Introduction Atrial septal defect (ASD) is one of the most common congenital heart defects diagnosed in adulthood. Diagnosis is made by echocardiogram; however, this procedure is not widely available, especially in remote hospitals. Various electrocardiogram (ECG) changes, including the Crochetage sign, may give important clues to aid in diagnosis. We report a case of a young woman with a Crochetage sign in her ECG later diagnosed with ostium secundum ASD.

Case Presentation An 18-year-old lady had multiple visits to our centre with intermittent palpitations and dull, aching chest discomfort with progressive exertional dyspnoea over the past three years. She did not experience pedal oedema, orthopnoea, or paroxysmal nocturnal dyspnoea. She was initially treated for gastritis and unstable angina. Upon initial questioning, there were no cardiovascular risk factors or significant family history. Clinical examination revealed an ejection systolic murmur over the left sternal edge with fixed splitting of the second heart sound. She was not cyanosed and was clinically euthyroid. Her ECG on presentation showed sinus rhythm and an incomplete right bundle branch block (RBBB) with a notch near the apex of the R wave in inferior leads, also known as the Crochetage sign. There was right atrial enlargement in her chest radiograph. An urgent echocardiogram was performed in a tertiary centre and confirmed the diagnosis of ostium secundum ASD with pulmonary hypertension.

Discussion ASD is a common acyanotic congenital heart disease diagnosed during adulthood. Palpitations and reduced effort tolerance are commonly reported symptoms. Clinical findings include a wide, fixed splitting heart sound with an ejection systolic murmur. The Crochetage sign is an independent ECG finding in ASD, especially in large ASD with shunt. Specificity and sensitivity increase further with the presence of RBBB.

Conclusion In a center with limited resources, the identification of the Crochetage sign in a patient’s ECG is vital to tailor an appropriate investigation for the diagnosis of ASD.