title: Ventricular arrhythmias originating from a papillary muscle in patients without prior infarction: a comparison with fascicular arrhythmias.
abstract: BACKGROUND
  The papillary muscles (PAP) have been implicated in arrhythmogenesis, largely based on theoretical considerations and experimental studies. Few clinical studies have described papillary muscle arrhythmias.
  
  
  OBJECTIVE
  This study sought to describe ventricular arrhythmias arising from the left ventricular PAPs in a consecutive series of patients without prior myocardial infarction and to compare these arrhythmias with fascicular arrhythmias.
  
  
  METHODS
  Nine of 122 consecutive patients (7%) presenting with symptomatic premature ventricular complexes (PVCs) or nonsustained ventricular tachycardia (VT) were found to have a site of origin in the anterolateral or posteromedial left ventricular PAP. Their mean age was 57 +/- 9 years, and the mean ejection fraction was 0.49 +/- 13. Four of 9 patients had idiopathic cardiomyopathy. The PAP involvement was established by intracardiac echocardiography. Eight of the 122 patients (6.5%) had idiopathic VT originating in the left anterior or posterior fascicle, and these patients served as a control group.
  
  
  RESULTS
  Compared with patients with fascicular arrhythmias, the QRS width was significantly greater in patients with PAP arrhythmias (150 +/- 15 ms vs. 127 +/- 11 ms; P = .001). Presystolic Purkinje potentials were identified at all effective ablation sites for fascicular arrhythmias, but in arrhythmias originating from PAPs, more distal Purkinje potentials often were recorded from the Purkinje-myocardial interface located at the PAP. All arrhythmias originating from the PAPs and the fascicles were effectively ablated. Echocardiography before and after radiofrequency ablation did not show new or worsened mitral insufficiency.
  
  
  CONCLUSIONS
  The PAPs can give rise to ventricular arrhythmias in normal and structurally abnormal hearts without prior infarcts. Intracardiac echocardiography seems helpful in recognizing and guiding radiofrequency ablation of PAP arrhythmias.
authors.affiliation: University of Michigan Medical Center, Ann Arbor, Michigan, USA.
authors.forename: Eric
authors.initials: E
authors.lastname: Good
authors.forename: Benoit
authors.initials: B
authors.lastname: Desjardins
authors.forename: Krit
authors.initials: K
authors.lastname: Jongnarangsin
authors.forename: Hakan
authors.initials: H
authors.lastname: Oral
authors.forename: Aman
authors.initials: A
authors.lastname: Chugh
authors.forename: Matthew
authors.initials: M
authors.lastname: Ebinger
authors.forename: Frank
authors.initials: F
authors.lastname: Pelosi
authors.forename: Fred
authors.initials: F
authors.lastname: Morady
authors.forename: Frank
authors.initials: F
authors.lastname: Bogun
mesh_terms: D002036:Bundle of His / Q000503:physiopathology*; D017115:Catheter Ablation; D004452:Echocardiography; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009203:Myocardial Infarction; D010210:Papillary Muscles / Q000503:physiopathology*; D017180:Tachycardia, Ventricular / Q000000981:diagnostic imaging* / Q000503:physiopathology* / Q000601:surgery