Corticosteroid therapy has become an important modality of treatment for diseases in which rapid control of immunoinflammatory processes is required. However, one of the serious, but less known adverse effect of this therapy is cardiac arrhythmias. This includes both tachyarrhythmias and bradyarrhythmias. Corticosteroid use may also be associated with electrolyte imbalances like hypokalaemia by its mineralocorticoid activity. Those side effects are mainly seen with high-dose intravenous methyl-prednisolone or oral pulse dose prednisolone therapy. Here we report our experience in a child with warm idiopathic autoimmune haemolytic anaemia who developed sinus bradyarrhythmias and treatment refractory hypokalaemia during low-dose steroid therapy with reduction in heart rate by 60% of baseline.

Dengue virus can affect the heart, with complications as bradycardia, arrhythmias, and death. We present a case of a 15-year-old patient, diagnosed 4 years before with severe idiopathic pulmonary hypertension, confirmed by catheterism, with continuous follow up. At that time, she was living in Bogotá (2640 m above sea level). Sildenafil and Macitentan were started. She was recommended to live at low altitude and she moved. The patient was transferred back to Bogota, from that place, due to flu-like symptoms and fever. Immunoglobulin M for dengue was confirmed and second-degree atrioventricular block Mobitz I with bradycardia (40 beats/minute) was documented throughout the clinical course. She recovered.

The coexistence of tetralogy of Fallot and Ebstein’s anomaly is extremely rare. There are only a few case reports in the literature, and surgical options for the treatment are controversial. There is insufficient data on long-term follow-up of patients and management of complications. In this case report, we present a 20-year-old adult with operated tetralogy of Fallot, Ebstein’s anomaly, and Glenn anastomosis who underwent transcatheter pulmonary valve implantation for severe pulmonary insufficiency.

Syncope occurs frequently in children, and the differential includes situational syncope, specifically micturition syncope. We report the youngest child to our knowledge to have micturition syncope associated with a prolonged asystolic pause. He underwent a neurological and cardiovascular evaluation without additional findings. Behavioural modifications were instituted with no recurrent syncope.

Atrioventricular block in children is not common but is a life-threatening disease. As no spontaneous regression of conductive disruption was reported, those sustaining idiopathic atrioventricular blocks are difficult to manage and often require pacemaker implantation. In this study, we presented the first case of a child who surprisingly recovered from idiopathic complete atrioventricular block without intervention 4 years after initial presentation.

We report a case of a 25-year-old man diagnosed with an unusual case of cor triatriatum sinister with a mobile left atrial thrombus. He was hospitalised with aggravating dyspnoea. Transthoracic echocardiography revealed a membrane-like structure traversing the left atrial and a small orifice of about 7.1 mm. The mean pressure gradient was 12.94 mmHg across the orifice of the membrane-like structure and there was a mobile mass in the post-erosuperior chamber. The anomaly was rectified by a surgical resection. Timely diagnosis and surgical repair may prevent stroke in patients with unusual cor triatriatum sinister.

Isolated origin of the subclavian artery is a congenital anomaly of the aortic arch in which one subclavian artery is attached to the ipsilateral pulmonary artery through ligamentous arteriosus. An isolated right subclavian artery with the left-sided aortic arch is an extremely rare condition. We report on an asymptomatic 2-year-old-girl, who was referred because of an incidental cardiac a murmur. She was diagnosed by echocardiography to have an isolated right subclavian artery connected to the right pulmonary artery in a left aortic arch with a ventricular septal defect. MRI confirmed the findings.

Percutaneous closure of atrial septal defect is recognised as a safe and effective procedure, however, in some patients complications may occur. Although chest pain has been sporadically reported, its exact aetiology has been poorly studied. Herein, a 14-year-old female with an atypical and long-lasting chest pain after percutaneous atrial septal defect closure is described.

We present the rare case of lipomatous atrial septal hypertrophy associated with adrenocorticotropin hormone therapy in an infant with West syndrome, highlighting their relatively benign nature and good prognosis in children, and the relevance of the differential diagnosis with more dangerous cardiac masses in order to avoid aggressive diagnostic and therapeutic interventions.