Low-Velocity Flow Doppler Enhancement for the Study of Spontaneous Echo Contrasts

George Thomas

doi:10.4103/jiae.jiae_47_21

INTERESTING IMAGES

Year : 2022 | Volume : 6 | Issue : 1 | Page : 84-85

Low-Velocity Flow Doppler Enhancement for the Study of Spontaneous Echo Contrasts

George Thomas
Department of Cardiology, Saraf Hospital, Kochi, Kerala, India

Date of Submission	01-Aug-2021
Date of Acceptance	02-Sep-2021
Date of Web Publication	11-Oct-2021

Correspondence Address:
Dr. George Thomas
Department of Cardiology, Saraf Hospital, Sreekandath Road, Kochi - 682 016, Kerala
India

Source of Support: None, Conflict of Interest: None

DOI: 10.4103/jiae.jiae_47_21

Abstract

Detection of spontaneous echo contrasts (SEC) is important in assessing the risk of stroke and thromboembolism. Transthoracic echocardiography is the most widely used primary imaging for left ventricular SEC. Although harmonic imaging improves visualization to an extent, further improvement in the detection of the phenomenon is desirable. We are presenting images of two patients acquired with a novel method using Doppler to enhance the detection of SEC.

Keywords: Enhancement, low-velocity flow Doppler, spontaneous echo contrasts, tissue Doppler

How to cite this article:
Thomas G. Low-Velocity Flow Doppler Enhancement for the Study of Spontaneous Echo Contrasts. J Indian Acad Echocardiogr Cardiovasc Imaging 2022;6:84-5

How to cite this URL:
Thomas G. Low-Velocity Flow Doppler Enhancement for the Study of Spontaneous Echo Contrasts. J Indian Acad Echocardiogr Cardiovasc Imaging [serial online] 2022 [cited 2023 Jun 10];6:84-5. Available from: https://jiaecho.org/text.asp?2022/6/1/84/328116

Patients with congestive heart failure and atrial fibrillation are at an increased risk of stroke and thromboembolism. This is attributed to a hypercoagulable state due to the operation of the Virchow's triad and low flow due to reduced cardiac output, among other operational factors.^[1] Spontaneous echo contrast (SEC) is an easily demonstrable phenomenon occurring at low flow states indicating an hypercoagulable or even pre-thrombotic state.^[2] Transthoracic echocardiography is the preferred examination to demonstrate SEC in the left ventricular (LV) cavity. With the availability of harmonic imaging, detection of SEC can be marginally enhanced. However, it would be beneficial if we could increase the sensitivity of this procedure for detection of SEC.

Since SEC is the result of fibrinogen-mediated aggregated red blood cell motion,^[3] color Doppler is a better method to study the phenomenon. Conventional flow Doppler fails to detect such low-velocity flow. It has been hypothesized that tissue Doppler can be used to study such low flow states.^[4] Use of such low-velocity flow Doppler (LVFD) has been demonstrated earlier.^[5] We are presenting images using LVFD (tissue Doppler) to enhance SEC detection in the LV.

This proof of concept technical innovation was performed on 2 patients with mild to moderate LV systolic dysfunction with varying degrees of LV SEC. The color LVFD recordings were obtained in the tissue Doppler mode on Acuson Juniper machine (Siemens Medical Systems, Andover, MA, USA) using a 5P1 transducer from the apical 4-chamber view as described earlier.^[5] The region of interest was adjusted to include the whole LV cavity, and the velocity scale was kept constant at 15 cm/s. The tissue colorization was ignored and the blood colorization observed.

LVFD enhanced the perception of SEC [Figure 1] and [Figure 2]. As a sensitive Doppler method, false positives are possible if the two-dimensional images are inadequate. The normal pattern of LVFD is no colorization of the LV cavity to some colorization in the apical regions. Colorization of the mid and basal regions of the LV cavity is indicative of SEC with greater specificity. Further large-scale studies are required to assess the utility of this sensitive method in the detection of subtle forms of SEC and its clinical implications.

Figure 1: Low-velocity flow Doppler enhancing spontaneous echo contrast. (a) Apical 4-chamber two-dimensional harmonic imaging view in a patient showing spontaneous echo contrast. (b) Same patient with low-velocity flow Doppler enhancement of spontaneous echo contrast

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Figure 2: Low-velocity flow Doppler enhancing spontaneous echo contrast. (a) Apical 4-chamber two-dimensional harmonic imaging view in another patient showing fainter spontaneous echo contrast. (b) Same patient with low-velocity flow Doppler enhancement of spontaneous echo contrast. Note the better display with enhanced perception of the same

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Informed consent

Informed verbal consent was obtained from the patients.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

References

1.	Lip GY, Gibbs CR. Does heart failure confer a hypercoagulable state? Virchow's triad revisited. J Am Coll Cardiol 1999;33:1424-6.
2.	Horstkotte D, Hering D, Faber L, Piper C. Cardiac morphology and physiology predisposing to thrombus formation. Eur Heart J Suppl 2001;3 Suppl Q: Q8-11.
3.	Rastegar R, Harnick DJ, Weidemann P, Fuster V, Coller B, Badimon JJ, et al. Spontaneous echo contrast videodensity is flow-related and is dependent on the relative concentrations of fibrinogen and red blood cells. J Am Coll Cardiol 2003;41:603-10.
4.	Thomas G. Tissue Doppler echocardiography-A case of right tool, wrong use. Cardiovasc Ultrasound 2004;2:12.
5.	Thomas G. Low-velocity flow Doppler sonography: A new Doppler application. J Ultrasound Med 2006;25:1105-7.