What is the murmur associated with Hypertrophic Obstructive Cardiomyopathy (HOCM)?

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Last updated: February 19, 2025View editorial policy

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From the Guidelines

The HOCM (Hypertrophic Obstructive Cardiomyopathy) murmur is typically a harsh crescendo-decrescendo systolic murmur best heard at the lower left sternal border [ 1 ]. It is usually louder with maneuvers that decrease ventricular volume, such as standing or Valsalva maneuver, and softer with maneuvers that increase ventricular volume, such as squatting [ 1 ].

Characteristics of the Murmur

  • The murmur is caused by systolic anterior motion (SAM) of the mitral valve [ 1 ]
  • It is a dynamic obstruction that can be provoked by maneuvers that decrease ventricular volume [ 1 ]
  • The murmur can be heard at rest or with provocative maneuvers such as Valsalva or standing [ 1 ]

Clinical Significance

  • The presence of a harsh crescendo-decrescendo systolic murmur is a key diagnostic feature of HOCM [ 1 ]
  • The murmur is often associated with left ventricular outflow tract obstruction (LVOTO) [ 1 ]
  • Accurate diagnosis and management of HOCM are crucial to prevent complications and improve outcomes [ 1 ]

From the Research

Hypertrophic Obstructive Cardiomyopathy (HOCM) Murmur

The murmur associated with Hypertrophic Obstructive Cardiomyopathy (HOCM) is not explicitly described in the provided studies. However, the studies discuss the characteristics and treatment of HOCM:

  • HOCM is a condition where a left ventricular outflow tract (LVOT) gradient is present at rest or during provocation, such as with Valsalva maneuver or exercise 2.
  • The main symptoms of HOCM include dyspnea on exertion, syncope, and in severe cases, subsequent development of heart failure symptoms with end-stage heart failure 3.
  • The primary goal of any surgical technique for HOCM is to relieve LVOT obstruction, avoid the occurrence and/or recurrence of systolic anterior movement (SAM) of the anterior mitral leaflet (AML), and reduce mitral valve (MV) regurgitation if present 3.

Characteristics of HOCM

Some key characteristics of HOCM include:

  • Dynamic left ventricular outflow tract obstruction and symptoms of dyspnea, angina, and syncope 4.
  • Basal obstruction with systolic anterior motion (SAM) treated by transaortic myectomy 5.
  • Thickening of the myocardium, which is a common primary myocardial disease with a prevalence of 1:500 6.

Treatment of HOCM

Treatment options for HOCM include:

  • Medical therapy with β-blockers and calcium antagonists as the initial therapy for symptomatic patients with obstruction 4, 6.
  • Septal reduction therapy, either surgical septal myectomy or alcohol septal ablation, for patients with continued severe symptoms unresponsive to medical therapy 4, 5.
  • Extended left ventricular septal myectomy as the procedure of choice if medical treatment is unsuccessful or intolerable 5.

References

Guideline

Guideline Directed Topic Overview

Dr.Oracle Medical Advisory Board & Editors, 2025

Research

Medical, surgical and interventional management of hypertrophic cardiomyopathy with obstruction.

Current treatment options in cardiovascular medicine, 2012

Research

Hypertrophic obstructive cardiomyopathy: the Mayo Clinic experience.

Annals of cardiothoracic surgery, 2017

Research

The Diagnosis and Treatment of Hypertrophic Cardiomyopathy.

Deutsches Arzteblatt international, 2024

Professional Medical Disclaimer

This information is intended for healthcare professionals. Any medical decision-making should rely on clinical judgment and independently verified information. The content provided herein does not replace professional discretion and should be considered supplementary to established clinical guidelines. Healthcare providers should verify all information against primary literature and current practice standards before application in patient care. Dr.Oracle assumes no liability for clinical decisions based on this content.

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