Cardiac Function and Hemodynamics Assessed by Speckle Tracking Echocardiography: Evolution from Structure to Function

Mini Review

Austin Med Sci. 2016; 1(3): 1012.

Cardiac Function and Hemodynamics Assessed by Speckle Tracking Echocardiography: Evolution from Structure to Function

Ryuhei Tanaka*

Department of Cardiology, Murakami Memorial Hospital, Japan

*Corresponding author: Ryuhei Tanaka, Department of Cardiology, Murakami Memorial Hospital, 3-23 Hashimoto Gifu 500-8523, Gifu Prefectural General Medical Center and Gifu Heart Center, Japan

Received: August 29, 2016; Accepted: September 20, 2016; Published: September 21, 2016

Abstract

Echocardiography provides information regarding cardiac structure and function and is the useful cardiovascular examination. Evolution of echocardiography has been performed including that of M-mode, twodimensional, Doppler, stress, transesophageal, contrast, three-dimensional, intracardiac and Speckle Tracking Echocardiography (STE).

Using STE, time-Left Atrial (LA) volume curve is easily obtained and LA phasic volume and function can be measured. It is reported that a novel index named KT index obtained from the time-LA volume curve using STE accurately predicts pulmonary capillary wedge pressure. This novel index may have incremental utility and discriminative value in routine clinical practice.

The complex mechanics of the heart must be best represented by realtime one-beat 3- Dimensional STE (3D-STE) with high volume rates in the examination of LV performance including LV layer function because of cyclic changes of LV in multiple dimensions. LV systolic function including strain and Strain Rate (SR) and diastolic function including relaxation assessed by tau and stiffness may be noninvasively evaluated using 3D-STE.

The alterations of LV structure function and deformation including torsion associated with HTN, especially alterations of torsion in three myocardial layers, may be examined by 3D-STE. Therefore, cardiac function including torsion, tau and stiffness assessed by echocardiography, especially by STE, will be described in this short commentary.

Keywords: Speckle tracking echocardiography; Pulmonary capillary wedge pressure; Cardiac function

Abbreviations

AF: Atrial Fibrillation; EF: Ejection Fraction; E/e’: Ratio of transmittal inflow velocity to mitral annular tissue Doppler velocity; HF: Heart Failure; HHF: Hypertensive Heart Failure; IVRT: Isovolumic Relaxation Time; PCWP: Pulmonary Capillary Wedge Pressure; STE: Speckle Tracking Echocardiography; LA: Left Atrium; LAEF: Left Atrial Emptying Function; SR: Strain Rate; LV: Left Ventricle; MR: Mitral Regurgitation; 3D: Three-Dimension

Introduction

Echocardiography noninvasively provides information regarding cardiac morphology, function and hemodynamics and is the most frequently performed cardiovascular examination after electrocardiography and chest X-ray [1]. In 1953, Hellmuth Hertz started his practical work with medical ultrasound at university of Lund. The first clinical applications of M-mode echocardiography were concerned with the assessment of the mitral valve from the shapes of the corresponding waveforms [2]. A technique for estimating the size of the Left Atrium (LA), right and Left Ventricle (LV) was developed using pulsed reflected ultrasound [3,4]. Evolution of echocardiography has been performed in half a century including that of M-mode, two-dimensional, Doppler, stress, transesophageal, contrast, three-dimensional, intracardiac and Speckle Tracking Echocardiography (STE).

As the progression of echocardiography, not only cardiac structure but also cardiac function and hemodynamics have been examined [5-14]. Using STE, emerging attention has been brought to LA that is very complex due to close coupling with LV and affected by LV properties. LA volume and function are thought to reflect LV diastolic function and may serve as strong and useful predictors for cardiovascular outcomes. LV Ejection Fraction (EF) was usually used as an index of LV shortening parameter and systolic function, which is load dependent. The ratio of transmitral inflow velocity to mitral annular tissue Doppler velocity (E/e’) is usually used as an index of LV filling pressure and diastolic function, which has several limitations [15,16]. Therefore, echo parameters of LV systolic function that is less load dependent and diastolic function that has less limitation are needed. It is of importance to accurately evaluate the cardiac function and hemodynamics as well as structure in the treatment of cardiac diseases. In this short commentary, cardiac function assessed by echocardiography, especially by STE, is described.

LA Function Assessed by STE

Using two- or Three-Dimensional STE (3D-STE), time-LA volume curve is easily and accurately obtained and LA phasic volume and function can be measured (Figure 1) [5-8, 10-14].