This document discusses cardiac rhythms and electrocardiogram (ECG) interpretation. It provides normal and abnormal heart rate ranges for the sinoatrial node, atrioventricular node, and bundle branches. It also describes ECG patterns such as sinus rhythm, arrhythmias, conduction abnormalities, myocardial infarction, and other cardiac conditions. Measurement techniques for rate, intervals, and waveform analysis on ECG strips are outlined.
10. Horizontally
One small box - 0.04 s
One large box - 0.20 s
Vertically
One large box - 0.5 mV
11.
12. Small boxes
Number of small boxes between RR or PP
1500 divide by number of small boxes
Example 15 small boxes between the peaks
of two RR - 1500/15 = HR 100bpm.
13. Number of large boxes between 2 RR/PP
intervals
Divide 300 by the number of large boxes
Example
5 large boxes between 2 RR complexes
300/5 =60bpm
14. Quick and dirty method great for an irregular
rhythm
Measure 6 second strip and x by ten.
15. Sinus Brady
Sino atrial arrest
Wenkebach
Mobitz type 2
CHB
17. Does a P wave precede every QRS
Is it positive or negative in the correct leads
Do all the p waves look alike
What is the shape of the p wave
What is the ratio of p waves to QRS
complexes
Normal p waves upright (except AVR) round
with 1:1ratio
18. P Mitrale
A wide bifurcated P - wave
Left atrial enlargement
19. P Pulmonale
Tall P wave
Right atrial hyptrophy
27. The length of time taken to depolarise the
ventricles
<0.12 secs (3 small squares)
Q - first negative deflection
R- first positive deflection
S negative deflection after R
Any upward deflection after the R above the
isoelectricline is classed as another R
28. QRS - 0.12 secs or greater
Common cause BBB
Abberant conduction
Think VT, VF, CHB
29. Dead or stunned myocardial tissue
Usually permanent
Can be reversed with early intervention
More than 1mm in depth
0.02 secs or greater in V1-V2
0.04 secs or more and greater than one-third of the
R wave (although their is much dispute over this)
30. Reflects length of time from the beginning of
ventricular depolarisation to the end of repolarisation
QT interval corrected for heart rate variability
The ECG machine corrects this
The corrected figure is called the QTc
Should be no more than 440ms
Slight variation in peadiatrics depending on age
31. Inherited
Medicine induced- amioderone, sotolol
Hypocalceamia, hypokaleamia,hypomagnesia
Induce torsades de points.
33. Represents recovery or repolarisation of the
ventricles
Measured from the end of the QRS to the
beginning of the T wave
The ST is normally isoelectric
37. • Reflects repolarisation or ventricular muscular
relaxation ,T wave changes seen in:
MI
Ischemia
electrolyte imbalances
medications
pericarditis
Cardiomyopathies
38.
39. Upright round wave seen in lead II after
Twave and before the next P wave
Not clearly understood
Associated with hypokaleamia, amioderone
& digoxin
40. The general flow of electrical activity of the
heart
It relates to the flow of depolarisation wave
through the heart
This can change with position of the heart
Generally related to changes in electricalflow
41.
42. Left ventricular hypertrophy
LBBB - bifasicular block
LBBB + 1st degree HB - trifasicular block
Mechanical shift of the heart
Normal variant
43. Right Ventricular Hypertrophy
RBBB
Dextrocardia
Mechanical shift
Normal variation