- Report the rate, rhythm,
conduction, p waves, frontal plane axis, QRS complex.
- Comment on T waves over R
chest. Look at QT interval
- Rate = 1500 / number of
little squares or
= 300 / number of big squares
Normal Values
| Age |
Ht Rate
/min |
QRS vector
o |
PR interval
sec |
QIII
mm
|
QV6
mm |
RV1
mm |
SV1
mm |
RSV1
sec |
RV6
mm |
SV6
mm |
R/S V6
sec |
SV1+ RV6
mm
|
R + S V4
mm
|
|
<1
day |
93-154
(123) |
+59 to -163
(137)
|
0.08-.16 (0.11) |
4.5 |
2 |
5-26
(14)
|
0-23
(8)
|
0.1- ?
(2.2) |
0-11
(4)
|
0-9.5
(3)
|
0.1 - ?
(2.0) |
28 |
52.5 |
|
1-2
days |
91-159
(123)
|
+64 to -161
(134)
|
0.08-.14
(0.11)
|
6.5 |
2.5 |
5-27
(14)
|
0-21
(9)
|
0.1 - ?
(2.0)
|
0-12
(4.5)
|
0-9.5
(3)
|
0.1 - ?
(2.5) |
29 |
52 |
|
3-6
days |
91-166
(129)
|
+77 to -163
(132)
|
0.07-.14
(0.10)
|
5.5 |
3 |
3-24
(13)
|
0-17
(7)
|
0.2 - ?
(2.7)
|
0.5-12
(5)
|
0-10
(3.5)
|
0.1 -?
(2.2) |
24.5 |
49 |
|
1-3
weeks |
107-182
(148)
|
+65 to -161
(110)
|
0.07-.14
(0.01)
|
6 |
3 |
3-21
(11)
|
0-11
(4)
|
1.0- ?
(2.9) |
2.5-16.5
(7.5)
|
0-10
(3.5)
|
0.1 - ?
(3.3) |
21 |
49 |
(mean), ? = undefined
Interpretation
P waves
|
Peaked
(>3mm) = RA hypertrophy |
 |
Broad or biphasic = LA
hypertrophy |
|
Right Ventricular
Hypertrophy
|
Pure
RV1 >10mm (no SV1) |
| RV1
>25 (SV1 present) |
| Upright
TV1 after 3 days (RV strain) |
| Right
axis deviation >+180° |
|
Left Ventricular Hypertrophy
|
RV6
>17mm in 1st week (>25mm in 1st month) |
| SV1
>20mm |
| SV1
+ RV6 >45mm |
| QV5
or V6 >5mm with tall symmetric T |
| Asymmetric
T inversion = LV strain |
| ST
depression = LV strain |
|
Biventricular Hypertrophy
|
Abnormal
voltages over R and L chest leads |
| Prominent
mid-precordial voltages |
|
AV Block
|
1° |
Prolonged
P-R interval |
| 2°
Mobitz Type 1 (Wenkebach) |
Progressive
increase in P-R then dropped beat |
| 2°
Mobitz Type 2 |
Dropped
beats without P-R prolongation |
| 3° |
Complete heart block |
|
Tachycardias
|
Atrial
flutter - atrial rate 300-400, and regular saw-tooth pattern
of P waves in LI and LIII.
Ventricular rate depends on degree of A-V block. |
| Atrial
fibrillation (rare in newborn). Often associated with
cardiac abnormalities, especialy if LA enlargement. |
| Atrial
tachycardia. |
| AV
re-entry tachycardia. |
| WPW:
Short P-R paroxysmal tachycardias. Wide QRS with
Δ wave re-entry through accessory pathway. |
| AV Nodal re-entry tachycardia |
| Sinus
tachycardia |
|
Ventricular Tachycardia
|
>5
ventricular ectopics in rapid succession |
| Identify independent
atrial activity |
| Direct |
|
| Indirect |
(Capture,
atrial capture beats with narrow complexes |
|
(Fusion,
supraventricular beat with ventricular complex) |
| Regular,
broad complex tachycardia |
| Concordant
pattern over chest leads |
|
|
|
|
|
Ectopic Beats
|
Common:
21-31% of healthy preterm and up to 23% of term infants |
|
Conditions with Specific ECGs
Preterm Infant
|
Shorter
QRS duration, shorter PR and QT interval |
| Less
RV dominance than term infant at birth |
|
AV Canal
|
QRS -30 to -90° |
| RA enlargement |
| Prolonged PR |
|
Ebstein's Anomaly
|
QRS
low voltage or RBBB or ventricular pre-excitation |
| PR
prolonged, RA enlargement |
|
Hypoplastic Right Heart
|
Variable. |
| Absent or
diminished RV voltages |
|
Transposition of the Great
Arteries
|
Often normal |
|
Tricuspid atresia
|
RA hypertrophy |
| Left axis deviation |
|
|
