MioAtlas
G4: Congenital heart disease

Perimembranous ventricular septal defect

Congenital defect of the interventricular septum located in the membranous portion of the septum, adjacent to the aortic valve and septal leaflet of the tricuspid valve.

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Definition

Congenital defect of the interventricular septum located in the membranous portion of the septum, adjacent to the aortic valve and septal leaflet of the tricuspid valve. It is the most common variety of ventricular septal defect (70–80%). It permits a high-pressure systolic shunt from left ventricle to right ventricle, producing volume overload of the pulmonary vascular bed, left atrium, and left ventricle [C5] [G4-05].

Severity criteria

  • Mild / Small restrictive (L):
    • Small restrictive defect with high-velocity systolic interventricular jet [C5] [G4-05].
    • Qp:Qs ratio < 1.5, normal pulmonary artery pressure, and absence of left heart chamber dilation [C4] [C5] [G4-05].
  • Moderate (M): Restrictive defect with moderate left-to-right shunt and moderate dilation of left atrium and left ventricle [C4] [C5].
  • Severe / Large non-restrictive (G):
    • Large non-restrictive defect with equalization of ventricular systolic pressures and reduction of translesional velocity [C5] [G4-05].
    • Large-volume shunt, hyperkinetic pulmonary arterial hypertension, and biventricular hypertrophy or severe left heart chamber volume overload [C4] [C5] [G4-05].

Findings by layer

Hemodynamics

  • 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].
  • Possible atrioventricular block due to anatomical proximity of perimembranous defect to bundle of His [E2] [G4-05].

ECG

  • Mild: Normal [G4-05].
  • 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

  • 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 or hyperdynamic in severe LV volume overload [B4].

Jugular venous pulse

  • Normal in mild; prominent a wave in severe forms with pulmonary hypertension [B3] [G4-05].

Maneuvers

  • 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].

Simulator severity grades

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

Also known as: Perimembranous ventricular septal defect · Membranous ventricular septal defect · Perimembranous VSD · Paramembranous VSD · VSD

Other pathologies in this group

Related clinical comparisons

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