Cardiovascular System Abnormal Findings II: Auscultation

An S3 gallop is an early diastolic sound that suggests heart failure and volume overload. It is best heard using the stethoscope bell at the apex in the fifth intercostal space at the midclavicular line, with the patient lying on their left side. This abnormal sound indicates the ventricle is filling too rapidly due to weakened cardiac function.

An S4 gallop is a late diastolic sound associated with atrial contraction against a stiff ventricle, commonly found in hypertension and aortic stenosis. Unlike the S3 gallop indicating volume overload, the S4 reflects decreased ventricular compliance. Both are heard at the apex with the patient in left lateral position, but they occur at different points in diastole.

A mid-systolic click is associated with mitral valve prolapse, where the valve leaflets bulge abnormally into the left atrium during systole. This click is often followed by a late systolic murmur and is best heard at the apex in the fifth intercostal space at the midclavicular line. The sound reflects the sudden tensioning of the valve leaflets and chordae tendinae.

Aortic stenosis produces a rough, harsh systolic murmur most audible at the right upper edge of the sternum in the second intercostal space, extending toward the carotid arteries. This murmur occurs between S1 and S2 due to turbulent blood flow through a narrowed aortic valve. The radiation to the carotids helps distinguish it from other systolic murmurs.

Mitral regurgitation causes a high-pitched, blowing systolic murmur best heard at the apex in the fifth intercostal space at the midclavicular line, radiating to the axilla. This murmur results from blood flowing backward into the left atrium during ventricular contraction. The high pitch and radiation pattern help clinicians identify this specific valve dysfunction.

A continuous murmur is heard throughout the entire cardiac cycle, spanning from systole into diastole without interruption. Patent ductus arteriosus produces a continuous, machine-like murmur best heard at the left infraclavicular area in the second intercostal space. Unlike systolic or diastolic murmurs occurring between specific heart sounds, continuous murmurs indicate persistent abnormal blood flow.

An opening snap is a high-frequency sound occurring shortly after S2, typically associated with mitral stenosis. It is best heard at the apex and indicates the sudden opening of a stiff, narrowed mitral valve. This abnormal sound reflects the abrupt cessation of valve opening as it reaches its maximum excursion during early diastole.