Introduction: ASD is one of the most common congenital heart diseases in adults. It is characterised by the presence of communication between the two atria (1). Most ASDs are asymptomatic until the fourth decade of life (2). Some present with fatigue, dyspnoea on exertion, exercise intolerance or, occasionally, syncopal attack (3). Others may go on to develop complications such as atrial arrhythmias, paradoxical embolism, and pulmonary hypertension. In untreated patients with ASD, some may go on to develop complications such as atrial arrythmias, pulmonary hypertension and Eisenmenger syndrome. Here, we would like to illustrate a case of ASD presenting with atrial flutter and secondary pulmonary hypertension in elderly man.

Case report: 65-year-old patient hospitalized due to symptoms and signs of heart failure. On admission, he complained of heart palpitations and intolerance of exertion. At admission, atrial flutter is verified, ventricular rate 120 per minute with a 2:1 block (Figure 1). The presence of a primum type ASD with a diameter of 2.12 cm (Figure 2) with a left-right shunt is confirmed (Figure 3) and moderate tricuspid regurgitation with a gradient of 36 mm Hg along with the inferior vena cava, 2 cm in diameter on admission. Present moderate mitral regurgitation with criteria for prolapse of both mitral cusps. The values of the performed laboratory parameters were referential. During hospitalization, the patient was treated with beta blockers, anticoagulants, antihypertensives and diuretics, which achieved clinical stabilization and heart rhythm control, with a satisfactory heart rate at discharge.

Conclusion: Although ASDs are common, they remain very much underdiagnosed, as most are asymptomatic. This case highlighted the importance of early diagnosis of ASD, as early interventions can help in preventing the development of complications.