Diagnostic Features of the ECG

Question 1

Looking at an ECG printout, you can extrapolate heart rate by __________.

Answer 1

using 300 / (# of bold lines between two QRSs)

Question 2

In a 12-lead ECG, there are _____ bipolar leads and ______ unipolar leads.

Answer 2

three; nine

Question 3

Lead 1 is a ______ lead that is _________.

Answer 3

bipolar; negative on the right hand and positive on the left

Question 4

Lead 2 is a ______ lead that is _________.

Answer 4

bipolar; negative on the right hand and positive on the left foot

Question 5

Lead 3 is a _______ lead that is ________.

Answer 5

bipolar; negative on the left hand and positive of the left foot

Question 6

V1 - V6 are the _______ leads.

Answer 6

precordial

Question 7

V1 and V2 are the ______ leads, and V5 and V6 are the ________.

Answer 7

right chest; left chest

Question 8

Hypertrophy leads to _________ on an ECG.

Answer 8

increased voltage amplitude

Question 9

Left ventricular hypertrophy will produce bigger R waves on the _______ leads.

Answer 9

I, aVL, V5, and V6

Question 10

Right ventricular hypertrophy will produce bigger R waves on the _______ leads.

Answer 10

aVR, V1, and V2

Question 11

Ischemia due to sudden high oxygen demand (such as secondary to exercise) will lead to a ________ pattern on an ECG.

Answer 11

depreesion of the ST segment

Question 12

Ischemia due to coronary obstruction will produce a ________ ECG pattern.

Answer 12

T wave inversion

Question 13

A significant Q wave is _______________.

Answer 13

(1) greater than 1/4 the amplitude of the R wave; (2) greater than or equal to one small box in width; and (3) present in at least two leads

Question 14

A transmural infarction is _______________.

Answer 14

death of myocardial tissue that extends from the endocardium to the epicardium as a result of a myocardial infarction

Question 15

A transmural infarction results in ___________ on an ECG.

Answer 15

ST elevation with significant Q wave

Question 16

A subendocardial infarction results in _____________ on an ECG.

Answer 16

ST depression without Q waves (similar to the exercise stress sign, but present in the absence of exertion)

Question 17

A QT interval is considered prolonged when it is greater than ___________.

Answer 17

half the RR interval

Question 18

Hypercalcemia leads to __________, while hypocalcemia leads to __________.

Answer 18

shortened QT interval; lengthened QT interval

Question 19

A U wave is a manifestation of ________.

Answer 19

hypokalemia

Question 20

The sine-wave sign results from __________.

Answer 20

extreme hyperkalemia