Noonan’s Syndrome

Report:

Sinus rhythm 119/min

Right axis deviation ± 180o

Right ventricular hypertrophy voltage

R/S < 1.2 in V6 (1 month – 15 yrs)

Right ventricular hypertrophy T wave criterion

Upright TV1 (5 days – 4 yrs)

Probable right ventricular hypertrophy

Comment:

This is not a true S1S2S3 pattern because S wave does not exceed R wave amplitude in lead 3. The axis is 180o: lead one points to it, at right angle to equiphasic aVF. Yet the evidence for RVH is significant – even without a dominant R in V1 – to find the ECG consistent with pulmonary stenosis, the commonest CHD in patients with Noonan’s syndrome.

The ECG, however, bears little relation to the actual phenotype; its determinants lie elsewhere215. Most typical is in fact LAD (maybe this one is, at 180o, an LAD) and small R wave in the left precordial leads. These findings and conclusions, from the study just quoted, have been recently confirmed, by the same group216.

With all the non-specificity of the ECG findings, I cannot resist the impression that hæmodynamic determinants do not come into play with time: a significant pulmonic stenosis will announce itself as RVH.