Diagnostic Utility of Three-Dimensional Rotational Angiography in Congenital Cardiac Catheterization

We evaluated the diagnostic utility of the three modalities of three-dimensional rotational angiography (3DRA): rotational angiography (RA), multiplanar reformat (MPR) and three-dimensional angiographic reconstruction (3D-R) in pediatric cardiac catheterization. The 3DRA studies were classified by anatomy of interest based on our injection protocol: pulmonary arteries (PA), aorta, cavopulmonary connection (CPC), and others. Retrospective review of 3DRA images by two reviewers for each modality was conducted with grading as inferior, similar, or superior in comparison with the diagnostic quality of fixed-plane angiography (FPA). The percentages of grades for each modality were averaged. Weighted kappa statistic was used to evaluate inter-rater reliability. In total, 114 3DRA studies were performed on 87 patients between August 2010 and March 2012. Median age was 2.7 years (1 day–48.4 years) and median weight 12.1 kg (3.6–106.5 kg). For RA: 79.4 % of the studies were of diagnostic quality and 52.2 % were superior; 3D-R: 82 % were of diagnostic quality and 65.8 % were superior; and MPR: 83.5 % were of diagnostic quality and 63 % were superior. Overall 3DRA technologies (RA, 3D-R, MPR) were of diagnostic quality or better in 111/114 (97.4 %) studies and 103/114 (90.4 %) were judged superior. Most common reasons for inferior grading were limited opacification and metallic artifact. In pediatric cardiac catheterization, 3DRA imaging was of diagnostic quality and frequently provided additional clinically relevant data when compared to FPA.     

Quantifying and Minimizing Radiation Exposure During Pediatric Cardiac Catheterization

This study reports findings from evaluations of new technologies to measure radiation exposure during pediatric cardiac catheterization procedures. A strategy of pulsed fluoroscopy and low power settings resulted in significantly lower patient radiation exposure compared to conventional 60 frames/sec, high-power settings during fluoroscopy. During radiofrequency ablation procedures, thyroid and thoracic skin sites outside the direct fluoroscopic field received minimal radiation exposure. Intrathoracic radiation exposure was measured with the use of an esophageal dosimeter. In conclusion, strategies to reduce total radiation exposure should be employed, radiation dose should be measured, and assessment of radiation skin injury should be included in postcatheterization assessment.     

Radiation Dose Reduction in Pediatric Cardiac Computed Tomography: Experience from a Tertiary Medical Center

Cardiac CT angiography (cCTA) has become an established method for the assessment of congenital heart disease. However, the potential harmful effects of ionizing radiation must be considered, particularly in younger, more radiosensitive patients. In this study, we sought to assess the temporal change in radiation doses from pediatric cCTA during an 8-year period at a tertiary medical center. This retrospective study included all patients ≤18 years old who were referred to electrocardiography (ECG)-gated cCTA for the assessment of congenital heart disease or inflammatory disease (Kawasaki disease) from November 2004 to September 2012. During the study period, 95 patients were scanned using 3 different scanner models—64-slice multidetector CT (64-MDCT) and first- (64-DSCT) and second-generation (128-DSCT) dual-source CT—and 3 scan protocols—retrospective ECG-gated helical scanning (RG), prospective ECG-triggered axial scanning (PT), or prospective ECG-triggered high-pitch helical scanning (HPH). Effective dose (ED) was calculated with the dose length product method with a conversion factor (k) adjusted for age. ED was then compared among scan protocols. Image quality was extracted from clinical cCTA reports when available. Overall, 94 % of scans were diagnostic (80 % for 64-slice MDCT, 93 % for 64-slice DSCT, and 97 % for 128-slice DSCT).With 128-DSCT, median ED (1.0 [range 0.6–2.0] mSv) decreased by 85.8 % and 66.8 % compared with 64-MDCT (6.8 [range 2.9–13.6] mSv) and 64-DSCT (2.9 [range 0.9–4.1] mSv), respectively. With HPH, median ED (0.9 [range 0.6–1.8] mSv) decreased by 59.4 % and 85.4 % compared with PT (2.2 [range 0.9–3.4] mSv) and RG (6.1 [range 2.5–10.6] mSv). cCTA can now be obtained at very low radiation doses in pediatric patients using the latest dual-source CT technology in combination with prospective ECG-triggered HPH acquisition.     

