Heart Murmur: Symptoms, Types, Causes and Treatment

Heart murmurs are a common clinical finding in both children and adults, often detected during routine physical examinations. While many heart murmurs are harmless, some can indicate underlying structural heart problems that require further investigation and possible intervention. Understanding the symptoms, types, causes, and treatment options for heart murmurs is essential for both healthcare providers and patients. This comprehensive guide will walk you through each aspect, combining the latest research and clinical insights.

Symptoms of Heart Murmur

A heart murmur itself is not a symptom, but rather a sound detected by a healthcare provider during auscultation (using a stethoscope). However, murmurs can be associated with a range of symptoms, especially if they result from an underlying heart condition.

Main Symptom	Description	Typical Age Group	Source(s)
Audible Murmur	Whooshing or swishing heard via stethoscope	All ages	4 5 7 9
Breathlessness	Shortness of breath, especially on exertion	Newborns, children, adults	5 9
Cyanosis	Bluish skin, especially in severe defects	Newborns, infants	5 9
Fatigue	Tiring easily, reduced activity tolerance	Children, adolescents	4 7
Poor Feeding	Difficulty feeding (infants)	Newborns, infants	5 9
Chest Pain	Uncommon, may indicate severe disease	Adolescents, adults	2

Table 1: Key Symptoms

What Are the Symptoms of a Heart Murmur?

Heart murmurs are most often discovered incidentally, as they generally do not cause direct symptoms. However, in cases where an underlying heart problem exists, additional signs may prompt further evaluation.

Audible Murmur

• The primary “symptom” is the presence of an abnormal sound heard by a clinician during a physical exam. This sound is described as a whooshing, swishing, or rumbling, reflecting turbulent blood flow in the heart or nearby vessels 4 5 7 9.

Associated Symptoms

• While many individuals with murmurs—especially children—are otherwise healthy, the presence of other symptoms may indicate a more serious heart problem:
  • Breathlessness: Difficulty breathing or rapid breathing may occur in newborns and children with certain congenital heart defects 5 9.
  • Cyanosis: A bluish tint to the lips, skin, or fingernails can suggest reduced oxygen levels in the blood, which may result from significant heart defects 5 9.
  • Fatigue & Poor Feeding: Infants may tire quickly during feeding, while older children and adults may experience reduced exercise tolerance 4 7.
  • Chest Pain or Palpitations: These are less common, but when present, especially in adolescents and adults, they prompt urgent investigation 2.

When to Seek Medical Attention

• If a heart murmur is detected along with any of the symptoms above, or if there is a family history of congenital heart disease, further testing such as echocardiography is often indicated 5 9.
• In children, a murmur with a sound level of grade 3 or louder, diastolic murmur, or one that increases with standing should be referred to a pediatric cardiologist 7.

Types of Heart Murmur

Heart murmurs are classified based on their characteristics and underlying cause. Differentiating between innocent (functional) and pathologic (abnormal) murmurs is crucial in clinical practice.

Type	Description	Usual Clinical Significance	Source(s)
Innocent	Normal flow, no structural issue	Benign, no treatment needed	4 7
Pathologic	Due to structural abnormality	May require intervention	4 5 7 9
Systolic	Occurs during heart contraction	Can be benign or pathologic	4 6 7
Diastolic	Occurs during heart relaxation	Often pathologic	4 7
Continuous	Heard throughout cardiac cycle	Usually pathologic	4 7

Table 2: Heart Murmur Types

Understanding the Different Types

Innocent (Functional) Murmurs

• These murmurs arise from normal blood flow and do not indicate heart disease.
• Common in healthy children and adolescents; often resolve with age 4 7.
• They tend to be soft, short, and vary with body position or breathing.

Pathologic (Abnormal) Murmurs

• Caused by structural heart problems such as septal defects, valve abnormalities, or congenital heart disease 4 5 7 9.
• Often louder, may have a harsh quality, and are less likely to change with position.
• Diastolic and continuous murmurs are almost always pathologic 4 7.

Systolic, Diastolic, and Continuous Murmurs

• Systolic murmurs: Heard when the heart contracts. Most innocent murmurs are systolic, but pathologic causes include ventricular or atrial septal defects and valve stenosis 4 6 7.
• Diastolic murmurs: Occur when the heart relaxes. These are almost always due to pathology, such as valve regurgitation or stenosis 4 7.
• Continuous murmurs: Persist throughout the heartbeat and often signal significant abnormalities, like a patent ductus arteriosus 4 7.

Sonic Qualities

• Murmurs can also be described by their acoustic qualities—musical, blowing, coarse, or soft—which can help in diagnosis and classification 3.
• Musical or blowing murmurs are often associated with specific structural abnormalities and can be differentiated using advanced acoustic analysis 3.

Causes of Heart Murmur

The underlying cause of a heart murmur can be benign or signal a more serious heart problem. Identifying the etiology is essential for appropriate management.

