1. Innocent murmur
2. Differences in child's heart vs. adult

Innocent murmur

• Normal split 2nd heart sound, split widens on inspiration.
• Systolic, soft, and short.
• Audible over L sternal border or pulmonary area, over a relatively small area.
• Child is asymptomatic.
• No associated cardiac abnormalities: no thrills palpable, peripheral pulses are present.

Differences in child's heart vs. adult

• Sinus (respiratory) arrhythmia is much more prominent.
• In child, heart occupies relatively more space in the thorax.
• <7 years: apex beat is in 4th intercostal space to the L of midclavicular line.