166. CardioNerds Rounds: Challenging Cases of Hypertrophic Cardiomyopathy with Dr. Michelle Kittleson

CardioNerds Rounds Co-Chair, Dr. Karan Desai, joins Dr. Michelle Kittleson (Director of Postgraduate Education in Heart Failure and Transplantation, Director of Heart Failure Research, and Professor of Medicine at the Smidt Heart Institute at Cedars-Sinai) to discuss challenging cases of hypertrophic cardiomyopathy. As a guideline author on the 2020 ACC/AHA Hypertrophic Cardiomyopathy Guidelines, Dr. Kittleson shows us how the latest evidence informs our management of HCM patients, while sharing many #Kittlesonrules and pearls on clinical care. Come round with us today by listening to the episodes now and joining future sessions of #CardsRounds!

This episode is supported with unrestricted funding from Zoll LifeVest. A special thank you to Mitzy Applegate and Ivan Chevere for their production skills that help make CardioNerds Rounds such an amazing success. All CardioNerds content is planned, produced, and reviewed solely by CardioNerds. Case details are altered to protect patient health information. CardioNerds Rounds is co-chaired by Dr. Karan Desai and Dr. Natalie Stokes. 

Speaker disclosures: None

Cases discussed and Show Notes • References • Production Team

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Show notes - Hypertrophic Cardiomyopaty Cases

Case #1 Synopsis:

Two non-white brothers in their early 20s come to clinic to establish care. They have no cardiopulmonary symptoms, normal EKGs and normal echos, but there was a possible family history of HCM. Their mother had LV hypertrophy and underwent septal myectomy, but she could not afford genetic testing and was no longer in the patients’ lives. The path report suggested “myocyte hypertrophy without disarray or bundles of myocytes.” How would you advise these patients regarding screening and surveillance? Listen to #CardsRounds for the full details!

 Quotes from Case #1:

“Let’s take a walk down memory lane and let’s get to our evolution of understanding hypertrophic cardiomyopathy… [our understanding] follows the parable of the six blind men and the elephant. Each of the six blind man approached it from different angles, its tusk, its ear, its tail, and they all try to convince each other what an elephant is … because none of them can see the big picture.”

Dr. Kittleson on the history of HCM and coming to a unifying diagnosis

 “The next time you are sitting there mashing your teeth because you have to memorize what the HCM murmur does squat to stand, Valsalva, or handgrip … remember you are standing on the shoulder of Giants. They [Drs. Braunwald and Morrow] pioneered surgical myectomy based on physical exam and cath lab findings”

Dr. Kittleson on the physical exam guiding HCM management

Takeaways from Case #1

Before we round, we think it is important to get on the same page regarding the nomenclature around HCM.

Since the original characterization of hypertrophic cardiomyopathy (HCM) more than 60 years ago (see the Braunwald Chronicles for the origin stories!), different terms have been used to describe the disease. These include idiopathic hypertrophic subaortic stenosis, hypertrophic obstructive cardiomyopathy (HoCM), and “burnt out HCM” when heart failure develops.The 2020 guideline committee recommended a common language to avoid confusion: since left ventricular (LV) outflow tract obstruction (LVOTO) occurs in >60% of patients over time, but one-third remain non-obstructive, the recommendation is t0 call the disease state HCM with or without outflow tract obstruction.Dr. Kittleson added that when heart failure develops we should characterize the pathology as HCM with heart failure rather than “burnt out HCM.”

 Do we use HCM to describe any LV that has thick walls?

Some clinicians will use HCM to describe all disease states that can...