High-frequency dual mode pulsed wave Doppler imaging for monitoring the functional regeneration of adult zebrafish hearts

Abstract

Adult zebrafish is a well-known small animal model for studying heart regeneration. Although the regeneration of scars made by resecting the ventricular apex has been visualized with histological methods, there is no adequate imaging tool for tracking the functional recovery of the damaged heart. For this reason, high-frequency Doppler echocardiography using dual mode pulsed wave Doppler, which provides both tissue Doppler (TD) and Doppler flow in a same cardiac cycle, is developed with a 30 MHz high-frequency array ultrasound imaging system. Phantom studies show that the Doppler flow mode of the dual mode is capable of measuring the flow velocity from 0.1 to 15 cm s 21 with high accuracy ( p-value ¼ 0.974 . 0.05). In the in vivo study of zebrafish, both TD and Doppler flow signals were simultaneously obtained from the zebrafish heart for the first time, and the synchronized valve motions with the blood flow signals were identified. In the longitudinal study on the zebrafish heart regeneration, the parameters for diagnosing the diastolic dysfunction, for example, E/Em , 10, E/A , 0.14 for wild-type zebrafish, were measured, and the type of diastolic dysfunction caused by the amputation was found to be similar to the restrictive filling. The diastolic function was fully recovered within four weeks post-amputation.

Effect of electrical stimulation on blood flow velocity and vessel size

“…In other words, the vessels dilated from low frequency-high intensity ESG stimulation contract the skeletal muscles to increase blood flow velocity [20]. Previous studies visualised data on the changes in blood flow velocity and vessel size in terms of shape, size, colour, position, and orientation to confirm and compare the study results at a glance [21].…”

Use of Coronary Ultrasound Imaging to Evaluate Ventricular Function in Adult Zebrafish

“…This represents a limitation of this device in comparison with previous publications, where all parts of the hearts were observed. [10][11][12]14 We suspect that our microprobe is too narrow to allow a full coverage of the whole heart.…”

“…Indeed, several studies have used high frequency echocardiography, often combined with doppler echography, to assess mechanical and hemodynamic heart function in adult zebrafish. [11][12][13][14][15] In this study, a microultrasound catheter designed for intravascular imaging of human subjects has been used to image the zebrafish heart. The microprobe of the IVUS system is easy to manipulate and can be placed on top of the visually beating thoracic area with ease.…”

A Systematic Exposition of Methods used for Quantification of Heart Regeneration after Apex Resection in Zebrafish

“…A total number of 45 out of 47 articles used histology on sections for assessing heart regrowth and regeneration after AR ( Table 2). The two articles [87,88] that did not use histology were focused on evaluating whether heart function as measured by echocardiography reflect heart regrowth. Thus, histology in general seems to be an accepted qualitative method for the evaluation of heart regeneration in zebrafish.…”

“…The zebrafish heart, despite having only two chambers and a lack of pulmonary vasculature, shows a similar pattern of electrical activity and pump function as measured in humans when using electrocardiography (ECG) and echocardiography (ECHO), respectively. Yet, the parametric values are different between species, and data are thus mainly suited for relative measures between groups such as AR and sham zebrafish [88,98].…”