Utility of Equilibrium Radionuclide Angiogram–Derived Measures of Dyssynchrony to Predict Outcomes in Heart Failure Patients Undergoing Cardiac Resynchronization Therapy

Abstract

We evaluated a novel scintigraphic method using new parameters of mechanical left ventricular (LV) dyssynchrony and correlated it with clinical outcomes in heart failure patients with reduced ejection fraction receiving cardiac resynchronization therapy (CRT). Methods: Sixty-six advanced heart failure patients referred for CRT with an LV ejection fraction (EF) of , 35% and QRS $ 120 ms were studied. We performed equilibrium radionuclide angiography (ERNA) before and 6 mo after CRT. We assessed ventricular dyssynchrony with parameters derived from the first harmonic phase (Ø) analysis of the ERNA time-activity curve and evaluated change in these parameters after 6 mo of CRT. These parameters include novel indices of synchrony (S), a measure of intraventricular contraction order, and entropy (E), a measure of intraventricular contraction disorder, and interventricular synchrony (IVS), a measure of synchronous biventricular function. Results: Forty-seven (71%) patients improved clinically (responders) at 6 mo after CRT whereas 19 (28.8%) showed no change in New York Heart Association class or worsened (nonresponders). The post-CRT changes in QRS duration (P 5 0.006), echocardiographic (P 5 0.03) and ERNA LVEF (P 5 0.0007), LVS (P 5 0.004), LVE (P 5 0.006), LV standard deviation of ventricular phase (LVSDØ) (P 5 0.004), and IVS (P 5 0.05) were significantly different between responders and nonresponders. Sixty-two percent of responders had either an LVS , 0.84 or an IVS $ 18.8°as opposed to only 16% of nonresponders (P 5 0.001). Twenty-nine of 32 (91%) patients with either of these measures responded to CRT (P , 0.01). Conclusion: LVS and IVS are novel measures of LV dyssynchrony derived from ERNA planar analysis. A baseline value of LVS , 0.84 or IVS $ 18.8°predicts a positive response to CRT.

Value of intraventricular dyssynchrony assessment by gated-SPECT myocardial perfusion imaging in the management of heart failure patients undergoing cardiac resynchronization therapy (VISION-CRT)

“…9,10 Assessment of LV dyssynchrony has been approached with a number of imaging techniques, such as echocardiography with tissue Doppler imaging, strain imaging and more recently speckle-tracking; magnetic resonance imaging; gated blood pool ventriculography and gated single photon emission computed tomography (gSPECT). [11][12][13][14][15][16][17] LV mechanical dyssynchrony, site of latest mechanical activation, and myocardial scarring are important parameters related to CRT response. 18,19 Since many heart failure patients will undergo a gSPECT myocardial perfusion imaging (MPI) study as part of the work-up, added to the ventricular function information and the perfusion images to assess the presence, extent and location of myocardial scar or fibrotic tissue, these patients can benefit from the simple additional phase analysis to measure LV dyssynchrony.…”

Equilibrium radionuclide angiography: Present and future

“…Currently, ERNA is used to: (A) quantify left ventricular and right stroke volumes and ejection fractions in patients with moderate to severe tricuspid regurgitation, 19 (B) obtain measures of dyssynchrony to predict outcomes in heart failure patients, [20][21][22][23] (C) assess left ventricular function and mechanical dyssynchrony in patients with right ventricular outflow tract pacing and right ventricular apical pacing, 24 (D) study the accuracy of automated LVEF measurements in the presence of large perfusion defects in a myocardial infarction, in which the estimation of endocardial borders might be expected to be difficult because of reduced or absent counts, requiring some degree of extrapolation with a geometric model, 25,26 (E) evaluate left and right ventricular volumes and function in patients with left ventricular assist devices, 2 (F) analyze the left and right ventricular function after surgical repair of Tetralogy of Fallot, 27 (G) validate ( Table 2) the ventricular function assessment by other imaging techniques, 13,25,[28][29][30][31][32][33][34] and (H) analyze left and right ventricular function before lung transplant ( Figure 2). Furthermore, in oncologic patients treated with chemotherapy, ERNA is a good imaging technique to detect systolic dysfunction through left and right ventricular ejection fraction analysis.…”

Comparison of radionuclide angiographic synchrony analysis to echocardiography and magnetic resonance imaging for the diagnosis of arrhythmogenic right ventricular cardiomyopathy

“…16 The technique has recently been adapted to measure both RV and left ventricular (LV) synchrony, and in this context, our group has developed 2 parameters to characterize ventricular function: synchrony (S) and entropy (E). [17][18][19][20] These parameters provide an objective measure of RV and LV dysfunction in patients with ARVC and have been shown to reproducibly differentiate varying contraction patterns. [17][18][19][20] Despite their potential, ERNA synchrony parameters have yet to be examined as a diagnostic tool for ARVC.…”

“…[17][18][19][20] These parameters provide an objective measure of RV and LV dysfunction in patients with ARVC and have been shown to reproducibly differentiate varying contraction patterns. [17][18][19][20] Despite their potential, ERNA synchrony parameters have yet to be examined as a diagnostic tool for ARVC. In this study, we evaluated ERNA synchrony parameters in patients with ARVC, patients with RVOT VT, and controls with structurally normal hearts and compared the performance of ERNA with that of ECHO and CMR.…”