Association of heart rate response with scan and left ventricular function on XXXX stress myocardial perfusion imaging.

@entity1 @entity2300 @entity859 @entity10979
To evaluate the association of heart rate (HR) response with abnormal scan and/or left ventricular (LV) function in @entity1 undergoing @entity859 myocardial perfusion imaging, we prospectively studied 164 consecutive @entity1 who underwent a standard @entity859 stress test (without exercise) and myocardial perfusion imaging (MPI) using @entity10979 radioisotope. Change in HR was calculated by subtracting HR at rest from peak HR. The percentage change in HR was calculated. All @entity1 underwent stress and resting single photon emission computed tomography (SPECT) imaging. Left ventricular ejection fraction (EF) was calculated using gated SPECT. Mean age was 54    11.7 years and 126 of the @entity1 (72%) were @entity1 . We divided the @entity1 into 2 groups: group 1(42 @entity1 , 25%) had normal scans and group 2(122 @entity1 , 74.3%) had abnormal scans; abnormal scans were defined as presence of either @entity2300 , reversible defects, or both. Average HR increased by 35 beats/min in the normal scan group compared with 23 beats/min in the abnormal scan group (p=0.002). Sixty four (64) @entity1 (39%) had reduced EF (<45%). This group had an average HR and percentage HR increase of 23 beats/min (27%) compared with an increase of 35 beats/min (38%) in @entity1 with normal EF (p=0.002 and p=0.02, respectively). Thus, a diminished HR response had a significant association with both an abnormal scan and reduced EF on @entity859 MPI.
