From the Guidelines
HCOM and HCM are terms that refer to heart conditions where the heart muscle is abnormally thickened, with HCOM being a specific type of HCM where the thickened muscle obstructs blood flow, particularly in the Left Ventricular Outflow Tract (LVOT). The management of these conditions, especially in relation to LVOT obstruction, is critical for preventing complications such as heart failure and improving quality of life. According to the most recent guidelines, including the 2024 AHA/ACC/ACS/ASNC/HRS/SCA/SCCT/SCMR/SVM guideline for perioperative cardiovascular management for noncardiac surgery 1, continuing beta blockers and/or nondihydropyridine calcium channel blockers without interruption in the perioperative period is recommended to manage patients with Hypertrophic Cardiomyopathy (HCM) and prevent worsening of LVOT obstruction. Key considerations in managing patients with HCM include:
- Avoiding hypovolemia and reduced preload, which can worsen LVOT obstruction
- Avoiding hypotension and reduced afterload, which can also worsen LVOT obstruction
- Avoiding tachycardia to ensure adequate LV filling
- Prioritizing intravenous fluid administration to correct hypovolemia if hypotension develops
- Using alpha-agonists, such as phenylephrine or vasopressin, rather than beta-agonists, which can worsen LVOT obstruction The 2020 AHA/ACC guideline for the diagnosis and treatment of patients with hypertrophic cardiomyopathy 1 provides further insight into the diagnosis and treatment of HCM, including the role of LVOT obstruction and the importance of monitoring disease progression with echocardiography. In terms of specific management strategies, the use of beta-blockers, calcium channel blockers, and disopyramide, as well as procedural interventions like septal myectomy or alcohol septal ablation in severe cases, may be considered 1. Overall, the goal of management is to reduce symptoms, prevent complications, and improve quality of life for patients with HCM and LVOT obstruction.
From the Research
HCM vs HOCM vs LVOT
- HCM (Hypertrophic Cardiomyopathy) is a primary, usually familial, disorder of heart muscle characterized by muscular hypertrophy without recognized cause that encroaches on the ventricular chamber, reducing chamber area and volume 2.
- HOCM (Hypertrophic Obstructive Cardiomyopathy) is a subtype of HCM, occurring in roughly 25% of cases, where there is associated obstruction to left ventricular outflow 2.
- LVOT (Left Ventricular Outflow Tract) obstruction is a common condition in HCM, which can be dynamic or latent, and is associated with symptoms of heart failure and increased risk of sudden cardiac death 3.
Clinical Characteristics and Outcomes
- Patients with latent LVOT obstruction have milder left ventricular hypertrophy but similarly impaired functional capacity compared to those with resting obstruction 4.
- Septal myectomy is an effective treatment for patients with HCM and LVOT obstruction, improving functional capacity and symptoms 4.
- Alcohol septal ablation is also a treatment option for patients with HOCM, but has higher chances for intracardiac device implantation and residual obstruction compared to septal myectomy 3.
Management Implications
- Patients with obstructive HCM should be treated at experienced centers, and decisions regarding surgical versus noninvasive therapies need to be individualized based on functional status, comorbidities, local expertise, and patient preference 2, 3.
- A new class of drugs that inhibit cardiac myosin activity is available for patients with obstructive HCM, and the correct clinical-therapeutic classification of affected patients becomes of fundamental importance for the cardiologist 5.