Title: Visualizing Chest Pain: A characterization of symptom localization and quality in patients with suspected coronary artery disease using a mobile health app

Background: Accurate symptom characterization is directional in distinguishing coronary artery disease (CAD)-related chest pain from non-coronary causes. App based self-assessment tools including digital pain drawings may improve the quality of medical history taking.

Objective: To prospectively evaluate chest pain quality and localization in patients with CAD-related and non-coronary chest pain using a tablet-based mobile health app and to compare traditional verbal anamnesis with a digitally self-reported patient history.

Methods: Patients presenting with chest pain were prospectively enrolled. Initially, a structured verbal history was obtained based on a questionnaire and transmitted to a tablet-based mobile health app by the investigator. Subsequently, patients independently used the same app to document their pain location, quality and intensity creating a digital pain drawing. Afterwards cardiac diagnostics were performed according to standard procedures to determine the final cause of the chest pain. Chest pain localization was compared for CAD-related chest pain and non-coronary causes by creating heatmaps for both groups based on the conducted pain drawings. In addition, the verbal history was compared to the digital self-reported history by performing visual and quantitative analysis on documented chest pain characteristics in the app for both approaches.

Results: 305 patients have been included to the study from July to November 2024. For baseline characteristics see Table 1. 59.3 % were diagnosed with CAD-related chest pain and 40.7 % with non-coronary chest pain. Visual comparison of the pain localization and intensity for both groups revealed overall similar chest pain distribution patterns (Figure 1). However, patients with CAD-related chest pain reported pain in the left upper arm more frequently and showed a higher retrosternal focus (Figure 1). In contrast, non-coronary chest pain distribution appeared slightly more diffuse in the chest area (Figure 1). 
Visual comparison of examiner-based and self-reported digital pain drawings indicated a broader pain area in the self-reported documentation, while overall localization patterns remained largely consistent (Figure 2). Furthermore, the total number of reported pain qualities was significantly higher during the digital self-assessment compared to the verbal anamnesis (2.96±1.92 vs. 1.78±0.94; p < .00001).

Conclusion: Digital pain drawings can reveal subtle but potentially clinically relevant differences in pain localization between CAD-related and non-coronary chest pain. Digital self-assessment using a tablet-based app provides more detailed information on chest pain characteristics and may enhance the diagnostic accuracy of initial chest pain evaluation in a cardiological clinical setting.

Table 1: Baseline characteristics.

Fig. 1 Heatmaps visualizing summed pain localization patterns (CAD vs non-CAD). 

Fig. 2 Heatmaps visualizing aggregated chest pain localization patterns (based on verbal  anamnesis vs. self-reported by patients).