|The revolution of echocardiography technology has produced an advanced echocardiography examination. It has numerous clinical applications with various form of ultrasound high technology being used in the field of cardiovascular. On the other hands, the advanced echo examination is an expensive procedure and it’s development needs significant financial support so that we as a developing country has to be more considerate regarding the indication and application of the examination for our daily practice. Some advanced echo procedure will be discussed below are; |
1. Transoesophageal Echocardiography (TEE)
2. Stress Echocardiography
3. Tissue Doppler Imaging (TDI)
4. 3 Dimension echocardiography (RT-3DE)
5. Contrast Echocardiography
6. Intracardiac Echocardiography (ICE)
In National Cardiovascular Center some modalities have been introduced for diagnosing, monitoring, and managing patients with cardiovascular diseases.
Transesophageal Echocardiography offers the advantages of improved image quality compared to transthoracic image, particularly in patients with poor echo window, poor patient’s condition, posterior heart structure, and small structures. TEE is used for patient in ICU, during operation, monitoring and directing interventional catheterization procedure. Image quality is improved due to decreased distance between transducer and the structure of interest and because there is lack of intervening of lung or bone tissue. However, because of its higher risk, typically TEE provides additional information only and does not replace a transthoracic examination, despite the fact that TEE can provide better image quality in some situation. Some low incidences of risk and complication have been recognized during this procedure.
In many cardiac conditions, abnormalities of cardiac function can only be detected when there is an increased of oxygen consumption that cannot be met by the adequate compensatory changes. This condition has led to the wide use of stress echocardiography. Stress echocardiography is both sensitive and specific for detecting myocardial ischemia and also has its role for viability study. Other indication for stress echocardiography could be evaluation of valvular heart disease, pulmonary hypertension, exertional dyspnoe and LV filling pressure. A variety method can be used to induced stress; such as exercise and pharmacological.
Tissue Doppler Imaging is a novel use of ultrasound to image the motion of tissue with Doppler echocardiography. The role of TDI has become more pronounced in management of cardiovascular problem. Indications for TDI includes ; assessing systolic global and segmental function, estimation of ventricular filling pressure, assessment of ischemia and viability study, and detecting mechanical dyssynchrony of the myocardium.
The 3 dimension echocardiography refers broadly to several approaches for acquisition and display of cardiac ultrasound images. It offers the ability to improve and expand the diagnostic capabilities of cardiac ultrasound. However, as many emerging technology, the enthusiasm used a new technique must be tempered by a critical appraisal and the evidence supporting its use. In fact the exact implementation of the optimal 3 D approach is in evolution. The clinical role will continue to evolve as this technology matures. Potentially, 3 D echocardiography could be faster than 2 D scanning and could reduce variability in image acquisition. Currently, specialized heart center are using 3D echo for patients with complex heart structural disease. However, 3D echo is not yet a standard part of the routine clinical examination.
Contrast Echocardiography has been available since the early stage of echocardiography, when agitated saline was used to identify cardiac structure. It refers to the injection of a contrast agent into the bloodstream that result in increased echogenicity of the blood or myocardium on ultrasound imaging, producing opacification of the cardiac chambers or an increase in echo- density of the myocardial. The clinical applications of contrast echocardiography have been expanded since some newer contrast agents were introduced. It is now used to identify intra-cardiac and intrapulmonary shunts, to augment Doppler velocity signals, to enhance the endocardial border (LV opacification), and most recently to assess myocardial perfusion.
As mentioned above, TEE is superior to TTE for certain indication. However, TEE has limitation, specifically the need for general anesthesia and potential problems related to airway management. For that reason, Intra-cardiac Echocardiography (ICE) was introduced. ICE uses a catheter like ultrasound probe that is passed into the right heart chambers from the femoral vein. This disposable probe inserted via a venous sheath as part of an invasive cardiac procedure in the cardiac catheterization or electrophysiology laboratory. ICE is primarily used for monitoring invasive procedures, although the diagnosis potential of this modality has not been fully evaluated. The most common applications are monitoring of percutaneous defect closure, valvuloplasty, and arrhythmia catheter ablation procedures.
The development of echocardiography technology has led to some sophisticated and expensive echocardiography examination. Understanding the principal, strengths, pitfalls and role of each modality in all cardiac problems prevents us of making an unnecessary advanced procedure.
19th Week End Course on Cardiology (WECOC)
Empowering Referral System in Clinical Cardiology
November 29 - December 1, 2007
Borobudur Hotel, Jakarta