Thread by @BhavyaVarma12

1/Ms. Pregs is a G1P0 woman presenting to your clinic at 28 weeks. She has a history of hypertrophic cardiomyopathy (HCM). How should we manage her pregnancy?

Get ready for a fun #CardioObstetrics tweetorial from the @Cardionerds!

2/I feel comfortable managing a pregnant patient who has HCM.

3/HCM is defined as LV wall thickness of ≥15 mm that is not explained by loading conditions (e.g., hypertension, valvular, congenital disease) or infiltrative cardiomyopathies.

Image: American Heart Assn

4/General principles of management for obstructive HCM include:

The 4⃣ Ps:

1⃣Prevent symptoms
2⃣Prevent SCD in patient
3⃣Prevent SCD in family
4⃣Prevent thromboembolism

Learn more! cardionerds.com/hypertrophic-c…

5/This includes:

♦️SCD risk stratification for the patient
♦️Genetic/family screening (including counseling mother for baby)
♦️need for AC if there is Afib regardless of CHADSVASc

6/Basic principles of preventing symptoms:
-⬆️ preload
-Avoid increases in contractility and heart rate
-Caution with aggressive diuretics and vasodilators as it can worsen LVOT gradient
-Mavacampten – another time
cardionerds.com/cardsjc-hypert… @KateAltaWilcox 🙌🏽, #HouseTaussig 💪🏽

7/Does pregnancy worsen these hemodynamics?

8/What happens in pregnancy?

-⬆️ plasma volume
-⬆️ cardiac output (trimester 1&2)
-⬆️ HR
- increased CO can counteract benefits of ⬆️ volume for LVOT obstruction

PMID: 23212678

Learn more! cardionerds.com/111-cardioobst…

9/What happens in delivery?

-500cc of autotransfusion from uterus with contractions
-⬆️ catecholamines
-⬆️ HR from blood loss, pain, stress
-expulsive efforts = ⬇️ venous return but autotransfusion = ⬆️ venous return

Overall differing effects on LVOT gradient

PM: 23212678

10/Despite the above, pregnancy is usually well tolerated in HCM due to general increase in LV size and filling.

However, some women are at higher risk! WHO classification of pregnancy risk with cardiac disease II to III

11/So who should we worry about?

Negative predictors ❤️‍🩹 for cardiac complications during pregnancy:
✴️LVEF < 40%
✴️NYHA class II or higher
✴️severe symptomatic LVOT obstruction
✴️prior arrhythmias

12/What should we do?

ESC guidelines:
♦️ WHO II follow with cardiology and TTE each trimester
♦️ WHO III monthly TTE and follow up
♦️ continue BB if taking prior to pregnancy
♦️ start BB if pt becomes dyspneic: to ⬆️diastolic filling and control a fib

PMID: 21873418

13/Which BB are safe in pregnancy?

Metoprolol and Labetolol are generally our preferred agent

However, Labetalol should be avoided in HOCM due to alpha blockade ➡️potential BP drop ‼️ ➡️less afterload

Atenolol should be avoided

14/Multi D team! 👩‍⚕️🧑‍⚕️

High risk deliveries:
♦️consider cardiac monitoring during delivery (PA cath)
♦️consider delivering with cardiac anesthesia in conjunction with OB anesthesia assistance if C-section
♦️consider expediting second stage of labor to prevent repeat valsalva

15/Overall:

🫀HCM is generally well tolerated in pregnancy but the ROPAC study shows that ~20% of the population can have non-fatal MACE occur (PM: 28934836)

🫀patients at higher risk should be identified and managed via multiD team

🫀an evolving field, we continue to learn

15/Thanks for tuning in! Huge thanks to @DrAnumMinhas and @AmitGoyalMD for helping me build this #CardioOb tweetorial from the @CardioNerds ! 😊

Let’s ask our experts:
What are your pearls with these patient populations?
@DrAnumMinhas @ErinMichos @DrMarthaGulati @DrKLindley
@BoydDamp @md_harrington @cardioPCImom @KBerlacher @annaokellymd

@drmalissawood @DrNupoorNarula @AfshanHameedMD @malamo512 @AHauspurg @GarimaVSharmaMD