Identification of congestive heart failure via respiratory variation of inferior vena cava diameter.

INTRODUCTION Rapid diagnosis of volume overload in patients with suspected congestive heart failure (CHF) is necessary for the timely administration of therapeutic agents. We sought to use the measurement of respiratory variation of inferior vena cava (IVC) diameter as a diagnostic tool for identification of CHF in patients presenting with acute dyspnea. METHODS The IVC was measured sonographically during a complete respiratory cycle of 46 patients meeting study criteria. Percentage of respiratory variation of IVC diameter was compared to the diagnosis of CHF or alternative diagnosis. RESULTS Respiratory variation of IVC was smaller in patients with CHF (9.6%) than without CHF (46%) and showed good diagnostic accuracy with area under the receiver operating characteristic curve of 0.96. Receiver operating characteristic curve analysis showed optimum cutoff of 15% variation or less of IVC diameter with 92% sensitivity and 84% specificity for the diagnosis of CHF. CONCLUSION Inferior vena cava ultrasound is a rapid, reliable means for identification of CHF in the acutely dyspneic patient.