What are the different murmurs associated with valvular lesions?

Cardiac Murmurs in Valvular Lesions

Cardiac murmurs in valvular heart disease are classified based on their timing in the cardiac cycle, configuration, location, radiation, pitch, intensity, and duration, with each type of murmur providing critical diagnostic information about specific valvular pathology. 1

Classification of Cardiac Murmurs

Systolic Murmurs

Holosystolic (Pansystolic) Murmurs

• Begin with S1 and continue throughout systole until S2, typically with a plateau configuration 1
• Generated when blood flows between chambers with significant pressure differences throughout systole 2
• Common causes:
  • Mitral regurgitation - best heard at apex, radiating to axilla 2
  • Tricuspid regurgitation - loudest at lower left sternal border, increases with inspiration 2
  • Ventricular septal defects - abnormal communications between ventricles 2

Midsystolic (Systolic Ejection) Murmurs

• Crescendo-decrescendo (diamond-shaped) configuration, starting shortly after S1 1
• Common causes:
  • Aortic stenosis - harsh quality, radiates to carotids 1
  • Pulmonic stenosis - best heard at left upper sternal border 1
  • Increased flow across normal valves (pregnancy, thyrotoxicosis, anemia) 1
  • Hypertrophic cardiomyopathy - increases with standing and Valsalva 1

Early Systolic Murmurs

• Begin with S1 and end in midsystole 1
• Common causes:
  • Tricuspid regurgitation without pulmonary hypertension 1
  • Acute mitral regurgitation 1
  • Large ventricular septal defects with pulmonary hypertension 1

Late Systolic Murmurs

• Start well after ejection and end before or at S2 1
• Common causes:
  • Mitral valve prolapse - often preceded by midsystolic click 1
  • Papillary muscle dysfunction 1

Diastolic Murmurs

Early Diastolic Murmurs

• Begin with or shortly after S2, typically high-pitched and decrescendo 1
• Common causes:
  • Aortic regurgitation - high-pitched, decrescendo murmur along left sternal border 1
  • Pulmonic regurgitation with pulmonary hypertension - high-pitched, decrescendo 1
  • Pulmonic regurgitation without pulmonary hypertension - lower pitched with delayed onset 1

Middiastolic Murmurs

• Occur early during ventricular filling 1
• Common causes:
  • Mitral stenosis - low-pitched, rumbling at apex 1
  • Tricuspid stenosis - at lower left sternal border, increases with inspiration 1
  • Increased flow across normal valves (severe mitral/tricuspid regurgitation) 1
  • Austin-Flint murmur in severe aortic regurgitation - low-pitched rumbling at apex 1

Presystolic Murmurs

• Begin during ventricular filling following atrial contraction (only in sinus rhythm) 1
• Common causes:
  • Mitral stenosis - crescendo murmur ending with S1 1
  • Tricuspid stenosis 1
  • Atrial myxoma - can mimic valvular stenosis 1

Continuous Murmurs

• Span systole and diastole, continuing through S2 1
• Almost always pathological, except for venous hums and mammary souffles 1
• Common causes:
  • Patent ductus arteriosus 1
  • Arteriovenous fistula 1
  • Coronary arteriovenous fistula 1

Dynamic Auscultation and Associated Findings

• Respiration: Right-sided murmurs generally increase with inspiration; left-sided murmurs are usually louder during expiration 1
• Valsalva maneuver: Most murmurs decrease in intensity, except hypertrophic cardiomyopathy (becomes louder) and mitral valve prolapse (becomes longer and often louder) 1
• Exercise: Murmurs caused by flow across stenotic valves become louder with both isotonic and isometric exercise 1
• Position changes: Standing typically diminishes most murmurs except hypertrophic cardiomyopathy 1

Important Associated Findings

• Fixed splitting of S2 with a midsystolic murmur suggests atrial septal defect 1
• Soft/absent A2 or reversed splitting of S2 may indicate severe aortic stenosis 1
• Early systolic ejection sound suggests bicuspid aortic valve 1
• Left ventricular dilatation on palpation with holosystolic murmur suggests severe mitral regurgitation 1
• Slow-rising, diminished arterial pulse (parvus et tardus) suggests severe aortic stenosis 1

Clinical Significance

• Diastolic murmurs virtually always represent pathological conditions requiring further cardiac evaluation 1, 3
• Most systolic murmurs do not signify cardiac disease and may be related to physiological increases in blood flow velocity 1
• Echocardiography is the gold standard for confirming the cause and severity of valvular murmurs 4
• Early identification and management of pathological murmurs can prevent complications such as heart failure, pulmonary hypertension, and arrhythmias 2