Voir la suite de cet article sur Cursus ECG
Patient
40-year-old woman, underwent surgery at the age of 10 for an ostium secundum atrial septal defect; balanced hemodynamics thereafter with absence of pulmonary hypertension or residual shunt;
Trace
Sinus rhythm with right atrial enlargement secondary to a volume overload of the left-to-right atrial shunt: normal P-wave duration, tall (3 mm) and peaked P-wave in lead II, greater amplitude in leads II, III than in lead I, exclusive positive deflection in V1; there are tall R waves in the right precordial leads suggestive of a right ventricular hypertrophy by diastolic overload;
Exergue
Right atrial enlargement is reflected on the ECG by an increase in the amplitude of the P-wave (> 2.5 mm in lead II) which can display a triangular pattern (peaked and narrow), a lack of prolonged P-wave duration, an exclusively positive pattern in V1 or with strong positive predominance. The diagnosis of right atrial enlargement is hence essentially based on the analysis of lead II and of V1.
As seen previously, right atrial activation begins and ends prior to that of the left atrium. In right atrial enlargement, the right atrial component of the P-wave is increased both in terms of amplitude and duration.