Hidden pulmonary arteries in tetralogy of Fallot and pulmonary artery pressure in patients operated with a pulmonary artery.

INTRODUCTION: The absence of a pulmonary artery is a rare congenital anomaly that occurs isolated or with other congenital cardiac disorders, particularly tetralogy of Fallot (TOF); meanwhile, a hidden pulmonary artery might exist and originate from a closed ductus arteriosus (DA), which can be stented to reach the artery. MATERIAL AND METHODS: This prospective study describes cardiac catheterization of nine TOF patients diagnosed with the absence of the left pulmonary artery before the operation. The patients were stratified into three groups: group one, whose closed DA was found and connected to the hidden pulmonary artery with a stent; group two, whose hidden pulmonary arteries were found via the pulmonary vein angiography; and group three, for whom we could not find the remnant of the DA, or our attempt to stent the DA to the hidden pulmonary artery was not successful. We also evaluated outcomes of six other surgically-corrected TOF patients who were operated with the absent left pulmonary artery. RESULTS: The first group included the patients aged 1, 24, and 30 months, whose CT angiography 6-9 months after stenting showed acceptable left pulmonary artery diameter for surgical correction, and the pulmonary vein angiography of the second group showed a hidden left pulmonary artery with a suitable diameter for surgical correction. However, we were unable to find or stent the DA of group three patients, aged 12, 38, 60, and 63 months. Earlier Angiography might have increased the chance of access to the hidden vessel. Apart from these three groups, follow-ups of six other patients previously corrected with only the right pulmonary artery revealed pulmonary artery hypertension in all patients. CONCLUSION: The concealed pulmonary artery might be found, and stenting of the closed DA to it might be performed to improve the diameter of the diminutive pulmonary artery. This procedure may allow TOF total surgical correction with two pulmonary arteries. Besides, pulmonary vein angiography can reveal the hidden pulmonary artery.

To evaluate the prevalence of symptomatic and non-symptomatic ductus arteriosus and accuracy of physical signs in diagnosing PDA in preterm infants using blinded comparison of clinical and echocardiographic findings during the first week of life: a prospective observational study from Iran.

AIMS: To evaluate the prevalence of symptomatic and non-symptomatic ductus arteriosus (PDA) and accuracy of physical signs in diagnosing PDA in preterm infants using blinded comparison of clinical and echocardiographic findings during the first week of life. METHODS AND MATERIAL: This prospective observational cross-sectional study enrolled 200 preterm infants, who underwent echocardiography on 4th-7th postnatal day. The neonates who were diagnosed to have PDA on echo were observed for clinical features of PDA to label it symptomatic PDA. Symptomatic PDA was defined as detecting one or all of these symptoms in a neonate with PDA: bounding pulse, pericardial hyperactivity, systolic or continuous murmur. RESULTS: Forty-five infants had PDA on echocardiography. 66.7% neonates with PDA were symptomatic and the most prevalent symptom in them was heart murmur (100%) either alone or combined with other clinical features. Isolated murmur was seen in 31.2%, murmur and hyperdynamic precordium was seen in 8.8%, murmur and bounding pulses were seen in 6.67% and all three features simultaneously were seen in 20% of infants. The sensitivity of murmur for diagnosing symptomatic PDA was highest. CONCLUSION: Presence of murmur is the most important clinical feature for diagnosis of symptomatic PDA and has good specificity.

Prevalence and risk factors associated with the patency of ductus arteriosus in premature neonates: a prospective observational study from Iran.

