[Verse 1]
Two vessels leaving a healthy chest,
Aorta struts left, pulmonary flexes right,
Each got a valve doing gatekeeper best,
Septum's sealed tight, no room for a fight,
Oxygen-rich cruises out through the arch,
Oxygen-poor ships out to the lung's back porch,
That's the blueprint, normal and true,
Now flip the chart — let's meet type II.
[Chorus]
Four differences, hear the call,
Valve's a ghost, there's no MPA at all,
One hole punched clean through the septum wall,
Single trunk doing the job for all,
PA ostia sprout where the branches fall,
That's your truncus map, don't let it stall,
Vanish, split, merge, and sprout,
Label 'em side by side, that's what it's about.
[Verse 2]
Look for the valve where the pulmonary used to sit,
It's absent, ghosted, erased from the script,
No main pulmonary artery stem in the frame,
That's difference number one, learn the name,
Next slide down to the ventricle floor,
A VSD's grinning, a hole in the core,
Blood don't care 'bout borders no more,
Left and right mixing, equalized for sure,
Instead of two roots you got a single trunk,
Aorta and pulmonary fused, no longer chunked,
One vessel doing double duty, overworked,
And where the branches used to fork from their own berth,
Now the pulmonary ostia perch right on the trunk itself,
Riding the wall like a hitchhiker's health,
Four fixes to label, four flags on the chart,
Compare 'em side by side — that's the art.
[Chorus]
Four differences, hear the call,
Valve's a ghost, there's no MPA at all,
One hole punched clean through the septum wall,
Single trunk doing the job for all,
PA ostia sprout where the branches fall,
That's your truncus map, don't let it stall,
Vanish, split, merge, and sprout,
Label 'em side by side, that's what it's about.
[Verse 3]
Now let's chase the oxygen, follow the tide,
Right atrium's still low, seventy give or take, nothing to hide,
It rolls through tricuspid, meets the right ventricle's crowd,
But that VSD's open, so the mixing's loud,
Left ventricle's rich blood spills through the gap,
Right and left ventricle sats basically overlap,
Call it eighty-five, roughly, both sides the same,
'Cause pre-truncal mixing rewrote the game,
Climb into the trunk, the single great vessel bed,
Same number holds, eighty-five instead,
Branch off to the lungs, branch off to the head,
Same saturation, no gradient ahead,
That's the tell — no step-up, no drop,
One number rules from the valve to the top,
Cyanotic baby, low but steady sats,
'Cause the trunk don't discriminate, that's just facts.
[Bridge]
Side by side, chart by chart, don't blend the lines,
Circle the ghost valve, circle the vessel that combines,
Circle the hole, circle the sprouting signs,
Four circles drawn and the diagnosis shines.
[Outro]
Vanish, split, merge, and sprout,
Eighty-five percent, that's what it's about,
Truncus type II, now you've got the sound,
Label it, trace it — you already found it.