What is the initial management for a patient presenting with an S3 (third heart sound)?

From the Guidelines

The initial management for a patient presenting with an S3 (third heart sound) should focus on treating the underlying heart failure, as an S3 gallop is typically a sign of volume overload and ventricular dysfunction. Begin with diuretics, particularly loop diuretics like furosemide (20-40mg IV or oral), to reduce fluid overload and relieve symptoms such as dyspnea and peripheral edema, as recommended by the European Society of Cardiology guidelines 1. Simultaneously, start guideline-directed medical therapy including an ACE inhibitor (such as lisinopril 2.5-5mg daily) or ARB if ACE inhibitor intolerant, a beta-blocker (such as carvedilol 3.125mg twice daily or metoprolol succinate 12.5-25mg daily), and consider an aldosterone antagonist (spironolactone 12.5-25mg daily) if ejection fraction is reduced below 35% 1.

Key Considerations

• Oxygen supplementation should be provided if hypoxemia is present, as indicated by the patient's symptoms and oxygen saturation levels.
• Restrict sodium intake to 2-3g daily and limit fluid intake to 1.5-2L daily to reduce volume overload.
• Bed rest with elevation of the head and legs in a cardiac chair position can help reduce preload and afterload.
• The S3 gallop occurs during early diastolic filling when blood rapidly enters a non-compliant or volume-overloaded ventricle, causing vibrations of the ventricular wall, and its resolution can serve as a useful clinical marker of treatment response 1.

Treatment Goals

• Reduce fluid overload and relieve symptoms such as dyspnea and peripheral edema.
• Improve ventricular function and reduce morbidity and mortality associated with heart failure.
• Optimize guideline-directed medical therapy to improve patient outcomes, as recommended by the European Society of Cardiology guidelines 1.

From the Research

Initial Management for S3

The initial management for a patient presenting with an S3 (third heart sound) involves several key considerations:

• Diagnosis: An S3 is highly specific for primary heart failure 2, and its detection can be useful in combination with B-type natriuretic peptide (BNP) levels to improve diagnostic accuracy in patients with dyspnea of unclear etiology 2.
• Prognosis: The presence of an S3 on admission is independently associated with adverse in-hospital outcomes, including increased risk of all-cause death and cardiac death 3.
• Treatment: The cornerstone of therapy for patients with heart failure involves left ventricular dysfunction, and includes angiotensin-converting enzyme (ACE) inhibitors and beta-blockers 4, 5.
• Additional Therapies: Other drug classes, such as angiotensin II receptor blockers (ARBs), aldosterone antagonists, and the combination of isosorbide dinitrate plus hydralazine, may provide additional morbidity and mortality benefits in patients with heart failure 4.
• Technologies: Computerized analysis of digitally recorded heart tones can aid in the detection of abnormal heart sounds, including the S3, in the emergency department setting 6.

Key Findings

• The sensitivity and specificity of an electronic S3 for primary heart failure were 34% and 93%, respectively 2.
• The presence of an S3 was associated with higher heart rate, higher serum level of B-type natriuretic peptide, and higher creatinine levels 3.
• ACE-inhibitors and beta-blockers can modify the left ventricular remodeling process, slowing disease progression and preserving contractile function 5.