2. Other impulses e.g. RV along LSB (e.g. ASD, PR) 3. Overall precordial activity; normal, quiet, hyperdynamic 4. Thrill; “palpable murmur”, correlates with areas of maximum intensity of audible murmurs
Cardiac auscultation A. Use bell to detect low-frequency sounds, diaphragm for high-frequency ones (do not need pediatric stethoscope) B. Heart sounds 1. First heart sound (S1) = closure of AV valves heard best at apex/LLSB; may be split at puberty 2. Second heart sound (S2) = closure of aortic and pulmonic valves heard best at ULSB a. Normal/ physiologic splitting; Increases with inspiration, decreases with expiration (greater negative intra-thoracic pressure during inspiration increases system venous return & right heart stroke volume-> prolongs RV ejection time) b. Abnormal splitting i. Wide and fixed; conditions which prolong RV ejection time - Volume overload (e.g., ASD) - Pressure overload (e.g. PS) - Delay in electrical activation (e.g. RBBB) ii. Narrow; seen in conditions with early pulmonary valve closure (e.g. pulmonary hypertension (PAH)) iii. Single (e.g. absent semilunar valve, severe PAH) iv. Paradoxical; seen in conditions in which LV ejection is delayed (e.g. LBBB, severe AS) c. Intensity of P2 (pulmonic component of S2) i. Increased in pulmonary hypertension ii. Decreased with decreased diastolic pressure d. Third heart sound (S3) = low frequency early diastolic sound related to rapid ventricular i. filling heard best at apex/ LLSB; may be normal in children/ athletes 3. Fourth heart sound (S4) = low frequency sound in late diastole secondary to atrial contraction; always pathologic 4. Gallop = triple or quadruple rhythm; with S3 or S4 or both C. Extra heart sounds 1. Systolic ejection click; follows S1 and occurs at onset of ventricular contraction a. Pulmonic; louder with expiration; heard best at 2nd-3rd ICS LSB b. Aortic; does not change with respiration; heard best at 2nd ICS RSB, mid LSB or apex 2. Mid-systolic click; heard best at apex (e.g. MVP) 3. Pericardial friction rub; grating to and fro sounds heard best with 7
