Point-of-care echocardiography - A road to future or a step backwards.

Echocardiography (Echo) has a myriad of clinical applications. Traditionally, it was performed and interpreted by cardiologist but the scope of its applications has lead physicians of other specialities to learn this useful skill. One of the newer and expanding scope of echocardiography is point-of-care (POC) echocardiography. In this review article, we aim to discuss the clinical applications of POC echo, common protocols and its limitations. Despite its widespread use, there is paucity of data describing its clinical efficacy and there is lack of guidelines regarding credentialing and quality control of POC echo.

Contrast microsphere enhancement of the tricuspid regurgitant spectral Doppler signal - Is it still necessary with contemporary scanners?

BACKGROUND: Accurate evaluation of the tricuspid regurgitant (TR) spectral Doppler signal is important during transthoracic echocardiographic (TTE) evaluation for pulmonary hypertension (PHT). Contrast enhancement improves Doppler backscatter. However, its incremental benefit with contemporary scanners is less well established. The aim of this study was to assess whether the TR spectral Doppler signal using contemporary scanners was improved using a second generation contrast agent, Definity® (CE), compared to unenhanced TTE (UE). METHODS: Analysis of patients who underwent UE then CE TR interrogation was performed. TR signal was evaluated by an experienced reader and graded 1 (clear-high level of confidence of interpretation and complete spectral Doppler envelope), 2 (suboptimal with medium-low level of confidence of interpretation and incomplete envelope), 3 (poor-absent and no measurable spectral Doppler signal). Maximal TR velocity (TRV) was defined as peak velocity that could be clearly identified. An inexperienced sonographer read 30 randomly selected studies. RESULTS: 176 TTE were performed in 173 patients (mean age 57 ± 14.8 years). Wilcoxon signed rank test demonstrated significant improvement (p < 0.0001) in TR spectral Doppler signal quality with CE TTE. Mean score CE TTE vs. TTE = 2.32 ± 0.85 vs. 2.56 ± 0.75 respectively (p < 0.0001). Mean maximal TRV CE TTE vs. UE TTE = 2.61 ± 0.44 m/s vs. 2.54 ± 0.49 m/s respectively (p < 0.0001). The inexperienced reader had a greater improvement in scoring CE TTE signals vs. UE TTE (p < 0.0001). CONCLUSION: In the era of contemporary scanners, CE improved the ability to detect and measure TRV, except in those with clear unenhanced TR spectral Doppler signals or greater than mild tricuspid regurgitation.

Update on echocardiography in the management of infective endocarditis.

Echocardiography is the major imaging modality used for the diagnosis of infective endocarditis (IE). It is also useful in detecting the complications of IE which often necessitate surgical intervention and strongly influence patient outcomes. Transesophageal echocardiography (TEE), with proven superiority over transthoracic echocardiography (TTE) for the detection of vegetations and complications such as abscess, should be performed in the vast majority of cases especially when TTE image quality is poor or implanted devices are present. Three-dimensional (3D) TEE provides enhanced display of anatomic-spatial relationships allowing more precise delineation of complex pathology, particularly of the mitral valve and annulus. Importantly, echocardiographic findings can be non-specific and should always be interpreted in the context of the pre-test probability of IE based on careful clinical assessment. IE remains a challenging disease associated with variable clinical presentations, and high mortality. Whenever IE is suspected, echocardiography should be utilized early for both diagnosis and detection of complications.

The role of echocardiography in the management of patients supported by extracorporeal membrane oxygenation.

Extracorporeal life support can be viewed as a spectrum of modalities based on modifications of a cardiopulmonary bypass circuit to provide cardiac and respiratory support, which can be used for extended periods, from hours to several weeks. Extracorporeal membrane oxygenation (ECMO) is among the most frequently used forms of extracorporeal life support. It can be configured for venovenous blood flow, to provide adequate oxygenation and carbon dioxide removal in isolated refractory respiratory failure, or in a venoarterial configuration, when support is required for cardiac and/or respiratory failure. Echocardiography plays a fundamental role throughout the entire journey of a patient supported on ECMO. It provides information that assists in patient selection, guides the insertion and placement of cannulas, monitors progress, detects complications, and helps in determining cardiac recovery and the weaning of ECMO support. Although there are extensive published data regarding ECMO, particularly in the pediatric population, there is a paucity of data outlining the role of echocardiography in guiding the management of adult patients supported by ECMO. ECMO is likely to become an increasingly used form of cardiorespiratory support within the critical care setting. Hence, clinicians and sonographers who work within echocardiography departments at institutions with ECMO programs require specific skills to image these patients.

Vascular Access Management II: AVF/AVG cannulation techniques and complications.

This second article, in a three-part Continuing Education (CE) series on Vascular Access Management, focuses on cannulation issues including complications relating to arteriovenous fistula and arteriovenous graft access. The first article (McCann et al. 2008) gave an overview of vascular access while the final article in this series will focus on central venous catheters (CVC).