The nurse auscultates the first heart sound, interpreting this sound as occurring:

Physiological splitting of S2 occurs when the aortic (A2) and pulmonic (P2) components of the second heart sound are heard as two distinct sounds during inspiration. This is a normal finding in healthy children and adults, caused by increased venous return during inspiration, which delays closure of the pulmonic valve.

Rationale for correct answer:

D. Document the findings as a normal finding: Physiological splitting is most prominent during deep inspiration and is considered normal, especially in children, adolescents, and young adults. No intervention or provider notification is required unless other abnormal findings are present such as cyanosis, murmurs, or signs of heart failure. Accurate documentation ensures continuity of care and reflects the child’s normal cardiac physiology.

Rationale for incorrect answers:

A. Notify the provider of suspected atrial-septal defect (ASD): ASD can cause fixed splitting of S2, which is present in both inspiration and expiration. Physiological splitting is variable with respiration and does not indicate a septal defect.

B. Notify the provider of suspected pulmonary stenosis: Pulmonary stenosis may produce a loud systolic ejection murmur with fixed splitting, not normal physiological splitting. The described finding does not suggest pathology.

C. Follow institutional policy for initiating an emergency response: This is unnecessary because physiological splitting of S2 is a normal, nonemergent finding.

Test-taking strategy:

• Distinguish physiological vs. pathological splitting:
  • Physiological splitting: occurs only with inspiration, varies with respiration, normal in children.
  • Pathological splitting: fixed or paradoxical, may indicate ASD, bundle branch block, or pulmonary stenosis.
• If the split changes with breathing and no other abnormalities are present, it is normal.

Take home points

• Physiological splitting of S2 is a normal variation in children and adults during deep inspiration.
• Documenting normal findings is appropriate; no emergency or provider notification is required.
• Fixed or paradoxical splitting, loud murmurs, or other abnormal signs should prompt further evaluation.
• Understanding normal cardiac sounds prevents unnecessary interventions and anxiety.

Heart murmurs are extra sounds, like whooshing or swishing, heard during a heartbeat, caused by turbulent blood flow through the heart or its valves. They can be harmless (“innocent”) or signal underlying heart problems such as valve defects or congenital heart disease. Heart murmurs are graded on a scale from 1 to 6 based on their loudness, audibility, and associated physical findings.

Rationale for correct answer:

B. A grade 1 murmur is very faint, requiring focused auscultation. It is softer than the normal S1 and S2 sounds. Often, these murmurs are innocent or functional and not indicative of significant heart disease.

Rationale for incorrect answers:

A. A murmur that is equal to the heart sounds describes a grade 3 murmur, not grade A. Grade 1 is softer, not equal in intensity.

C. This describes grade 6 murmurs which can be heard with the naked ear.

D. A precordial thrill indicates a grade 4 or higher murmur, which is louder and more significant than grade A.

Test-taking strategy:

• Recall the Levine scale for murmur grading:
  • Grade 1: Barely audible; softer than the normal heart sounds; heard only with careful auscultation in a quiet room.
  • Grade 2: Soft but easily heard immediately.
  • Grade 3: Loud murmur, comparable to heart sounds.
  • Grade 4: Loud murmur with a palpable thrill.
  • Grade 5: Very loud, heard with stethoscope partially off the chest, with thrill.
  • Grade 6: Extremely loud, heard with stethoscope off the chest, with thrill.
• Focus on descriptive words like “soft,” “faint,” or “palpable thrill” to differentiate grades.

Take home points

• Grade 1 murmur is very faint, softer than heart sounds, requires careful auscultation.
• Murmur grading helps determine clinical significance and guides further evaluation.
• Thrills and loud murmurs suggest more severe cardiac pathology, while grade 1 murmurs are often innocent in children.