Exam 9: Introduction to the 12-Lead Electrocardiogram

Patients who experience a(n) _____ myocardial infarction have a greater incidence of heart failure and cardiogenic shock than those who have myocardial infarctions affecting other areas of the left ventricle.

Where should the positive electrode for lead V₁ be positioned?

Describe the appearance of a pathologic Q wave.

Completion -When reviewing a 12-lead ECG, intervals and duration are usually expressed in _____.

Anterior or lateral wall myocardial infarctions are most often a result of an occlusion of the _____ coronary artery.

Lead aVL views the _____.

The chest leads are the only unipolar leads in the standard 12-lead ECG.

An abnormal (i.e., pathologic) Q wave indicates the presence of dead myocardial tissue.

Completion -The axes of leads I, II, and III form an equilateral triangle with the heart at the center (Einthoven's triangle). If the augmented limb leads are added to this configuration and the axes of the six leads moved in a way in which they bisect each other, the result is the _______________.

Lead V₃ views the _____ wall of the left ventricle.

Lead I is perpendicular to lead _____.

Which leads look at adjoining tissue in the inferior region of the left ventricle?

Lead I views the _____.

What two factors determine the portion of the heart that each lead "sees"?

Which leads look at adjoining tissue in the anterior region of the left ventricle?

Where should the positive electrode for leadd V₅ be positioned?