Introduction and Overview

Echocardiography on specific casesMinilecture. June 3, 2005

INTRODUCTION & OVERVIEW

Echocardiography has emerged as the most frequently performed imaging test in cardiology. The examination is inexpensive and provide definitive assessment of both cardiac anatomy and hemodynamics. Through the use of Doppler echocardiography, it is possible to define both the etiology and the severity of valvular stenosis and regurgitation, as well as intracardiac shunts.

The greatest limitation to echocardiography is that both image acquisition and interpretation are extremely dependent upon the expertise of the user. (operator dependent)

In routine examination, Motion mode (M-mode), 2 Dimension (2D) and Doppler examination are always be performed to evaluate cardiac anatomy and hemodynamics within the cardiac chambers.VALVULAR HEART DISEASE

Over the last four decades echocardiography has emerged as the definitive procedure for evaluating patients with all varieties of valvular heart disease

Mitral Stenosis (MS)

The etiology of MS are: 1. Sequalae of rheumatic fever. 2. Congenital abnormalities, such as

parachute mitral valve, and 3. Severe mitral annular calcification that encroaches onto the leaflets, reducing their mobilityThe features of MS are: 1. Diastolic doming of the valve and 2. Calcification and immobility of theleaflets. Another features of mitral stenosis such as: 1.Left atrial enlargement. 2.Atrial fibrillation. 3.Thrombosis (better in transthoracal approach), and 4. Pulmonary hypertension w/o tricuspid regurgitation are due to secondary effect of MS. Evaluating the Severity of MS

1.Planimetry of the mitral stenotic orifice by transthoracic echocardiography .2. Doppler evaluations are the most frequent method to evaluate the mitral valve area and its pressure gradient as well.

The mitral score has been using as a routine examination to evaluate the mitral valve and to make a treatment recommendations as well.

Mitral Regurgitation (MR)The etiology of MR are: 1. Myxomatous degeneration (the most common in the US), 2. Rupture of

the chordae 3. Rheumatic mitral regurgitation (shortening and immobility of the leaflet) 4. Cleft mitral leaflet (congenital) 5. A secondary consequence of left ventricular dilatation. 5.Ischemic cardiac disease (scarring, retraction of the subvalvular apparatus) 6. Rupture of the papillary muscle 7.Mitral endocarditis.

Evaluating the Severity of MRThe measurement methods are : 1. Measurement of the jet area. 2. Measurement of the proximal convergence. (more accurate) 3. Calculated from the measurements of forward mitral and aortic stroke volume.Secondary Effects of MR

1.`Left atrial enlargement (frequently leading to atrial premature beats and atrial fibrillation), 2. Pulmonary hypertension and 3. Ventricular dilatation ( with both overt and latent left ventricular dysfunction) Aortic Stenosis (AS)The etiology of aortic stenosis are: 1. Bicuspid aortic valve. 2. Rheumatic heart disease and 3. Calcific degeneration in older age is the most common (in the United States)

Quantifying the Severity of AS

Planimetry of the valve (best measured by transthoracic echocardiography)

Attempt to quantify the severity of AS precisely both peak and mean gradients should be measured and reported.

Aortic Regurgitation (AR)The etiology of AR are: (many of the same causes as aortic stenosis)

1. Congenitally bicuspid valve. 2. Rheumatic aortic valve 3. Prominent dilatation of the aortic root. 4. Aortic dissection, and 5. Endocarditis Evaluating the Severity of ARThere are a variety of methods but none of them particularly precise. 1. Fluttering of the anterior mitral leaflet (as a clue) 2.Measurement of the size of the regurgitant jet. 3. Semiquantitative assessment of regurgitation (which is more accurate) 4. Measurement of the AR and 5. The proximal convergence method

CARDIOMYOPATHY

Hypertrophic Cardiomyopathy The characterization of hypertrophic cardiomyopathy are: 1. Severe asymmetric septal hypertrophy and 2. Systolic anterior motion (SAM) of the mitral valve. 3. Abnormal diastolic function.

Dilated Cardiomyopathy

The etiology of Dilated cardiomyopathy are: 1. Idiopathic generalized process. 2. End stage of ischemic cardiac disease. The manifestation of dilated cardiomyopathy is impairment of both diastolic and systolic function

Hypertensive Cardiomyopathy

The significant features of hypertensive cardiomyopathy is concentric left ventricular hypertrophy. A delayed filling pattern (diastolic dysfunction) may reveal and in the end stage, pseudonormalization or a restrictive pattern may ensue.

CORONARY ARTERY DISEASE (CAD)

Acute chest pain and myocardial infarction.Echocardiography is extremely helpful in evaluating patients with chest pain. A documentation of completely normal wall motion during actual pain virtually excludes cardiac ischemia as the cause of the pain. Echocardiography is also the diagnostic procedure of choice for many of the mechanical complications of myocardial infarction (ventricular septal defect, papillary muscle rupture)

Chronic Coronary Disease

Stress echocardiography is a helpful method in investigating the presence of CAD but milder grades of coronary stenosis may not produce any regional wall motion abnormality. Stress echocardiography has been proven to be of particular value in certain cases, such as women, left bundle branch block, and left ventricular hypertrophy. Ventricular wall motion must be interpreted in a structured manner with an appreciation for the usual perfusion territories of the coronary arteries.

.The new 17-segment adopted by the Cardiac Imaging Committee of the Council on Clinical Cardiology of the American Heart AssociationStress echocardiography has been proven to be of great prognostic value in a variety of clinical settings. The presence of normal wall motion at high exercise levels is associated with an extremely low event rate moreover exercise echocardiography is a particularly useful technique for the assessment of prognosis after acute events. Pharmacologic stress echocardiography has also been shown to be of value in risk stratification following myocardial infarction and for for identifying high-risk patients with planned major noncardiac surgery .In chronic ischemic heart disease, ischemia and the extent of abnormal wall motion are independent predictors of cardiac death .