Pressure tracing in variably obstructive hypertrophic cardiomyopathy

Top tracing shows simultaneously recorded left ventricular (LV) and aortic (Ao) pressures. The systolic LV and Ao pressures are equivalent and no gradient is present, even after a ventricular premature beat (VPB). Valsalva induces more frequent VPBs and an intraventricular gradient is provoked; the beat following the VPB results in a LV pressure that is significantly greater than the Ao pressure (arrows).