Does Atrial Fibrillation (AF) decrease presystolic accentuation in Mitral Stenosis (MS)?

From the Guidelines

Atrial fibrillation does indeed decrease or eliminate presystolic accentuation in mitral stenosis. In normal mitral stenosis with sinus rhythm, there is a characteristic presystolic accentuation of the diastolic murmur that occurs just before S1. This accentuation happens because of atrial contraction, which forces additional blood through the stenotic mitral valve at the end of diastole, creating increased turbulence and a louder murmur component. When atrial fibrillation develops, the organized atrial contraction is lost and replaced by chaotic, ineffective atrial activity. Without the coordinated atrial kick, the presystolic component of the murmur disappears. This loss of presystolic accentuation is an important auscultatory finding that can help clinicians recognize when a patient with mitral stenosis has developed atrial fibrillation. The remaining diastolic murmur in mitral stenosis with atrial fibrillation typically has a more uniform intensity throughout diastole, often described as a rumbling quality, and varies in duration with the length of diastole (louder after longer R-R intervals due to increased filling time) 1.

Key Points to Consider

• The development of atrial fibrillation in patients with mitral stenosis is a significant clinical event that can impact the management and prognosis of the disease 1.
• The loss of presystolic accentuation in the diastolic murmur is a key auscultatory finding that can help clinicians diagnose atrial fibrillation in patients with mitral stenosis.
• The management of atrial fibrillation in patients with mitral stenosis typically involves anticoagulation therapy to prevent thromboembolic events, as well as rate or rhythm control to improve symptoms and quality of life 1.
• The choice of anticoagulant therapy, such as warfarin or direct oral anticoagulants, depends on the individual patient's risk factors and clinical characteristics 1.

Clinical Implications

• Clinicians should be aware of the potential for atrial fibrillation to develop in patients with mitral stenosis, and should monitor these patients closely for signs and symptoms of atrial fibrillation.
• The diagnosis of atrial fibrillation in patients with mitral stenosis can be made using a combination of clinical, electrocardiographic, and echocardiographic findings.
• The management of atrial fibrillation in patients with mitral stenosis should be individualized based on the patient's underlying clinical characteristics and risk factors.

From the Research

Atrial Fibrillation and Presystolic Accentuation in Mitral Stenosis

• The relationship between atrial fibrillation (AF) and presystolic accentuation in mitral stenosis (MS) is complex and influenced by various factors, including the dynamics of left ventricular diastolic pressure 2.
• In patients with MS, AF can lead to increased heart failure, larger left atria, and more severe coronary artery narrowing compared to those with sinus rhythm 3.
• The presence of AF in patients undergoing mitral valve repair or replacement may be associated with increased mortality and morbidity, and concomitant surgical treatment of AF during mitral surgery has become a commonly performed procedure 4.
• The risk of stroke is significant in patients with AF and MS, and anticoagulation therapy is mandatory, although the use of direct anticoagulants in these patients is still being studied 5.
• Regarding the specific question of whether AF decreases presystolic accentuation in MS, there is evidence to suggest that AF can affect the dynamics of left ventricular diastolic pressure, which may in turn influence presystolic accentuation 2. However, the direct impact of AF on presystolic accentuation in MS is not clearly established in the available studies.

Key Findings

• AF is frequent in patients with rheumatic MS and worsens the haemodynamic tolerance of MS 6.
• The occurrence of AF increases with age and is associated with more severe symptoms and larger left atria 3, 5.
• Concomitant surgical treatment of AF during mitral surgery may improve outcomes for patients 4.
• Anticoagulation therapy is essential for patients with AF and MS, but the optimal approach is still being studied 5.