Cause	Typical Examples	Notes	Source(s)
Structural Heart Defect	VSD, ASD, PDA, valve stenosis	Common in newborns/children	5 7 9
Turbulent Flow	High blood velocity, anemia, fever, pregnancy	Often benign (innocent)	4 6 8
Dynamic Obstruction	Ventricular outflow tract obstruction	Seen in cats, also humans	6
Congenital Heart Disease	Various malformations	Often detected at birth	5 9
Acquired Heart Disease	Rheumatic heart disease, infective endocarditis	More common in adults	4

Table 3: Causes of Heart Murmur

Delving Into the Causes

Structural Heart Defects

• Congenital Defects: The majority of pathological murmurs in newborns and children are due to structural abnormalities present at birth:
  • Ventricular Septal Defect (VSD): Most common cause in newborns, leading to a murmur due to abnormal blood flow between heart chambers 5 9.
  • Patent Ductus Arteriosus (PDA): Failure of a fetal blood vessel to close, causing a continuous murmur 5 9.
  • Atrial Septal Defect (ASD): Opening between atria; may be mistaken for a functional murmur 7 9.
  • Valve Stenosis: Pulmonary or aortic valve narrowing can cause turbulent flow and an audible murmur 5 7 9.

Turbulent Blood Flow

• Physiological factors such as increased blood flow (from fever, anemia, exercise, or pregnancy) can produce an “innocent” murmur in the absence of heart disease 4 6 8.
• In animals, as in humans, turbulent blood flow or vibration of cardiac structures is the root cause of murmurs 6 8.

Dynamic Obstruction

• In both veterinary and human medicine, dynamic obstruction of blood flow (e.g., left or right ventricular outflow tract obstruction) can create murmurs 6.
• In cats, most murmurs are due to such obstructions, highlighting the importance of echocardiographic assessment even in asymptomatic animals 6.

Acquired Heart Disease

• In adults, murmurs can develop from acquired conditions such as rheumatic heart disease (damaged valves), infective endocarditis, or degenerative valve diseases 4.

Innocent Versus Pathologic

• It can be challenging to distinguish innocent from pathologic murmurs based solely on auscultation. Clinical history, physical examination, and diagnostic tests (e.g., echocardiography, ECG) are critical for accurate diagnosis 2 4 5 9.

Treatment of Heart Murmur

The approach to managing a heart murmur depends on its underlying cause. While most innocent murmurs require no intervention, pathologic murmurs may necessitate further evaluation and treatment.

Approach	Indication	Description/Action	Source(s)
Observation	Innocent murmur, asymptomatic	No treatment; periodic monitoring	4 7
Echocardiography	Pathologic murmur suspected	Non-invasive imaging to diagnose	5 6 9
Medical Therapy	Heart failure, infection, or risk	Medications as appropriate	4 5
Surgical/Procedural	Significant structural defect	Valve repair, septal closure, etc	5 9
Referral	Uncertain diagnosis, abnormal signs	Pediatric or adult cardiologist	4 7 9

Table 4: Treatment Strategies

Managing Heart Murmurs

Observation and Reassurance

• Innocent murmurs, especially in children and adolescents, require no specific treatment. Education and reassurance for families are key 4 7.
• Regular follow-up may be advised to ensure no changes develop over time.

Diagnostic Evaluation

• Echocardiography is the gold standard for evaluating murmurs in newborns and children, especially when structural heart disease is suspected 5 6 9.
• ECG may be useful, particularly in adolescents to screen for hypertrophic cardiomyopathy or other conditions associated with sudden cardiac death 2.

Medical Management

• For certain heart defects or complications (e.g., heart failure, infection), medications such as diuretics, beta-blockers, or antibiotics may be indicated 4 5.
• Infective endocarditis prophylaxis is sometimes considered in high-risk individuals.

Surgical or Interventional Procedures

• Significant defects (e.g., large VSD, severe valve stenosis, persistent PDA) may require surgical repair or catheter-based interventions 5 9.
• Timing and type of intervention depend on the severity and symptoms.

Specialist Referral

• Any child or adult with a pathologic murmur, suspicious symptoms, or unclear diagnosis should be referred to a cardiologist 4 7 9.
• Prompt referral is crucial for murmurs associated with cyanosis, heart failure symptoms, or abnormal physical findings.

Conclusion

Heart murmurs are a frequent finding in clinical practice, especially among children and newborns. While most murmurs are harmless, some can be a sign of significant heart disease. Early identification, thorough evaluation, and appropriate referral are essential to ensure optimal outcomes.

Key Points:

• Heart murmurs are sounds produced by turbulent blood flow in the heart, detected during a physical exam.
• Most murmurs in children are innocent and require no treatment, but some may indicate structural heart defects.
• Symptoms like breathlessness, cyanosis, or poor feeding—especially in infants—require urgent assessment.
• Murmurs are classified as innocent or pathologic, with further subtypes based on timing (systolic, diastolic, continuous) and acoustic qualities.
• Causes range from benign (innocent flow) to serious (congenital or acquired heart disease).
• Echocardiography is vital in evaluating pathologic murmurs and identifying underlying heart conditions.
• Treatment is guided by the underlying cause, ranging from observation to medication or surgery.
• Referral to a cardiologist is important when a pathologic murmur or suspicious symptoms are present.

By understanding the nuances of heart murmurs, patients and healthcare professionals can work together to ensure timely diagnosis and appropriate care.