Abstract 428: Assessment of the Force Frequency Relationship in Patients With and Without Heart Failure: A Comparison of Invasive Measures With Two-Dimensional Echocardiographic Strain Analysis
Introduction: We compared 2DE speckle-tracking derived LV systolic strain and strain rate (SR) to simultaneous invasive measures of LV function. Response to increases in heart rate (HR) were recorded in patients with or without heart failure (HF).
Methods: Seven patients with normal LV (NLV) function (60±7 yrs), and 7 HF patients (52±7 yrs) were studied. After diagnostic cardiac catheterization, patients were instrumented with a RA pacing catheter, and the LV pressure was recorded with a micromanometer-tipped catheter. LV peak positive dP/dt, LVEDP, and tau were recorded at the intrinsic HR and in response to incremental increases in RA pacing. 2DE-doppler images were simultaneously recorded and analyzed off-line for peak global strain (GS) and peak systolic SR.
Results: As expected, NLV patients had higher LV +dP/dt and peak GS than HF patients. In response to increased HR, NLV and HF patients demonstrated increases in LV +dP/dt, and decreases in LVEDP, tau, and stroke volume (SV). With increased HR, there was a decrease in peak GS and a trend to increased peak systolic SR.
Conclusions: Peak GS discriminates patients with and without HF, and decreases in response to increases in HR. Unlike other contractile stimuli, increases in HR attenuate SV and LVEDP. These data suggest that changes in preload confound the utility of strain as a measure of LV contractility.