TY  - CHAP
M1  - Book, Section
TI  - Nuclear Cardiology Procedures in the Evaluation of Myocardial Viability
A1  - Wiefels, Christiane
A1  - Erthal, Fernanda
A1  - Chow, Benjamin
A1  - Heller, Gary V.
A1  - Beanlands, Rob S.B.
A2  - Heller, Gary V.
A2  - Hendel, Robert C.
PY  - 2022
T2  - Nuclear Cardiology: Practical Applications, 4e
AB  - KEY  POINTSFollowing  an  acute  or  chronic  ischemic  injury,  dysfunctional  myocardium  can  be  classified  as  viable  (stunned  or  hibernating  myocardium)  or  nonviable  (necrotic  and  scar).Hibernating  myocardium  is  characterized  by  reduced  perfusion  at  rest  after  repeated  episodes  of  ischemia  and/or  stunning,  and  despite  being  dysfunctional,  it  is  viable.  It  has  the  capacity  for  functional  recovery  if  adequate  and  timely  revascularization  can  be  achieved.During  fasting  conditions,  free-fatty  acids  are  the  preferred  energy  substrate  of  the  myocardium.  However,  ischemia  can  cause  a  shift  toward  glucose  utilization  making  positron  emission  tomography  (PET)  with  18F-fluorodeoxyglucose  (FDG)  a  highly  sensitive  means  to  evaluate  the  presence  of  hibernating  myocardium.While  all  techniques  (18FDG  PET,  dobutamine  echocardiography,  201Tl-single-photon  emission  computed  tomography  [SPECT],  99mTc-SPECT,  and  cardiac  magnetic  resonance  imaging  [CMR]  can  be  used  for  viability  assessment  and  guidance  in  decision  making,  some  may  be  better  in  certain  circumstances.  Among  these  18FDG  PET  and  CMR  are  considered  more  sensitive,  while  dobutamine  echocardiogram  and  CMR  are  considered  more  specific.The  use  of  viability  studies  is  best  targeted  to  patients  at  higher  risk  for  cardiac  death  or  other  cardiac  events  whose  benefit  from  cardiac  revascularization  may  be  considered  less  certain  due  to  factors  such  as  comorbidities  and  poor  vascular  targets.  The  revascularization  benefit  must  outweigh  the  risk  of  a  potential  surgery  or  intervention  and  enable  improved  outcome  and  quality  of  life.Several  prospective  outcomes  trials  have  demonstrated  clinical  benefit  when  revascularization  is  guided  by  the  presence  or  absence  of  viable  tissue  by  18FDG  PET  imaging,  especially  with  viable  myocardium  over  20%.  
SN  - 
PB  - McGraw Hill LLC
CY  - New York, NY
Y2  - 2024/04/20
UR  - accesscardiology.mhmedical.com/content.aspx?aid=1190157573
ER  -