BACKGROUND: Patent ductus arteriosus (PDA) is a common problem in the preterm infants. The frequency of PDA varies with the time of study, and the characteristics of the population included in the trial. AIMS AND OBJECTIVE: To determine the prevalence and prenatal risk factor associated with PDA. METHODS AND MATERIAL: This prospective cross-sectional observational study was carried out on neonates who had gestational age below 37 weeks during the period of February 2014 to September 2014. Echocardiography was done at 4-7 days of postnatal age. The association between prenatal risk factors of the infants and the PDA was studied. RESULTS: From a total population of 200 enrolled infants 22.5% had PDA. The mean gestational age and birth weight were 32.1 ± 2.65 (weeks) and 1741 ± 622.85 (g), respectively. Maternal antepartum hemorrhage, respiratory distress syndrome (RDS), need for surfactant, birth weights, female gender, gestational age, Apgar scores at 1 and 5 min of the infants were found to be associated with the prevalence of PDA. CONCLUSION: Several prenatal factors make preterm newborns susceptible to PDA. These risk factors should be identified as soon as possible for early commencement of PDA management.

Follow-Up Results of Device Occlusion of Patent Ductus Arteriosus.

BACKGROUND: Transcatheter patent ductus arteriosus (PDA) closure is an established procedure. OBJECTIVES: The aim of the study was to assess midterm follow up of the Nit-Occlud coil and the amplatzer ductal occluder (ADO) closure of PDA. PATIENTS AND METHODS: In this cohort study, we collected the longitudinal data of patients who underwent percutaneous closure using coil or ADO from November 2005 to November 2013. A total of 404 patients with PDA closure by devices were included during the study period. Coil occlusion was performed in 220 patients and 184 patients underwent catheterization using ADO. Follow-up evaluations were performed with echocardiography at two weeks, two months, six months, and during the study period (in average 4.8 ± 3.8 years). RESULTS: The patients' mean age was 24 months (range: 1 - 312). The catheterization was successful in 393 (97.2%) patients and unsuccessful in 11 (2.7%). Immediate complete occlusion was seen in 290 (73.7 %) patients. The occlusion rates at two weeks, two months, six months, and during the study period were 73.7%, 84%, 93.6%, 98.7%, and 99.5%, respectively. Complications occurred in 23 (5.8%) patients during or immediately after the catheterization, and device embolization with 2.7% was the most common complication. Most complications occurred in a patient with pulmonary hypertension who was less than one year old and was undergoing the first year of experience with devices. CONCLUSIONS: Our findings showed that transcatheter occlusion of the PDA is an effective and safe intervention by coil or Amplatzer with excellent early and one-year outcomes. Pulmonary hypertension, age of less than 12 months and experience of less than one year may increase the complications of device closure.

Noninvasive Assessment of Pulmonary Artery Pressure in Patients with Extracardiac Conduit Total Cavopulmonary Connection.

To assess quantitative measurement of mean pulmonary artery pressure (PAP) in extracardiac total cavopulmonary connection (TCPC) patients by noninvasive echocardiographic inferior vena cava collapsibility index (IVC-CI) and also correlation between the peripheral vein pressure and mean PAP. In 19 TCPC patients with at least 1-year follow-up after completion of TCPC, complete echocardiography including IVC-CI was recorded. All patients underwent cardiac catheterization for mean PAP pressure, peripheral vein pressure (PVP) and contrast study. Different cutoff points of mean PAP were analyzed, and based on the highest cutoff point, patients were categorized into two groups: mean PAP < 17 mmHg (acceptable) and > = 17 mmHg (high) for comparison analysis. Between 2006 and 2015, from 43 patients who had undergone TCPC, nineteen patients with a mean age 12.9 ± 6.6 years and mean follow-up time of 3.4 ± 1.9 years were included in this study. Mean PAP was 14.6 ± 3.97 (range 8-22 mmHg). Thirteen (68 %) patients had PAP < 17 mmHg. No significant statistical difference was detected with respect to age, sex, type of congenital heart disease and fenestration between these two groups. But, right ventricular dominancy was more prevalent in the high PAP group (50 % vs. 7.7 % P value 0.03). IVC-CI had a correlation with mean PAP (r 0.67, P < 0.001). IVC-CI < 21.8 % can predict PAP > = 17 mmHg with 83 % sensitivity and 100 % specificity. Regression analysis proposed an equation for PAP measurement: PAP (mmHg) = 20.2097-0.1796 × (IVC-CI), (r2 = 0.56). Peripheral vein pressure measurement also showed a good correlation with mean PAP and may be used to estimate PAP with the following equation: PAP (mmHg) = 0. 8675 × PVP, (r 0.90, P < 0.0001). In conclusion, IVC-CI as noninvasive and peripheral vein pressure measurement as a minimal invasive method may be useful for quantitative estimation of PAP in patients with extracardiac TCPC.

