Skip to main content
  • Poster presentation
  • Open access
  • Published:

Right/left ventricular area ratio does not correlate with right ventricular impedance


The right ventricular/left ventricular (RV/LV) area ratio is often used to titrate airway pressure during mechanical ventilation [1]. This ratio has only been validated for detecting pulmonary embolism [2]. The purpose of this study was to evaluate the relationship between RV/LV area ratio and RV impedance in a pig model with a closed pericardium.


Eight anesthetized pigs were instrumented with closed pericardium for the measurement of arterial blood pressure, central venous pressure, RV and pulmonary pressure. On the main pulmonary artery, an ultrasonic flowprobe (MA14PAX; Transonic) was positioned to obtain pulmonary flow. Distally, a balloon occluder was positioned facilitating gradual constriction of the pulmonary artery. To obtain a stepwise pressure difference increment over the banding we gradually inflated the balloon occluder. Occluder resistance is computed as the systolic right ventricle pressure minus systolic pulmonary pressure divided by cardiac output times 79.9. An ECG-gated CT scan of the heart was performed, 10 minutes after each banding. The RV/LV area ratio was computed by reconstructing the CT images to a typical echocardiographic four-chamber view and dividing the RV area by the LV area. All measurements were performed in triplicate and averaged. As repeated measurements in eight independent animals were used, a significant relation was sought between RV/LV area ratio and occluder resistance with ANOVA. Correlation was obtained by a Spearson's correlation.


Cardiac output dropped from 4.4 ± 0.8 to 1.7 ± 0.9 l/minute. The relations between occluder resistance and RV/LV area ratio during diastole and during systole were not significant (r = 0.48 resp. r = 0.54).


The RV/LV area ratio does not correlate with right ventricular impedance in this closed pericardium model.


  1. Bouferrache K: Acute respiratory distress syndrome, mechanical ventilation, and right ventricular function. Curr Opin Crit Care 2011, 17: 30-35. 10.1097/MCC.0b013e328342722b

    Article  PubMed  Google Scholar 

  2. Mansencal N: Comparison of different echocardiographic indexes secondary to right ventricular obstruction in acute pulmonary embolism. Am J Cardiol 2003, 92: 116-119. 10.1016/S0002-9149(03)00485-5

    Article  PubMed  Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit The Creative Commons Public Domain Dedication waiver ( applies to the data made available in this article, unless otherwise stated in a credit line to the data.

Reprints and permissions

About this article

Cite this article

Paalvast, F., Miranda, D.R., Knook, M. et al. Right/left ventricular area ratio does not correlate with right ventricular impedance. Crit Care 16 (Suppl 1), P215 (2012).

Download citation

  • Published:

  • DOI: