Heart Sounds and Murmurs — Physiology MCQ — NEET PG Practice Question | NEETPGAI
Heart Sounds and Murmurs — Physiology
easy
heart-pulse Physiology
During a routine cardiac auscultation workshop, a cardiologist demonstrates the most common site of origin for an innocent (physiologic) systolic murmur in children. Which anatomical location is most frequently associated with this murmur?
A. Apex of the heart (mitral area)
B. Right sternal border (aortic area)
C. Left infraclavicular region
D. Left sternal border (pulmonary area)
Explanation
Innocent Systolic Murmurs in Children
Key Point
The most common site of an innocent (physiologic) systolic murmur in children is the left sternal border in the pulmonary area, arising from increased flow across a normal pulmonary valve.
Pathophysiology of Innocent Murmurs
Innocent murmurs result from:
1.
Increased blood flow velocity through a normal valve (fever, anemia, hyperthyroidism, pregnancy)
2.
Turbulent flow in the pulmonary artery or aorta due to normal anatomical variations
3.
Absence of structural cardiac disease
The pulmonary area murmur is the most common because:
The pulmonary circulation is a low-resistance system prone to flow-related murmurs
Pulmonary valve area is the most frequent site of innocent flow murmurs
These murmurs are typically grade 1–2/6, soft, and early-to-midsystolic
Classification of Innocent Murmurs
Table
Type
Location
Characteristics
Frequency
Pulmonary flow murmur
Left sternal border (pulmonary area)
Early-midsystolic, soft, no radiation
Most common
Aortic flow murmur
Right sternal border
Midsystolic, ejection quality
Common
Vibratory murmur (Still's)
Left lower sternal border
Musical, vibratory quality
Common in children
Venous hum
Infraclavicular region
Continuous, diastolic component
Less common
Clinical Pearl
Innocent murmurs are characterized by:
No associated cardiac symptoms
Normal S₂ splitting (physiologic)
No diastolic component
Absence of thrills or heaves
Normal echocardiography
High-YieldNEET PG
The pulmonary area murmur is the single most common innocent murmur in children and is a frequent NEET PG examination topic. Recognition of innocent murmurs prevents unnecessary investigations and parental anxiety.