The Effect of Oral High-dose Ibuprofen on Patent Ductus Arteriosus Closure in Preterm Infants.

OBJECTIVE: The aim of this study is to compare the efficacy and possible adverse effects of the oral high-dose ibuprofen regimen to that of standard regimen in closing patent ductus arteriosus (PDA). STUDY DESIGN: This clinical trial study was performed from April 2012 to May 2013 on preterm infants with gestational age<37 weeks and postnatal age 3 to 7 days with echocardiographic diagnosis of hemodynamically significant PDA. These neonates were randomly assigned to two treatment groups that respectively received high dose (20-10-10 mg/kg/d) and standard dose (10-5-5 mg/kg/d) oral ibuprofen regimen for 3 days. Effect of ibuprofen therapy was evaluated by echocardiography and neonates were followed for renal dysfunction, gastrointestinal complication, bleeding, and hyperbilirubinemia. RESULTS: From a total of 60 enrolled infants, 30 cases received the high dose of ibuprofen and the remaining 30 received the standard dose. Complete ductal closure was observed in 20 (70%) infants treated with high-dose regimen in comparison with 11 (36.7%) in the standard-dose regimen group (p=0.010). No gastrointestinal, renal, or hematological adverse effects were reported. CONCLUSION: The high-dose oral ibuprofen seems to be more effective than the current standard dose regimen for PDA closure in premature neonates without increasing the adverse effects.

Evaluation of left ventricular function by tissue Doppler and speckle-derived strain rate echocardiography after percutaneous ductus closure.

The aim of this study was to evaluate the left ventricular systolic and diastolic function before and after transcatheter percutaneous patent ductus arteriosus (PDA) closure. 21 children (age >6 months old) diagnosed with hemodynamically significant PDA underwent percutaneous PDA closure. Conventional, Doppler and tissue Doppler imaging and speckled-derived strain rate echocardiography were done at pre-closure, 1 day (early) and 1 month (late) post-closure. Mean age of the patients (female/male: 1.3) was 17.54 ± 24.7 months with the mean PDA diameter of 3.6 ± 0.8 mm. Systolic measures (ejection fraction, shortening fraction) reduced significantly early after PDA closure (P < 0.05). After 1 month, both improved significantly; ultimately, after 1 month no change was observed in systolic function measures compared with the pre-closure status. Early and late diastolic flow velocities of mitral (E M and A M) reduced considerably in early and late post-closure time (P < 0.05). Both early tissue Doppler early velocity of lateral mitral annulus (E'M) and early to late velocity ratio (E'M/A'M) of lateral mitral annulus decreased significantly (P = 0.02) in early post-closure. After 1 month, E'M increased considerably. (P = 0.01) but E'M/A'M had an insignificant rise (P > 0.05). E M/E'M ratio did not change in early post-closure but it had a considerable reduction in the subsequent month compared with the pre- and early post-closure (P < 0.001 for both occasions). Global and segmental longitudinal strain measures reduced significantly early after PDA closure (P < 0.05) but it improved remarkably in the subsequent month. Transcatheter PDA closure causes a significant decrease in left ventricular performance early after PDA closure which recovers completely within 1 month. Also PDA size can affect post-closure left ventricular function.

Role of speckle tracking echocardiography in the assessment of post-repair left ventricular function in patients with late presentation of anomalous origin of the left coronary artery from the pulmonary artery.

