1. How to read ECG
PG corner

2. Mr do not Miss  Lead reversal and ECG artefacts

3. Technology
does not
understood
science of ECG
 Do not believe in COMPUTERIZED ECG INTERPRETATIONS

4. At least 14
observations
before
answering

5. Standardizati
on
 Usual 1 mV = 10 mm
 In special cases ECG may be intentionally recorded at one-half
standardization (1 mV =5mm) or two times normal standardization
(1 mV = 20 mm). However, overlooking this change in gain may lead
to the mistaken diagnosis of low or high voltage.

6. Rhythm
 Sinus rhythm
 bradycardia or tachycardia
 SR with APBs orVPBs
 SR with AV block
 Nonsinus:PSVT),Afib or flutter,VT and AV junctional escape

7. Sinus rhythm  Discrete P waves that are always positive (upright) in lead II (and
negative in aVR

8. Heart Rate
 Normally, the ventricular (QRS) rate and atrial (P) rates are the
same (1:1 AV conduction)
 Tachycardia >100
 Bradycardia <60
 Irregular
 Regularly irregular :Wenchebach’s
 Irregularly irregular :Fib

9. PR Interval
 The normal PR interval (measured from the beginning of the P
wave to the beginning of the QRS complex) is 0.12 to 0.2 sec
 First-degree AV block
 A short PR interval with sinus rhythm and with a wide QRS
complex and a delta wave is seen in theWolff-Parkinson-White
(WPW) pattern
 A short PR interval with retrograde P waves (negative in lead II)
generally indicates an ectopic (atrial or AV junctional) pacemaker.

10. P wave
 Normal not exceed 2.5 mm in amplitude and is less than 3 mm
(120 ms) wide in all leads
 Tall, peaked P waves may be a sign of right atrial overload (P
pulmonale)
 Wide (and sometimes notched P) waves are seen with left atrial
abnormality.

11. QRS Interval
 0.1 sec (100 ms) or less, measured by eye
 110 ms if measured by computer

12. QT/QTc
Interval
 Shortened :hyperkalaemia and digitalis effect
 Prolonged:hypocalcemia or hypokalemia, drug effects (quinidine,
procainamide, amiodarone, or sotalol), or myocardial ischemia

13. QRSVoltage  Stick to criteria for Normal /LVH/RVH

14. QRS Axis
 Frontal plane
 Normal: −30° to +100°

15. R wave
progression
 Inspect leadsV1 toV6
 Normal increase in R/S ratio occurs as you move across the chest
 Poor: (small or absent R waves in leadsV1 toV3)
 AWMI
 The term reversed R wave progression
 Tall R waves in leadV1 that progressively decrease in
amplitude:RVH, posterior (or posterolateral) infarction, and
dextrocardia

16. Q,T,U Document changes

17. UWave
 U Waves Look for prominent U waves.These waves, usually most
apparent in chest leadsV2-V4, may be a sign of hypokalemia or
drug effect or toxicity (e.g., ami-odarone ami-odarone, dofetilide,
quinidine, or sotalol).

18. Normal frontal
loop:
1.q in II/III/aVF
2.No q in I/AVL

19. Counter clock
loop in frontal
plane:
1.q inAVL
2.No q in
II/III/AVF

20. (1) standardization—10 mm/mV; 25 mm/sec
(2) rhythm—normal sinus
(3) heart rate—75 beats/min
(4) PR interval—0.16 sec
(5) P waves—normal size
(6) QRS width—0.08 sec (normal)
(7) QT interval—0.4 sec (slightly prolonged for rate)
(8) QRS voltage—normal
(9) QRS axis—about 30° (biphasic QRS complex in lead II with positive QRS complex
in lead I)
(10) R wave progression:early precordial transition with relatively tall R wave in lead
V2
(11) abnormal Q waves—leads II, III, and aVF
(12) ST segments: elevated in leads II, III, aVF,V4,V5, andV6 slightly depressed in
leads V1 and V2
(13)T waves—inverted in leads II, III, aVF, andV3 throughV6
(14) U waves—not prominent. Impression:This ECG is consistent with an
inferolateral (or infero-posterolateral) wall myocardial infarction of indeterminate
age, possibly recent or evolving. Comment:The relatively tall R wave in lead V2 could
reflect loss of lateral potentials or actual posterior wall involvement
EXAMPLE

21. Calcium and 12
Lead ECG

22. What ECG
findings may
be present in
pulmonary
embolus?
 Sinus tachycardia (the most common ECG finding)
 Right atrial enlargement (P pulmonale)—tall P waves in the
inferior leads
 Right axis deviation
 T wave inversions in leadsV1-V2
 Incomplete right bundle branch block (IRBBB)
 S1Q3T3 pattern—an S wave in lead I, a Q wave in lead III, and an
invertedT wave in lead III.Although this is only occasionally seen
with pulmonary embolus, it is quite suggestive that a pulmonary
embolus has occurred.

23. I can only give
you hint
because I
know less