A Model Simulation for Decreased Left Ventricular Stroke Volume in Obstructive Sleep-Disordered Breathing

Figure 1

Simulations of the inspiratory left ventricular stroke volume (LVSV)-intrathoracic pressure (Pth) relationships showed the steady LVSV decline with airway resistance and the parallel displacement from baseline by parameter modifications: decreased left ventricular end-diastolic compliance (open square), increased central blood volume (closed triangle), decreased right ventricular end-diastolic compliance (crossed square), increased systemic veins compliance (closed square), and increased 400 mL of the unstressed volume of systemic veins (to 3 L, gray closed circle). The typically more pronounced increase in left ventricular end-systolic volume (LVESV) than in left ventricular end-diastolic volume (LVEDV) with airway resistance is shown for the baseline (thin line) and for the 3 L simulations (heavy line). The largest decrease in LVESV and LVEDV was obtained with the 3 L simulation (similar changes in simulated right ventricular end-systolic and end-diastolic volumes are not shown for clarity).