Thanks for your query.
First of all keep in mind ECG machine dose not always interpret or trace correctly, it should be interpreted by expert after watching the ECG strip.
1. T wave
abnormality can be normal in child, may be due to interior wall infarct, electrolyte imbalance
or other cardiac conduction problems. treatment depends on underlying cause.
2. qrs(t) contour abnormality consistent with inferior infract is self defining an old infarct of inferior heart wall or may be due to any other reason.
ECG readings can be biased by machinery,technician or patient. Seek doctor's opinion or repeat ECG.
Hope it helps.