ABSTRACT
Mobile electrocardiograms (ECGs) (mECGs) using smartphone applications are an emerging technology. In the coronavirus disease 2019 (COVID-19) era, minimizing patient contact has gained increasing importance. Additionally, increased QT/corrected QT (QTc) monitoring has concurrently been required. The KardiaMobile 6L ECG device, cleared by the United States Food and Drug Administration (FDA) for recording ECGs, along with the KardiaStation tablet application is a platform (AliveCor, Mountain View, CA, USA) that addresses these two issues. A team of residents, fellows, hospitalists, and cardiologists identified inpatients in need of QT/QTc interval monitoring to pilot the adoption of a system composed of a KardiaMobile 6L ECG device with the accompanying KardiaStation tablet application. Concurrent standard ECGs provided validation. Adoption and performance issues were recorded. Four patients agreed to participate in QT/QTc interval monitoring, three of whom were positive for severe acute respiratory syndrome coronavirus 2 viral infection. After basic instructions were given to the patients and their clinical nurses, all patients recorded mECGs successfully. Patients were able to record their own mECG tracings at least once without any assistance. The 12-lead ECGs and mECGs each showed the correct rhythm, and the measured QTc intervals on each modality were consistently acceptable (< 500 ms). Contactless ECGs were successfully uploaded to KardiaStation for QT/QTc interval measurement and archiving. In this study, we showed that an FDA-cleared product, KardiaMobile 6L, has the ability to provide high-quality contactless ECGs for reliable QT/QTc interval measurements. Hospitalized patients were able to perform recordings when requested after receiving simple instructions at the time of first use. This technology has applications during the COVID-19 pandemic and beyond.
ABSTRACT
BACKGROUND: Myriad manifestations of cardiovascular involvement have been described in patients with coronavirus disease 2019 (COVID-19), but there have been no reports of COVID-19 affecting the cardiac conduction system. The PR interval on the electrocardiogram (ECG) normally shortens with increasing heart rate (HR). The case of a patient with COVID-19 manifesting Mobitz type 1 atrioventricular (AV) block that normalized as the patient's condition improved prompted us to investigate PR interval behavior in patients with COVID-19. OBJECTIVE: The purpose of this study was to characterize PR interval behavior in hospitalized patients with COVID-19 and to correlate that behavior with clinical outcomes. METHODS: This study was a cross-sectional cohort analysis of confirmed COVID-19 cases (March 26, 2020, to April 25, 2020). We reviewed pre-COVID-19 and COVID-19 ECGs to characterize AV conduction by calculating the PR interval to HR (PR:HR) slope. Clinical endpoints were death or need for endotracheal intubation. RESULTS: ECGs from 75 patients (246 pre-COVID-19 ECGs and 246 COVID-19 ECGs) were analyzed for PR:HR slope. Of these patients, 38 (50.7%) showed the expected PR interval shortening with increasing HR (negative PR:HR slope), whereas 37 (49.3%) showed either no change (8 with PR:HR slope = 0) or paradoxical PR interval prolongation (29 with positive PR:HR slope) with increasing HR. Patients without PR interval shortening were more likely to die (11/37 [29.7%] vs 3/38 [7.9%]; P = .019) or require endotracheal intubation (16/37 [43.2%] vs 8/38 [21.1%]; P = .05) compared to patients with PR interval shortening. CONCLUSION: Half of patients with COVID-19 showed abnormal PR interval behavior (paradoxical prolongation or lack of shortening) with increasing HR. This finding was associated with increased risk of death and need for endotracheal intubation.