Electrical and hemodynamic correlates of the maximal rate of pressure increase in the human left ventricle

Background:The rate of left ventricular (LV) pressure increase (LV +dP/dt) may be related to QRS duration, as well as to a number of hemodynamic param eters. Methods and Results:We studied the relation between basal LV +dP/dt and RS duration in 43 patients with normal LV function and 81 patients with heart failure undergoing diagnostic catheterization. We also examined the relatio nship between LV +dP/dt and heart rate, as well as measures of both LV prel oad and afterload. In patients with normal LV function, there was a strong relationship between basal LV +dP/dt and resting heart rate, whereas the re lationship with QRS duration was of borderline significance. In patients wi th heart failure, the relationship with heart rate was lost; however, LV sy stolic pressure, QRS duration, and LV end-diastolic pressure all made signi ficant contributions to a model predicting LV +dP/dt. Conclusions:These data show a strong relationship between resting heart rat e and LV +dp/dt in the healthy human LV. In patients with heart failure, th e relationship with heart rate is not maintained; however, there is a syste matic relationship between LV +dP/dt and both the time-course of the electr ical activation and measures of LV loading conditions.