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Behavior of the PR interval with increasing heart rate in patients with COVID-19
Behzad B Pavri1, Juergen Kloo1, Darius Farzad1
1Department of Medicine, Thomas Jefferson University Hospital, Philadelphia, Pennsylvania.
Insights
Half of COVID-19 patients exhibited abnormal PR interval behavior on ECGs, with this finding linked to a higher risk of death or intubation. This suggests a potential impact of COVID-19 on cardiac conduction.
Area of Science:
- Cardiology
- Infectious Diseases
- Electrocardiography
Background:
- Cardiovascular complications are known in COVID-19 patients.
- However, effects on the cardiac conduction system were previously unreported.
- A case of Mobitz type 1 atrioventricular block in a COVID-19 patient prompted further investigation.
Purpose of the Study:
- To characterize PR interval behavior in hospitalized COVID-19 patients.
- To correlate PR interval behavior with clinical outcomes, including mortality and need for intubation.
Main Methods:
- Cross-sectional cohort analysis of 75 confirmed COVID-19 cases.
- ECG analysis to calculate the PR interval to heart rate (PR:HR) slope.
- Comparison of pre-COVID-19 and COVID-19 ECGs; clinical endpoints were death or endotracheal intubation.
Main Results:
- Nearly half of patients (49.3%) showed abnormal PR interval behavior (no shortening or paradoxical prolongation) with increasing heart rate.
- Patients with abnormal PR interval behavior had a significantly higher likelihood of death (29.7% vs 7.9%).
- These patients also showed an increased risk of requiring endotracheal intubation (43.2% vs 21.1%).
Conclusions:
- Abnormal PR interval behavior during COVID-19 infection is common, affecting approximately half of patients.
- This ECG finding is associated with a significantly increased risk of severe outcomes, including death and mechanical ventilation.
- These results highlight a previously unrecognized impact of COVID-19 on cardiac electrical conduction.
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.
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