Efficacy of Transthoracic Echocardiography for Diagnosing Heart Failure in Septic Shock

Background: Cardiac dysfunction occurs in up to 80% of patients with septic shock. Transthoracic echocardiography (TTE) is an ideal tool for the detailed characterization of cardiac function. Its feasibility is perceived to be poor in critically ill patients, but this has never been studied. To address this question, the authors evaluated the efficacy of TTE to diagnose heart failure in septic shock. Methods: This was a retrospective study. Patients admitted to the intensive care unit with septic shock and who had a TTE within 72 hours of intensive care unit admission were identified by a computer algorithm and validated by chart review. Echocardiography images were reviewed by a single cardiologist blinded to clinical outcomes. Clinical information was collected from patients' medical record. Results: Seventy-six patients met the studies' inclusion criteria. The feasibility of TTE to calculate left ventricular ejection fraction was 90% and to assess diastolic function was 74%. Significant mitral regurgitation or aortic stenosis was the most frequent impediments for the assessment of diastolic function. Seventy-four percent of all patients showed some type of cardiac dysfunction (left or right ventricular systolic dysfunction and/or left ventricular diastolic dysfunction). In regression analyses, TTE feasibility was not impacted by factors previously associated with poor image acquisition: high body mass index, mechanical ventilation, tachycardia, advanced age or high severity of illness. Conclusions: This study demonstrated that TTE is a useful tool to assess myocardial function in critically ill patients and suggested its potential to assist in the management of patients with septic shock.