What are the clinical findings of acute severe mitral regurgitation (MR) on auscultation?

From the Guidelines

Auscultation of acute severe mitral regurgitation may reveal a soft or even absent systolic murmur due to rapid equalization of pressures between the left ventricle and left atrium, and is often accompanied by signs of heart failure and pulmonary edema. The clinical findings of acute severe mitral regurgitation (MR) on auscultation can be subtle, and a high index of suspicion is necessary to make the diagnosis. According to the most recent and highest quality study 1, mitral regurgitation is a common form of valvular heart disease that is associated with significant morbidity and mortality, and accurate diagnosis of both mechanism and severity of MR is crucial for treatment decisions.

Key Findings

• A holosystolic murmur may be present, but its intensity does not correlate with severity in acute cases, as hemodynamic collapse can result in a deceptively soft murmur 2
• Associated findings include a hyperdynamic precordium, an S3 gallop, and possibly a soft S1 due to premature mitral valve closure
• Pulmonary examination may reveal crackles from pulmonary edema
• Signs of heart failure, including tachycardia, hypotension, jugular venous distention, and peripheral edema, should also be assessed

Diagnosis and Management

The diagnosis of acute severe mitral regurgitation is often made using a combination of clinical findings, echocardiography, and other imaging modalities. Transthoracic echocardiography (TTE) is the most commonly used imaging test for MR, but transesophageal echocardiography (TEE) may be necessary to better define morphology and MR severity 1. Prompt recognition and treatment of acute severe mitral regurgitation is crucial, as it is a medical emergency requiring immediate intervention with afterload reduction, diuretics for pulmonary edema, and often inotropic support, followed by definitive surgical repair or replacement of the valve 3, 4.

From the Research

Clinical Findings of Acute Severe Mitral Regurgitation (MR) on Auscultation

The clinical findings of acute severe mitral regurgitation (MR) on auscultation include:

• A new systolic murmur occurring in the setting of sudden development of acute congestive heart failure, hypotension, and shock 5
• S3 and S4 gallops and sinus rhythm usually are present 5
• Gross left ventricular or left atrial enlargement usually is not evident radiologically 5
• Signs and symptoms of congestive heart failure, slight left ventricular enlargement, a relatively normal left atrial size, and markedly elevated left atrial and pulmonary arterial pressures 5
• Pulmonary edema and cardiogenic shock are common in patients with MR due to acute myocardial infarction 6, 7
• Respiratory disorders and arrest can occur soon after admission 8

Auscultation Findings

Auscultation findings in acute severe MR include:

• A new systolic murmur 5, 7
• S3 and S4 gallops 5
• Sinus rhythm usually is present 5

Prognosis

The prognosis for patients with acute severe MR is poor without treatment 5, 6, 7

• Medical therapy can reverse temporarily some of the hemodynamic aberrations, but it does not influence survival or eliminate the need for surgical treatment 5
• Surgery consisting of mitral valve replacement and possibly simultaneous coronary revascularization appears to offer some hope in increasing the survival rate among these patients 5, 8, 6, 7
• Transcatheter interventions have opened a new door for management that may improve survival 7