The aim of this study was to determine the left ventricular myocardial deformation and segmental myocardial dysfunction by speckle tracking echocardiography and tissue Doppler imaging among the operated patients with anomalous origin of the left coronary artery from the pulmonary artery. The study was conducted on 12 patients diagnosed with anomalous origin of the left coronary artery from the pulmonary artery, who had been operated upon between 2001 and 2013 at the medical centres of Shiraz University of Medical Sciences, Shiraz, Iran. The mean age of the patients at the time of surgical correction was 12.6 years ranging from 6 months to 43 years, and the duration of postoperative follow-up was between 1 and 12 years. Comparison of the strain rate between the patients with acceptable ejection fraction and the control group by tissue Doppler imaging showed significant differences between the two groups regarding the lateral wall (p<0.001), but not the septal wall of the left ventricle (p=0.65). Moreover, the strain values by the speckle tracking method revealed significant differences between the patient and the control group regarding the global strain (p=0.016) and anterior, lateral, and posterior segments of the left ventricle. Although postoperative conventional echocardiography revealed normal global left ventricular function with acceptable ejection fraction, abnormal myocardial deformation of the variable segments of the left ventricle with regional and global myocardial dysfunction were well defined by speckle tracking echocardiography.

Acute hemodynamic effects of single oral dose of bosentan in patients with pulmonary arterial hypertension related to congenital heart disease.

BACKGROUND: Endothelin-1 is a potent endogenous vasoconstrictor and an important remodeling factor in the pathogenesis of pulmonary arterial hypertension (PAH). Bosentan, a nonselective and active dual endothelin receptor antagonist, is used as a vasodilator in treatment of such patients. This study aimed to evaluate acute response to a single oral dose of bosentan as a vasodilator agent in comparison with nasal oxygen (O2) in patients with PAH related to congenital heart disease (CHD). MATERIALS AND METHODS: We enrolled 20 patients with PAH-CHD, with a mean age of 5.45 ± 4.5 years. Hemodynamic variables were measured at baseline state, after administration of nasal O2 (5 L/min) for 20 minutes, and then when hemodynamic variables returned to the baseline, the measurements were repeated for the third time 3 hours after administration of a single oral dose of bosentan (2 mg/kg). RESULTS: Mean pulmonary vascular resistance was 9.92 ± 2.97 Wood units · m(2) at baseline and was lowered by O2 to 6.17 ± 2.71 Wood units · m(2) (P = .001) and by bosentan to 5.90 ± 2.69 Wood units · m(2) (P = .0001). Mean pulmonary artery pressure was 71.2 ± 15.4 mm Hg at baseline and was reduced to 62.6 ± 15.2 mm Hg (P = .001) by O2 and to 61.6 ± 14.8 mm Hg (P = .0003) by bosentan. CONCLUSION: A single oral dose of bosentan has the same acute vasodilatory effect on the pulmonary vascular bed as nasal O2 in patients with PAH related to CHD. Such patients may benefit from long-term therapy with this novel medication.

Evaluation of electrocardiographic changes after arterial switch operation.

