Chapter 9 Flashcards
TRUE/FALSE
The chest leads are the only unipolar leads in the standard 12-lead ECG.
false
TRUE/FALSE
When you read a 12-lead ECG from left to right, the ECG tracing is continuous.
true
TRUE/FALSE
Placement of right chest leads is identical to the standard chest leads except on the right side of the chest.
true
TRUE/FALSE
An abnormal (i.e., pathologic) Q wave indicates the presence of dead myocardial tissue.
true
Where should the positive electrode for lead V5 be positioned?
Where should the positive electrode for lead V5 be positioned?
A standard 12-lead ECG provides views of the heart in _____.
both the frontal and the horizontal planes
Poor R-wave progression is a phrase used to describe R waves that decrease in size from V1 to V4. This is often seen in an _____ infarction.
anteroseptal
Which leads look at adjoining tissue in the anterior region of the left
V2, V3, V4
Lead V1 views the _____.
septum
Lead aVL views the _____.
lateral wall of the left ventricle
Which of the following leads should be used to view the right ventricle?
V4R
Lead V3 views the _____ wall of the left ventricle.
anterior
Anterior or lateral wall myocardial infarctions are most often a result of an occlusion of the _____ coronary artery.
left
Which leads look at adjoining tissue in the inferior region of the left ventricle?
II, III, aVF
Lead V5 views the _____ wall of the left ventricle.
lateral
The inferior wall of the left ventricle is supplied by the _____ coronary artery in most of the population.
right
Where should the positive electrode for lead V1 be positioned?
Right side of the sternum, fourth intercostal space
Lead II views the _____ wall of the left ventricle.
inferior
Which leads face the septum?
V1, V2
Which of the following ECG changes is one of the earliest to occur during an ST-elevation infarction, but may have resolved by the time the patient seeks medical assistance?
Hyperacute T waves
Hypertrophy refers to a(n) _____.
increase in the thickness of a heart chamber because of chronic pressure overload
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.
anterior
An ECG machine’s sensitivity must be calibrated so that a 1-millivolt electrical signal will produce a deflection measuring exactly _____ mm tall.
10
Normal electrical axis lies between _____ degrees.
–30 and +90
Lead I is perpendicular to lead _____.
aVF
Lead I views the _____.
lateral wall of the left ventricle
Indicative ECG changes observed in leads V1, V2, V3, and V4 suggest that the _____ wall of the _____ ventricle is affected.
anteroseptal; left
