MioAtlas
Comparison

Ostium secundum atrial septal defect vs Perimembranous ventricular septal defect: clinical and ECG differences

Side-by-side comparison of Ostium secundum atrial septal defect and Perimembranous ventricular septal defect according to the MioAtlas 3D cardiac simulator model.

Ostium secundum atrial septal defect
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Perimembranous ventricular septal defect
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Findings by layer and diagnostic parameters

Layer / Finding Ostium secundum atrial septal defect Perimembranous ventricular septal defect
Hemodynamics
  • Pulmonary-to-systemic flow ratio: L < 1.5 (without overload); M and G ≥ 1.5 (with RV volume overload) [C4] [C5].
  • Shunt direction: Left-to-right at atrial level [C5] [G4-04].
  • Pulmonary artery pressure (systolic pulmonary artery pressure, mean pulmonary artery pressure): Normal in mild forms; possible elevation in the presence of substantial hyperflow [C5].
  • Pulmonary-to-systemic flow ratio: L low (<1.5); M intermediate; G elevated in the absence of advanced pulmonary vascular disease [C4] [C5].
  • Peak velocity and gradient of interventricular jet: L high-velocity jet with large transventricular gradient; M intermediate velocity; G low-velocity jet due to equalized ventricular pressures [C5] [G4-05].
  • Pulmonary artery systolic pressure: L normal; M normal or mildly elevated; G markedly elevated (pulmonary hypertension) [C5].
Rhythm
  • Normal sinus rhythm habitual [C5].
  • Atrial fibrillation or atrial flutter in adults due to chronic right atrial remodeling and dilation [C4] [C5].
  • Normal sinus rhythm habitual [C5].
  • Possible atrioventricular block due to anatomical proximity of perimembranous defect to bundle of His [E2] [G4-05].
ECG
  • Incomplete right bundle branch block (incomplete right bundle branch block, rsR' or rSr' pattern in V1) due to RV diastolic overload [E2] [G4-04].
  • Moderate: Left atrial enlargement (P mitrale wave) and left ventricular hypertrophy with volume overload (left ventricular hypertrophy voltage criteria) [E1] [G4-05].
  • Severe: Biventricular hypertrophy with tall biphasic complexes in V2–V4 (Katz-Wachtel phenomenon) and right ventricular hypertrophy in the setting of pulmonary hypertension [E1] [G4-05].
Heart sounds and murmurs
  • Second heart sound (S2): Wide and fixed splitting of S2 (S2 split fixed), unvarying with respiration, pathognomonic of atrial septal defect [G1-11] [G4-04].
  • Systolic murmur: Soft ejection midsystolic murmur (grade 2–3/6) in pulmonary area due to hyperafflux across the normal pulmonary valve [G1-14] [G4-04].
  • Tricuspid rumble: In severe form (G), soft mid-diastolic rumble in tricuspid area (lower left sternal border) due to relative tricuspid stenosis from high-volume flow [G1-15] [G4-04].
  • Systolic murmur in restrictive VSD (L/M): Harsh, high-frequency, loud holosystolic murmur (grade 4–6/6) with palpable thrill at 3rd-4th left intercostal space (lower left sternal border) [G1-14] [G4-05].
  • Murmur in large VSD (G): Softer and shorter holosystolic murmur (grade 2–3/6) due to pressure equalization [G1-14] [G4-05].
  • Second heart sound (S2): Accentuated pulmonic component P2 in severe forms with pulmonary hypertension (P2 loud) [G1-11] [G4-05].
  • Mitral rumble: In severe forms with large shunt, functional mid-diastolic rumble at apex due to transmitral hyperflow [G1-15] [G4-05].
  • Third heart sound (S3): Rapid filling gallop at apex in LV volume overload [G1-12].
Arterial pulse
  • Normal carotid and peripheral pulse [B4].
  • Normal or hyperdynamic in severe LV volume overload [B4].
Jugular venous pulse
  • Normal or mildly elevated jugular venous pressure with prominent and equalized a and v waves in the presence of RV overload [B3].
  • Normal in mild; prominent a wave in severe forms with pulmonary hypertension [B3] [G4-05].
Maneuvers
  • Respiration: S2 splitting interval remains fixed between inspiration and expiration [G1-11] [G4-04].
  • Valsalva maneuver: Decreases pulmonary ejection murmur intensity during strain phase [B1].
  • Isometric handgrip: Increases systemic afterload and enhances VSD murmur intensity [B1].
  • Valsalva maneuver: Decreases murmur during strain phase [B1].
  • Inspiration: Does not increase murmur intensity (differentiation from tricuspid regurgitation) [B1].

Sources and bibliographic references

Ostium secundum atrial septal defect

  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. [G1-14] Systolic Murmurs . Clinical Methods: The History, Physical, and Laboratory Examinations (1990) . PubMed: 21250186
  10. [G1-15] Diastolic Murmurs . Clinical Methods: The History, Physical, and Laboratory Examinations (1990) . PubMed: 21250187
  11. [G4-04] Atrial septal defects . Lancet (2014) . DOI: 10.1016/S0140-6736(13)62145-5 PubMed: 24725467

Perimembranous ventricular septal defect

  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. [G4-05] Ventricular septal defect . Lancet (2011) . DOI: 10.1016/S0140-6736(10)61339-6 PubMed: 21349577