Patient Radiation Exposure in a Modern,Large-Volume,Pediatric Cardiac Catheterization Laboratory

Radiation exposure from pediatric cardiac catheterization may be substantial, although published estimates vary. We sought to report patient radiation dose across a range of diagnostic and interventional cases in a modern, high-volume pediatric catheterization laboratory. We retrospectively reviewed diagnostic and interventional cases performed in our pediatric catheterization laboratory from 1 April 2009 to 30 September 2011 for which radiation usage data were available as reported by the Artis Zee^® (Siemens Medical Solutions) system. Electrophysiology cases were excluded. Radiation dose was quantified as air kerma dose (mGy) and dose-area product (DAP; μGy m²). The DAP was converted to an effective dose millisievert (mSv) using the Monte Carlo method. Radiation usage data were available from 2,265 diagnostic and interventional cases with an overall median air kerma dose of 135 mGy [interquartile range (IQR) 59–433], median DAP of 760 μGy m² (IQR 281–2,810), of which 75 % (IQR 59–90 %) was derived from fluoroscopy, and median effective dose of 6.2 mSv (IQR 2.7–14.1). Air kerma dose from a single camera >2,000 mGy occurred in 1.8 % of cases. Significant differences in all measures of radiation exposure existed based on procedural and interventional types (p = 0.0001), with interventional cases associated with the highest effective dose after adjusting for patient weight category (p < 0.001). Patient weight, age, fluoroscopy time, and proportional use of digital acquisition were independent predictors of exposure (p ≤ 0.001; R ² = 0.59–0.64). In a modern, large-volume pediatric catheterization laboratory, the median effective dose is 6.2 mSv with a wide range of exposure based on patient- and procedure-specific factors. Radiation monitoring is an important component of a pediatric laboratory and further dose reduction strategies are warranted.     

Radiation Dose and Image Quality in Pediatric Cardiac Computed Tomography: A Comparison Between Sequential and Third-Generation Dual-Source High-Pitch Spiral Techniques

The aim of this study was to investigate whether there is a reduction in radiation dose and improvement in image quality of pediatric cardiac computed tomography scans performed using the high-pitch spiral technique on a new third-generation dual-source 2 × 192-slice scanner (group B) compared with scans performed using the sequential technique on a single-source 256-slice scanner (group A). We performed a retrospective observational study on 40 patients aged ≤18 years who underwent prospectively electrocardiogram-triggered cardiac computed tomography. Image quality was assessed by pre-defined objective indices and a four-point subjective score. Apart from a higher mean heart rate in group A (P = 0.016), there were otherwise no significant inter-group differences in patient characteristics. The median effective dose was 4.41 mSv (interquartile range 2.58–5.90 mSv) in group A and 0.52 mSv (interquartile range 0.39–0.59 mSv) in group B (P < 0.001), representing a 88 % reduction. Subjective image quality score was significantly better in group B (4 = excellent with no artifact, mode 57.1 %) than in group A (3 = good with mild artifact, mode 57.9 %) (P < 0.001). Noise index, signal-to-noise ratio and contrast-to-noise ratio between both groups were not statistically significant. New third-generation dual-source high-pitch spiral scan technique can deliver excellent image quality with low radiation dose. Our results suggest that it should be considered as a first-choice technique for performing cardiac computed tomography in the pediatric population.     

X-Ray Dose from Pediatric Cardiac Catheterization: A Comparison of Materials and Methods for Measurement or Calculation

Pediatric cardiac catheterization procedures have the potential to transmit high X-ray doses, which may lead to acute effects or latent skin reactions. Direct measurement of radiation dose was facilitated using nanodot dosimeters and radiochromic film. Direct measurement results were compared with vendor-listed dosimetry and calculation using phantom data. Vendor-listed data demonstrated a wide discrepancy with measured data, whereas the calculation reproducibly overestimated the actual dose. A simple formula was derived to calculate the dose using fluoroscopy time, cine frame quantity and average cine mA in a biplane environment.     

Chest Pain in Pediatric Patients

One hundred and twenty-three patients (72 males and 51 females) with the chief complaint of chest pain, seen at our department during the five-year period from January 1982 to December 1986, were studied regarding their past medical history, physical findings, results of diagnostic tests, and prognosis. The ages of the subjects ranged from 3 to 16 years (mean 11.7 years) in boys and 3 to 20 years (mean 10.9 years) in girls, constituting 0.54% of the total number of the mean annual outpatients. Of these 123, 80 patients (65%) had chest pain lasting over one month, and 91 patients (74%) had a short time of duration of pain which improved within a few seconds to five minutes. In nine (7%) of the 123 patients, the pain was considered to be related to cardiovascular lesions and in 82 patients (67%) as being idiopathic chest pain. Chest pain in children is rarely due to serious primary cardiovascular diseases.     

