TY  - CHAP
M1  - Book, Section
TI  - Polymorphic Ventricular Tachycardia and Ventricular Fibrillation
A1  - Sauer, William H.
A1  - Tedrow, Usha B.
A2  - Loscalzo, Joseph
A2  - Fauci, Anthony
A2  - Kasper, Dennis
A2  - Hauser, Stephen
A2  - Longo, Dan
A2  - Jameson, J. Larry
Y1  - 2022
N1  - 
T2  - Harrison's Principles of Internal Medicine, 21e
AB  - Sustained  polymorphic  ventricular  tachycardia  (VT)  has  a  continuously  changing  QRS  configuration  from  beat  to  beat,  indicating  a  continually  changing  ventricular  activation  sequence.  However,  unlike  sustained  monomorphic  VT,  polymorphic  VT  does  not  necessarily  indicate  a  fixed  structural  abnormality  or  focus  of  automaticity.  Reentry  can  occur  with  continually  changing  reentrant  paths,  spiral  wave  reentry,  and  multiple  automatic  foci  as  potential  mechanisms.  This  type  of  reentry  can  occur  near  fibrotic  areas  of  myocardium,  potentiated  by  proximity  to  damaged  Purkinje  cells  or  ventricular  hypertrophy.  Abnormal  transmural  dispersion  of  repolarization  can  occur  in  the  setting  of  channelopathies  or  antiarrhythmic  drugs  in  the  absence  of  structural  heart  disease.  Sustained  polymorphic  VT  usually  degenerates  into  ventricular  fibrillation  (VF).  Polymorphic  VT  is  typically  seen  in  association  with  acute  myocardial  infarction  or  ischemia  (MI),  ventricular  hypertrophy,  and  a  number  of  genetic  mutations  that  affect  cardiac  ion  channels.  
SN  - 
PB  - McGraw-Hill Education
CY  - New York, NY
Y2  - 2024/04/19
UR  - accessmedicine.mhmedical.com/content.aspx?aid=1190497018
ER  -