2 New Measurements Used to Describe the Filling Phase of the Left Ventricle (LV).
Condition: Diastolic Heart Failure; Left Ventricular Diastolic Dysfunction; Left Ventricular Diastolic Collapse
MeSH terms: Heart Failure, Diastolic; Ventricular Dysfunction, Left
Study type: Observational

Summary: 
      As we live longer our population experiencing heart failure (HF) continues to grow consuming
      an increasing percent of healthcare dollars. Systolic heart failure or pump failure is easy
      to recognize and measure and is expressed as ejection fraction. Diastolic heart failure (DHF)
      or failure to fill adequately is much more difficult to quantify with no single measure or
      number being used to express the severity instead groupings are used with normal and Grade I,
      II or Grade III to classify with Grade III being the direst.

      Heart Failure with Reduced Ejection Fraction (HFrEF) and Heart Failure with Preserved
      Ejection Fraction (HFpEF) are used to identify the primary clinical presentation of HF but do
      not adequately describe the combined effect often presenting within the same subject. It is
      estimated 35 to 50% of those with HFrEF, having Left Ventricle Ejection Fraction (LVEF) <
      50%, and 50 to 70% of those with HFpEF, having ejection fraction ≥ 50%, also have moderate to
      severe diastolic dysfunction (DD).

      The purpose of this study is two fold. The first is to determine if the rate of change
      measured from the left ventricular inflow inspiratory phase Doppler waveform provides insight
      into a cause of diastolic heart failure by comparing echocardiographic data points obtained
      prior to and immediately following optimization of a bi-ventricular pacemaker. This HF
      population requires an ejection fraction of 35 percent or lower to qualify for the device.
      These echocardiograms have been previously completed and will be reanalyzed.

      The second purpose is to determine if relationships between different features of a LV volume
      curve can be used to generate a single number to describe global diastolic function using the
      same echocardiograms from the pacemaker group.

      Results will be compared to a small group of healthy normal participants as a control for
      validation.
    

Detailed description: 
      The purpose of this study is to introduce novel measurements to improve the classification of
      ventricular diastolic performance.

      There are 2 cohorts. Cohort 1 consists of 100 subjects who were referred and received echo
      guided biventricular pacemaker optimization. This retrospective component data is being
      retrieved to compare baseline and final cardiac performance measures. Comparisons will be
      made between Doppler and 3D echo diastolic and systolic markers. The Doppler diastolic
      markers will include D-E slope measuring the rate of pressure equalization between the left
      atrium (LA) and left ventricle (LV) during inspiration and expiration. MV VTI, the velocity
      time integral of the left ventricular inflow tract (LVIT) a surrogate measure for LV filling
      volume, averaging three consecutive complexes and minimal and maximal variability. TDI,
      tissue Doppler Imaging, when coupled with LVIT measures provides an estimation of left
      ventricular diastolic pressure. IRT, isovolemic relaxation time, an indicator of LA preload,
      S/D ratio, an indicator of LA compliance/pressure compared to pulmonary venous pressure. LAv,
      LA volume, a criteria for diastolic dysfunction grading. TRvmax, tricuspid regurgitation
      maximum velocity, used to estimate right ventricular systolic pressure. 3D measures will be
      obtained from the volume curve generated from the 3D full volume image acquisition. The 2
      slopes being compared are the initial filling (R1) and intermediate filling (R2) rates of
      volume change over time or R1/R2. LV ejection fraction, diastolic filling time (DFT),
      ejection time (ET), heart rate (HR), initial filling time (IFT), and stroke volume (SV) are
      all being measured from the 3D volume curve.

      Cohort 2 consists of normal healthy participants to serve as a comparison providing HF
      diseased state differentiation. All baseline measures performed in cohort 1 will be done for
      cohort 2.

      Primary Objective/Aim/Goal/Hypothesis Hypothesis: To determine if LV volume curves can be
      used to generate a single number that globally describes diastolic function and identify
      relationship to current grouping algorithm.

      Secondary Objective/Aim/Goal/Hypothesis Hypothesis: To determine if the pulse wave Doppler of
      the left ventricular inflow tract D-E slope measure and changes correlate with changes in
      diastolic performance of the LV.

      Hypothesis: Does weighting of the volume curve analysis with various features of the curve
      such as stroke volume, initial filling volume, and initial filling volume percent provide
      greater sensitivity or specificity in differentiating diastolic performance.

      Study Design: This study is a retrospective observational data analysis of echocardiographic
      images and Doppler waveforms comparing data between measurements and calculations taken at
      baseline and after final programming of biventricular pacemaker devices performed during a
      single visit. Additionally, the echo data from 5 normal healthy participants will be acquired
      during a single visit to establish normal values and demonstrate reproducibility.
    

Observational model: Cohort
Time perspective: Retrospective
Sampling method: Probability Sample
Study population: 
        Cohort 1 participants are individuals who have received a baseline and final
        echocardiogram.

        Cohort 2 is comprised of cardiac healthy participants.