Cardiac Exam: Benchmarks

Inspect and then palpate the precordium for the the point of maximal impulse (PMI), noting its position and diameter. If you cannot feel the PMI in the supine position, ask the patient to roll to the partial left lateral decubitus position, and palpate again.

Inspect and then palpate the precordium for abnormal, sustained outward movement, called a lift or heave. If a patient has a murmur, palpate for thrills.

The normal PMI (which is palpable in only 30% of normal adults) is < 2 cm in diameter in the supine patient, and < 4 cm in the partial left lateral decubitus position. It is palpated at or medial to the mid-clavicular line in the 4th--5th intercostal space of the supine patient.

A heave or lift is a sustained, systolic outward movement of the precordium, associated with heart failure.

• A right ventricular heave or lift is best palpated at the left sternal border
• A left ventricular heave or lift is best palpated at the cardiac apex

A thrill is a vibration (like a cat purring) felt when a cardiac murmur is grade IV-VI / VI.

Listen at four basic locations using the diaphragm of the stethoscope firmly applied to bare skin in a completely quiet room:

• Cardiac apex (mitral valve area)
• Tricuspid area (left lower sternal border [LLSB])
• Pulmonic area (left 2nd ICS)
• Aortic area (right 2nd ICS)

At each location, listen first to S1 and S2, observing amplitude and splitting. Then, for several cardiac cycles, pay attention only to systole, listening for murmurs and extra sounds. Then do the same for diastole. If you hear a murmur or extra sound, “inch” your stethoscope across the precordium, noting where it is loudest and where it radiates.

Use the bell of the stethoscope lightly applied to bare skin to listen at the cardiac apex for S3, S4, and the murmur of mitral stenosis. If you suspect but don’t hear any of these, roll the patient to the partial left lateral decubitus position and listen again.

The order of closure of the heart valves is mitral & tricuspid followed by aortic & pulmonic.

S2 normally splits with inspiration, and when it does, the “dup” sound of S2 now sounds like “drup.” Splitting is best heard with the diaphragm in the pulmonic area, but can be appreciated in only about 50% of healthy adults.

A rub is a high-pitched, scratchy sound caused by pericardial inflammation. A rub is best heard along the lower left sternal border using the diaphragm of the stethoscope with the patient sitting up, leaning forward, and briefly holding the breath.

S3 and S4 best heard with the bell of the stethoscope at the cardiac apex with patient in the left lateral decubitus position. An S1 S2 followed by an S3 sounds like: “lub-dup pah” or “I be-lieve.” An S4 S1 then S2 sounds like “luh lub-dup” or “Be-lieve me.”

S3 occurs during early diastole, when blood flowing into an overfilled, non-compliant left ventricle suddenly decelerates. In patients over 40, it indicates valvular regurgitation or systolic heart failure. In young people without symptoms of heart disease, an S3 can be normal finding.

S4 is heard in late diastole, when atrial contraction pushes blood into the ventricle, and indicates the ventricle is abnormally stiff, due to hypertrophy or fibrosis. An S4 should not be present in the setting of atrial fibrillation or flutter.

Describe five characteristics of any murmur:

• Grade on a I to VI scale
• Timing - systolic or diastolic
• Quality of the sound (e.g., harsh or blowing)
• Location where it is loudest
• Radiation – listen across the precordium and in the carotids

How to grade a murmur:

• I—don’t hear it immediately; very faint
• II—heard fairly easily as soon as you start auscultating the chest
• III—seems loud
• IV—has a thrill (i.e., you can feel it when you palpate the precordium)
• V—thrill present & heard with only the edge of the stethoscope touching the chest wall
• VI—thrill present & heard with the stethoscope just above the precordium, not touching the skin

Usual characteristics of common systolic murmurs:

• Mitral regurgitation: any grade, holosystolic, blowing, loudest at apex, sometimes radiating to axilla.
• Aortic stenosis: any grade, diamond shaped, harsh, loudest at right upper sternal border, often radiating to carotids
• Flow or innocent murmur: Grade I or II/VI, early or midsystolic, loudest at left sternal border, no associated symptoms or abnormal exam findings

Diastolic murmurs are less common than systolic murmurs, and are always abnormal. The most common diastolic murmurs are aortic insufficiency and mitral stenosis.

Position the patient’s bed so that you can see the top of the internal and/or external jugular vein. Begin with the head of the bed at 30°, and adjust it up and down as necessary. An oblique light source (a penlight shone across the neck) may help you identify the veins.

The right atrium sits 5 cm below the sternal angle. Measure the vertical distance from the top of the venous pulsations in the internal jugular vein, or the blood column in the external jugular vein, to the sternal angle. Add this distance to 5 cm. This is the jugular venous pressure.

If you suspect that central venous pressure is elevated, check the abdominojugular test (also called hepatojugular reflux). Place firm pressure on the patient’s midabdomen for 10 seconds. Locate the neck veins, and observe them as you release the pressure. If JVP falls by more than 4 cm with release of pressure, the test is positive.

The normal JVP is up to 10 cm of H2O.

The clinical significance of the abdominojugular test: In normal patients, the JVP will may rise with abdominal pressure but will fall before pressure is released. When the JVP stays up with pressure then comes down with release, that is a positive test, and an accurate sign of elevated central venous pressure.

Gently palpate each carotid artery separately and assess the strength of the pulse and the briskness of the carotid artery upstroke.

Auscultate lightly with the bell of the stethoscope along each carotid artery for heart murmur radiation and/or carotid artery bruits. (Ask the patient to briefly hold their breath as you auscultate each artery in turn).

The murmur of aortic stenosis may radiate to the carotid arteries (especially the right).

The term bruit is French for “noise” or “sound.” It refers to an extra or "adventitial" sound of arterial or venous origin caused by a pathological narrowing of the blood vessel.

A carotid artery bruit in an older adult is associated with atherosclerotic vascular disease and an increased incidence of both cardiovascular and cerebrovascular events.