omical Drawing of Human Heart Role of the Physical Examination

Proper cardiovascular assessment requires the execution of the following steps:

a) Assessment of skin color, respiratory effort, respiratory and heart rate;
b) Precordial examination by inspection and palpation;
c) Cardiac auscultation;
d) Auscultation of lung fields;
e) Abdominal palpation;
f) Palpation of peripheral pulses and
g) Measurements of blood pressure.

CARDIAC AUSCULTATION: Must be done with a clear understanding of the events of the cardiac cycle, origin and significance of the heart sounds and of murmurs. It must be done in an orderly fashion using both the diaphragm and the bell.

Cardiac auscultation is an important component of the cardiovascular assessment. To benefit most from this program the participant must understand the mechanical events of the cardiac cycle, and the mechanism of production of the cardiac sounds and of the various murmurs.

See the cardiac cycle.

I routinely start with the diaphragm from the apex (mitral valve area), move next to the second left intercostal space (pulmonic valve area), then to the second right intercostal space (aortic valve area), then to the mid precordium and xiphoid region (tricuspid valve area). I then switch to the bell and listen again at the apex and xiphoid areas for third and fourth heart sounds.

 

First identify S1.

S1 is produced by closure of the mitral and the tricuspid valve in that order, and signals the beginning of systole. We perceive S1 as a single sound.

Next identify S2.

S2 is produced by closure of the aortic (A2) and the pulmonic (P2) valves in that order and signals the beginning of diastole. The two components of S2 can be identified while the child is breathing quietly. The A2 P2 interval widens with inspiration and narrows with expiration (physiologic splitting of S2). In some normal individuals S2 may become single at the end of expiration.
Next listen for diastolic sounds: S3 and S4.
S3 is produced by turbulence within the ventricle during early diastole (rapid filling phase). S3 may be physiologic in high-output states such as anemia, fever, infections. S4 is produced by enhanced atrial systole. It is a late diastolic sound reflecting decreased ventricular distensibility, always pathologic.

Next listen for murmurs; if present, characterize them with respect to the cardiac cycle:

a) Systolic murmurs

start either with S1 (during isovolumic contraction) or just after S1 (during the ejection period). The former, called regurgitant, obliterate S1, the latter called ejection, preserve S1. Mitral valve regurgitation causes a typical regurgitant murmur while pulmonic valve stenosis causes a typical ejection murmur. Both murmurs may cover part of systole or all of systole. Regurgitant systolic murmurs end with A2. Systolic ejection murmurs produced by pulmonic valve stenosis may extend beyond A2, causing obliteration of A2.
b) Diastolic murmurs
may start right at A2 or P2 (protodiastolic), after the opening of the mitral / tricuspid valves, or late during atrial systole (diastolic rumbles). c) Continuous murmurs start after S1 and extend past A2 into diastole. Often there is no pause between cardiac cycles.
View the cardiac cycle.

Objectives | History | Physical Exam | Cardiac Cycle | Murmurs |
Criteria for Referral | Compare Sounds | Case Studies | Samples of Murmurs