Leveraging Advanced Cardiac POCUS in the Diagnosis of Infective Endocarditis with Negative Conventional Imaging: A Case Report

Abstract

Introduction. Infective endocarditis (IE) is a life-threatening condition that includes bacteremia and echocardiographic findings. However, many cases yield inconclusive results with transthoracic (TTE) or transesophageal echocardiography (TEE), creating diagnostic challenges. This report highlights the role of advanced cardiac point-of-care ultrasound (POCUS) in addressing these limitations, using daily POCUS exams to address these limitations.

Case report. A 68-year-old male with methicillin-sensitive Staphylococcus aureus (MSSA) bacteremia and recurrent fevers underwent multiple conventional TTEs and a TEE, that failed to detect valvular vegetations. Advanced cardiac POCUS, including parasternal long-axis (PLAX), parasternal short-axis (PSAX), right ventricular (RV) inflow/outflow, and apical four-chamber views, was performed daily at the bedside. The PLAX view enabled visualization of new onset of aortic regurgitation, and Color Doppler imaging was applied to assess the severity of the valve disfunction. A vegetation in the aortic valve was identified, later confirmed by a consultative TTE and TEE, leading to a change in management.

Discussion. This case highlights the utility of advanced cardiac POCUS in diagnosing IE when conventional imaging is inconclusive. Advanced cardiac POCUS offers immediate, bedside diagnostic insights, making it a valuable tool for critically ill patients. Compared to basic cardiac POCUS, the advanced cardiac POCUS includes the RV inflow/outflow (that can be achieved through tilting or fanning of the probe), and use of color Doppler. A study by Hellmann et al. demonstrated that medical residents could achieve significant proficiency with color Doppler, with minimal formal training, aligning with our experience. Despite limitations such as operator dependency and patient characteristics, the integration of advanced cardiac POCUS into diagnostic workflows has the potential to improve diagnostic accuracy and outcomes. Additionally, the case emphasizes the need for advanced cardiac POCUS education among trainees, expanding their ability to address complex clinical scenarios.