Home Monitoring trends during COVID‐19 infection

Abstract Background Cardiac implantable electronic device (CIED) recipients could have an unfavorable prognosis if infected with the novel coronavirus (COVID‐19). We aimed to analyze the data daily transmitted by the Home Monitoring (HM) system (BIOTRONIK, Berlin, Germany) of CIEDs during the infection. Methods We identified CIED patients followed with the HM who experienced COVID‐19 clinical manifestations. The daily trends of the following HM variables were analyzed: mean heart rate (HR), physical activity, thoracic impedance (TI), ventricular and atrial arrhythmic burden. Results The study cohort included 10 CIED patients (median age 90 [84‐92] years, male 90%) with acute respiratory syndrome. The HR showed an increase of a value ranging from 10 to 30 bpm well in advance of the severe clinical manifestations. The physical activity was generally low during the entire infection course. The TI decreased in patients presented with pulmonary edema, but increased significantly (8 to 25 Ω) in most COVID‐19 patients (8 out of 10) suggesting an association with pulmonary fibrosis. Arrhythmic complications were also found in half of the patients. Conclusion The trends of HR and TI in CIEDs recipients infected by the COVID‐19 often showed early recurrent patterns before adverse clinical manifestations.


| Heart rate
The heart rate information was available for eight patients out of 10, as two patients had III° atrioventricular block and 100% ventricular pacing. The mean HR appeared to increase before hospitalization in most cases (6 out

| Physical activity
The physical activity observed was generally very low due to the patients' advanced age and the lockdown status for the COVID-

| Thoracic impedance
A total of eight patients out of 10 had an increasing pattern of TI with a timing ranging from 2 to 23 days before hospitalization ( Figure 2) and an overall increase ranging from 8 to 25 Ω. Two patients presented a decreasing trend starting 3 and 10 days before hospitalization, respectively, with a final absolute reduction of around 25 Ω (Figure 1). Interestingly, all patients with increasing pattern of TI had the pleural thickening without effusion finding at chest x-ray exam. Only 1 patient with the same pattern of TI showed pleural effusion at the chest x-ray, but it should be noted that this patient had history of heart failure with an acute worsening reported one month before the COVID-19 infection. Conversely, in the two patients with decreasing pattern of TI, lungs pleural effusion, and thickening was reported at X-ray examination. Among the available variables, the mean HR was the one showing the most recurrent pattern during infection course. A significant increase (from 10 to 30 bpm) was observed in 7 cases out of 8. As this pattern often appeared well in advanced than hospital admission, it could be potentially suggested for early infection screening.

| Arrhythmic findings
This finding was not unexpected as tachycardia is a common feature of sepsis and indicative of a systemic response to stress; it is the physiologic mechanism by which cardiac output, and thus oxygen delivery to tissues, is increased. 6 Of note, we observed also a single case of drop of mean HR leading to 100% paced rhythm. Transient bradycardia was also reported as possible manifestation of COVID-19 in a recent case report. 7 Some interesting observations were also found for the TI. This parameter is measured between the right ventricular lead and the device generator and could detect fluid accumulation in the lungs.
The role of TI in predicting a worsening state of compensation has been known for several years; it is inversely correlated with pulmonary capillary wedge pressure and decrease before the onset of patient symptoms for volume overload. 8 Accordingly, we observed a F I G U R E

| CON CLUS IONS
The daily trends of mean HR and TI in CIEDs recipients infected with the COVID-19 virus often showed early recurrent patterns before adverse clinical manifestations. Arrhythmic complications were also observed in some patients in a later stage.
Continuous remote monitoring data could have potential benefits in a context of COVID-19 pandemic in terms of early screening for more specific diagnostic tests in a high-risk population.

ACK N OWLED G EM ENTS
This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors. The authors thank Gianluca Ceravolo for his help in manuscript preparation.

CO N FLI C T O F I NTE R E S T S
D. G. is employee of BIOTRONIK Italia. All the remaining authors declare no Conflict of Interests for this article.