Radiation Exposure by Three-Dimensional Rotational Angiography (3DRA) During Trans-catheter Melody Pulmonary Valve Procedures (TMPV) in a Pediatric Cardiac Catheterization Laboratory

This retrospective study aims to evaluate radiation exposure by three-dimensional rotational angiography (3DRA) during trans-catheter Melody pulmonary valve (TMPV) procedures. 3DRA has been reported to have added value in the management of complex congenital heart disease aiding in the performance of interventional procedures albeit with concerns of higher radiation exposure. We test the hypothesis that 3DRA does not cause additional radiation exposure during TMPV procedures. We analyzed all 81 TMPV procedures performed at St. Louis Children’s Hospital, MO, USA, from January 1, 2011 to December 31, 2014. Dose-area product (DAP), DAP indexed to body weight (DAP/BW), fluoroscopy time (FT), and weight–fluoroscopy time product of each procedure were recorded. We reviewed each procedure’s images to determine whether additional interventions were performed (e.g., pulmonary artery angioplasty or treatment of conduit pseudo-aneurysm). 3DRA was used in 36 % of the procedures. 3DRA group had a higher number of additional procedures performed. The 3DRA group did not differ from the non-3DRA group in DAP, DAP/BW, and weight–fluoroscopy time product. 3DRA does not cause greater radiation exposure during TMPV procedures.     

Selective Coronary Angiography in Pediatric Patients

Selective coronary angiography (SCA) is an important diagnostic tool in pediatric cardiology; however, there are few reports on its feasibility and safety in young patients. We reviewed our experience with SCA from July 1, 1993 to December 31, 1997. There were 158 cardiac catheterizations that included SCA in patients whose ages ranged from 2 days to 46 years (median, 5.3 years). The most common indication was surveillance for coronary vasculopathy after heart transplantation. A retrograde approach was used in all patients through the femoral artery (n= 157) or umbilical artery (n= 1). Preformed coronary catheters were used and the Judkins left (JL) and Judkins right (JR) were the most common catheters, with the catheter curve size correlating with patient height (R ²= .76 for JL, R ²= .673 for JR). Complications during SCA included brief ST–T wave changes (11%), bradycardia (2.5%), and ventricular fibrillation (0.6%). Complications of vascular access were transient pulse loss (6%), hematoma (5%), and rebleeding (0.6%). Only one case of femoral artery occlusion was encountered on subsequent cath. In conclusion, complications of SCA were infrequent and serious complications were rare. SCA can be safely performed in pediatric patients at any age including neonates.     

Ultrasound-Guided Versus Landmark-Guided Femoral Vein Access in Pediatric Cardiac Catheterization

Background This study aimed to evaluate whether an ultrasound-guided technique can improve upon a landmark-guided technique in achieving femoral vein access in pediatric cardiac catheterization. Methods This study examined 87 consecutive subjects with a median age of 2 years (range, 1 month to 19 years) who had congenital or other heart disease. Femoral vein puncture was attempted using either an ultrasound-guided technique (US group, n = 43) or a landmark-guided technique (LM group, n = 44). The patients were assigned alternately to either an ultrasound- or landmark-guided group. Overall success and traumatic complication rates were compared between the two groups, as well as the influence of patient size and age. Results The overall rate of success in achieving femoral vein access did not differ between the two groups. Among the successful cases in the two groups, there were no significant differences in patient size or age. Inadvertent femoral artery puncture occurred with 3 (7%) of 43 patients in the US group and with 14 (31.8%) of 44 patients in the LM group, for a significantly higher complication rate in the LM group (p < 0.01). Conclusions Ultrasound-guided access to the femoral vein minimizes the complication of inadvertent arterial puncture as compared with the landmark-guided approach.     

Computed Tomographic Angiography of Infants with Congenital Heart Disease Receiving Extracorporeal Membrane Oxygenation

Patients with respiratory and/or cardiac failure occasionally require the use of extracorporeal membrane oxygenation (ECMO), which presents an obstacle for standard imaging modalities. Computed tomographic angiography (CTA) can be used in patients with congenital heart disease, usually to define extra-cardiac anatomy in the chest. We describe the use of CTA to evaluate two infants with congenital heart disease while on ECMO. The first infant had totally anomalous pulmonary venous connection, and the second had a pulmonary sling that resulted in tracheal stenosis. The studies achieved high diagnostic quality with minimal radiation exposure. Subsequently, both infants had successful surgical repairs.     

A Case of Renal Artery Stenosis in a Child Confirmed by Multidetector Computed Tomographic Angiography

Renovascular hypertension is an uncommon disease, but it causes 5–10% of all childhood hypertension. The most common cause of renal artery stenosis is fibromuscular dysplasia, resulting in at least 60% of renovascular hypertension cases. This report describes a case of a renal artery stenosis confirmed by multidetector computed tomographic angiography.     

