac biomarker testing (troponin T), and coronary angiography to rule out true coronary artery disease.

What this study cannot tell us

Single case report, so the findings cannot be generalized. The cannabis was laced with PCP, making it impossible to separate the cardiac effects of each substance. No follow-up data on whether the patient experienced recurrent episodes.

How to read the evidence

Preliminary. Single case report without controls or broader population data.

When this study was published

Published in 2018. Pseudo-Wellens' syndrome remains an uncommon but recognized diagnostic consideration.

The bigger picture

This adds to a small but growing literature on cardiovascular effects of combined substance use. Cannabis alone has been associated with acute cardiovascular events, but the combination with PCP (which has its own sympathomimetic effects) may create distinct cardiac presentations that clinicians should recognize.

Questions still open

Can cannabis alone cause pseudo-Wellens' ECG patterns, or was PCP the primary driver? How common are cardiac ECG mimics in emergency departments among patients presenting after cannabis use?

Common questions

What is Wellens' syndrome?

Wellens' syndrome is a specific ECG pattern (deep T-wave inversions in certain leads) that signals critical blockage of the left anterior descending coronary artery. It's considered a medical emergency because it indicates high risk of a major heart attack.

Was this caused by the cannabis or the PCP?

It is not possible to determine from this case. The cannabis was laced with PCP, and both substances have cardiovascular effects. PCP is a potent sympathomimetic that can raise blood pressure and heart rate significantly.

Read the original research

Pseudo-Wellens' syndrome secondary to concurrent cannabis and phencyclidine intoxication.

BMJ case reports, 2018

View on PubMed ↗Publisher’s paper ↗

Citation

Inayat, Faisal; Riaz, Iqra; Ali, Nouman Safdar; Figueredo, Vincent M. (2018). Pseudo-Wellens' syndrome secondary to concurrent cannabis and phencyclidine intoxication.. BMJ case reports, 2018. https://doi.org/10.1136/bcr-2018-225755