BACKGROUND: Transposition of Great Arteries (TGA) is a serious congenital heart disease which can be accompanied by good outcomes with anatomic correction within the first few weeks of life. OBJECTIVES: The present study aimed to evaluate electrocardiographic changes in the children with uncomplicated Arterial Switch Operation (ASO). PATIENTS AND METHODS: Twelve lead electrocardiograms were obtained from thirty-three patients with TGA after ASO. Then, the patients' QT-dispersion and P-wave dispersion were compared to those of 33 age- and gender-matched individuals as the normal control group. Both groups were also evaluated by M-mode echocardiography. Student's t-test and Pearson correlation were used to analyze the data. Besides, P < 0.05 was considered as statistically significant. RESULTS: The mean age of the patients and the control group was 41 ± 3.7 and 40.12 ± 4.2 months, respectively. Comparison of P wave, T wave, QRS complex, PR interval, QT segment, and corrected QT segment showed significant differences in the frequency of inverted T wave in pericardial leads [V3, V4, V5, and V6] (P = 0.004; more in patients), P wave amplitude in lead II (P < 0.001; more in patients), R wave amplitude in V1 (P = 0.016; smaller in patients), R and S waves amplitude in V6 (P = 0.004 and P = 0.001; taller in patients), corrected QT segment (in lead V5; P < 0.0001: prolonger in patients), and PR interval (P = 0.001; prolonger in patients). However, no significant differences were found regarding the vector axis and heart rate. Right bundle branch block (18% vs. 0%), Bifascicular (3% vs. 0%), and first-degree blocks (15% vs. 0%) were significantly more in the patients. Besides, the PR interval was longer in the corrected complex TGA (146 ± 24.4 vs. 127.7 ± 23.1, P = 0.001). Moreover, R/S ratio in lead V1 was significantly prolonger, among the patients (2.86 ± 3.35 vs. 0.706 ± 0.53, P = 0.002). Nonetheless, no significant was observed between the patients and controls concerning the mean of QT dispersion. On the other hand, the two groups were significantly difference in terms of P wave dispersion (25.7 ± 13.8 vs. 33.74 ± 12.9, P = 0.024). CONCLUSIONS: In this study, first-degree block and right bundle branch were detected in the operated patients with TGA. Increased P dispersion in these patients may increase the risk of atrial arrhythmia. Thus, long-term follow-up is necessary in these patients.

Evaluation of cardiac and valvular function after arterial switch operation: a midterm follow-up.

OBJECTIVES: Transposition of Great Arteries (TGA) is a serious congenital heart disease and anatomic correction in the first few weeks of life has revealed good outcomes nowadays. In this study, we aimed to evaluate the myocardial and valvular function at midterm postoperative follow-up. PATIENTS AND METHODS: In this study, thirty-three patients with TGA and Arterial Switch Operation (ASO) were evaluated by 2-dimensional, M-mode, Doppler, and pulsed Tissue Doppler. These patients were compared with 33 healthy children of the same age and gender as the normal control group. Student's t-test and Pearson correlation were used to analyze the data. Besides, P<0.05 was considered as statistically significant. RESULTS: The mean follow up time was 40.9±5.6 months. Among the 33 patients with ASO, 6% had mild pulmonary stenosis, while 3% had mild pulmonary insufficiency. Aortic stenosis and aortic insufficiency of trivial to mild degree was seen in 12% and 12% of the patients, respectively. The patients' systolic velocity of tricuspid (S), early diastolic velocity of tricuspid (Ea), and late velocity of tricuspid valve (Aa) were significantly different from those of the controls (P<0.001). Also, pulmonary annulus diameter was significantly dilated in the patients compared to the controls (1.67±0.41 vs. 1.29±0.28, P≤0.001). Besides, aortic annulus diameter (1.56±0.42 vs. 1.24±0.21, P=0.001) and also aortic sinus diameter (2.06±0.41 vs. 1.44±0.34, P=0.002) were significantly dilated, while sinutuboar junction diameter (1.65±0.5 vs. 1.28±0.29, P=0.094) was not dilated. Left ventricular function was in the normal range. CONCLUSIONS: This study showed good left ventricular function, but some abnormalities in lateral tricuspid tissue Doppler velocities. Neoaortic and pulmonary diameters were significantly dilated, while aortic and pulmonary insufficiencies were clinically insignificant in most of the patients. Long-term follow-up is necessary in these patients.

Pericardial effusion and atrial thrombosis: a rare complication of childhood leukemia.

