Background The Covid-19 is an infectious disease, caused by SARS-CoV-2 virus. Cardiovascular complications of Covid-19 are reported more often, from inflammatory cardiac diseases to acute coronary syndromes, thromboembolic events and arrhythmias. Sometimes, these arrhythmias may be life threatening and require urgent intervention. Case summary This is a case of one year old boy, who was referred to our hospital because of premature ventricular complexes on ECG. The child had genetic chimerism with a karyotype of 46XY(12)/46XX(3) and small patent ductus arteriosus. We observed non sustained episodes of bidirectional ventricular tachycardia (VT) on 24 h Holter monitor, which increased over time and caused multiple planned and urgent shocks, despite antiarrhythmic drugs and deep sedation and intubation. Patient was tested positive for COVID-19 using PCR. After thorough echocardiographic testing and a negative genetic analysis for arrhythmogenic disorders he was diagnosed with Covid-19 associated ventricular tachycardia, taking into account that he also developed multisystem inflammatory syndrome. Further, a significant decrease of ventricular activity was observed, which allowed us to implant a cardioverter-defibrillator (ICD). Soon after the implantation the storm of ventricular tachycardia restarted with multiple shocks of the device. This time left partial thoracic sympathectomy was performed and the patient didn't have ICD shocks any more. Discussion Covid-19 infection can be associated with significant arrhythmias, including fatal ventricular arrhythmias also in children. Left partial thoracic sympathectomy can be a helpful option in patients with sustained ventricular tachycardia and multiple ICD shocks, in whom antiarrhythmic treatment or VT ablation is useless or not available.

Background Tetralogy of Fallot (TOF) is one of the most widespread cyanotic congenital heart disease (CHD), which can be successfully repaired in the neonatal period. However, residual problems and the surgical technique itself can create a favourable basis for arrhythmias and conduction abnormalities in these patients. Sometimes, these arrhythmias may worsen during pregnancy and require urgent intervention. Case summary This is a case of a 25-year-old woman, who underwent a surgical repair of TOF at the age of 2 years. She suffered an ischaemic stroke postoperatively, which was complicated with secondary seizures and syncope. These episodes were evaluated as epilepsy. The patient was admitted to our hospital with the above-mentioned complaints in the 10th week of pregnancy. A comprehensive cardiac examination was performed. Her presyncopal event was captured during Holter monitoring, which documented a severe dysfunction of the sinus node. She was diagnosed with postoperative sick sinus syndrome and implanted with a permanent dual-chamber pacemaker (PM). After the operation, the patient did not have any episodes of syncope or seizures and the PM check-up showed almost 30% of atrial pacing. Conclusion No matter how obvious the neurological or other nature of syncope may seem, it is advised to exclude the cardiac origin of syncope, especially in patients with repaired CHD. One of the most common complications after surgery of CHD is rhythm and conduction disturbances. In some of these cases, permanent PM implantation can be unavoidable, even during pregnancy. The implantation of the PM device during pregnancy can be performed safely.

Background: The number of cardiac implantable electronic device implantation procedures has increased dramatically in recent decades due to population aging and expansion of indications. At the same time, the number of cardiac implantable electronic device associated complications has increased too. Infection is a very important and heavy complication of cardiac implantable electronic device implantation, which significantly increases mortality and morbidity. This study aimed to estimate the risk of cardiac implantable electronic device infection in a group of patients who received an aggressive scheme of postoperative antibiotic therapy and compare this with the risk of infection in another group, where a mild antibiotic therapy scheme was used. Methods: A retrospective, observational study was performed. The study sample included 355 patients. Two antibiotic prophylaxis and wound follow-up protocols (mild and aggressive) were used. In this study the effectiveness of both methods to prevent a cardiac implantable electronic device related infection was compared. Results: The prevalence of infection was 3.5% in the group with mild scheme and 1.13% in the group with the aggressive scheme. The difference in two subgroups was not significant (p=0,149). According to this study severe renal failure, chronic obstructive pulmonary disease and thyroid dysfunction were found as significant predictors for having cardiac implantable electronic device infection. In participants who underwent a reimplantation and in those with postoperative hematoma the odds of having infection was higher, compared to patients with primary implantation and absence of hematoma. Age of participants with cardiac implantable electronic device infection was younger compared to patients without infection. Conclusion: According to this study there is no statistically significant difference on cardiac implantable electronic device infection between mild and aggressive antibiotic therapy schemes.

Funding Acknowledgements Type of funding sources: None. Background The number of CIED  implantation procedures has increased dramatically in recent decades due to population aging  and expansion of indications. At the same time, the number of CIED-associated complications has increased too. Infection is a very important and heavy complication of CIED implantation, which significantly increases mortality and morbidity. Aim and objectives This study aimed to estimate the risk of CIED-infection in a group of patients who received an aggressive scheme of postprocedural antibiotic therapy and compare with the risk of infection in another group, where a mild antibiotic therapy scheme was used. The study objectives were to assess the incidence and prevalence of CIED-related infection in patients operated in a tertiary cardiovascular center, as well as identify infection-related risk factors. Methods A retrospective, observational, cross-sectional study was performed. The study sample included 355 patients, who underwent CIED-related procedure in a single center between 01.12.2017 and 30.07.2020. Two antibiotic prophylaxis and wound follow-up protocols (mild and aggressive) were used. In this study, we compared the effectiveness of both methods to prevent a CIED related infection. Patient’s demographic data, clinical features, comorbidities, the device and procedure-related information were also assessed for having a relationship with CIED infection rate. Data entry and statistical analyses were performed with SPSS version 23 software. Binomial logistic regression analyses were performed for adjusted analyses. Results The prevalence of infection was 3.5% in the group with mild scheme and 1.13% in the group with the aggressive scheme. The difference in two subgroups was not significant (p = 0,149). In the whole sample the prevalence of infection was 1,69%. According to this study severe renal failure with glomerular filtration rate (GFR)<30 mL/min (OR = 32.6, CI = 2.5-420.8, p = 0.008),  chronic obstructive pulmonary disease (OR = 8.2, CI = 1.4-47.6, p = 0.019), and  thyroid disfunction (OR = 7.065, CI = 1.2-40.6, p = 0.028) were found as significant predictors for having CIED infection. In participants who underwent a reimplantation and in those with postoperative hematoma the odds of having infection was respectively 6.2 fold (CI = 1.086-35.5, p = 0.04) and 48.8 fold (CI = 8.4-285.9, p = 0.028) higher, compared to patients with primary implantation and absence of hematoma. Age of participants with CIED-infection (mean age = 52.5 )  was younger  compared to patients without infection (mean age = 61.2, p = 0.039). Conclusion According to our study the risk of infection in our center is comparable to recorded prevalence in other countries. There is no statistically significant difference on CIED infection between mild and aggressive antibiotic therapy schemes. Recommendations   The routine use of  aggressive antibiotic therapy is not justified and carries a risk of microbial resistance, as well as additional healthcare costs.