Speculum - University of Melbourne

18 SPECULUM
A
Fig. 8—E.C.G. in Fallot's tetralogy. Note the
upright Q-wave in lead B (0.05 m.V.—the
usual potential found) and large R-waves
and absent S-waves of pulmonary stenosis.
There is little evidence of right ventricular
strain as there is no Q(B).
C has disappeared and the inversion of T(B)
is of normal distribution.
Fig. 7—E.C.G. and phonocardiogram in ventricular
septal defect. Note the unusually
large upright Q(B) fused into the R-wave,
complete heart block and systolic bruit.
5. Coarctation of the Aorta.
In all instances of hypertension, especially
in young people, the femoral pulses
farcts with perforation also show this small
upright Q-wave, with a left or normal axis
pattern.
4. Patent Ductus.
The E.C.G. of patent ductus is not distinctive.
Some degree of right heart preponderance
with strain is seen depending on
the degree of overaction and strain imposed
on the right ventricle by the abnormal communication.
Such a tracing is shown in fig.
9, a tracing obtained from a healthy girl
aged 24 years with only slight symptoms.
There is slight right axis deviation and some
indication of right ventricular strain by the
inverted T(C). After tying the ductus the
E.C.G. became completely normal. The
tracing shown in fig. 10 was taken 8 days
after operation and the inverted T-wave in
,
Fig. 9—E.C.G. in patent ductus arteriosis prior
to operation. Note the slight right axis
deviation which would be normal in a
younger subject (this patient was aged 24
years), and also the inverted T(C) and deep
inverted T(B). Further details in text.