BACKGROUND: Acute lymphoblastic leukemia (ALL) is the most common malignancy diagnosed in children. Extramedullary leukemia including hepatosplenomegaly, lymphadenopathy, and mediastinal mass are the clinical presentations of T-cell ALL. Pericardial effusion and atrial mass are rare presentations of pediatric leukemia. CASE PRESENTATION: We report a 15-year-old girl with T-cell ALL, who presented initially with pericardial effusion and cardiac tamponade and subsequently developed right atrial mass. The mediastinal and right atrial masses were excised by surgical procedure as a treatment strategy for prevention of arrhythmia and sudden death. CONCLUSION: T-cell ALL can present with pericardial and mediastinal involvement as an initial manifestation. Pericardiocenthesis and systemic anticancer chemotherapy without local chemotherapy should be considered in these cases.

Short-term result of ductus arteriosus stent implantation compared with surgically created shunts.

This report aims to compare the researchers' early experience with the safety, efficacy, short-term outcomes, and complications of patent ductus arteriosus (PDA) stents in neonates having duct-dependent pulmonary circulation with those of surgically created shunts. Between April 2009 and April 2011, 18 infants with duct-dependent pulmonary circulation underwent cardiac catheterization for PDA stenting as the first palliative procedure in a referral center. For comparison, 20 infants who underwent surgical aortopulmonary shunt placement in another center were used. Follow-up assessment included clinical examination, echocardiography, oxygen saturation, and cardiac catheterization studies. Access and stenting for the PDA were successful in 15 patients (83.3 %). The mean procedure time was 58.43 ± 41.25 min, and the mean fluoroscopy time was 18.81 ± 5.64 min. Three patients (20 %) in the stented group and 6 patients (30 %) in the surgical group died (P = 0.09). After a 6-month follow-up period, none of the patients had significant stent stenosis requiring reintervention. The oxygen saturation increase did not differ significantly between the two groups either immediately after the procedure or 6 months later (P > 0.5). The left pulmonary artery diameter, McGoon ratio, and Nakata index did not differ significantly between the two groups (P > 0.05), but the right pulmonary diameter was larger in the stented group (5.01 ± 0.45 vs 4.1 ± 0.49 mm; P = 0.0001). Stenting for the PDA is an appropriate alternative to surgical shunt creation in many patients with duct-dependent circulation. In our sample, the two groups did not differ significantly in terms of outcome or mortality.

Accuracy of Doppler-derived estimation of pulmonary vascular resistance in congenital heart disease: an index of operability.

Pulmonary vascular resistance (PVR) is a critical and essential parameter during the assessment and selection of modality of treatment in patients with congenital heart disease (CHD) accompanied by pulmonary arterial hypertension (PAH). Cardiac catheterization is the "gold standard" but is an invasive method for PVR measurement. A noninvasive and reliable method for estimation of PVR in children has been a major challenge and most desirable during past decades, especially for those who need repeated measurements. In a prospective study and among consecutive patients who were referred for cardiac catheterizations, PVR was calculated as the ratio of the transpulmonary pressure gradient (∆P) to the amount of the pulmonary flow (QP) accordingly for 20 patients with CHD and high PAH. Subsequently and noninvasively, PVR was assessed for these patients by a Doppler echocardiography-derived index defined as the ratio of the tricuspid regurgitation velocity (TRV(m/s)) to the velocity time integral (VTI(cm)) of the right-ventricular outflow tract (RVOT). There was a good correlation between PVR measured at catheterization (PVR(cath)) and TRV/VTI(m) ratio; the mean of three measurements of VTI (VTI(m)) with R (2) = 0.53 (p = 0.008). In addition, a TRV/VTI(m) value of 0.2 provided a sensitivity of 71.4% and a specificity of 100% for PVR >6 Woods units (WU) as well as sensitivity of 90% and specificity of 90% for a PVR equal to 8 WU. PVR value between 6 and 8 WU by catheterization has been considered as a cut-off point for intervention in children with left-to-right shunts and PAH. In conclusion, Doppler-derived TRV/VTI(m) ratio is a reliable index that may be helpful as a supplementary diagnostic tool for the selection of modality of treatment and follow-up of patients with PAH and increased PVR.

