Recent Trends In Frequency And Characteristics Of Congenital Heart Diseases

Objective:To evaluate the recent frequency and characteristics of congenital heart diseases(CHDs)in neonates admitted to the neonatal intensive care unit(NICU)of our hospital.Materials and Methods:i.Retrospective analysis of the 4004 medical records of neonates admitted or transferred from other local hospitals,and country sides of Nanjing to NICU of Zhongda hospital affiliated with Southeast University during the study period of three years(January 2014 to December 2016),was performed.Out of 4004 neonates,959 neonates underwent echocardiography or computed tomography angiography.All neonates with clinical signs and symptoms of possible CHD were examined by a senior pediatrician before undergoing echocardiography or CTA.Neonates with survival of(<12 hours)after birth,patent ductus arteriosus(PDA)of prematurity(<37 weeks),patent foramen ovale(PFO),atrial septal defect(ASD)(<3mm),and mild pulmonary stenosis/pulmonary valve stenosis(PS/PVS)(peak flow velocity<2.0mm/s),were excluded.ii.Neonates diagnosed with CHD were further divided according to their gender for comparison of CHD's frequency.iii.Neonates diagnosed with CHD were further divided into full-term and pre-term subgroups for comparison of CHD,s frequency.iv.Neonates diagnosed with CHD were further divided into(1)normal birth weight,(2)low birth weight,(3)very low birth weight,and(4)extremely low birth weight subgroups for comparison of CHD's frequency.v.Neonates diagnosed with CHD were further divided into(1)appropriate for gestational age(AGA),(2)large for gestational age(LGA),(3)small for gestational age(SGA)for comparison of CHD's frequency.Results:?.Reasons for undergoing echocardiography or CTA in our CHD patients were tachypnea,murmur,cyanosis,and poor response after birth,tachypnea with the murmur,murmur with cyanosis,tachypnea with cyanosis,and others.The majority of the CHD patients underwent echocardiography or CTA during early 1-5 days of their birth(n=299),while(n=53),(n=13),(n=4),and(n=1)CHD patients underwent echocardiography or CTA in their 6-10,11-15,16-20,and>21 days of their birth.?.370 neonates were diagnosed with CHD out of 959 neonates who underwent echocardiography or CTA.An overall increase in the frequency of CHD was observed.During the year of 2014,the frequency of CHD was 6.1%(83 patients out of 1366 inpatients),while in the year of 2015 and 2016,the frequency of CHD was 9.7%(123 patients out of 1269 inpatients)and 12.0%(164 cases out of 1369 inpatients),respectively.Among these 370 CHD diagnosed patients,82 were born in our hospital,158 were transferred to our NICU from other local hospitals of Nanjing,and remaining 130 were transferred to our NICU from country sides or suburbs of Nanjing.We observed a gradual increase in frequency of CHD in our NICU,while the number of inpatients remained stable with an average of 1,335 patients each year during the study period.?.Among the subtypes of CHD,atrial septal defect(ASD)was the most common with a frequency of 47.0%,followed by(PDA)29%,ventricular septal defect(VSD)15.9%,tetralogy of Fallot(TOF)1.6%,coarctation of the aorta(COA)1.6%,aortic stenosis(AS)1.08%,transposition of the great arteries(TGA)1.08%,total anomalous pulmonary connection(TAPVC)0.5%,atrioventricular septal defect(AVSD)0.3%,Dextrocardia 0.3%,hypoplastic right heart syndrome(HRHS)0.3%,double outlet of right ventricle(DORV)0.3%,and pulmonary stenosis(PS)0.3%,respectively.iv.Left-to-right shunt lesions(92%)were the most frequent,followed by left ventricle outflow tract obstruction(2.7%),pulmonary outflow tract obstruction(1.89%),TGA(1.08%),conditions with intra-cardiac mixing(0.8%),and others(0.5%),respectively.v.Male to female(M:F)ratio was(207:163).Overall higher frequency was observed in males,but a high frequency of VSD,TOF,AVSD,Dextrocardia,DORV,and PS,was observed in females.vi.Among the 1,551 pre-term inpatients,91 patients(5.9%)had CHD,whereas,among the 2,453 full-term inpatients,279 patients(11.4%)had CHD.Full-term patients showed PDA(34%),the most frequent CHD,followed by ASD(40%),and VSD(15.4%),respectively.Whereas,pre-term patients showed ASD(68%),the most frequent CHD,followed by VSD(16.4%),and PDA(3.2%),respectively.In accordance with the proportion of each group,overall frequency of CHD was higher in full-term patients(P<0.001).vii.When patients were categorized according to their birth weight into normal birth weight(NBW 2.5 kg),low birth weight(LBW<2,5 kg),very low birth weight(VLBW<1.5 kg),and extremely low birth weight(ELBW<1.0 kg)subgroups;the frequency of CHD was highest in the subgroup of normal birth weight patients(P<0.01,compared to the other three subgroups).viii.When patients were categorized according to their gestational age and birth weight relationship into 1)appropriate for gestational age(AGA),2)large for gestational age(LGA),and small for gestational age(SGA),the frequency of CHD was higher in AGA patients(n= 230)62.2%,followed by LGA patients(n=95)25.6%,and SGA patients(n=45)12.2%.Conclusion:The overall frequency of CHD has been increased in our NICU.The possible reason for the gradual increase in the frequency of CHD was due to a gradual increase in the number of inpatients transferred from the country sides of Nanjing city to our NICU.Due to possible lack or missed antenatal ultrasound examination,many patients with CHD have not diagnosed antenatally,which increased the frequency of CHD in our NICU.