An eight-year-old boy presented to the pediatrician due to auscultation of a cardiac murmur in the review of the child health program.
The patient has no personal or family history of interest and is not currently taking any pharmacological treatment.
Assignment from the cardiovascular point of view, with adequate daily physical activity for their age with good tolerance.
On physical examination, a grade I-II systolic murmur is detected on the left edge with a low-backed, non-irradiated to the axilla, back, or to the carotid artery, which is requested only per se.
Elevated liver function tests revealed no evidence of hepatomegaly.
Pulses are symmetric in the four limbs and the rest of the examination is normal with tension within percentiles appropriate for age and height.
The pediatrician decides to perform an electrocardiogram (ECG), and after analyzing it, he leads the child to the pediatric cardiology consultation.
What might have called your attention?
Before you continue to read, closely observe the ECG.
1.
What is the interpretation of the ECG?
When the ECG showed normal reading1, it showed sinus rhythm (positive P waves in I and in aVF) with a heart rate of 110 beats per minute (lpm) (within the range).
P waves are normal in duration and amplitude.
Attention is paid to the PR interval, which seems prolonged.
Including from the beginning of the P wave to the beginning of the QRS complex, there are five quartiles, equivalent to 0.2 seconds, above the upper limit of normality.
1.
We observed that the duration of the PR interval is the same in different beats, and that each P wave is followed by a QRS complex.
The QRS complex presents an axis in the left lower quadrant (positive in I and in aVF), with normal duration and without morphological changes (RSR' pattern is observed in V1 with narrow QRS, the pathological finding called incomplete block).
No abnormalities were observed in repolarization, since there are no ST-segment depressions, the T wave has positive polarity in the leads of the lower face (II, III, left precordial aVF) and in the leads of the right precordial aV2.
No premature beats or ectopic activity are observed in the rhythm dip.
The pediatrician performed very carefully an ECG as part of the study of the systolic murmur detected.
The characteristics of the murmur are those of a functional murmur, and the finding of the first degree atrioventricular block motivated the referral of the child to the specialist.
The diagnosis was confirmed by a new ECG, which confirmed the presence of PR interval in an ECG performed after the child was asked to perform "sitting" in the same consultation.
The study was completed with an echocardiography that was normal, citing the child in one year for review.
