Modified Right Heart Contrast Echocardiography Versus Traditional Method in Diagnosis of Right-to-Left Shunt: A Comparative Study

Abstract

SummaryBackgroundThe purpose of this study was to evaluate the reliability, effectiveness, and safety of modified right heart contrast transthoracic echocardiography (cTTE) in comparison with the traditional method.Material/MethodsWe performed a modified right heart cTTE using saline mixed with a small sample of patient’s own blood. Samples were agitated with varying intensity. This study protocol involved microscopic analysis and patient evaluation. 1. Microscopic analysis: After two contrast samples had been agitated 10 or 20 times, they underwent a comparison of bubble size, bubble number, and red blood cell morphology. 2. Patient analysis: 40 patients with suspected RLS (right- to-left shunt) were enrolled. All patients underwent right heart contrast echocardiography. Oxygen saturation, transit time and duration, presence of RLS, change in indirect bilirubin and urobilinogen concentrations were compared afterward.ResultsModified method generated more bubbles (P<0.05), but the differences in bubble size were not significant (P>0.05). Twenty-four patients were diagnosed with RLS (60%) using the modified method compared to 16 patients (40%) with the traditional method. The transit time of ASb20 group was the shortest (P<0.05). However, the duration time in this group was much longer (P<0.05). Also, in semi-quantitative analysis mean rank of RLS was higher after injecting the modified contrast agent agitated 20 times (P<0.05).ConclusionsModified right heart contrast echocardiography is a reliable, effective and safe method of detecting cardiovascular RLS.

The size distribution of the agitated saline microbubbles for contrast transcranial Doppler generated using standard manual methods

“…Each operator in each repeated experiment uses a 10 mL syringe (Kang De Lai China) to extract 9 mL of 0.9% saline solution from the infusion bottle, then extract 1 mL of air. Then, each syringe plugger was pushed forward and backward 10 times in 20 s (Overall reciprocating motion 20 times) to mix the air with saline solution to activate the contrast agents (Wang et al, 2016). Finally, the operator quickly and manually switched the three‐way stopcock (Jie Rui China), injecting the saline‐bubble mixture (within 1–2 s) into the flow test section.…”