Cardiology: Electrocardiogram

Question 1

Assess ECG using what method?

Answer 1

rate, rhythm, axis, intervals, waveforms, and chamber enlargement

Question 2

estimate heart rate by counting the number of large boxes between 2 consecutive QRS complexes as follows

Answer 2

300-150-100-75-60-50-43 bpm

Question 3

what is the normal HR? what is bradycardia? what is tachycardia?

Answer 3

normal=60-100bpm

brady100

Question 4

name 4 types of rhythms to look for

Answer 4

sinus (p before every QRS and QRS after every p wave)
irregular
junctional or ventricular rhythms (no p before a QRS)
ectopic beats

Question 5

define normal axis

Answer 5

an upright QRS in leads I and avF (0-90 degrees)

Question 6

define left axis deviation. what is limit for normal variant?

Answer 6

an upright QRS in lead I and downwards QRS in lead avf.

up to -30 degrees (positive in II) is considered normal variant

Question 7

define right axis deviation. what is limit for normal variant?

Answer 7

a downward QRS in lead I and a upright QRS in avF

up to 105+ is considered a normal variant

Question 8

what is normal PR interval?

what is normal QRS interval

Answer 8

PR 120-200 (3-5 small boxes)

QRS <120 (3small boxes)

Question 9

define AV block

Answer 9

PR interval >200msec, or P wit nor QRS afterward

Question 10

define LBBB

Answer 10

QRS duration> 120msec; or R wave in V1; wide, tall R waves in I, V5, V6

Question 11

define RBBB

Answer 11

QRS duration ?120 msec, RSR’ complex (rabbit ears); qR or R morphology with a wide R wave in V1; QRS pattern with a wide S wave in I, V5, and V6

Question 12

define Long QT syndrome

Answer 12

QTc>440msec. an under diagnosed congenital disorder that predisposes to ventricular tachyarrhythmias. QTC=QT/sqrt(RR); QT=qt interval and RR=rr interval

Question 13

define ischemia (3 characteristics)

Answer 13

new inverted t waves, poor R-wave progression in precordial leads, ST segment changes (elevation or depression)

Question 14

define transmural infarct (2 characteristics)

Answer 14

significant Q waves (>40msec or more than one-third of the QRS amplitude); ST elevation with T wave inversions

Question 15

define right atrial enlargement

Answer 15

P pulmonale (peaked p waves)
p wave amplitude in lead II is >2.5mm

Question 16

define left atrial enlargement (2 different criteria, what is frequently seen?)

Answer 16

p mitrale (m shaped p waves)
p-wave width in lead II is >120msec or terminal  -deflection in V1 is >1mm in amplitude and >40msec in duration. notched pwaves can be frequently seen i lead II

Question 17

left ventricular hypertrophy (2 main criteria and 1 alernative criteria

Answer 17

amplitude of S in V1 +R in V5 or V6 is >35mm (7 big boxes)
OR
amplitude in R of aVL +S in V3 > 28mm (5 big boxes+3 small boxes) in men or >20mm (4 big boxes) in women

Question 18

right ventricular hypertrophy (2 characteristics)

Answer 18

right axis deviation and an R wave in V1>7mm