This article reported two cases of brucellosis in children on the waiting list for a cardiac transplant who have been referred with the diagnosis of Fever of Unknown Origin. The serology was positive and patients were treated with cardiac transplantation in the 6th week. They had no recurrence or rejection. Therefore, brucellosis should be considered in patients on the waiting list for cardiac transplants.

Although rare, children with active coronavirus disease 2019 are at risk of developing malignant arrhythmia. Herein, we present the first paediatric case of refractory ventricular tachycardia from acute fulminant myocarditis secondary to acute COVID-19 infection. This 5-year-old boy required venoarterial extracorporeal membrane oxygenation support, but made a complete recovery without significant morbidity.

We report a case of a pseudoaneurysm in the sinus of Valsalva, secondary to infective endocarditis in a child with trisomy 21. The patient had a history of subaortic stenosis, bicuspid aortic valve, and ventricular septal defect. Patch closure of the ostium of the pseudoaneurysm and aortic valve replacement was performed. The patient was discharged without severe complications.

Myopericarditis is a condition, which primarily involves the pericardium, with minimal myocardial involvement. In myopericarditis, chest pain, elevated cardiac enzymes, and electrocardiographic changes occur. Although COVID-19 mRNA vaccines significantly contribute to preventing the COVID-19 disease, rarely myocarditis and/or pericarditis may develop due to these vaccines. We present a previously healthy 14-year-old male patient who developed myopericarditis after receiving the second dose of the COVID-19 mRNA vaccine.

We describe the case of a 2-month-old born with hypoplastic left heart syndrome who presented with fever and vomiting and was found to be infected with the novel corona virus (COVID-19). He underwent treatment with supplemental oxygen, heparin, and dexamethasone. After a 6-day hospitalisation, he recovered remarkably well without major adverse effects.

An 11-year-old male was admitted with cough and fever for the last 4 days and also complained of pain in the right lung for some weeks. The boy did not show any other symptoms and his past medical history was unremarkable as well. The radiologist findings showed an aspect that suggested for echinococcosis.

At first, it was realised the heart intervention. About a 2-month period later, the child underwent another cyst removal in lung. He had begun taking albendazole 5 days before the heart intervention. The therapy was continued until the lung intervention and for 12 weeks post-operatively. The patient had an uneventful recovery and after about 4 years.

We report two cases of acute hypotension after intravenous azithromycin administration in children with acute, decompensated heart failure. In each of our reported cases, azithromycin was being used to treat possible Mycoplasma myocarditis. In this report, we aim to describe hypotension as a potentially rare adverse reaction to intravenous azithromycin and encourage judicious use in patients with cardiac dysfunction.

We describe an adolescent with Streptococcus pneumoniae meningitis and symptomatic high-grade, second-degree atrioventricular block requiring permanent pacemaker placement. It is difficult to ascertain if these two diagnoses were independent or had a causal relationship though ongoing symptoms were not present prior to the infection. Because of this uncertainty, awareness that rhythm disturbances can be cardiac in origin but also secondary to other aetiologies, such as infection, is warranted.