ECG: Rhythms

Question 1

Normal ECG measurements

Answer 1

PR: 0.12s
QRS: 0.08-0.12s

Question 2

QTc (Bazett’s Formula)

Answer 2

QT interval / RR interval

450 ms is upper limit of normal

Question 3

Romhilt-Estes Criteria for LVH

Answer 3

Any of: (3 pts)
R or S in limb leads >20mm
S in V1/V2 >30 mm
R in V5/V6 >30 mm
ST-T abnormalities:
w/o digitalis (3 pts)
with digitalis 1 pt
LAE in V1: 3 pts
LAD: 2 pts
QRS >0.09s: 1 pt
Delayed intrinsicoid deflection in V5/V6 (>0.05s): 1 pt

Question 4

Normal Axis

Answer 4

-30 to +90 degrees

Question 5

Normal ejection fraction

Answer 5

55-70%

Question 6

ST segment measuremet

Answer 6

80 ms from J point

Question 7

ETT BP Drop

Answer 7

10 mm/Hg during test from pre-test value is absolute indication to terminate test

Question 8

Ashman Phenomenon

Answer 8

an aberrant ventricular conduction, usually of RBBB morphology, which follows a short R-R interval and preceding relatively prolonged R-R interval, typically seen with a. fib but can also occur with other SV arrhythmias
clinically on its own is asymptomatic, does not req specific treatment