Unilateral versus Bilateral Middle Cerebral Artery Detection of Right-to-Left Shunt by Power M-Mode Transcranial Doppler

Authors

  • Jill T. Jesurum PhD,

    1. Department of Cardiovascular Scientific Development, Swedish Medical Center, Seattle, Washington (JTJ, CJF); Spencer Technologies, Seattle, Washington (MAG); and Spencer Vascular, Seattle, Washington (JR, MH, MPS).
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  • Cindy J. Fuller PhD,

    1. Department of Cardiovascular Scientific Development, Swedish Medical Center, Seattle, Washington (JTJ, CJF); Spencer Technologies, Seattle, Washington (MAG); and Spencer Vascular, Seattle, Washington (JR, MH, MPS).
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  • Mark A. Moehring PhD,

    1. Department of Cardiovascular Scientific Development, Swedish Medical Center, Seattle, Washington (JTJ, CJF); Spencer Technologies, Seattle, Washington (MAG); and Spencer Vascular, Seattle, Washington (JR, MH, MPS).
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  • Joshua Renz V. T.,

    1. Department of Cardiovascular Scientific Development, Swedish Medical Center, Seattle, Washington (JTJ, CJF); Spencer Technologies, Seattle, Washington (MAG); and Spencer Vascular, Seattle, Washington (JR, MH, MPS).
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  • Meryl Harley R.V.T.,

    1. Department of Cardiovascular Scientific Development, Swedish Medical Center, Seattle, Washington (JTJ, CJF); Spencer Technologies, Seattle, Washington (MAG); and Spencer Vascular, Seattle, Washington (JR, MH, MPS).
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  • Merrill P. Spencer MD

    1. Department of Cardiovascular Scientific Development, Swedish Medical Center, Seattle, Washington (JTJ, CJF); Spencer Technologies, Seattle, Washington (MAG); and Spencer Vascular, Seattle, Washington (JR, MH, MPS).
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    • *

      Deceased.


Correspondence: Address correspondence to Jill T. Jesurum, PhD, Scientific Director, Swedish Heart and Vascular Institute, Swedish Medical Center, 550 17th Avenue, Suite 6351, Seattle, WA 98122. E-mail: jill.jesurum@swedish.org.

Abstract

ABSTRACT

BACKGROUND AND PURPOSE

Comparison was performed between unilateral and bilateral power M-mode transcranial Doppler to detect right-to-left circulatory shunt (RLS).

METHODS

Recorded Doppler data from 87 patients with confirmed RLS referred for transcatheter closure of patent foramen ovale were reanalyzed for embolic tracks (ET) counted from left and right temporal bone windows during bubble study. Unilateral counts were obtained by multiplying each side by 2; bilateral counts were obtained by summing left and right ET. Both unilateral and bilateral ET were converted to a 6-point logarithmic grade. Sex and age group subanalyses were performed.

RESULTS

At rest, significantly more ET were detected with bilateral versus unilateral detection (P= .01), but not following Valsalva (P= .13). Unilateral and bilateral detection were equally able to detect large RLS (grades IV or V) following Valsalva (P= 1.00). For the group aged ≥55 years, the right-hand side yielded greater ET than the left-hand side (mean difference 9%± 37; 95% confidence interval −3 to 21%) at rest (P= .01), but not following Valsalva (mean difference 1%± 25; 95% confidence interval −7 to 9%, P= .10).

CONCLUSIONS

Unilateral detection of ET by power M-mode transcranial Doppler is equivalent to bilateral detection to assess RLS.

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