Two cases of acute endocarditis misdiagnosed as COVID-19 infection.

The COVID-19 pandemic has presented countless new challenges for healthcare providers including the challenge of differentiating COVID-19 infection from other diseases. COVID-19 infection and acute endocarditis may present similarly, both with shortness of breath and vital sign abnormalities, yet they require very different treatments. Here, we present two cases in which life-threatening acute endocarditis was initially misdiagnosed as COVID-19 infection during the height of the pandemic in New York City. The first was a case of Klebsiella pneumoniae mitral valve endocarditis leading to papillary muscle rupture and severe mitral regurgitation, and the second a case of Streptococcus mitis aortic valve endocarditis with heart failure due to severe aortic regurgitation. These cases highlight the importance of careful clinical reasoning and demonstrate how cognitive errors may impact clinical reasoning. They also underscore the limitations of real-time reverse transcription-polymerase chain reaction (RT-PCR) for SARS-CoV-2 testing and illustrate the ways in which difficulty interpreting results may also influence clinical reasoning. Accurate diagnosis of acute endocarditis is critical given that surgical intervention can be lifesaving in unstable patients.