title: Incidence of cardiac arrhythmias with therapeutic versus diagnostic ultrasound and intravenous microbubbles.
abstract: OBJECTIVE
  The purpose of this study was to determine the type of arrhythmias induced with therapeutic versus diagnostic transthoracic low-frequency ultrasound (TLFUS) transducers in the presence of intravenous microbubbles.
  
  
  METHODS
  Intravenous perfluorocarbon-exposed sonicated dextrose albumin (PESDA) microbubbles were infused or given as a bolus injection while TLFUS was applied in the standard parasternal and apical views with either a 1-MHz therapeutic ultrasound transducer or high-mechanical-index diagnostic ultrasound (1.7 MHz).
  
  
  RESULTS
  Significantly more ectopy was produced by the therapeutic transducer, especially at higher-intensity settings in the continuous wave mode after bolus injections of PESDA (P < .001 compared with lower intensities and lower continuous infusion rates). Six patients (15%) had either clinical supraventricular tachycardia or nonsustained ventricular tachycardia after intravenous PESDA with therapeutic TLFUS. In comparison, diagnostic high-mechanical-index ultrasound produced only isolated ventricular ectopy and no sustained ventricular arrhythmias.
  
  
  CONCLUSIONS
  Intravenously injected microbubbles and low-frequency therapeutic transducers operating at longer duty cycles and wide beam widths have the capability of eliciting clinically important arrhythmias in patients at high risk for such events.
authors.affiliation: University of Nebraska Medical Center, Omaha, 68198-1165, USA.
authors.forename: Scott
authors.initials: S
authors.lastname: Chapman
authors.forename: John
authors.initials: J
authors.lastname: Windle
authors.forename: Feng
authors.initials: F
authors.lastname: Xie
authors.forename: Anna
authors.initials: A
authors.lastname: McGrain
authors.forename: Thomas R
authors.initials: TR
authors.lastname: Porter
mesh_terms: D000328:Adult; D000368:Aged; D000704:Analysis of Variance; D001145:Arrhythmias, Cardiac / Q000209:etiology*; D003287:Contrast Media / Q000009:adverse effects*; D004562:Electrocardiography; D005260:Female; D005466:Fluorocarbons / Q000009:adverse effects*; D005947:Glucose / Q000009:adverse effects; D006801:Humans; D015994:Incidence; D008297:Male; D045423:Microbubbles; D008875:Middle Aged; D012709:Serum Albumin / Q000009:adverse effects; D000075462:Serum Albumin, Human; D018709:Statistics, Nonparametric; D014159:Transducers / Q000009:adverse effects; D014464:Ultrasonic Therapy / Q000009:adverse effects*; D014463:Ultrasonography / Q000009:adverse effects*
chemical_list: D003287:Contrast Media; D005466:Fluorocarbons; D012709:Serum Albumin; C094311:dextrose albumin solution; D005947:Glucose; D000075462:Serum Albumin, Human