A Prospective Study of Right Ventricular Pulse Pressure and dP/dt to Discriminant‐Induced Ventricular Tachycardia from Supraventricular and Sinus Tachycardia in Man

Abstract

In the future, automatic implantable cardioverter defibrillators (AICD) may incorporate sensors to differentiate hemodynamically stable from unstable ventricular tachycardias (VT). These sensors should also discriminate between ventricular and supraventricular tachycardias to avoid inappropriate responses from the device. Right ventricular pulse pressure (RVPP) and maximal systolic right ventricular dP/dt (dP/dt) were measured before, during and after 91 episodes of hemodynamically stable VT (VTs), hemodynamically unstable VT (VTus), supraventricular tachycardia (SVT) and sinus tachycardia (ST) induced in 49 male patients. The mean percent changes (mean +/- S.E.M.) in RVPP from baseline (% delta RVPP) during VTs and VTus were -35 +/- 3% and -72 +/- 3%, respectively (both P less than 0.001). The % delta RVPP during ST was +56 +/- 11% (P less than 0.01) and % delta RVPP was unchanged from baseline during SVT (+2 +/- 9%; P greater than 0.01). Mean % change in RV dP/dt from baseline was -20 +/- 3% during VTs (P less than 0.001), -36 +/- 5% during VTus (P less than 0.001), +15 +/- 13% during SVT (P less than 0.01), and +85 +/- 23% during ST (P greater than 0.01). The mean percent changes in RVPP were significantly different between each arrhythmia group (P less than 0.01). The mean % changes in RV dP/dt were significantly different only between ST and VTs or VTus and between SVT and VTus. The range of values for % delta RVPP during VTs overlapped considerably with the ranges of % delta RVPP during VTus and SVT. The ranges of % delta RVPP overlapped minimally between VTus and SVT. Percent change RVPP separated each episode of VTs and VTus from those of ST. The range of common values for % delta dP/dt between all four groups was extensive. It is concluded that % delta RVPP from baseline is significantly different between groups of patients during VTs, VTus, SVT, and ST, but that a large degree of overlap in the range of values for % delta RVPP and RV dP/dt between different arrhythmias groups may limit the specificity of these hemodynamic variables in separating different arrhythmias.