The photoplethysmography dictionary: practical guidance on signal interpretation and clinical scenarios from TeleCheck-AF

Introduction

During the coronavirus disease 2019 (COVID-19) pandemic, numerous centres in Europe used on-demand photoplethysmography (PPG) technology to remotely assess heart rate and rhythm in conjunction with teleconsultations within the TeleCheck-AF project.

Purpose

To develop an educational structured stepwise practical guide on how to interpret PPG signals and to study typical clinical scenarios how on-demand PPG was used in the TeleCheck-AF project.

Methods

During an online conference, the structured stepwise practical guide on how to interpret PPG signals was discussed and further refined during an internal review process. We provide the number of respective PPG recordings and number of patients managed within a clinical scenario during the TeleCheck-AF project.

Results

To interpret PPG recordings, we introduce a structured stepwise practical guide and provide representative PPG recordings. In the TeleCheck-AF project, 2522 subjects collected 90.616 recordings. The majority of these recordings was classified by the PPG algorithm as sinus rhythm (57.6%), followed by atrial fibrillation (AF) (23.6%). In 9.7% of recordings the quality was too low to interpret. Other observed rhythms were tachycardia (1.4%), extra systoles (4.7%), bigeminy episodes (1.8%), trigeminy episodes (0.6%) and atrial flutter (0.2%). The most frequent clinical scenario where PPG technology was used in the TeleCheck-AF project was follow-up after AF ablation (1110 patients) followed by heart rate and rhythm assessment around (tele)consultation (966 patients), sometimes including remote PPG-guided adaption of rate or rhythm control. 275 patients were followed around cardioversion, either (semi-)acute or elective. Other possible scenarios are assessment of palpitations, assessment of symptom-rhythm correlation and monitoring during up-titration of heart failure medication.

Conclusion

We introduce a newly developed structured stepwise practical guide on PPG signal interpretation developed based on presented experiences from TeleCheck-AF. The present clinical scenarios for the use of on-demand PPG technology derived from the TeleCheck-AF project will help to implement PPG technology in the management of arrhythmia patients.

Funding Acknowledgement

Type of funding sources: None. TeleCheck-AF clinical scenariosClassification of PPG recordings

The TeleCheck-AF project on remote app-based management of atrial fibrillation during the COVID-19 pandemic: Patient experiences

Funding Acknowledgements

OnBehalf

Aims

Methods

Results

Conclusions

Cost of severe haemophilia in Toronto

Our objective was to determine costs and trends in treating boys with severe haemophilia A before our centre routinely used prophylaxis. One reviewer extracted data from patient charts to determine resource consumption for 17 boys with severe haemophilia A from 1978 to 1998 at Toronto's Hospital for Sick Children. Resources included factor concentrate, doctors and health care professionals (physiotherapists/social workers), tests (laboratory, radiological and diagnostic) and hospitalizations. Subgroup analysis on those patients infected with HIV and/or hepatitis were also performed. Costs in Canadian Dollars were taken from standard lists and discounted at 3%. Total average cost (range) 62 292 dollars (3339-121 738) per year patient(-1); the largest fraction, 59 910 dollars (3103-119 480), 96.2% was accounted for by factor VIII. Hospitalizations accounted for 1832 dollars (0-5217) per patient year(-1) including drugs, nursing care and stay. Doctor and health care professionals visits averaged 252 dollars (36-462) and 72 dollars (0-175) per patient year(-1), laboratory and other tests cost 201 dollars (22-377) and 26 dollars (2-60) per patient year(-1), respectively. The average number of bleeds was 12.9 (2.0-22.0) per patient year(-1), decreasing since 1977 by 0.68 per patient year(-1) (R(2) = 0.56). Hospitalizations averaged 0.22 (0-4) per patient year(-1), lasting 2.3 days. From 1984, hospitalizations decreased by 0.025 patient(-1) year(-1) (R(2) = 0.76). Concurrently, the average treatment costs increased by 5456 dollars patient(-1) year(-1) (R(2) = 0.81). Clotting factor concentrate cost per patient increased by 5521 dollars year(-1) (R(2) = 0.82). Patients with virally transmitted diseases had considerable higher costs. The cost per year was substantial. Costs increased with virally transmitted diseases. Number of bleeds and hospitalizations over the period of study decreased and costs increased because of factor use in secondary prophylaxis.