# Right Heart Contrast Echocardiography Microbubble Count and Migraine Severity: A Dose–Effect Relationship Study

## TL;DR

This study found that more microbubbles in heart imaging are linked to more severe migraines, suggesting a possible physical cause.

## Contribution

The study demonstrates a dose–effect relationship between microbubble count in right heart contrast echocardiography and migraine severity.

## Key findings

- Higher microbubble grades correlated with significantly elevated migraine disability and impact scores.
- Regression analysis confirmed higher microbubble burden independently predicts migraine severity.
- Sensitivity analyses confirmed the robustness of the findings.

## Abstract

This study aimed to investigate whether a dose–effect relationship exists between the number of microbubbles detected on right heart contrast echocardiography (RHCE) and the clinical severity of migraine.

We conducted a cross‐sectional study of 190 adult patients diagnosed with migraine who underwent RHCE. Microbubble counts were categorized into four grades per frame (Grades 0–III) based on their appearance in the left atrium within three to six cardiac cycles after right atrial opacification. Migraine severity was assessed using the Migraine Disability Assessment (MIDAS) score and the Headache Impact Test (HIT‐6). Multivariate linear regression was used to evaluate the association between microbubble grades and migraine severity. The predictive ability of the model was assessed using the residual plots and variance inflation factors. Sensitivity analyses were performed to test the robustness of the findings by adjusting for potential confounders.

A clear dose–response relationship was identified, with patients in higher microbubble‐grade groups demonstrating significantly elevated MIDAS and HIT‐6 scores (p < 0.001). Patients with Grade III microbubbles reported the highest mean MIDAS (18.2 ± 6.1) and HIT‐6 (64.8 ± 4.9) scores, compared to those in lower grades (p < 0.001). Regression analyses confirmed that the higher microbubble burden independently predicted migraine severity (β = 0.46, p < 0.001). Sensitivity analyses yielded consistent findings.

Our results suggest a notable dose–effect relationship between RHCE microbubble count and migraine severity. These findings highlight the potential role of right‐to‐left shunting as a physiological contributor to migraine.

We conducted a cross‐sectional study of 190 adult patients diagnosed with migraine (with or without aura) who underwent RHCE for suspected right‐to‐left shunt. Our results suggest a notable dose–effect relationship between RHCE microbubble count and migraine severity. These findings highlight the potential role of right‐to‐left shunting as a physiological contributor to migraine.