as in the cardiology threads, play up your interest in pulmonary hypertension and the whole heart lung connection. any scholarly activity you can do about pulmonary hypertension could help bridge the gap between cardiology and PCCM when you are writing your personal statements.
You'll have a much better time in pulmonary i'd bet.
unless you're into advanced cardiology stuff like interventional, LVADs, transplant, arrhythmia/EP stuff...
let's just say it is easier for the "pulm crit doctor to pretend to be the general cardiologist than it is for the general cardiologist to pretend to be the pulm crit doctor"