Coronary artery disease (CAD) and its sequelae affect millions of individuals. In addition, many patients present with symptoms that may be due to ischemic heart disease. Echocardiography has assumed a central role in the evaluation and management of patients with known or suspected CAD. By virtue of its ability to noninvasively assess cardiac structure and function, echocardiography can provide anatomic information that is useful in the evaluation of these patients.
In patients with ongoing chest pain, an echo in the acute setting can provide evidence against myocardial ischemia as the etiology of the symptoms if there are no regional wall motion abnormalities and may provide clues to other potential diagnoses such as a pericardial process, acute pulmonary embolism, or aortic pathology.
In the postmyocardial infarction (MI) setting, echocardiography plays a critical role in the evaluation and management of the patient, including an assessment of ejection fraction (EF) postmyocardial infarction (MI), which is essential to provide prognostic information as well as to help guide medical management and assess these patients for potential device therapy such as implantable cardiac defibrillators (ICD).
In the acute setting, for patients who develop hemodynamic instability or evidence of acute heart failure, echocardiography is invaluable to assess the EF. In addition, echocardiography is essential for evaluating the patient for post-MI mechanical complications such as acute mitral regurgitation (MR) or ventricular septal defects (VSD), free wall rupture, or RV infarction.
The advent of stress echocardiography in the mid to late 1980s provided an alternative to stress nuclear (perfusion) imaging as a noninvasive means of evaluating and risk stratifying patients with chest pain syndromes. With improvement in digital image acquisition and displays, stress echo now provides a robust method of evaluating such patients, with results comparable to nuclear techniques. Exercise stress echo using treadmill, or less commonly bicycle stress, and pharmacologic stress echo, most often employing dobutamine in the US, are frequently used tests to evaluate patients with known or suspected CAD.
In this chapter, Dr. Larry will explore the use of echocardiography in the patient with chest pain and suspected or known CAD (stress testing) and in the assessment of the post-MI patient, including patients with mechanical complications of an acute MI.
SECTION 1: NEGATIVE STRESS ECHO
CLINICAL CASE PRESENTATION
A 45 year old man with hypertension that has not been well controlled presents for evaluation. He was seen in the office and mentioned 3 separate episodes of non-radiating chest discomfort, lasting 30 minutes, located in the left chest, accompanied by mild dyspnea during the third episode.
His exam revealed blood pressure of 135/88 mm Hg, pulse of 75 beats/min, and a respiratory rate of 16 breaths/min. The jugular venous pressure (JVP) was normal; carotid upstrokes were normal; no bruits were appreciated. The lungs were clear to auscultation ...