Uses ultrasound waves to create still and moving images.

Assesses cardiac anatomy and physiology.

An essential tool in the evaluation of patients with unexplained dyspnea.

Estimated 9 million performed in 2004 in the Medicare system.

Maps normal and abnormal blood flow signals and to measure blood flow velocity.

Utilizes a transducer applied to the chest wall, ref2242ed to as a transthoracic echocardiogram (ECHO).

The transducer is a microphone like device sending and receiving ultrasound waves.

Transducer is attached to computerized software that calculates the distance of heart structures from the transducer and creates images of the heart.

Images formed can be one-two or tree dimensional displaying the heart beat in a cine-loop.

Blood flow velocities are measured and color encoded to provide flow maps.

The single most useful diagnostic tool in the management of patients with heart failure, as all stages of left ventricular remodeling in failure can be categorized by two dimensional echocardiography.

Provides information about left ventricular systolic performance, valvular disease and pericardial disease.

May provide information about left atrial enlargement, left ventricular hypertrophy, and pulmonary hypertension.

Can diagnose diastolic dysfunction and it’s grade of mild, moderate or severe

Can estimate left ventricular filling pressures.

Most frequent type is the transthoracic echocardiogram (TTE).

TTE obtains images from the chest wall, with limitations that the ribs and air in the lung do not allow penetration of the ultrasound waves to penetrate the heart.

TTE views may be inadequate in approximately 20% of the adult population because of obesity, chronic obstructive pulmonary disease, or chest-wall deformities.

Transthoracic echocardiography has the advantages of being fast and easy to perform.

TTE specificity for cardiac vegetations is 98%; however, sensitivity is lower than 60%.

Transthoracic echocardiography has a poor sensitivity of detecting prosthetic valve dehiscence compared with transesophageal echocardiography.

Transesophageal echocardiographic is recommended for the detection of prosthetic valve dehiscence in most patients with suspected infective endocarditis, and is the initial investigation in patients with staphylococcal aureus bacteremia.

Transesophageal echocardiography has the advantage of having higher sensitivity for vegetations and greater specificity and sensitivity for perivalvular extension than TTE.

Technicians perform the transthoracic echocardiograms and transesophageal studies are performed by physicians.

Transthoracic echocardiography has a low sensitivity and specificity for the diagnosis of aortic dissection.

Transesophageal echocardiography has a high sensitivity and specificity for acute aortic dissection.

Indications for study include the evaluation for: shortness of breath, fatigue, chest pain, syncope, hypotension, embolic stroke, suspected endocarditis, and pulmonary hypertension, congestive heart failure and suspected heart valve abnormalities.

May be repeated to monitor the progression of disease and to assess effectiveness of medications or other treatments.

All heart structures can be displayed in an ECHO.

The left ventricle is normally about one cm thick.

The left ventricular cavity is shaped like a cone and accommodates approximately 100 cc at the end of diastole.

The left ventricular cavity at the end of systole contains approximately 40 cc.

The percentage of blood ejected is the ejection fraction and is about 60%, with a range of 55-70%.

Can measure the size of the left ventricular chamber, the thickness of its wall, calculate the ejection fraction and demonstrate any abnormalities in the contraction of the muscle to establish if it is uniform and synchronous.

Regional left ventricular dysfunction indicates myocardial ischemia, infarction or both.

Can evaluate the shape, size and thickness of the right ventricle.

Can measure the left atrium size.

Can measure the right atrium size.

Indicated in patients with a systolic murmur and any cardiac symptoms, a loud murmur alone, or other cardiac findings on physical examination.

Measurement of left ventricular ejection fraction can vary 8.5% above or below the mean calculated result on repeated weekly echocardiograph evaluations.

Changes in intravascular volume and adrenergic drive vary loading conditions on a daily basis and can cause differences in ejection fraction outcomes.

When mechanical complications of myocardial infarction are suspected, echocardiogram is indicated to narrow differential diagnosis, speed the diagnosis and implement treatment.

Echocardiogram results for mild diastoloic dysfunction is typified by abnormal myocardial relaxation with normal left atrial pressures-grade I.

Echocardiographic markers of diastolic dysfunction are absent in a significant proportion of patients with heart failure and preserved ejection fraction.

Echocardiogram grade II findings of moderate diastolic dysfnction indicates a pseudonormal pattern, while grade III shows a restrictive pattern.

Echocardiogram findings in moderate and severe diastolic dysfunction increases in the mean left atrial pressures occur in addition to the impairment of left ventricular relaxation and compliance.

In a randomized clinical study screening for structural and valvular heart disease in the general population provides no benefit for mortality, for the risk of myocardial infarction, or stroke (Lindekleiv H et al).

Hand held echocardiography is an accurate and sensitive tool for enhancing the physical examination and improving the detection of valve pathologies.

Hand held echocardiography is more sensitive than auscultation and its accuracy is comparable to standard echocardiography.

Integrating hand held echocardiography as part of the physical examination can lead to more rapid bedside diagnosis, triage, and treatment valvular heart disease.

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