FEBRUARY 2012 • VOL. 60                           SPECIAL ISSUE: CHRONIC OBSTRUCTIVE PULMONARY DISEASE (COPD)

Case Report

Idiopathic Dilatation of Inferior Vena Cava

SR Mittal

Deptt of Cardiology, St. Francis Hospital, Ajmer, Rajasthan
Received: 02.07.2010; Accepted: 23.07.2010

Abstract

A case of isolated dilation of inferior vena cava with diminished inspiratory collapse is reported. There was no other abnormality. Diameter and collapsibility of IVC should be interpreted in collaboration with other clinical and echocardiographic parameters before drawing any definative conclusion.

Introduction

Maximum diameter of IVC and degree if it’s inspiratory collapse are considered to correlate with mean RA pressure. We had a patient who had increased diameter of IVC with diminished inspiratory collapse without any other abnormality.

Case Report

A 33 years old asymptomatic male was reffered for echocardiography. Clinical examination, ECG and skiagram of chest were normal. Echocardiography revealed dilated inferior vena cava (IVC) with diminished inspiratory collapse (Expiration-24.6mm, Inspiration-20.5mm) (Figures 1 a,b). Spontaneous contrast was present. There was no obstruction to flow up to it’s entry in right atrium. Hepatic vein was mildly dilated (13.9mm) but flow was normal (Systolic-0.5m/sec, Diastolic-0.4m/sec, atrial reversal-0.24m/sec) (Figure 2a). Rest of the echocardiographic examination was normal. PA flow peak velocity-1.01m/sec, acceleration time-156ms (Figure 2b), no pulmonary regurgitation. Tricuspid flow- E-0.82m/sec, A-0.26m/sec, minimal tricuspid regurgitation- peak velocity-2.4m/sec (Figure 2c). Superior vena cava flow- systolic-0.5m/sec, diastolic-0.3m/sec, atrial reversal-0.15m/sec (Figure 2d). Right atrium and right ventricle were normal in size and RV contractility was normal (Figure 3 a,b). There was no regional wall motion abnormality. On transesophageal echocardiography IVC, SVC, interatrial septum, RA and RV were normal.

Discussion

Echocardiographic estimation of right atrial pressure is based on size and inspiratory collapse of IVC.1 Maximum diameter 12mm and collapse >50% suggests normal RA pressure (around 5-7mmHg). Maximum diameter up to 20mm and collapse >50% suggests RA pressure around 10mmHg. Maximum diameter up to 20mm but collapse 50% suggests RA pressure around 15mmHg. Maximum diameter >20mm without inspiratory collapse suggest RA pressure of >15mmhg2. Spontaneous swirling smoke like echoes moving slowly in IVC suggest increased RA pressure with slow flow in IVC. It should be differentiated from “Particulate matter” which are relatively more dense, discrete and move rapidly towards RA. Particulate matter in IVC can also be seen in subjects with increased hematocrit, increased fibrinogen levels and renal failure.3 Our patient did not have any other clinical, electrocardiographic, or echocardiographic evidence of increased RA pressure. Ethical committee of hospital and patient did not agree for invasive evaluation. We feel that diameter and collapsibility of IVC should be interpreted in collaboration with other parameters before making any definate conclusion.

References

1. Feigenbaum H, Armstrong WF, Ryan T. Hemodynamics. In Feigenbaum H, Armstrong WF, Ryan T ed. Feigenbaum’s Echocardiography 6th ed. Lipincott Williams and Wilkins, Philadelphia 2005:214-246.
2. Kircher BJ, Himelman RB. Schiller NB. Non-invasive estimation of right atrial pressure from inspiratory collapse of the inferior vena cave. Am J Cardiol 1990;66:493-496.
3. Meltzer RS, Klig V, Visser CA, Teichholz LE. Spontaneous echographic contrast in the inferior vena cava. Am Heart J 1985;110:826-830.