Introduction: Congenital heart diseases (CHD) have a major role in mortality and morbidity from cardiovascular disorders in both children and adults. The prevalence of CHD is around 1 in 100 live births with a broad spectrum of severity, from minor septal defects to critical CHD. Out of all congenital heart diseases, those with left-to-right shunts are most frequent.

Objective: To evaluate the clinical and paraclinical characteristics of CHD with left-to-right shunt in relation to defect type and specific characteristics.

Methods: In this observational study, we have included children with atrial septal defects (ASD) and ventricular septal defects (VSD). 80 patients were randomly chosen: 40 patients with ASD as group 1 and 40 with VSD as group 2. Criteria of inclusion: preoperative pe-riod, patients aged 0 to 18. Criteria of exclusion: those who have undergone surgical or interventional therapy.

Results: T he general study group, for the most part, consisted of neonates and infants. Group 1 had mainly children of 1-5 years (n= 23; 57.5%), while in group 2 the majority of patients were 0-1 years old (n= 29; 72.5%), p< 0.05. In group 1, ASD of the ostium secun-dum type was found in 32 (80%) cases, ostium primum ASD in 4 (10%) cases, sinus venosus ASD in 4 (10%) cases. In group 2, membranous VSD was diagnosed in 28 (77.5%) patients, muscular VSD in 9 (22.5%) pati-ents and infundibular VSD in 3 (7.5%) cases. Several potentially significant risk factors have been observed: associated disorders (Down syndrome in 10% of group 1), alcohol consumption (15% in group 1), age over 35 years (10% in group 1; 11.9% in group 2). In group 1 only 11 (27.5%) patients were symptomatic, whereas 21 (52.5%) patients had symptoms in group 2. Patients most often presented with: fatigability on exertion or during feeding (90.1% in group 1; 95.2% in group 2); dyspnea (36.4% in group 1; 62.5% in group 2); poor physical development (36.4% – group 1; 71.4% – group 2); frequent respiratory infections (18.2% – group 1; 23.8% – group 2); respiratory retractions (9.1% – group 1; 23.8% – group 2); p< 0.05. Patients in group 2 more frequently developed pulmonary hypertension in com-parison to those in group 1 (n=12, 30% vs. n= 4, 10%; p< 0.05).

Conclusions: The majority of patients with ASD and VSD were diagnosed in the neonatal period or infancy. Most of the aforementioned are asymptomatic and are detected on routine clinical examinations, although in VSD clinical signs tend to appear much earlier. We have observed a more benign evolution of the disease in patients with ASD in comparison to VSD. Despite the fact that the majority of small VSDs close spontane-ously, large and moderately-sized defects can lead to rapid development of complications, such as pulmonary hypertension and cardiac insufficiency.