Cargando…

Timing of high-intensity pulses for myocardial cavitation-enabled therapy

BACKGROUND: High-intensity ultrasound pulses intermittently triggered from an ECG signal can interact with circulating contrast agent microbubbles to produce myocardial cavitation microlesions of potential therapeutic value. In this study, the timing of therapy pulses relative to the ECG R wave was...

Descripción completa

Detalles Bibliográficos
Autores principales: Miller, Douglas L, Dou, Chunyan, Owens, Gabe E, Kripfgans, Oliver D
Formato: Online Artículo Texto
Lenguaje:English
Publicado: BioMed Central 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4183070/
https://www.ncbi.nlm.nih.gov/pubmed/25279221
http://dx.doi.org/10.1186/2050-5736-2-20
_version_ 1782337656445730816
author Miller, Douglas L
Dou, Chunyan
Owens, Gabe E
Kripfgans, Oliver D
author_facet Miller, Douglas L
Dou, Chunyan
Owens, Gabe E
Kripfgans, Oliver D
author_sort Miller, Douglas L
collection PubMed
description BACKGROUND: High-intensity ultrasound pulses intermittently triggered from an ECG signal can interact with circulating contrast agent microbubbles to produce myocardial cavitation microlesions of potential therapeutic value. In this study, the timing of therapy pulses relative to the ECG R wave was investigated to identify the optimal time point for tissue reduction therapy with regard to both the physiological cardiac response and microlesion production. METHODS: Rats were anesthetized, prepared for ultrasound, placed in a heated water bath, and treated with 1.5 MHz focused ultrasound pulses targeted to the left ventricular myocardium with an 8 MHz imaging transducer. Initially, the rats were treated for 1 min at each of six different time points in the ECG while monitoring blood pressure responses to assess cardiac functional effects. Next, groups of rats were treated at three different time points: end diastole, end systole, and mid-diastole to assess the impact of timing on microlesion creation. These rats were pretreated with Evans blue injections and were allowed to recover for 1 day until hearts were harvested for scoring of injured cardiomyocytes. RESULTS: The initial results showed a wide range of cardiac premature complexes in the ECG, which corresponded with blood pressure pulses for ultrasound pulses triggered during diastole. However, the microlesion experiment did not reveal any statistically significant variations in cardiomyocyte injury. CONCLUSION: The end of systole (R + RR/3) was identified as an optimal trigger time point which produced identifiable ECG complexes and substantial cardiomyocyte injury but minimal cardiac functional disruption during treatment.
format Online
Article
Text
id pubmed-4183070
institution National Center for Biotechnology Information
language English
publishDate 2014
publisher BioMed Central
record_format MEDLINE/PubMed
spelling pubmed-41830702014-10-03 Timing of high-intensity pulses for myocardial cavitation-enabled therapy Miller, Douglas L Dou, Chunyan Owens, Gabe E Kripfgans, Oliver D J Ther Ultrasound Research BACKGROUND: High-intensity ultrasound pulses intermittently triggered from an ECG signal can interact with circulating contrast agent microbubbles to produce myocardial cavitation microlesions of potential therapeutic value. In this study, the timing of therapy pulses relative to the ECG R wave was investigated to identify the optimal time point for tissue reduction therapy with regard to both the physiological cardiac response and microlesion production. METHODS: Rats were anesthetized, prepared for ultrasound, placed in a heated water bath, and treated with 1.5 MHz focused ultrasound pulses targeted to the left ventricular myocardium with an 8 MHz imaging transducer. Initially, the rats were treated for 1 min at each of six different time points in the ECG while monitoring blood pressure responses to assess cardiac functional effects. Next, groups of rats were treated at three different time points: end diastole, end systole, and mid-diastole to assess the impact of timing on microlesion creation. These rats were pretreated with Evans blue injections and were allowed to recover for 1 day until hearts were harvested for scoring of injured cardiomyocytes. RESULTS: The initial results showed a wide range of cardiac premature complexes in the ECG, which corresponded with blood pressure pulses for ultrasound pulses triggered during diastole. However, the microlesion experiment did not reveal any statistically significant variations in cardiomyocyte injury. CONCLUSION: The end of systole (R + RR/3) was identified as an optimal trigger time point which produced identifiable ECG complexes and substantial cardiomyocyte injury but minimal cardiac functional disruption during treatment. BioMed Central 2014-10-02 /pmc/articles/PMC4183070/ /pubmed/25279221 http://dx.doi.org/10.1186/2050-5736-2-20 Text en Copyright © 2014 Miller et al.; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/4.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly credited. The Creative Commons Public Domain Dedication waiver (http://creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.
spellingShingle Research
Miller, Douglas L
Dou, Chunyan
Owens, Gabe E
Kripfgans, Oliver D
Timing of high-intensity pulses for myocardial cavitation-enabled therapy
title Timing of high-intensity pulses for myocardial cavitation-enabled therapy
title_full Timing of high-intensity pulses for myocardial cavitation-enabled therapy
title_fullStr Timing of high-intensity pulses for myocardial cavitation-enabled therapy
title_full_unstemmed Timing of high-intensity pulses for myocardial cavitation-enabled therapy
title_short Timing of high-intensity pulses for myocardial cavitation-enabled therapy
title_sort timing of high-intensity pulses for myocardial cavitation-enabled therapy
topic Research
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4183070/
https://www.ncbi.nlm.nih.gov/pubmed/25279221
http://dx.doi.org/10.1186/2050-5736-2-20
work_keys_str_mv AT millerdouglasl timingofhighintensitypulsesformyocardialcavitationenabledtherapy
AT douchunyan timingofhighintensitypulsesformyocardialcavitationenabledtherapy
AT owensgabee timingofhighintensitypulsesformyocardialcavitationenabledtherapy
AT kripfgansoliverd timingofhighintensitypulsesformyocardialcavitationenabledtherapy