ECG in Congenital Heart Disease

Secundum atrial septal defect

• Rhythm: normal sinus rhythm, increased risk of AF with age
• PR interval: first degree AV block in 6-19%
• QRS axis: 0° to 180°; RAD; LAD in Holt-Oram or LAHB
• QRS Configuration: rSr´ or rsR´ with RBBBi>RBBBc
• Atrial Enlargement: RAE 35%
• Ventricular hypertrophy: Uncommon
• Particularities: "Crochetage" pattern

Ventricular Septal Defect

• Rhythm: normal sinus rhythm, PVCs
• PR interval: Normal or mild ↑; 1o AVB 10%
• QRS axis: RAD with BVH; LAD 3% to 15%
• QRS Configuration: Normal or rsr´; possible RBBB
• Atrial Enlargement: Possible RAE±LAE
• Ventricular hypertrophy: BVH 23% to 61%; RVH with Eisenmenger
• Particularities: Katz-Wachtel phenomenon

AV canal defect

• Rhythm: NSR; PVCs 30%
• PR interval: 1° AVB >50%
• QRS axis: Moderate to extreme LAD; normal with atypical
• QRS Configuration: rSr´ or rsR´
• Atrial Enlargement: Possible LAE
• Ventricular hypertrophy: Uncommon in partial; BVH in complete; RVH with Eisenmenger
• Particularities: Inferoposteriorly displaced AVN

Patent ductus arteriosus

• Rhythm: NSR; ↑ IART/AF with age
• PR interval: ↑ PR 10% to 20%
• QRS axis: Normal
• QRS Configuration: Deep S V₁, tall R V₅ and V₆
• Atrial Enlargement: LAE with moderate PDA
• Ventricular hypertrophy: Uncommon
• Particularities: Often either clinically silent or Eisenmenger

Pulmonary stenosis

• Rhythm: NSR
• PR interval: Normal
• QRS axis: Normal if mild; RAD with moderate/severe
• QRS Configuration: Normal; or rSr´; R´ increases with severity
• Atrial Enlargement: Possible RAE
• Ventricular hypertrophy: RVH; severity correlates with R:S in V₁ and V₆
• Particularities: Axis deviation correlates with RVP

Aortic coarctation

• Rhythm: NSR
• PR interval: Normal
• QRS axis: Normal or LAD
• QRS Configuration: Normal
• Atrial Enlargement: Possible LAE
• Ventricular hypertrophy: LVH, especially by voltage criteria
• Particularities: Persistent RVH rare beyond infancy

Ebstein’s anomaly

• Rhythm: NSR; possible EAR, SVT; AF/IART 40%
• PR interval: 1° AVB common; short if WPW
• QRS axis: Normal or LAD
• QRS Configuration: Low-amplitude multiphasic atypical RBBB
• Atrial Enlargement: RAE with Himalayan P waves
• Ventricular hypertrophy: Diminutive RV
• Particularities: Accessory pathway common; Q II, III, aVF, and V₁–V₄

Surgically repaired TOF

• Rhythm: NSR; PVCs; IART 10%; VT 12%
• PR interval: Normal or mild ↑
• QRS axis: Normal or RAD; LAD 5% to 10%
• QRS Configuration: RBBB 90%
• Atrial Enlargement: Peaked P waves; RAE possible
• Ventricular hypertrophy: RVH possible if RVOT obstruction or PHT
• Particularities: QRS duration±QTd predictive of VT/SCD

Congenitally corrected TGA

• Rhythm: NSR
• PR interval: 1° AVB >50%; AVB 2%/year
• QRS axis: LAD
• QRS Configuration: Absence septal q; Q in III, aVF, and right precordium
• Atrial Enlargement: Not if no associated defects
• Ventricular hypertrophy: Not if no associated defects
• Particularities: Anterior AVN; positive T precordial; WPW with Ebstein’s

Complete TGA/intra-atrial baffle

• Rhythm: Sinus brady 60%; EAR; junctional; IART 25%
• PR interval: Normal
• QRS axis: RAD
• QRS Configuration: Absence of q, small r, deep S in left precordium
• Atrial Enlargement: Possible RAE
• Ventricular hypertrophy: RVH; diminutive LV
• Particularities: Possible AVB if VSD or TV surgery

UVH with Fontan

• Rhythm: Sinus brady 15%; EAR; junctional; IART >50%
• PR interval: Normal in TA; 1° AVB in DILV
• QRS axis: LAD in single RV, TA, single LV with noninverted outlet
• QRS Configuration: Variable; ↑R and S amplitudes in limb and precordial leads
• Atrial Enlargement: RAE in TA
• Ventricular hypertrophy: RVH with single RV; possible LVH with single LV
• Particularities: Absent sinus node in LAI; AV block with L-loop or AVCD

Dextrocardia

• Rhythm: NSR; P-wave axis 105° to 165° with situs inversus
• PR interval: Normal
• QRS axis: RAD
• QRS Configuration: Inverse depolarization and repolarization
• Atrial Enlargement: Not with situs inversus
• Ventricular hypertrophy: LVH: tall R V₁–V₂; RVH: deep Q, small R V₁ and tall R right lateral
• Particularities: Situs solitus: normal P-wave axis and severe CHD

ALCAPA

• Rhythm: NSR
• PR interval: Normal
• QRS axis: Possible LAD
• QRS Configuration: Ant-lat Q waves; possible ant-sept Q waves
• Atrial Enlargement: Possible LAE
• Ventricular hypertrophy: Selective hypertrophy of posterobasal LV
• Particularities: Possible ischemia