Derived telemetry-based electrocardiograms in the intensive care unit:
insights from a COVID-19 epicenter
Abstract
Introduction: Severely ill inpatients with SARS-CoV-2 infection,
Coronavirus Disease 2019 (COVID-19) require close electrocardiographic
(ECG) monitoring due to frequent cardiac involvement of the disease and
cardiovascular side effects of therapies. This study aimed to compare
ECG parameters measured from conventional 12-lead ECGs to those from a
telemetry-generated 7-lead or single lead ECG to determine if the latter
may be an alternative for screening and monitoring patients,
particularly during a pandemic. Methods and Results: We identified 33
patients with respiratory failure due to COVID-19 undergoing telemetry
monitoring in the intensive care unit. Each received a 12-lead ECG
utilizing standard lead placement. A concurrent 7-lead ECG and single
lead (lead II) tracing were obtained using the central telemetry system.
Each ECG was interpreted and intervals manually measured by 2
cardiologists with disagreements adjudicated by a third. Compared to the
12-lead ECG measurement, the 7-lead ECG underestimated the corrected QT
by on average 13.45±32.05 msec, and the single lead ECG underestimated
corrected QT by 19.62±33.19 msec (Bazett, p < 0.05). Bland
Altman analysis also demonstrated evidence of a positive bias,
suggesting that the telemetry-derived tracings underestimated the QT
interval. The presence of T wave abnormalities and ST segment changes
were overestimated by the telemetry-derived tracings as compared to
standard ECGs. Conclusion: Though telemetry-derived ECGs may be useful
in screening patients for significant ECG abnormalities, they likely do
not represent a reliable replacement of the standard 12-lead ECG in the
routine diagnosis and management of critically ill patients.