Noninvasive assessment of left ventricular contractility in pediatric patients using the maximum rate of pressure rise in peripheral arteries

Abstract

The maximum rate of left ventricular pressure rise (LV dp/dt(max)) is a good indicator of ventricular contractility. However, its measurement requires invasive cardiac catheterization. By applying the relationship between the ratio of aorta (Ao) dp/dt(max) to LV dp/dt(max) and the mean artery pressure (MAP), we tested the possible noninvasive estimation of LV dp/dt(max) by the maximum rate of pressure rise in peripheral arteries, as measured by tonometry. The study subjects were 31 children with cardiovascular disease. The LV and Ao pressures were measured during cardiac catheterization, with simultaneous recording of the brachial (BrA) or radial (RaA) artery pressure. The relationships between BrA dp/dt(max) and Ao dp/dt(max) and between RaA dp/dt(max) and Ao dp/dt(max) were determined (Ao dp/dt(max) = 0.299 × BrA dp/dt(max) + 210.6, n = 17, r = 0.78, SEE = 74.0, P = 0.0002, and Ao dp/dt(max) = 1.442 × RaA dp/dt(max) + 165.9, n = 14, r = 0.87, SEE = 66.1, P = 0.0001). Using these relationships and the equation Ao dp/dt(max)/LV dp/dt(max) = 0.694 - 4.00 × 10(-3) × MAP, LV dp/dt(max) was estimated from BrA dp/dt(max) or RaA dp/dt(max). The estimated LV dp/dt(max) correlated well with the measured LV dp/dt(max) independent of the site of measurement (y = 0.912 × x + 112.9, r = 0.91, P < 0.0001). Furthermore, there was excellent correlation between the measured and estimated LV dp/dt(max) after changes in contractility with dobutamine in 10 randomly selected patients (y = 0.86 × x + 34.2, r = 0.77, P = 0.01). It is possible to estimate LV dp/dt(max) noninvasively in children using tonometry. This procedure can be useful for bedside assessment of LV contractility and the clinical management of patients with cardiovascular disease.