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Perioperative cardiovascular evaluation

IVUS, intravascular ultrasonography; TEE, transesophageal echocardiography; TTE, transthoracic echocardiography.

IVUS, intravascular ultrasonography; TEE, transesophageal echocardiography; TTE, transthoracic echocardiography.

Table 2

Practical Advantages of Echocardiography Over Other Noninvasive Cardiac Imaging Modalities (e.g., Cardiac CT, Cardiac MRI)

Good diagnostic performance Excellent clinical utility Widely available

Portable (in-hospital and point-of-care testing)

Immediate results

Safe

Lower cost

Minimal patient discomfort

No radiation (compare CT, angiography, and so on)

No special breath-holding (compare MRI)

CT, computed tomography; MRI, magnetic resonance imaging.

should underscore the clinical context, the questions that need to be answered, and how the results would impact further management (Table 3).

This chapter incorporates the 2003 joint guidelines issued by the American College of Cardiology (ACC), the American Heart Association (AHA), the American Society of Echocardiography (ASE), and others.

It is within this broad context that the evidence for echocardiography (two-dimensional, M-mode, Doppler, and transesophageal echocardiography) was evaluated by the ACC/AHA/ASE task force. They employed a three-class system to limit the use of echocardiogra-phy to situations in which the incremental information provided can benefit patient management. Follow-up

Table 3

Determination of Utility for Echocardiography

1. How will it affect the referring physician's diagnosis (impact on diagnostic and prognostic thinking)?

2. Does it then influence patient management (therapeutic impact)?

3. Now does the test compare with other modalities.

or serial studies are generally indicated only when there is a change in clinical status, and when the information thereby provided can improve patient care.

AHA/ACC Classification

Class I: Evidence and/or general agreement of benefit.

Class Ila: Weight of evidence in favor.

Class IIb: Evidence not well established.

Class III: No evidence of its utility.

Newer and rapidly evolving echocardiographic modalities and techniques (Table 1A,B), e.g., three-dimensional, tissue Doppler, myocardial contrast imaging, intracardiac, and intravascular ultrasound were not addressed in the ACC/AHA/ASE guidelines and are not covered in this chapter.

Because echocardiographic techniques are heavily operator-dependent, the guidelines also highlighted the need for appropriate training and competence in echocar-diography. This is especially relevant as techniques and their applications evolve.

echocardiography in clinical practice: general considerations

A careful history and physical examination remains the cornerstone of sound medical management. Echocardiography assists in the diagnosis and management of patients who exhibit symptoms and signs suggestive of heart disease, as well as those with existing cardiovascular disease. Common requests for echocar-diography include patients with murmurs, chest pain, dyspnea, palpitations, syncope, or an abnormal electrocardiogram (ECG) (Tables 4-6).

An abnormal finding on echocardiography may be incidental to the clinical question. Therefore, discussions between the referral and the echocardiography teams are encouraged. This ensures that appropriate emphasis is given to answer the clinical question. Although echocar-diographic screening of the general population and athletes with a normal cardiovascular history is not recommended, conditions exist where such screening is advisable (Table 7).

Echocardiography in Acute Chest Pain and Myocardial Ischemia

Chest pain may be cardiac or noncardiac in origin. Echocardiography, although useful, should not interfere with the management of patients with myocardial infarction. It adds little to the diagnosis if ECG and cardiac enzymes are already clearly diagnostic for acute myocardial infarction (Table 8). When doubt exists, e.g., nondiagnostic ECG changes, or when other causes of chest pain are entertained, transthoracic echocardio-graphy can be of value. New regional wall motion abnormalities appearing in previously normal ventricular segments support the diagnosis of acute myocardial ischemia and may precede changes in the ECG. Likewise, other findings may argue against acute coronary syndrome, including pericardial effusion (as might be seen in pericarditis), and right ventricular enlargement (as might be seen in pulmonary embolism). Although new regional wall motion abnormalities can be highly suggestive of acute ischemia or infarction, this diagnosis can be considerably more challenging in patients with prior history of myocar-dial infarction or abnormal regional wall motion.

Following myocardial infarction, echocardiography can have substantial value (Chapter 7). Early and late post-myocardial infarction complications, e.g., ventricular septal defect or papillary muscle rupture can be diagnosed with echocardiography. In the postinfarction period, echocardiography can assist with the diagnosis, risk assessment, and prognosis (Table 8).

In chronic myocardial ischemia, echocardiography can provide added information on disease severity and risk stratification that impacts further clinical management (Tables 8 and 9; Chapter 8). Where indicated, exercise or pharmacological stress echocardiography are useful adjuncts in assessing global and regional systolic function as well as myocardial contractile reserve.

pulmonary embolism

Although less sensitive and specific than ventilationperfusion scans and pulmonary angiography in acute

Table 4

Common Clinical Signs, Symptoms, or Conditions for Which Echocardiography Is Indicated

Clinical symptom Possible echocardiographic or sign findings Indications for echocardiography

Clinical signs

Systolic murmur

Aortic sclerosis

Indicated in patients with cardiac symptoms or ECG abnormalities

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