Thread by @EvelynSongMD

1/ Are you ready for another #CNCR tweetorial?

👏👏👏 to another amazing case with @cardionerds and @DrRachelGoodwin @Dr_Isang_MD @WBlackDoc from U Tennessee

Catch up on the episode here:
cardionerds.com/58-case-report…

2/ Pt was Dx'ed with constrictive pericarditis (CP) which is often a dreaded topic 😱

Fear not! Let's break it down & focus on the echo findings of CP.

👉🏽👉🏽 💯 tweetorial on RCM by @CBlumenthal2 & 🌟 #CNCR case of hereditary RCM from @DukeCardFellows

https://twitter.com/CBlumenthal2/status/1299288219410862081

3/ First, let's review basic anatomy :

✅Pericardium contains all ❤️ chambers
✅Cardiac chambers are affected by changes in intrathoracic pressure b/c same pressure changes are transmitted inside pericardium
✅ Pulm vasculature, SVC/IVC are external to pericardium

4/During Inspiration without CP

✅Intrathoracic pressure ⬇
✅Intrapericardial pressure also ⬇
✅blood return to RA ⬆

The opposite is true with expiration

5/ In constriction, pericardium = calcified

✅ ⬇️ intrathoracic P 🚫 transmitted inside pericardium
✅but 🫁 vessels sense the ⬇ P
✅mitral inflow ⬇ in inspiration 2/2 ⬇driving P

Opposite is true for expiration

👆🏽called intrathoracic-intracardiac pressure dissociation

6/ Calcified pericardium -> compromised diastolic filling

This is reflected on the TTE as…

✅Rapid early ventricular filling = ⬆️ E wave velocity
✅Abrupt cessation due to stiff pericardium = ⬇️ A wave velocity
✅Increased E/A ratio >1

7/ Calcified pericardium also 🚫 accommodate the change in ventricular volume with respiration

So…

✅Inspiration -> ⬆️ blood to RA/RV -> interventricular septum is pushed towards Left 👈🏽
✅Expiration -> ⬆️ blood to LA/LV-> interventricular septum is pushed towards Right 👉🏽

8/ ☝️☝️☝️This leads to interventricular interdependence and is seen as respirophasic septal shift on TTE

👇🏽👇🏽 Case TTE: Apical 4 chamber view showing abnormal septal motion due to interventricular dependence

9/ Interventricular dependence also leads to:

1⃣Respirophasic Variation in mitral and tricuspid inflow

✅ Inspiration -> septum shifts towards right -> ⬇️ in mitral E-wave velocity and ⬆️ in tricuspid E-wave velocity

Opposite happens during expiration

10/ Interventricular dependence also leads to:

2⃣hepatic vein diastolic flow reversal

✅ Septum is pushed towards right during expiration -> ⏬⏬ RV filling -> flow reversal back to IVC and hepatic veins

11/ Another finding on doppler is annulus reversus

Normally, lateral wall moves more freely than medial so lateral e' > medial e' velocity

In CP, medial e' > lateral e' velocity b/c the lateral wall movement is more restricted in CP

This is called ‼️ annulus reversus ‼️

12/ That was a lot! Let's recap!

The characteristics of CP on echo include:

1⃣⬆️ E/A ratio
2⃣Variation in mitral and tricuspid inflow
3⃣Respirophasic septal shift
4⃣Hepatic vein diastolic flow reversal
5⃣Annulus reversus

❓Which of the following is most specific for CP?

13/ #drumroll

🥁
🥁
🥁

You are right! 👏👏🙌🙌

Hepatic vein diastolic flow reversal has the highest specificity of 88% with a PPV of 96%

And respirophasic septal shift is most SENSITIVE.

14/ Alright! Hope now CP is easier to understand

👀 for a future tweetorial by @varghes_bibin differentiating constriction vs. restriction

Thanks again to U Tennessee for a Glowing star case and
@cardionerds & @karanpdesai for continued mentorship and dedication to #MedEd