How to decrease the intensity of a murmur in a patient with Hypertrophic Cardiomyopathy (HCM)?

From the Guidelines

To decrease the intensity of a murmur in a patient with HCM, septal myectomy is the most effective treatment, as it can substantially reduce the basal outflow gradient and mitral regurgitation, and restore normal LV systolic and end-diastolic pressures 1.

Medical Management

Before considering surgical options, medical management with beta-blockers or non-dihydropyridine calcium channel blockers can be attempted to reduce the intensity of the murmur. However, these treatments may not be as effective as septal myectomy in reducing the outflow gradient and improving symptoms 1.

Septal Myectomy

Septal myectomy is a surgical procedure that involves the resection of a portion of the septal wall to reduce the outflow gradient and improve symptoms. This procedure has been shown to be effective in reducing the intensity of the murmur and improving symptoms in patients with HCM, with persistent, long-lasting improvement in disabling symptoms and exercise capacity 1.

Patient Selection

The decision to perform septal myectomy should be made on a case-by-case basis, taking into account the severity of symptoms, the presence of outflow obstruction, and the patient's overall health status. Patients with severe refractory symptoms and marked outflow gradients elicited by exercise may benefit from myectomy, even if they are asymptomatic at rest 1.

Post-Operative Care

After septal myectomy, patients should be monitored closely for any signs of complications, such as bleeding or infection. They should also be advised to avoid activities that involve Valsalva maneuvers, as these can worsen obstruction, and to maintain adequate hydration to prevent dehydration 1.

From the FDA Drug Label

Patients with hypertrophic cardiomyopathy (IHSS): In 120 patients with hypertrophic cardiomyopathy (most of them refractory or intolerant to propranolol) who received therapy with verapamil at doses up to 720 mg/day, a variety of serious adverse effects were seen The answer to decreasing the intensity of murmur in a patient with HCM is not directly addressed in the provided drug label. Key points:

• The label discusses the use of verapamil in patients with hypertrophic cardiomyopathy (HCM), but does not provide information on decreasing murmur intensity.
• The label reports on adverse effects and dosage information, but does not address the specific question of murmur intensity reduction 2.

From the Research

Decreasing Murmur Intensity in HCM Patients

To decrease the intensity of murmur in a patient with Hypertrophic Cardiomyopathy (HCM), several treatment options can be considered:

• Medication:
  • Beta-blockers such as metoprolol 3 have been shown to reduce left ventricular outflow tract (LVOT) gradients and improve symptoms in patients with obstructive HCM.
  • Verapamil 4 can also be effective in reducing LVOT gradients and improving exercise capacity, although its effects may be more variable.
  • Disopyramide 5 can be added to patients who do not respond to first-line therapy with beta-blockers or verapamil.
• Surgical Intervention:
  • Septal myectomy 5, 6 is a surgical procedure that can relieve obstruction and reduce murmur intensity in patients with severe refractory symptoms.
  • Alcohol septal ablation 5, 6 is an alternative to surgery for selected patients.
• Other Considerations:
  • Bedside maneuvers such as the Valsalva maneuver, squatting-to-standing action, and handgrip 7 can help diagnose and assess the severity of HCM, but may not directly reduce murmur intensity.

Treatment Goals

The goal of treatment is to reduce the intensity of the murmur, relieve symptoms, and improve quality of life for patients with HCM. Treatment strategies should be individualized based on patient selection, symptom severity, and response to therapy 5, 6.