Left ventricular mechanical dyssynchrony in patients with chest pain and normal epicardial coronary arteries.

Abstract

BACKGROUND\nTo detect ischemia in patients with angina and normal coronaries frequently represents a complex diagnosis.\n\n\nMETHODS\nTo investigate whether left ventricular mechanical dyssynchrony by phase analysis contributes in the evaluation of patients with chest pain and normal coronaries, gated-SPECT myocardial perfusion imaging (MPI) at rest and 30 minutes post-stress was performed in 218 patients with normal epicardial coronaries, who were divided into two groups: those with summed difference score (SDS) ≥\xa04 (54 patients, Group 1), and those with SDS\xa0<\xa04 (164 patients, Group 2). Intraventricular synchronism-phase standard deviation (PSD) and histogram bandwidth (HBW)-was evaluated by phase analysis.\n\n\nRESULTS\nWomen were significantly more frequent in Group 2 (those without ischemia in SPECT MPI): 113 (69%) vs 25 (46%), P\xa0=\xa0.00001. In males, left ventricular ejection fraction (LVEF) and ventricular volumes were not significantly different between patients with or without ischemia. However, ischemic females showed significantly higher ventricular volumes, minor post-stress LVEF and more negative delta LVEF (-\xa03.9 vs 0.34, P\xa0=\xa0.0008) than the non-ischemic ones. There was a significant post-stress increase of PSD and HBW among males, although not among females. According to SSS (≥\xa04, with ischemia/necrosis; <\xa04, without ischemia/necrosis), post-stress PSD and HBW significantly increase both in male and female, and PSD and HBW were significantly higher in females with SSS\xa0≥\xa04 compared to those with SSS\xa0<\xa04 (PSD rest: 19.04° vs 11.72°, P\xa0<\xa0.0001; HBW rest: 58.85° vs 38.21°, P\xa0<\xa0.0001). PSD and HBW were also higher among males with SSS\xa0≥\xa04 compared to those with SSS\xa0<\xa04, although not significantly.\n\n\nCONCLUSION\nHigher ventricular volumes in females and dyssynchrony are associated with inducible ischemia in MPI in patients with chest pain and normal coronaries. Stress-induced ischemia increases degree of dyssynchrony.