Surreal illustration of a brain intertwined with coronary arteries, highlighting diagnostic uncertainty in a medical case.

Brain Bleed or Contrast Leak? A Rare Post-Angiography Mystery

Lena Kashyap in Health & Wellness September 2025 • 4 min read.

"When a routine heart procedure leads to a brain scare: understanding the complexities of diagnosis and potential risks."

In the realm of cardiac care, coronary angiography (CAG) stands as a crucial diagnostic tool, allowing physicians to visualize the heart's blood vessels and identify potential blockages. While generally safe, CAG, like any invasive procedure, carries inherent risks. Bleeding, a common complication of antithrombotic treatments in acute coronary syndrome (ACS), can be exacerbated by invasive procedures.

Contrast media (CM) and heparin, essential components of CAG, contribute to this risk profile. While the overall bleeding rate in ACS patients undergoing percutaneous coronary intervention (PCI) is significant, a far less common but potentially devastating complication is subarachnoid hemorrhage (SAH) – bleeding in the space surrounding the brain.

This article delves into a fascinating and rare case where a patient undergoing CAG developed SAH, mimicking contrast media leakage. It highlights the diagnostic challenges, the importance of considering alternative explanations, and the need for vigilance in post-CAG monitoring.

The Case: A Diagnostic Puzzle

Surreal illustration of a brain intertwined with coronary arteries, highlighting diagnostic uncertainty in a medical case.

A 55-year-old man with a history of a previous heart attack (acute ST elevation myocardial infarction or STEMI) was admitted for a follow-up CAG. The procedure itself was seemingly routine: a transradial approach, a minimal dose of heparin for catheter lubrication, and a standard amount of non-ionic contrast media (iodixanol) for visualization.

However, immediately post-CAG, the patient developed alarming symptoms: nausea, neck stiffness, and a rapidly declining level of consciousness. An emergency brain CT scan revealed a diffuse increase in density within the brain's cisterns, initially suggesting contrast media leakage.

Initial Suspicion: Contrast media leakage due to the immediate timing and the CT scan findings.
Further Investigation: Cerebral angiography was performed to rule out vascular malformations.
The Twist: No malformations were found, and the patient showed partial recovery, only to reveal subacute SAH on a follow-up MRI two weeks later.

This case underscores a critical point: while contrast media leakage can mimic SAH, clinicians must maintain a broad differential diagnosis and consider alternative explanations, even when initial findings point towards a specific cause. The subtle nuances in presentation and the evolution of symptoms over time can be crucial in arriving at the correct diagnosis.

Key Takeaways: Vigilance and Comprehensive Diagnosis

This case highlights the importance of maintaining a high index of suspicion for SAH following CAG, even in the absence of obvious risk factors or with seemingly clear initial explanations. While contrast media-induced neurotoxicity is a recognized phenomenon, clinicians must be vigilant in considering other potential causes of bleeding.

The use of advanced imaging techniques like MRI, in addition to CT scans, can be invaluable in differentiating between contrast leakage and true SAH, especially when symptoms are atypical or evolve over time. Furthermore, a thorough neurological assessment and continuous monitoring are essential in the post-CAG period.

Ultimately, this case serves as a reminder that in medicine, the most accurate diagnosis often requires a comprehensive approach, considering all possibilities and utilizing the full range of available diagnostic tools.

About this Article -

This article was crafted using a human-AI hybrid and collaborative approach. AI assisted our team with initial drafting, research insights, identifying key questions, and image generation. Our human editors guided topic selection, defined the angle, structured the content, ensured factual accuracy and relevance, refined the tone, and conducted thorough editing to deliver helpful, high-quality information.See our About page for more information.

This article is based on research published under:

DOI-LINK: 10.4070/kcj.2012.42.3.197, Alternate LINK

Title: Subarachnoid Hemorrhage Mimicking Leakage Of Contrast Media After Coronary Angiography

Subject: Cardiology and Cardiovascular Medicine

Journal: Korean Circulation Journal

Publisher: The Korean Society of Cardiology

Authors: Min Seok Oh, Jee Eun Kwon, Kyung Jun Kim, Joon Hwan Jo, Yun Ju Min, Jun Soo Byun, Kyung Tae Kim, Sang Wook Kim, Tae Ho Kim

Published: 2012-01-01

Everything You Need To Know

What is Coronary Angiography (CAG), and what are the potential risks associated with it?

Coronary Angiography (CAG) is a diagnostic procedure used to visualize the heart's blood vessels to identify blockages. It's generally safe, but like any invasive procedure, it carries risks. These risks are bleeding complications from antithrombotic treatments, contrast media (CM), and heparin. While rare, a serious potential complication is subarachnoid hemorrhage (SAH), which is bleeding in the space surrounding the brain.

How did the initial diagnosis of contrast media leakage mislead doctors in this brain bleed case?

In this specific case, the initial CT scan showed a diffuse increase in density within the brain's cisterns immediately after Coronary Angiography (CAG). This suggested contrast media leakage. However, subsequent cerebral angiography ruled out vascular malformations. It wasn't until a follow-up MRI two weeks later that subacute subarachnoid hemorrhage (SAH) was revealed.

What's the most important thing doctors and patients should understand after a Coronary Angiography (CAG) procedure to avoid misdiagnosis?

The key takeaway is that clinicians must maintain a high level of suspicion for subarachnoid hemorrhage (SAH) following Coronary Angiography (CAG), even if initial findings suggest contrast media leakage. While contrast media-induced neurotoxicity is possible, other potential causes of bleeding should be considered. The diagnostic process should involve comprehensive investigation, including ruling out vascular malformations and considering alternative explanations.

Why is heparin used during Coronary Angiography (CAG), and how does it contribute to the risk of bleeding complications?

Heparin is used during Coronary Angiography (CAG) as a lubricant to prevent blood clots during the procedure. However, it can increase the risk of bleeding, which is a common complication in patients undergoing Percutaneous Coronary Intervention (PCI). The interaction between heparin and antithrombotic treatments is a concern in Acute Coronary Syndrome (ACS) patients.

Besides contrast media leakage, what other explanations should doctors consider when a patient shows signs of brain issues after a heart procedure?

While the case described a situation mimicking contrast media leakage, it ultimately revealed subarachnoid hemorrhage (SAH). It's important to understand that while contrast media can sometimes cause neurotoxicity, other potential causes of bleeding need to be explored. These alternative explanations are crucial to consider for accurate diagnosis and appropriate patient management. This is particularly important when a patient has a history of heart attack (acute ST elevation myocardial infarction or STEMI) and is undergoing a follow-up Coronary Angiography (CAG).