The nurse is auscultating the heart of a patient with congestive heart failure. The nurse hears an extra sound with a very low pitch, immediately after the second heart sound (S2). The nurse interprets this as
• S3 occurs immediately after S2. It has a very low pitch and has been described as a "gallop" or vibration. It can occur normally in people under 40 and in athletes. Later in life, it may indicate heart failure (ventricular dysfunction) and/or fluid overload.
• Incorrect: Split S2 is when the pulmonary valve closes slightly after the aortic valve. This normally occurs on inspiration, due to the increased pressure in the pulmonary circulation. It may also be caused by septal defects, pulmonary stenosis, or a right bundle branch block.
• Incorrect: A split S1 occurs when the closure of the mitral valve is slightly delayed. This is caused by a dysfunction in conduction, such as a left bundle branch block.
• Incorrect: A murmur due to aortic regurgitation has a high pitch, not very low, and is described as a decrescendo during early diastole.