First-in-Human Experience of Mechanical Preload Control in Patients With HFpEF During Exercise

Figures

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  Figure 1. Fluoroscopic Image of Partial IVC Balloon Occlusion Fluoroscopic image of partial balloon inflation within the inferior vena cava (IVC) to control pulmonary pressures. The occlusion balloon was advanced from the right internal jugular vein so that the legs were free to cycle unencumbered.

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  Figure 2. Invasive Cardiopulmonary Testing Data: Control Versus Partial IVC Occlusion Trajectories of oxygen consumption (VO2), minute ventilation (VE), carbon dioxide consumption (VCO2), pulmonary artery (PA) systolic pressure, right atrial pressure, and respiratory rate with and without partial inferior vena cava balloon occlusion during each exercise phase.

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  Figure 3. Detailed Data in Selected Patients During Invasive Cardiopulmonary Testing Trajectories of VE-to-VCO2 ratio (VE/VCO2), cardiac output, and PA diastolic pressure at each stage of exercise in 5 of 6 subjects with optimal left ventricular (LV) filling pressures (left). The same trajectories in the 1 subject in whom overinflation reduced LV filling and a reduction in cardiac output (right). IVC = inferior vena cava; other abbreviations as in Figure 2.

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  Figure 4. Theoretical Effect of Partial IVC Occlusion to Reduce External Restraint and Paradoxically Improve Left Ventricular Stroke Volume Theoretical relationship between LV filling pressures and stroke volume in heart failure subjects. The effective transmural distending pressure is the measured LV pressure minus external forces, typically the pericardial restraint (Ptm = Pmeasured – Pext). Partial IVC occlusion may reduce pericardial restraint and paradoxically increase the transmural pressure and subsequently the cardiac output, despite reducing the measured LV pressure. Abbreviations as in Figure 3.