Heart Murmur Overview

Introduction

By auscultating the heart you gain an understanding of cardiac rate and rhythm, condition of the valves and possible anatomical abnormalities such as congenital defects.

Timing and Cadence

Our lessons often describe heart murmur timing within a cardiac cycle. Systolic murmurs occur between the first heart sound (S1) and the second heart sound (S2). Diastolic murmurs occur between S2 and S1. In addition, timing is used to describe when murmurs occur within systole or diastole. For example, early systolic, mid-systolic or late systolic. See our courses on Systolic and Diastolic Murmurs for more information including audio recordings, waveforms and animations.

Cardiac Auscultation Locations

Cardiac auscultation is performed systematically over five locations on the anterior chest wall. Use the stethoscope's diaphragm, switching to the bell to hear lower pitched sounds.

auscultation location areas
aortic valve auscultation location area Aortic Valve Area Second right intercostal space (ICS), right sternal border
pulmonic valve auscultation location area Pulmonic Valve Area Second left intercostal space (ICS), left sternal border
Erb's Point  auscultation location area Erb's Point Third left ICS, left sternal border
tricuspid valve auscultation location area Tricuspid Valve Area Fourth left ICS, left sternal border
mitral valve auscultation location area Mitral Valve Area Fifth ICS, left mid-clavicular line














Duration

Heart murmur duration refers to the portion of systole or diastole that the murmur occupies. Terms used include short and long. Murmurs lasting throughout systole are referred to as holosystolic or pansystolic.

Pitch

Evaluation of the heart murmur's pitch should be made by classifying the pitch (frequency) as low, medium or high. The stethoscope's bell can be helpful with low pitched sounds while the diaphragm is used for medium or high pitched sounds.

Shape

A heart murmur can described by the sound's shape. Common classifications include crescendo (increasing intensity), decrescendo (decreasing intensity), crescendo-decrescendo (increasing then immediate decreasing intensity). Crescendo-decrescendo is also called diamond shaped. Rectangular, also termed plateau indicates a heart murmur of constant intensity.

Most of our lessons include a waveform with a moving cursor synchronized to the murmur audio. Many users find that the visual depiction of the murmur sounds is a useful educational tool.

heart murmur example diamond shape heart murmurs with decrescendo


Tonal Quality

Listen for additional aspects of the murmur's sounds. Heart murmurs may have qualities that can be noted as musical, harsh, blowing, booming, sharp or dull.

Respiration and Patient Position

Respiration or patient position can influence murmur intensity as well as heart sound splitting. These factors will be described within the heart sound lessons. Generally speaking, murmurs increasing with expiration originate with left side (aortic or mitral) valves, while murmurs increasing in intensity with inspiration originate with tricuspid or pulmonary valves.

Within each lesson, the author provides an sketch of the patient's position during auscultation, such as supine, left lateral decubitus, squatting or sitting.


Heart Murmur Courses

The following free online courses provide text, audio, dynamic waveforms and animated cardiac videos for many heart murmurs.

Systolic Murmurs
Diastolic Murmurs
Complex Conditions
Congenital Abnormalities
Cardiac Conditions Associated with Sudden Death
Auscultation in Primary Care