Pediatric Cardiovascular Assessment: Auscultation and Clinical Management

Exam Tip: Hearing Gallops To hear an $S_{3}$ or $S_{4}$, place the bell of the stethoscope lightly over the apex. The patient should be in a left lateral recumbent position. Ask the patient to exhale and temporarily suspend respiration to provide maximal silence.

Physiological Norms: Heart Rate and PMI

The Point of Maximal Impulse (PMI) and heart rate change significantly as a child grows:

The PMI is located at the 4th ICS midclavicular line in newborns and gradually moves down to the 5th ICS around age 3.

Murmurs: Innocent vs. Pathologic

Up to 80% of children exhibit innocent (functional) murmurs. These are often characterized by specific qualities, such as the "Still's murmur," which is a common innocent murmur in pediatrics.

Grading Murmurs

Murmurs are graded on a scale of I to VI based on intensity:

• Grade I: Barely audible; requires attentive listening.
• Grade II: Soft but easily audible.
• Grade III: Moderately loud; no palpable thrill.
• Grade IV: Loud; a palpable thrill is present.
• Grade V: Very loud; heard with the stethoscope barely touching the chest; thrill present.
• Grade VI: Heard without a stethoscope.

Clinical Red Flags A murmur should be treated with high suspicion if it is accompanied by:

• Oxygen saturation $<95\%$.
• Symptoms of Congestive Heart Failure (CHF).
• A palpable thrill.
• Difficulty differentiating between innocent and pathologic origins.

Congestive Heart Failure (CHF) and Shunting

Congestive heart failure in children is a progressive syndrome often caused by malformations leading to volume or pressure overload. The largest group of CHF cases results from excessive left-to-right shunting.

Recognizing CHF

Clinicians must distinguish between symptoms in infants versus older children:

Infants:

• Tachypnea and tachycardia.
• Rales or wheezing.
• Cardiomegaly and hepatomegaly.
• Periorbital edema.
• Poor feeding, tiring easily during feeds, and poor weight gain.
• Diaphoresis.

Children and Teens:

• Tachypnea and tachycardia.
• Rales or wheezing.
• Cardiomegaly and hepatomegaly.
• Orthopnea.
• Dyspnea with exertion.
• Peripheral edema and poor growth/development.

Congenital Heart Defects (CHD)

• Left-to-Right Shunts (Acyanotic): Includes Atrial Septal Defect (ASD), Ventricular Septal Defect (VSD), and Patent Ductus Arteriosus (PDA). VSDs often present with a classic loud, holosystolic murmur.
• Right-to-Left Shunts (Cyanotic): Includes Transposition of the Great Arteries (TGA) and Tetralogy of Fallot (TOF). TGA presents with immediate cyanosis, while TOF may present with "Tet spells" (hypercyanotic episodes) during crying or feeding.

Arrhythmias, Hypertension, and Syncope

Rhythm Disturbances

• Sinus Arrhythmia: A normal finding where the heart rate varies with inspiration.
• Supraventricular Tachycardia (SVT): A pathologic condition that may require adenosine or cardioversion.
• Long QT Syndrome: A genetic risk for ventricular tachycardia that requires referral to an electrophysiologist.

Hypertension (HTN)

Blood pressure should be screened annually for all children $\ge3$ years.

• Classification: Based on percentiles (e.g., Stage 1 is $\ge95$th to $99$th percentile; Stage 2 is $\ge99$th percentile).
• Secondary HTN: In children, hypertension is often secondary to other causes (e.g., renal or endocrine) if they are under age 6.

Syncope

Syncope is a transient loss of consciousness. While often benign (vasovagal), clinicians must rule out cardiovascular causes—especially if syncope occurs during or after exercise—by performing an ECG, checking orthostatic vitals, and potentially ordering an echocardiogram.

Screening for Sudden Cardiac Death (SCD)

When screening athletes or children with symptoms, a thorough history is vital to mitigate the risk of SCD.

Personal History Checklist:

• Exertional chest pain or pressure.
• Unexplained syncope (especially during/after exercise).
• Palpitations or excessive dyspnea with exertion.

Family History Checklist:

• Premature death ($<50$ years) due to heart disease.
• History of Hypertrophic Cardiomyopathy, Marfan Syndrome, or Long QT Syndrome.

Physical Exam Pro-Tip for SCD Screening To identify dynamic left ventricular outflow tract obstruction (common in Hypertrophic Cardiomyopathy), auscultate the patient in both supine and standing positions, or have them perform a Valsalva maneuver. Additionally, always check femoral pulses to exclude aortic coarctation.