Comparative study of pulmonary circulation and myocardial function in patients with ß-thalassemia intermedia with and without hydroxyurea, a case-control study.

OBJECTIVES: To compare myocardial systolic and diastolic functions and pulmonary circulation by two-dimensional, M-mode, Doppler, and pulsed tissue Doppler imaging in patients with ß-thalassemia intermedia who received hydroxyurea at least for 1 yr, patients who did not receive hydroxyurea, and a healthy control group. METHODS: We assigned 84 patients with thalassemia intermedia into two groups: one of two was treated with hydroxyurea for at least 1 yr and no hydroxyurea. M-mode echocardiographic, Doppler, and pulsed Doppler tissue images were compared in these two groups and in 20 control participants who did not have thalassemia. For the estimation of pulmonary hypertension, pulmonary acceleration time below 100 ms was considered as an index of pulmonary hypertension. RESULTS: There were no significant differences in M-mode echocardiographic findings between three groups. Doppler echocardiography detected no significant differences between the treated and untreated groups. In treated hydroxyurea group, 11.7% patients had pulmonary acceleration time below 100 ms and in untreated group 21% (LR = 1.45, P = 0.22). Pulsed Doppler tissue imaging parameters did not differ significantly between treated and untreated patients (P > 0.05). Pulsed Doppler tissue images showed significant changes between patients and controls in peak systolic velocity of the septum, peak atrial velocity of the septum (Aas), the peak systolic velocity of the tricuspid valve (St), the peak early diastolic velocity of the tricuspid valve (Eat), and the peak late diastolic velocity of the tricuspid valve (Aat). CONCLUSION: This study revealed that in spite of decrease in estimated pulmonary hypertension in treated group, HU has no statistically significant effect on pulmonary acceleration time and M-mode, Doppler, and tissue Doppler changes of patients with TI.

Risk of nephropathy after consumption of nonionic contrast media by children undergoing cardiac angiography: a prospective study.

Despite increasing reports on nonionic contrast media-induced nephropathy (CIN) in hospitalized adult patients during cardiac procedures, the studies in pediatrics are limited, with even less focus on possible predisposing factors and preventive measures for patients undergoing cardiac angiography. This prospective study determined the incidence of CIN for two nonionic contrast media (CM), iopromide and iohexol, among 80 patients younger than 18 years and compared the rates for this complication in relation to the type and dosage of CM and the presence of cyanosis. The 80 patients in the study consecutively received either iopromide (group A, n = 40) or iohexol (group B, n = 40). Serum sodium (Na), potassium (K), and creatinine (Cr) were measured 24 h before angiography as baseline values, then measured again at 12-, 24-, and 48-h intervals after CM use. Urine samples for Na and Cr also were checked at the same intervals. Risk of renal failure, Injury to the kidney, Failure of kidney function, Loss of kidney function, and End-stage renal damage (RIFLE criteria) were used to define CIN and its incidence in the study population. Accordingly, among the 15 CIN patients (18.75%), 7.5% of the patients in group A had increased risk and 3.75% had renal injury, whereas 5% of group B had increased risk and 2.5% had renal injury. Whereas 33.3% of the patients with CIN were among those who received the proper dosage of CM, the percentage increased to 66.6% among those who received larger doses, with a significant difference in the incidence of CIN related to the different dosages of CM (p = 0.014). Among the 15 patients with CIN, 6 had cyanotic congenital heart diseases, but the incidence did not differ significantly from that for the noncyanotic patients (p = 0.243). Although clinically silent, CIN is not rare in pediatrics. The incidence depends on dosage but not on the type of consumed nonionic CM, nor on the presence of cyanosis, and although CIN usually is reversible, more concern is needed for the prevention of such a complication in children.