Hey everyone, welcome back to MasterUSMLE! Today, we’re tackling ahigh-yield but often missed condition—cardiac sarcoidosis.

Here’s the scenario: Ayoung patient under 55 walks in withbradycardia, AV block, maybe a left bundle branch block (LBBB)—and no clear explanation. This is when youmust think aboutcardiac sarcoidosis.

What’s happening?Noncaseating granulomas infiltrate the heart, messing up the conduction system and leading toarrhythmias, AV block, heart failure, or even sudden cardiac death.

So how do you diagnose it?

• ECG showing AV block or LBBB? That’s your first clue.
• Cardiac MRI or PET scan—this picks up active granulomatous inflammation.
• Biopsy can confirm, but it has low sensitivity—so don’t rely on it too much.

And treatment?High-dose steroids to suppress inflammation, and if the heart block is bad?Get that pacemaker in.

The key takeaway?Young patient with unexplained AV block = Think sarcoidosis. Get an MRI or PET scan ASAP.

That’s it for today—keep it simple, stay sharp, and I’ll catch you next time on MasterUSMLE!