Figure 7

Flow Variation with Different Respiratory Excursions. Percent variation between inspiratory and expiratory flows for different breathing waveform excursions (e.g., -2 to -6 mmHg) for control (Panel A) and tamponade (Panel B). As respiratory excursion increases, respiratory variation increases for all flows. Under control conditions, respiratory variation is significantly higher in the right heart than in the left. However, with severe tamponade, the level of respiratory variation in the left heart increases, becoming more comparable to that of the right heart. (QVC = vena cava flow; QTC = tricuspid flow; QPA = pulmonary artery flow; QM = mitral flow; QAO = aortic flow).