Evaluation of left ventricular mechanical dyssynchrony with phase analysis in end-stage renal disease patients with normal gated SPECT-MPI.

Abstract

Phase analysis using gated single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI) is a relatively new tool for the assessment of ventricular synchrony. Hypertension, diabetes, renal diseases, and dyslipidemia may affect the phase parameters though their impact is not well understood. The present study aimed to evaluate the incidence of the left ventricular mechanical dyssynchrony (LVMD) in end-stage renal disease (ESRD) patients with normal gated SPECT-MPI and QRS duration (<120 ms) on electrocardiogram. Data of 129 patients (86 males) referred for gated SPECT-MPI for their pretransplant evaluation with normal gated stress SPECT-MPI (SSS <3 and ejection fraction ≥50%) were included in the study analysis. Documented clinical history along with confounding factors such as hypertension, dyslipidemia, smoking, and alcoholism were evaluated. Left ventricle functional (end-diastolic, end-systolic, and LV myocardial volume) and phase parameters (phase standard deviation [PSD], phase bandwidth [PBW] and entropy) were calculated using the QPS-QGS program. LVMD was noted in 36 (28%) of ESRD patients with normal QRS duration and gated SPECT-MPI. The mean attenuated corrected LV myocardial volume, ejection fraction, mean PSD, and PBW values were 84.3 ± 38.1 ml, 65.3 ± 13.5%, 9.8° ± 3.9°, and 61.4° ± 24.7°, respectively. The LV myocardial volume shows statistically significant correlation with the phase parameters (r = 0.31–0.47; P < 0.001). LVMD is present in a significant number of ESRD patients, and its extent is more with increase in LV myocardial volume. It may have an additional role in risk-stratification for cardiovascular disease in ESRD patients.