Heart murmurs made easy pdf series#

The Levine scale for grading cardiac murmurs according to intensity.

Heard loudest on inspiration or expiration?.

Do any manoeuvres exaggerate the murmur?.

Is the murmur heard loudest using the bell or the diaphragm of the stethoscope?.

What are the characteristics of the murmur? What is the intensity (Table 1)?.

When during the cardiac cycle is the murmur heard?.

If a murmur is heard during auscultation, consider the following questions: It is important to have a structured approach to interpreting heart murmurs during a cardiovascular examination.

A Wiggers diagram showing the events of the cardiac cycle. Heart sounds and the cardiac cycle Figure 2. Therefore, S2 may not always be heard as one discrete sound but may be muffled or have two discrete sounds ( split S2). Closure of the pulmonary valve just after the aortic valve is prolonged during inspiration, or in defects which cause more blood to be pumped out of the right ventricle. The pulmonary valve may close just after the aortic valve. It marks the end of ventricular systole and the start of diastole. The second heart sound (S2) is caused by the closure of aortic and pulmonary valves. It marks the start of ventricular systole, and a peripheral pulse is felt at the same time (or shortly after) S1. The first heart sound (S1) is caused by the closure of the mitral and tricuspid valves. Normal heart sounds are caused by the closure of heart valves. 1įor more information, see the Geeky Medics guides to the cardiac cycle and electrical conduction system of the heart. The drop in pressure within the ventricle causes the aortic and pulmonary valves to close, to prevent backflow (regurgitation) of blood into the ventricles. The ventricles then begin to relax following contraction ( ventricular diastole). Blood is ejected from the ventricles during ventricular ejection phase. This phase of ventricular systole is called isovolumetric contraction.Įventually, the pressure within the ventricles exceeds the pressure in the pulmonary artery and aorta causing the pulmonary and aortic valves to open. The increased pressure causes the closure of the mitral and tricuspid valves, this prevents regurgitation of blood from the ventricles into the atria.Īt this point, the volume of blood within the ventricles remains constant as the aortic and pulmonary valves have not yet opened. Ventricular systole occurs as the ventricles contract, increasing the pressure within the ventricles. The next stage of the cycle is atrial systole, contraction of the atria to finish “filling” the ventricles with blood. The aortic and pulmonary valves are shut, which prevents an abnormal backflow of blood into the ventricles from the aorta and pulmonary artery. This allows blood to flow freely into the right ventricle and left ventricle from the atria. At this point, the mitral and tricuspid valves are open. Blood enters the right atrium (from the vena cava) and the left atrium (from the pulmonary vein). The cardiac cycle starts with the atria and ventricles in diastole. The cycle involves contraction (systole) and relaxation (diastole) of the atria and ventricles to effectively pump blood.

Heart murmurs made easy pdf series#

The cardiac cycle refers to a series of physiological events making up a single heartbeat.

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