Why is intracardiac echocardiography helpful? Benefits, costs, and how to learn.

Current interventional procedures in structural heart disease and cardiac arrhythmias require peri-interventional echocardiographic monitoring and guidance to become as safe, expedient, and well-tolerated for patients as possible. Intracardiac echocardiography (ICE) complements and has in part replaced transoesophageal echocardiography (TEE), including real-time three-dimensional (RT-3D) imaging. The latter is still widely accepted as a method to prepare for and to guide interventional treatments. In contrast to TEE, ICE represents a purely intraprocedural guiding and imaging tool unsuitable for diagnostic purposes. Patients tolerate ICE much better, and the method does not require general anaesthesia. Accurate imaging of the particular pathology, its anatomic features, and spatial relation to the surrounding structures is critical for catheter and wire positioning, device deployment, evaluation of the result, and for ruling out complications. This review describes the peri-interventional role of ICE, outlines current limitations, and points out future implications. Two-dimensional ICE has become a suitable guiding tool for a variety of percutaneous treatments in patients who are conscious or under monitored anaesthesia care, whereas RT-3DICE is still undergoing clinical testing. Continuous TEE monitoring under general anaesthesia remains a widely accepted alternative.

Device closure of interatrial communications: peri-interventional echocardiographic assessment.

The interventional closure of interatrial communications requires peri-interventional echocardiographic assessment and guidance to make those treatments as safe as possible. Transoesophageal echocardiography (TEE) including real-time three-dimensional (RT-3D) imaging, later complemented and in part replaced by intracardiac echocardiography (ICE), has become established as the standard approach to prepare for and to guide the interventional treatment of interatrial communications. Accurate imaging of the anatomic features of the particular communication is critical for case selection, planning, and intraprocedural guidance. Especially in the atrial septal defect (ASD) closure, which tends to be more challenging than the patent foramen ovale (PFO) closure, a certain risk of severe complications remains and may result from suboptimal device performance. Other complications may be related to discontinuous use of echocardiographic monitoring. Image fusion and RT-3D ICE are currently under clinical testing and might be suitable to facilitate spatial orientation. Nowadays, two-dimensional ICE is the method of choice for guiding percutaneous device closure, especially of ASDs and 'complex' PFOs. Uninterrupted TEE under deep sedation is an alternative. In contrast, the closure of 'simple' PFOs will often require nothing but final confirmation of the result, and therefore, short echocardiographic viewing is sufficient in many cases.

Noninvasive assessment of microvascular function in arterial hypertension by transthoracic Doppler harmonic echocardiography.

OBJECTIVES: The present study sought to investigate the use of transthoracic Doppler harmonic echocardiography (TTDHE) to evaluate changes in coronary flow dynamics due to microvascular dysfunction. BACKGROUND: Coronary flow velocity reserve (CFVR) measurements by TTDHE are useful for assessing epicardial coronary artery stenoses. It remains unclear, however, if microvascular disease can be detected. METHODS: In 54 patients with chest pain, intracoronary Doppler (ICD) and TTDHE were used to measure average peak velocity at baseline and hyperemia. Significant coronary lesions had been ruled out by both angiography and intravascular ultrasound. Comparative measurements were performed in the distal left anterior descending coronary artery after intracoronary and intravenous administration of adenosine, and CFVR was calculated. Hypertensive patients (n = 25) were studied and compared to a control group (26 normotensive individuals). RESULTS: Three patients (5%) had to be excluded because of insufficient image quality or side effects. In both groups, TTDHE-derived CFVR data correlated closely with ICD measurements (group 1: y = 0.67x + 0.076, standard error of estimate [SEE] = 0.25, r = 0.87, p < 0.001; group 2: y = 0.64x + 1.11, SEE = 0.26, r = 0.87, p < 0.001). CFVR was lower in hypertensives than in normotensive controls (2.44 +/- 0.49 vs. 3.33 +/- 0.40, p < 0.001, cut point = 2.84). CONCLUSIONS: The newly described echocardiographic method is suitable for assessing microvascular dysfunction noninvasively and corresponds well to invasive measurements.

Evaluation of Hemodynamic Determinants of Quantitative Tissue Doppler Echocardiography in the Assessment of Left Ventricular Function.

The aim of the present study was to determine whether quantitative tissue Doppler echocardiography has a role in the assessment of left ventricular hemodynamics. Thirty patients with suspected or known heart disease, but no wall motion abnormalities, took part in the study. Quantitative tissue Doppler echocardiography was performed using new software for digital analysis of the tissue Doppler signal. Average systolic subendocardial (S1), subepicardial (S2), and transmural (S3) wall velocity data were obtained from the inferoposterior wall and compared with the hemodynamics, including high fidelity pressure readings. S1 and S3 rates were found to be most reliable, being directly related to the peak rate of left ventricular pressure rise (dP/dt(peak)) and inversely to systemic vascular resistance (SVR) and resistance index (SVRI). The best correlation was between S1, dP/dt(peak), and SVRI (multiple regression analysis: r = 0.76, P < 0.0001; simple regression analysis relating S1 to dP/dt(peak)/SVRI: r = 0.77, SEE = 0.25, P < 0.0001). Thus, wall velocity indices as defined in this study have promise to become helpful in guiding the therapeutic modulation of inotropy and afterload in patients with heart failure.