title: Frequency analysis of high-intensity transient signals of transcranial Doppler ultrasound in patients supported with a left ventricular assist device.
abstract: Left ventricular assist devices (LVADs) have become more important than ever for patients with terminal heart disease. The chronic shortage of donors for heart transplantation may enhance the importance of LVADs as destination therapy. To prevent cerebral complications, the evaluation of high-intensity transient signals (HITS) of transcranial Doppler (TCD) ultrasound is important. In the present study, HITS were measured on seven occasions in patients supported with LVADs. The high-frequency counts in HITS were greater than the low-frequency counts (47 +/- 42 vs. 9 +/- 9 in 3 min, P = 0.025), and declined further with oxygen delivery to the patient. The high frequency of signals may imply air microemboli, and the counts may increase with time.
authors.affiliation: Division of Thoracic and Cardiovascular Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachidori, Niigata 951-8510, Japan.
authors.forename: Koichi
authors.initials: K
authors.lastname: Sato
authors.forename: Kazuhiko
authors.initials: K
authors.lastname: Hanzawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Okamoto
authors.forename: Shunei
authors.initials: S
authors.lastname: Kyo
authors.forename: Jun-ichi
authors.initials: J
authors.lastname: Hayashi
mesh_terms: D002561:Cerebrovascular Disorders / Q000175:diagnosis* / Q000209:etiology; D006353:Heart-Assist Devices / Q000009:adverse effects*; D006801:Humans; D017585:Ultrasonography, Doppler, Transcranial