Multiple ultrasound cavitation-enabled treatments for myocardial reduction

Abstract

BackgroundUltrasound myocardial cavitation enabled treatment (MCET) is an image-guided method for tissue reduction. In this study, a strategy of fractionated (multiple) treatments was tested for efficacy.MethodsDahl SS rats were anesthetized and prepared for treatment with a focused ultrasound transducer in a warm water bath. Aiming at the anterior left ventricular wall was facilitated by imaging with a 10 MHz phased array (10S, GE Vivid 7, GE Vingmed Ultrasound, Horten, Norway). MCET was accomplished at 1.5 MHz by pulse bursts of 4 MPa peak rarefactional pressure amplitude, which were intermittently triggered 1:8 from the ECG during infusion of a microbubble suspension for cavitation nucleation. Test groups were sham, a 200 s treatment, three 200 s treatments a week apart, and a 600 s treatment. Treatment outcome was observed by plasma troponin after 4 h, echocardiographic monitoring and histology at 6 wk.ResultsThe impacts of the fractionated treatments summed to approximately the same as the long treatment; e. g. the troponin result was 10.5 ± 3.2 for 200 s, 22.7 ± 5.4 (p < 0.001) for the summed fractionated treatments and 29.9 ± 6.4 for 600 s (p = 0.06 relative to the summed fractionated). While wall thickness was not reduced for the fractionated treatment, tissue strain was reduced by 35% in the target area relative sham (p < 0.001).ConclusionThe ability to fractionate treatment may be advantageous for optimizing patient outcome relative to all-or nothing therapy by surgical myectomy or alcohol ablation.

Immunomodulatory effects of icariin in a myocardial infarction mouse model

“…At 28 days after ligation, the mice were anesthetized with sodium pentobarbital (50 mg/kg, i.p., Merck). We performed transthoracic echocardiography using an ultrasound machine (Vivid 7, GE Medical, Horten, Norway) equipped with a 10-MHz phased array transducer to test the left ventricular ejection fraction (EF) and calculated fractional shortening from M- (FS) [ 20 ].…”

Leveraging the Imaging Transmit Pulse to Manipulate Phase-Change Nanodroplets for Contrast-Enhanced Ultrasound

“…CONTRAST agents play an important role in medical ultrasound, in terms of both diagnostic imaging and therapy [1][2][3]. Microbubbles are ideal contrast agents for ultrasound imaging, and have been used for vascular imaging [4,5], drug delivery [6,7], and cavitationbased therapies [8][9][10][11] (e.g. temporal blood-brain barrier opening [12]).…”

Low-intensity ultrasound promotes the horizontal transfer of resistance genes mediated by plasmids in E. coli

“…Ultrasound has been widely used in water treatment and therapy of diseases. For example, ultrasound is used to improve the therapeutic effects in transdermal drug delivery, thrombolysis, and transfection of gene vectors (Hsu et al 2013;Miller et al 2017;Sun et al 2013). It has been reported that low-intensity ultrasound enhances the bactericidal effect of antibiotics towards bacteria including planktonic bacteria, bacterial biofilms, and chlamydia (Yu et al 2012).…”