Frequency analysis of high-intensity transient signals of transcranial Doppler ultrasound in patients supported with a left ventricular assist device.
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.
Sato
Koichi
K
Division of Thoracic and Cardiovascular Surgery, Niigata University Graduate School of Medical and Dental Sciences, 1-757 Asahimachidori, Niigata 951-8510, Japan.
Hanzawa
Kazuhiko
K
Okamoto
Takeshi
T
Kyo
Shunei
S
Hayashi
Jun-ichi
J
D002561:Cerebrovascular Disorders / Q000175:diagnosis* / Q000209:etiology; D006353:Heart-Assist Devices / Q000009:adverse effects*; D006801:Humans; D017585:Ultrasonography, Doppler, Transcranial