title: Left atrial booster pump function is an independent predictor of subsequent life-threatening ventricular arrhythmias in non-ischaemic cardiomyopathy.
abstract: OBJECTIVE
  Left atrial (LA) function helps to preserve cardiac output and to control pulmonary capillary wedge pressure in the setting of left ventricular (LV) impairment, but little is known about the contribution of the LA function to ventricular arrhythmia. We sought whether LA booster pump function was associated with arrhythmias in patients undergoing primary prevention implantable cardioverter-defibrillator (ICD) implantation for non-ischaemic dilated cardiomyopathy (NICM), independent of global longitudinal strain (GLS) and mechanical dispersion (MD).
  
  
  RESULTS
  We identified 124 NICM patients (56 ± 13, 67 male) who underwent echocardiography pre-ICD implantation for primary prevention. The main outcome measure was appropriate ICD therapy (anti-tachycardia pacing or shock). The mitral A-wave was used as an LA functional marker. MD was defined as standard deviation of time to peak strain of each segment. Over a median follow-up of 3.8 ± 2.2 years, 36 patients had appropriate ICD therapy, including 23 shocks. Patients with appropriate ICD therapy had lower A-wave velocity (P < 0.001), larger LA volume (P < 0.001), and impaired circumferential MD (P = 0.006), but similar ejection fraction (EF) (P = 0.40) and GLS (P = 0.11). In sequential Cox proportional hazards models, A-wave, E/A ratio, and GLS were significantly associated with outcomes, independent of age, sex, and cardiac resynchronization therapy defibrillator or left bundle branch block. In nested Cox models, mitral A-wave had a prognostic value incremental to models with LV systolic (EF and GLS) and diastolic functional parameters (E/A, E/e', and LA volume) and MD.
  
  
  CONCLUSIONS
  LA booster pump function was an independent and incremental predictor of arrhythmias in NICM over GLS and MD, and may aid better risk stratification in this population.
authors.affiliation: Menzies Institute for Medical Research, 17 Liverpool Street, Hobart, Tasmania 7000, Australia Cleveland Clinic, Cleveland, OH, USA kazz.negishi@nifty.com.
authors.forename: Kazuaki
authors.initials: K
authors.lastname: Negishi
authors.affiliation: Menzies Institute for Medical Research, 17 Liverpool Street, Hobart, Tasmania 7000, Australia Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Tomoko
authors.initials: T
authors.lastname: Negishi
authors.affiliation: Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Omeed
authors.initials: O
authors.lastname: Zardkoohi
authors.affiliation: Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Elizabeth A
authors.initials: EA
authors.lastname: Ching
authors.affiliation: Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Nivedita
authors.initials: N
authors.lastname: Basu
authors.affiliation: Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Bruce L
authors.initials: BL
authors.lastname: Wilkoff
authors.affiliation: Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Zoran B
authors.initials: ZB
authors.lastname: Popović
authors.affiliation: Menzies Institute for Medical Research, 17 Liverpool Street, Hobart, Tasmania 7000, Australia Cleveland Clinic, Cleveland, OH, USA.
authors.forename: Thomas H
authors.initials: TH
authors.lastname: Marwick
mesh_terms: D000367:Age Factors; D000368:Aged; D058406:Cardiac Resynchronization Therapy / Q000379:methods; D002311:Cardiomyopathy, Dilated / Q000175:diagnosis / Q000628:therapy; D016208:Databases, Factual; D016757:Death, Sudden, Cardiac / Q000517:prevention & control*; D017147:Defibrillators, Implantable; D004452:Echocardiography / Q000379:methods; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D017202:Myocardial Ischemia; D015588:Observer Variation; D011237:Predictive Value of Tests; D011322:Primary Prevention / Q000379:methods; D011379:Prognosis; D016016:Proportional Hazards Models; D012189:Retrospective Studies; D018570:Risk Assessment; D012737:Sex Factors; D013318:Stroke Volume; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000000981:diagnostic imaging / Q000401:mortality / Q000503:physiopathology / Q000601:surgery*; D016277:Ventricular Function, Left / Q000502:physiology*
keywords: Implantable cardioverter-defibrillator; Left atrial function; Non-ischaemic cardiomyopathy; Primary prevention; Strain