Update on Echocardiography of the Inferior Vena Cava

Demonstration of inferior vena cava compression by probe pressure during subxiphoid echocardiography

We sought to compare the inferior vena cava diameter measured by transthoracic echocardiography and by transesophageal echocardiography in human and animals. Transthoracic echocardiography yielded lower inferior vena cava diameter values than transesophageal echocardiography. Adult and pediatric intensivists should pay attention to the risk of false measurement of the inferior vena cava anterior-posterior diameter that may be due to compression of the inferior vena cava by the sonographic probe when the subxiphoid view is used.

Deterioration of renal function by chronic heart failure is associated with congestion and oxidative stress in the tubulointerstitium

OBJECTIVE

We examined the hypothesis that renal congestion is responsible for the decline in renal function in patients with heart failure (HF) via tubulointerstitial inflammation.

METHODS

First, in a longitudinal study, we retrospectively examined the relationship between cardiac functions and the decline of renal function during a period of 6.4±3.2 years in 20 patients who had a left ventricular ejection fraction of <40% and an estimated glomerular filtration ratio (eGFR) of <60 mL/min/1.73 m(2). Second, we compared the renal histology in autopsy cases of HF-induced renal dysfunction (HF-RD), cases of nephrosclerosis (NSC) and cases of neither RD nor HF (controls) in a cross-sectional study. Third, we retrospectively examined renal function in HF patients with predominantly right, but not left, ventricular dysfunction. Results eGFR decreased at 9.4±4.6%/year in the cohort of the longitudinal study. The rate of eGFR decline was correlated with blood pressure and with diameter of the inferior vena cava (IVCd) (r=0.5) measured at the initial work-up. Multivariate analysis indicated that the IVCd is an independent determinant of decline of eGFR in HF. In the cross-sectional study, fibrosis, Rac1 expression, protein nitrosylation, and number of CD68-positive cells were increased in the tubulointerstitium in both cases of HF-RD and NSC. Peritubular capillaries in HF-RD were dilated by 35% without any change in density compared with those in the controls. In right sided HF, the reduction of IVCd after treatment was associated with improvement of eGFR.

CONCLUSION

Venous congestion may contribute to HF-induced deterioration of renal function by augmenting oxidative stress-mediated inflammation in the tubulointerstitium.

Three-dimensional echocardiographic appearances of pericardial effusion with tamponade

A patient with pericardial effusion and tamponade was studied by routine two-dimensional as well as three-dimensional echocardiogram. Chamber "collapses" of the right atrium, left atrium, right ventricle, and inferior vena cava were visualized by both modalities, but were better appreciated on three-dimensional echo imaging, perhaps because three-dimensional echo imaging is more suited to depicting three-dimensional changes in chamber shape.