title: Frequent additional tachyarrhythmias in patients with inappropriate sinus tachycardia undergoing sinus node modification: an important cause of symptom recurrence.
abstract: BACKGROUND
  Symptom recurrence following sinus node modification (SNM) for inappropriate sinus tachycardia (IST) remains significant despite achieving acute procedural success. The impact of non-IST tachyarrhythmias on symptom recurrence remains poorly characterized.
  
  
  OBJECTIVE
  The objective was to determine the prevalence and nature of additional tachyarrhythmias preceding and following SNM for IST.
  
  
  METHODS
  Consecutive patients with IST undergoing SNM at the University of Pennsylvania were studied. SNM was initially performed using an anatomic approach targeting the superolateral crista terminalis under intracardiac echocardiographic guidance and later using an electrophysiologic approach, targeting the site of the earliest right atrial activation during maximum heart rate (HR) with isoproterenol infusion. An effort was made to shift the site more caudally until a decrease of >25% in resting HR was achieved, with a blunted response to isoproterenol and flattening of the P-wave axis in leads III and aVF. Patients were followed for arrhythmia recurrence. Tachyarrhythmias were documented with electrocardiographic monitoring and then characterized during EP study.
  
  
  RESULTS
  Thirty-three patients underwent SNM and were followed for a mean of 2.0 ± 1.5 years. During follow-up, 27% developed a non-IST tachyarrhythmia and 18% developed recurrent IST. Additionally, 42% of patients had a non-IST tachyarrhythmia prior to SNM.
  
  
  CONCLUSIONS
  Non-IST tachyarrhythmias are common in patients with IST before and after SNM. A major reason for symptom recurrence following SNM is development of a non-IST tachyarrhythmia. These tachyarrhythmias should be detected and treated to optimize patient outcomes.
authors.affiliation: Cardiovascular Division, Electrophysiology Section, Hospital of the University of Pennsylvania, Philadelphia, PA, USA. david.frankel@uphs.upenn.edu
authors.forename: David S
authors.initials: DS
authors.lastname: Frankel
authors.forename: David
authors.initials: D
authors.lastname: Lin
authors.forename: Nicholas
authors.initials: N
authors.lastname: Anastasio
authors.forename: Stavros E
authors.initials: SE
authors.lastname: Mountantonakis
authors.forename: Sanjay
authors.initials: S
authors.lastname: Dixit
authors.forename: Edward P
authors.initials: EP
authors.lastname: Gerstenfeld
authors.forename: Mathew D
authors.initials: MD
authors.lastname: Hutchinson
authors.forename: Michael P
authors.initials: MP
authors.lastname: Riley
authors.forename: Francis E
authors.initials: FE
authors.lastname: Marchlinski
authors.forename: David J
authors.initials: DJ
authors.lastname: Callans
mesh_terms: D000318:Adrenergic beta-Agonists; D000328:Adult; D017115:Catheter Ablation / Q000009:adverse effects; D016009:Chi-Square Distribution; D022062:Electrophysiologic Techniques, Cardiac; D005260:Female; D006339:Heart Rate; D006785:Hospitals, University; D006801:Humans; D007545:Isoproterenol; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D010414:Pennsylvania / Q000453:epidemiology; D011237:Predictive Value of Tests; D015995:Prevalence; D016016:Proportional Hazards Models; D012008:Recurrence; D012189:Retrospective Studies; D018570:Risk Assessment; D012307:Risk Factors; D012849:Sinoatrial Node / Q000503:physiopathology / Q000601:surgery*; D013610:Tachycardia / Q000175:diagnosis / Q000453:epidemiology* / Q000503:physiopathology; D013616:Tachycardia, Sinus / Q000175:diagnosis / Q000453:epidemiology / Q000503:physiopathology / Q000601:surgery*; D013997:Time Factors; D016896:Treatment Outcome
chemical_list: D000318:Adrenergic beta-Agonists; D007545:Isoproterenol