Treatment of Vasodepressor Carotid Sinus Syndrome with Midodrine: A Randomized, Controlled Pilot Study

Authors

  • Allan Moore MRCPI,

    1. From the *Clinical Age Assessment Unit, Mid-Western Regional Hospital, Dooradoyle, Limerick, Ireland; and University of Limerick, Limerick, Ireland.
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  • Michael Watts MRCPI,

    1. From the *Clinical Age Assessment Unit, Mid-Western Regional Hospital, Dooradoyle, Limerick, Ireland; and University of Limerick, Limerick, Ireland.
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  • Tina Sheehy RGN,

    1. From the *Clinical Age Assessment Unit, Mid-Western Regional Hospital, Dooradoyle, Limerick, Ireland; and University of Limerick, Limerick, Ireland.
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  • Ann Hartnett BSc,

    1. From the *Clinical Age Assessment Unit, Mid-Western Regional Hospital, Dooradoyle, Limerick, Ireland; and University of Limerick, Limerick, Ireland.
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  • David Clinch MD, FRCP, FRCPI,

    1. From the *Clinical Age Assessment Unit, Mid-Western Regional Hospital, Dooradoyle, Limerick, Ireland; and University of Limerick, Limerick, Ireland.
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  • Declan Lyons MSc, MD, FRCP, FRCPI

    1. From the *Clinical Age Assessment Unit, Mid-Western Regional Hospital, Dooradoyle, Limerick, Ireland; and University of Limerick, Limerick, Ireland.
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  • This study was funded from the research resources of the Department of Medical Gerontology, Mid-Western Regional Hospital, Limerick, Ireland. The authors of this study did not receive any external financial support for the conduct of this study.

Address correspondence to Dr. Allan Moore, Clinical Age Assessment Unit, Mid-Western Regional Hospital, Dooradoyle, Limerick, Republic of Ireland. E-mail: alanmoore@elivefree.net

Abstract

Objectives: To evaluate the efficacy of treatment of the vasodepressor form of carotid sinus hypersensitivity (carotid sinus syndrome (CSS)) with midodrine.

Design: A prospective, double-blind, randomized, controlled trial of crossover design.

Setting: A dedicated outpatient facility with access to tilt-table, digital arterial photoplethysmography, and 24-hour ambulatory blood pressure (BP) monitoring equipment.

Participants: Ten older adults (4 male, 6 female, mean age 75, range 66–86 years) with a history of unexplained syncope who displayed an asymptomatic decrease in systolic BP (SBP) of more than 50 mmHg or a symptomatic decrease of more than 30 mmHg within 30 seconds of carotid sinus massage (CSM).

Measurements: Symptom reproduction and BP and heart rate changes were evaluated after CSM in supine and semierect positions on the right and then left sides. These measurements were performed on the final day of placebo and active-treatment phases. Ambulatory 24-hour BP monitoring took place on the penultimate and final days of each treatment phase.

Results: Eight patients were symptomatic after their initial CSM. The mean±standard deviation SBP decrease after initial CSM was 54±22 mmHg. Initial mean 24-hour ambulatory BP was 127/70±7/5 mmHg. Eight patients reported symptoms after CSM at the end of the placebo phase. The mean SBP decrease at the end of the placebo phase was 49±12 mmHg. The mean 24-hour ambulatory BP was 127/69±9/7 mmHg. One patient reported symptoms after CSM at the end of the active-treatment phase. The mean SBP decrease at the end of the active-treatment phase was 36±9 mmHg. The mean 24-hour ambulatory BP at the end of the treatment phase was 133/75±7/6 mmHg. The differences in symptom reporting and mean SBP decrease after CSM were both significant (P<.01 and P=.03, respectively).

Conclusion: The results of this pilot study suggest that treatment of vasodepressor CSS with midodrine significantly reduced the rate of symptom reporting and attenuated SBP decreases after CSM but increased mean 24-hour ambulatory BP.

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