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Ebook A practical approach to clinical echocardiography (E): Part 2

(BQ) Part 2 book “A practical approach to clinical echocardiography” has contents: Diastolic function, tissue doppler echocardiography - current status and applications, rotation, twist and torsion, congenital heart disease in adults, pericardial diseases, ischemic heart disease, cardiomyopathies, tumors, masses and infection, and other contents. | Chapter 11 Echocardiographic Assessment of Right Ventricular Function: Methods and Clinical Applications INTRODUCTION Importance of the right ventricle (RV) in health and disease has seen a sea-change from being just a conduit to an important contractile chamber, which significantly impacts cardiac physiology, hemodynamics and development of symptoms.1 It is the final barrier between compensated versus decompensated heart. Right ventricular musculature when stressed expresses several important enzymes and activates several signal transduction pathways involved in hypertrophy, fibrosis and pulmonary vasoconstriction.2 These changes bring new meaning to pharmacotherapy of heart failure and the role of the RV. Under normal conditions, the RV is coupled with a low-impedance, highly distensible pulmonary vascular system (Figs 11.1 to 11.3). Compared with the systemic circulation, pulmonary circulation has a much lower vascular resistance and greater pulmonary artery distensibility.3 Under normal conditions, right-sided pressures are significantly lower than comparable left-sided pressures. Despite this, the RV ejects similar or somewhat greater volume during systole compared to the left ventricle (LV) 4–6 (Figs 11.4 and 11.5). PECULIARITIES OF THE RIGHT VENTRICLE • The right ventricular systolic function is predominantly afterload-dependent and minimally affected by the preload. Fig. 11.1: Schematic diagram of low impedance right heart circulation. Short-axis view. • Unlike the LV, there is no torsion of any significance and hence hardly any circumferential shortening (Fig. 11.6). • Radial shortening is unimpressive unlike the LV, partly because myofiber orientation and muscle volume is different (Fig. 11.7). • Highly trabeculated and spongy appearance of the cavity allows it to work as an efficient volume pump but poses challenges with regard to geometric volume estimations7 (Fig. 11.8). 190 Section 3: Systolic and Diastolic Function Fig. 11.2: .