To assess the effect of applying scatter diagram in prehospital screening for arrhythmia via analyzing patients' data monitored by the single lead, wearable remote ECG monitoring system.

Participants (n=1 076) were primary care patients who were selected from Yinchuan from September 2018 to September 2019. All of them used single lead, wearable remote ECG monitoring system to monitor cardiac rhythms prehospitally when they had palpitation, dizziness, chest tightness, shortness of breath and other symptoms, and real-timely uploaded 24-hour ambulatory ECG data to be used for screen for arrhythmia by different approaches: approach A (diagnosis made using scatter diagram analysis by primary care physicians) , approach B (diagnosis made using scatter diagram analysis by physicians from Remote ECG Center, the First People's Hospital of Yinchuan) , and approach C (diagnosis made using scatter diagram analysis and ECG analysis by physicians from Remote ECG Center, the First People's Hospital of Yinchuan) . Prevalence and types of arrhythmia detected by these approaches and diagnostic coincidence rate of these approaches were analyzed. The sensitivity, specificity, positive and negative predictive values of approaches A and B were assessed with those of approach C as the gold standard.

(1) The frequencies of arrhythmias detected by approaches A, B and C were 1 301, 1 323, and 1 647, respectively. The types of arrhythmias detected by approaches A, B and C were 14, 14, and 15, respectively. And the prevalence of arrhythmias detected by approaches A, B and C were 80.9%, 81.2% and 87.5%, respectively. (2) The diagnoses made by approaches A and B were highly consistent〔Kappa=0.891, 95%CI (0. 711, 1.071) , P=0.617〕, and the diagnostic coincidence rate was 96.7%. The diagnoses made by approaches B and C were highly consistent〔Kappa=0.759, 95%CI (0.489, 1.029) , P<0.001〕, and the diagnostic coincidence rate was 93.6%. The diagnoses made by approach A were relatively consistent with those by approach C〔Kappa=0.692, 95%CI (0.392, 0.992) , P<0.001〕, and the diagnostic coincidence rate was 91.7%. (3) The sensitivity, specificity, positive and negative predictive values of approach A in diagnosing arrhythmia were 91.5%, 93.3%, 99.0% and 61.2%, and those of approach B were 92.8%, 99.3%, 99.9% and 66.3%.

Using scatter diagram in prehospital screening for arrhythmia through analyzing the monitoring results of single lead, wearable remote ECG monitoring system will contribute to the development of arrhythmia diagnosis and treatment in primary care, and the establishment of an arrhythmia prevention and treatment network with the participation of residents, primary care physicians and remote ECG center physicians.