Which of the following cardiac conditions does a fourth heart sound (s4) indicate?

An S4 heart sound is a low-pitched sound that may indicate the presence of an underlying health condition, often one affecting the left ventricle.

During an exam, doctors, nurses, and other technicians will listen to a person’s heartbeat with a stethoscope that they place against the chest.

A person’s heart typically makes two noises that correspond with the valves opening and closing and the movement of blood through the heart. The sounds come from the vibrating structures in the heart. In general, the more turbulent the blood flow, the stronger the vibrations and the louder the heart sounds.

There are four names for the noises that doctors use to describe heart sounds. The S1 and S2 sounds are typical heart sounds, but the S3 and S4 sounds may indicate atypical sounds of this organ.

The S4 sound, typically audible before the S1 sound, occurs when the atria have difficulty pushing blood into the ventricles, often due to stiffness.

This article reviews what the S4 sound is, what conditions it can indicate, their possible treatments, and more.

As the heart pumps, it makes sounds that doctors, nurses, and other medical professionals listen for. Healthcare professionals number these sounds from S1 to S4.

The S4 sound, also known as the atrial sound or S4 gallop, features a low pitch. It is one of two heart sounds, S3 being the other, indicating a potential problem with the heart. S4 sounds are generally atypical, indicating the presence of a pathological condition.

The S4 sound occurs right before the first sound of the heart (S1) toward the end of the diastole. Diastole is the part of the heart cycle where it relaxes and fills with blood. The systole part, where the heart pushes or pumps the blood out, immediately follows it.

The S4 sound occurs as a result of resistance in pumping blood from the atria into the left ventricle due to stiffness. The difficulty in pushing the blood creates a turbulent flow that doctors can listen for.

Several underlying conditions may cause the ventricles to become stiff, including hypertension, or high blood pressure, and obstructions, such as aortic stenosis, which lead to ventricular wall thickening.

Doctors listen for the S4 sound because it often indicates an issue with the heart. According to experts, diastolic sounds — S3 and S4 — present a concern for doctors since all but a few cases of S3 sounds indicate the presence of a pathological condition.

The presence of S4 sounds may indicate an issue with the ventricles in a person’s heart, such as left ventricular hypertrophy, which refers to the thickening of the ventricle.

The presence of an S4 gallop often indicates the left ventricle has stiffened. Several conditions can lead to the presence of the S4 sound, including:

• hypertrophic cardiomyopathy, a disease where the heart muscle thickens
• hypertension, which refers to high blood pressure
• aortic stenosis, which is where the aortic valve narrows
• ischemic cardiomyopathy, which involves the enlargement of the left ventricle that impedes the pumping of blood

S4 is one of four main potential sounds the heart makes as it pumps.

S1 and S2 sounds occur in everyone and are high-frequency sounds the heart makes. Doctors and medical professionals often refer to them as “lub” and “dub.”

However, some people may have a third (S3) and fourth (S4) sound. An S3 can occur in healthy individuals, such as athletes and children, but it can also indicate an underlying health condition, such as an early sign of heart failure.

Treatments for S4 sounds in the heart will vary depending on the exact underlying cause. A person should work with their doctor to determine what is causing the sound to determine the best treatment option for them.

For hypertension, or high blood pressure, a doctor will likely recommend a combination of medication and lifestyle changes. Many of the changes may help with other conditions that also affect the heart.

Some lifestyle changes a doctor may recommend include:

• limiting alcohol
• increasing daily activity or exercise
• eating a nutritious diet
• maintaining a moderate weight
• getting sufficient quality sleep
• learning to manage stress
• quitting smoking, if applicable

Medications for blood pressure include:

• angiotensin converting enzyme inhibitors
• diuretics
• beta-blockers
• calcium channel blockers
• angiotensin II receptor blockers

For mild cases of aortic stenosis, a doctor may recommend watchful waiting. In more severe cases, they may recommend aortic valve replacement.

If a person has cardiomyopathy, a doctor will likely recommend changes to their lifestyle and using specific heart medications.

In some cases, a doctor may recommend surgical interventions, which can include using a pacemaker and total heart replacement.

An S4 sound usually indicates an underlying problem with the heart. A person should work with their doctor to determine the cause and treat the underlying condition.

A person’s outlook will depend on several factors, including the severity of the underlying condition, their response to treatment, age, and overall health.

Treatment and lifestyle changes should help improve the condition, but a doctor can best determine someone’s overall outlook.

An S4 heart sound indicates an underlying problem is occurring in the heart. A person’s doctor will likely want to run tests to figure out the exact cause and treat the underlying condition.

Treatments may include medications to help treat high blood pressure, lifestyle changes, and, in more severe cases, surgical intervention.