2. PQRST

Question 1

P wave

Answer 1

depolarization/contraction of atria

UP: I, aVF
Biphasic: III, V1
DOWN: aVR

Question 2

Q wave

Answer 2

Depolarization/contraction of septum

Question 3

QRS complex

Answer 3

Depolarization/contraction of ventricle

UP: I, aVF
DOWN: aVR

Question 4

T wave

Answer 4

Repolarization/relaxation of ventricles

Question 5

Criteria for normal sinus rhythm

Answer 5

Regular rhythm

Normal HR

P wave prior to QRS

Question 6

Cardiac ischemia

Answer 6

Down-sloping ST segment

1.0 mm or greater

Question 7

ST elevation

Answer 7

At least 1mm in limb leads

2mm in precordial leads

Question 8

Pathologic Q wave

Answer 8

“Walking off a cliff” - simultaneous loss of R wave

greater then or equal to 1/3 height of R wave

Duration. Greater then or equal to 0.04s

Sign of previous MI/ irreversible myocardial damage

II, III, aVF

Question 9

Wide QRS

Answer 9

Greater then 0.2 s

Should not be greater then 3 small boxes

Electrical impulse begins at ventricles

Conduction block in left or right bundle branch

Ventricular tachycardia

Impulse takes aberrant pathway through ventricles

Question 10

Prolonged PR interval

Answer 10

Normal is 0.12-0.2 s = one big box

Greater then 1 big box

Heart block

Question 11

Prolonged QT

Answer 11

Look at RR interval

Normal is less then half the way between 2 QRS complexes

From beginning fo ventricular depolarization to end of vent repolarization

Rapid HR - inversely proportional to HR

Question 12

PR segment

Answer 12

Time from end of atrial depolarization to beginning of ventricular depolarization

Up to 1 big box

Prolonged: think heart block

Question 13

ST segment

Answer 13

Time from end of ventricular depolarization to start of ventricular repolarization

Question 14

QT interval

Answer 14

From beginning of ventricular depolarization to end of ventricular repolarization

Inversely proportional to HR