MioAtlas
G8: Complications of myocardial infarction

Post-infarction ventricular septal defect

Mechanical complication of transmural acute myocardial infarction characterized by transmural necrosis and rupture of interventricular septum, generating acute left-to-right shunt with biventricular volume overload and cardiogenic shock.

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Definition

Mechanical complication of transmural acute myocardial infarction characterized by transmural necrosis and rupture of interventricular septum, generating acute left-to-right shunt with biventricular volume overload and cardiogenic shock [C9] [G810-01].

Severity criteria

  • Literal numbers and statements from GUSTO-I trial [G810-01, Abstract]:
    • Incidence and presentation: «84 of the 41 021 patients (0.2%) developed VSD» and «median time from symptom onset to VSD diagnosis was 1 day».
    • Coronary involvement: «infarct artery was more often the left anterior descending and more likely to be totally occluded in patients who developed VSD».
    • Mortality: «Mortality at 30 days was higher in patients with VSDs than in those without this complication (73.8% versus 6.8%, P<0.001)».
  • Shunt (Qp:Qs): Flow ratio Qp/Qs > 2.0 [C9] [G810-01].
  • Shock hemodynamics: Systolic blood pressure < 90 mmHg; critical drop in cardiac output and elevation of filling pressures [C9].

Findings by layer

Hemodynamics

  • Systemic-to-pulmonary flow ratio: > 2.0 [C9] [G810-01].
  • Shunt direction: Left-to-right (LV systole → RV) [C9].
  • Systolic blood pressure: < 90 mmHg (hypotension/shock) [C9].
  • Pulmonary capillary wedge pressure: > 20 mmHg [C9].
  • Cardiac output: Markedly depressed (< 3.5 L/min) [C9].

Rhythm

  • Compensatory sinus tachycardia secondary to sympathetic hyperactivation in low output state [C9].

ECG

  • Pathological Q waves of transmural necrosis (infarct Q waves) in anterior leads (V1–V4) or inferior leads (II, III, aVF) with residual ST-segment elevation [C9] [E1].

Heart sounds and murmurs

  • Harsh holosystolic murmur: Loud, harsh pansystolic murmur (grade 3–5/6) auscultated at lower left sternal border and radiating in cartwheel pattern toward right hemithorax and apex [C9] [G810-01] [B1].
  • Tactile thrill: Palpable holosystolic thrill at left parasternal border [C9] [G810-01].
  • Third heart sound (S3): Frequent S3 gallop due to volume overload [C9].

Arterial pulse

  • Thready and fast-rising arterial pulse (parvus) due to drop in effective forward stroke volume into aorta [B4] [C9].

Jugular venous pulse

  • Severe jugular distension with elevated mean JVP and prominent 'v' wave [B3] [C9].

Maneuvers

  • Not performable in unstable cardiogenic shock; afterload increase (handgrip) would increase LV–RV gradient, worsening shunt [B1].

Simulator severity grades

Simulator severity grades: Single grade
Baseline rhythm: Sinus Tachycardia

Also known as: Post-infarction ventricular septal defect · Post-MI VSD · Post-infarction ventricular septal rupture · Post-infarct 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. [C9] Mechanical Complications of Acute Myocardial Infarction: A Scientific Statement From the American Heart Association . Circulation (2021) . DOI: 10.1161/CIR.0000000000000985 PubMed: 34126755
  5. [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
  6. [G810-01] Risk factors, angiographic patterns, and outcomes in patients with ventricular septal defect complicating acute myocardial infarction. GUSTO-I (Global Utilization of Streptokinase and TPA for Occluded Coronary Arteries) Trial Investigators . Circulation (2000) . DOI: 10.1161/01.cir.101.1.27 PubMed: 10618300