When is s2 heard the loudest

Because it radiates up the aortic arch, which curves toward right, can also be heard at the right base. Pulmonic stenosis : systolic ejection murmur, heard best at the left base. Mitral insufficiency : murmur is best heard at the left apex, usually holosystolic, but in early stages of the disease may be soft and decrescendo shaped.

Its intensity is related to severity of the mitral valve disease. Tricuspid insufficiency : holosystolic murmur, loudest at the right apex. It is often accompanied by jugular pulsation. Ventricular septal defect : holosystolic murmur of low to moderate intensity, heard best at the right sternal border. A large ventricular septal defect may also cause the murmur of relative pulmonic stenosis.

Diastolic murmurs Diastolic murmurs are uncommon in dogs and cats. Continuous murmurs Continuous murmurs occur through whole cardiac cycle. Mosby Elsevier, Fuentes V. Ask the patient to breathe quietly, and then a bit more deeply. During inspiration you should hear the inspiratory splitting of S2 into A2 and P2. To the untrained ear this sounds more like a prolongation of sound rather than two distinct sounds.

In general the interval between A2 and P2 is quite short, although in some situations the patient may have a widened interval. Next, listen for splitting of S2 to disappear during expiration. To explore why an ASD results in a fixed split S2, we must consider the altered cardiac hemodynamics present, which result in a fixed delay in PV closure. During inspiration, as usual, there is an increase in venous return to the right side of the heart and thus increased flow through the PV — delaying its closure.

The alteration in a person with an ASD occurs during expiration. As the person expires, the pressure in the right atrium decreases because there is less venous return. The decreased pressure allows more blood to flow abnormally through the ASD from the high pressured left atrium to the right atrium, ultimately resulting again in increased flow through the pulmonic valve — again, delaying its closure.

The S3 sound is actually produced by the large amount of blood striking a very compliant LV. Enlarge If the LV is not overly compliant, as is in most adults, a S3 will not be loud enough to be auscultated.

A S3 can be a normal finding in children, pregnant females and well-trained athletes; however, a S4 heart sound is almost always abnormal. A S3 can be an important sign of systolic heart failure because, in this setting, the myocardium is usually overly compliant, resulting in a dilated LV; this can be seen in the image below.

Enlarge Normal LV vs. Dilated LV S3 Present. S3 is a low-pitched sound; this is helpful in distinguishing a S3 from a split S2, which is high pitched. A S3 heart sound should disappear when the diaphragm of the stethoscope is used and should be present while using the bell; the opposite is true for a split S2.

Also, the S3 sound is heard best at the cardiac apex, whereas a split S2 is best heard at the pulmonic listening post left upper sternal border. To best hear a S3, the patient should be in the left lateral decubitus position. If the LV is noncompliant, and atrial contraction forces blood through the atrioventricular valves, a S4 is produced by the blood striking the LV.

Therefore, any condition that creates a noncompliant LV will produce a S4, while any condition that creates an overly compliant LV will produce a S3, as described above. A S4 heart sound can be an important sign of diastolic HF or active ischemia and is rarely a normal finding. Diastolic HF frequently results from severe left ventricular hypertrophy, or LVH , resulting in impaired relaxation compliance of the LV. In this setting, a S4 is often heard.

Also, if an individual is actively having myocardial ischemia, adequate adenosine triphosphate cannot be synthesized to allow for the release of myosin from actin; therefore, the myocardium is not able to relax, and a S4 will be present. It is important to note that if a patient is experiencing atrial fibrillation, the atria are not contracting, and it is impossible to have a S4 heart sound. Like S3, the S4 sound is low pitched and best heard at the apex with the patient in the left lateral decubitus position.

Below is comparative information for S3 and S4. If anything abnormal is found, move the stethoscope around until the abnormality is heard most clearly. Earpieces should be angled forwards to match the direction of the practitioner's external auditory meati. Pericardial sounds are sometime best heard with the patient on hands and knees.

Auscultate the heart at various sites At the apex. At the base the part of the heart between the apex and the sternum In the aortic and pulmonary areas to the right and left of the sternum, respectively Listen for normal heart sounds: The 1 st heart sound, S1 lub , marks the beginning of systole end of systole. Related to the closure of the mitral and tricuspid valves. Loudest at the apex.