MioAtlas
G4: Congenital heart disease

Patent ductus arteriosus

Persistence of the fetal vascular structure connecting proximal descending aorta (immediately distal to origin of left subclavian artery) to the roof of main pulmonary artery bifurcation.

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Definition

Persistence of the fetal vascular structure connecting proximal descending aorta (immediately distal to origin of left subclavian artery) to the roof of main pulmonary artery bifurcation. Since a continuous pressure gradient exists between aorta and pulmonary artery throughout the entire cardiac cycle (systole and diastole), a continuous left-to-right shunt is generated that produces volume overload of pulmonary vascular bed, left atrium, and left ventricle [C5] [G4-08].

Severity criteria

  • Mild / Small restrictive (L): Small restrictive defect with Qp:Qs ratio < 1.5, normal pulmonary pressures, and absence of left heart chamber volume overload [C5] [G4-08].
  • Moderate (M): Moderate defect with significant shunt and moderate volume overload of left atrium and left ventricle [C4] [C5].
  • Severe / Large with hemodynamic compromise (G): Large defect with high-volume shunt, severe dilation of left-sided chambers (LV and LA), pulmonary arterial hypertension, and wide pulse pressure with marked drop in diastolic blood pressure due to continuous diastolic runoff into pulmonary bed [C4] [C5] [G4-08].

Findings by layer

Hemodynamics

  • Pulmonary-to-systemic flow ratio: L < 1.5; M and G significant shunt with left chamber overload [C4] [C5].
  • Systemic blood pressure (systolic blood pressure, diastolic blood pressure): In severe forms, wide pulse pressure with reduced diastolic pressure due to continuous diastolic runoff into pulmonary artery [B4] [G4-08].
  • Shunt direction: Continuous left-to-right from aorta to pulmonary artery throughout systole and diastole [C5] [G4-08].
  • Pulmonary artery pressure (systolic pulmonary artery pressure, mean pulmonary artery pressure): L normal; M and G progressive elevation due to pulmonary hyperflow [C5].

Rhythm

  • Normal sinus rhythm habitual [C5].
  • Atrial fibrillation in older adults with prolonged left atrial dilation [C4] [C5].

ECG

  • Mild: Normal [G4-08].
  • Moderate / Severe: Left atrial enlargement (P mitrale wave) and left ventricular hypertrophy from volume overload (left ventricular hypertrophy voltage criteria, tall R waves and deep Q waves in I, aVL, V5–V6) [E1] [G4-08].
  • In severe forms with severe pulmonary hypertension: biventricular hypertrophy [E1] [G4-08].

Heart sounds and murmurs

  • Continuous machinery murmur (Gibson murmur): Harsh, rough continuous murmur at 1st and 2nd left infraclavicular intercostal space (left subclavicular region), beginning in early systole, peaking in late systole enveloping the second heart sound (S2), and waning during diastole without interruption [G1-14] [G1-15] [G4-08].
  • Thrill: Palpable continuous thrill in left infraclavicular fossa in moderate and severe forms [G4-08] [G4-09].
  • Second heart sound (S2): Masked by continuous murmur peak; if audible, accentuated P2 if coexisting pulmonary hypertension [G1-11] [G4-08].
  • Apical rumble: In large shunts (Qp:Qs > 2.0), functional mid-diastolic rumble at apex due to transmitral hyperflow [G1-15] [G4-08].
  • Third heart sound (S3): Ventricular gallop at apex due to LV volume overload [G1-12].

Arterial pulse

  • In moderate/severe forms: Hyperdynamic, wide, bounding pulse (pulsus celer et altus / Corrigan or water-hammer pulse), with rapid upstroke and abrupt diastolic collapse due to continuous runoff of blood from aorta into pulmonary artery [B4] [G4-08].

Jugular venous pulse

  • Generally normal; elevated mean venous pressure in the presence of associated right ventricular overload or ventricular failure [B3].

Maneuvers

  • Isometric handgrip: Increases systemic vascular resistance and aortic pressure, increasing transductal gradient and continuous murmur intensity [B1].
  • Valsalva maneuver: Decreases murmur intensity during strain phase [B1].

Simulator severity grades

Simulator severity grades: Mild, Moderate, Severe
Baseline rhythm: Normal Sinus Rhythm

Also known as: Patent ductus arteriosus · Persistent ductus arteriosus · Patent arterial duct · PDA

Other pathologies in this group

Sources

  1. [B1] Bedside diagnosis of systolic murmurs . N Engl J Med (1988) . DOI: 10.1056/NEJM198806163182404 PubMed: 2897627
  2. [B3] The jugular venous pressure revisited . Cleve Clin J Med (2013) . DOI: 10.3949/ccjm.80a.13039 PubMed: 24085809
  3. [B4] The Carotid Pulse . Clinical Methods: The History, Physical, and Laboratory Examinations (1990) . PubMed: 21250154
  4. [C4] 2025 ACC/AHA/HRS/ISACHD/SCAI Guideline for the Management of Adults With Congenital Heart Disease: A Report of the American College of Cardiology/American Heart Association Joint Committee on Clinical Practice Guidelines . Circulation (2026) . DOI: 10.1161/CIR.0000000000001402 PubMed: 41411375
  5. [C5] 2020 ESC Guidelines for the management of adult congenital heart disease . Eur Heart J (2021) . DOI: 10.1093/eurheartj/ehaa554 PubMed: 32860028
  6. [E1] AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part V: electrocardiogram changes associated with cardiac chamber hypertrophy: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society: endorsed by the International Society for Computerized Electrocardiology . Circulation (2009) . DOI: 10.1161/CIRCULATIONAHA.108.191097 PubMed: 19228820
  7. [E2] AHA/ACCF/HRS recommendations for the standardization and interpretation of the electrocardiogram: part III: intraventricular conduction disturbances: a scientific statement from the American Heart Association Electrocardiography and Arrhythmias Committee, Council on Clinical Cardiology; the American College of Cardiology Foundation; and the Heart Rhythm Society: endorsed by the International Society for Computerized Electrocardiology . Circulation (2009) . DOI: 10.1161/CIRCULATIONAHA.108.191095 PubMed: 19228822
  8. [G1-11] The Second Heart Sound . Clinical Methods: The History, Physical, and Laboratory Examinations (1990) . PubMed: 21250183
  9. [G1-12] The Third Heart Sound . Clinical Methods: The History, Physical, and Laboratory Examinations (1990) . PubMed: 21250184
  10. [G1-14] Systolic Murmurs . Clinical Methods: The History, Physical, and Laboratory Examinations (1990) . PubMed: 21250186
  11. [G1-15] Diastolic Murmurs . Clinical Methods: The History, Physical, and Laboratory Examinations (1990) . PubMed: 21250187
  12. [G4-08] Patent ductus arteriosus . Circulation (2006) . DOI: 10.1161/CIRCULATIONAHA.105.592063 PubMed: 17060397
  13. [G4-09] Congenital heart disease in adults. First of two parts . N Engl J Med (2000) . DOI: 10.1056/NEJM200001273420407 PubMed: 10648769