Use of Low-Dose Ketamine and/or Midazolam for Pediatric Cardiac Catheterization

Ketamine and midazolam are commonly used in children undergoing cardiac catheterization. However, there is controversy regarding the safety of administering these agents in the absence of an anesthesiologist. We retrospectively reviewed pediatric cardiac catheterization procedures at our institution between 1996 and 1997. A total of 154 patients (0.3-192 months) underwent a total of 205 procedures. They received ketamine (n = 79, 1.05 +/- 0.88 mg/kg/hr), midazolam (n = 35, 0.14 +/- 0.09 mg/kg/hr), or both (n = 91; ketamine, 1.13 +/- 0.84 mg/kg/hr; midazolam, 1.57 +/- 1.03 mg/kg//hr). In 18.5% of patients there were complex cardiac lesions. Mean procedure time was 79 +/- 36.2 minutes. Pre- and postprocedure systolic and diastolic mean blood procedure 72 +/- 14 and 68 +/- 12 mmHg, respectively. Pre- and postprocedure O2 saturation was 93.19 +/- 8.72 and 93.63 +/- 8.3, respectively. One patient required intubation, and 15% required oxygen therapy. The mortality rate was zero. The anesthesiologist's assistance was requested by the cardiologist in 21 procedures (group A) and not requested in 184 procedures (group B). The two groups were not different in relation to the drug used (p = 0.283) or the complexity of the cardiac lesions (p = 0.051). However, there was significant difference between the two regarding the need for supporting drugs (3/21 vs 3/184, p = 0.02) or oxygen treatment (7/21 vs 26/184, p = 0.014). No patients in group B required intubation, whereas 14% and 1.6% required oxygen therapy and supporting drugs, respectively. We conclude that low-dose ketamine and midazolam can be administered safely to most pediatric patients by the cardiologist, who can safely predict the need for an anesthesiologist.     

Permanent Cardiac Pacing in Pediatric Patients

Pediatric pacemaker (PM) implants comprise less than 1 % of all PM implants. This study aimed to investigate permanent cardiac pacing among the pediatric population, identifying different indications and complications of pediatric cardiac pacing, especially focusing on the effect of the pacing sites, the PM lead type, and the indications for pacing. The current work is a cross-sectional study of 103 procedures for permanent PM insertion in pediatric patients between January 2001 and December 2010. The patients were followed up 1, 3, and 6 months after implantation, then every 6 months or as needed. Evaluation included routine clinical examination, electrocardiography, chest X-ray, echocardiography, and a full analysis of the pacing system measurements. The ages of the patients ranged from 0.09 to 12 years (median, 2.3 years). The most common indication for pacing was postoperative complete heart bock, noted in 54 patients (52.4 %). Transvenous endocardial PM insertion was performed in 92 procedures (89.3 %), whereas transthoracic epicardial insertion was performed in 11 procedures (10.7 %). The most common site of pacing was the right ventricular apex (n = 64, 62 %), followed by the right ventricular outflow tract (n = 25, 24.3 %). Transthoracic epicardial PM insertion was associated with a significantly higher percentage and greater severity of complications. In this study, 65 % of the patients with left ventricle (LV) dilation before pacing showed a significant improvement in LV dimensions and function after pacing. This was noted only in those with endocardially inserted PM leads in both the congenital and the postoperative groups regardless of the pacing site. Endocardial PM insertion in children is a safe procedure with fewer complications and a lower ventricular threshold than the epicardial route. Permanent single-chamber right ventricle pacing is safe and can lead to significant improvement in LV function and dimensions. However, long-term follow-up assessment is needed for further evaluation.     

Use of 320-Detector Computed Tomographic Angiography for Infants and Young Children with Congenital Heart Disease

Pediatric patients with complex congenital heart disease (CHD) face a lifetime of treatment with interventional therapeutic and palliative procedures. Echocardiography remains the mainstay for noninvasive imaging of congenital heart lesions. This often is supplemented with diagnostic cardiac catheterization for additional anatomic and physiologic characterization. However, recent technological improvements in computed tomography (CT) and magnetic resonance imaging (MRI) have led to an increased focus on the use of these techniques given their better safety profile. This study aimed to review the authors' experience with a 320-slice multidetector CT scanner in the evaluation of CHD in children. This retrospective case study investigated 22 infants and young children with a provisional diagnosis of CHD. Their anatomic evaluation was performed using a 320-slice Aquilon ONE CT scanner. Of these 22 patients, 14 were examined without cardiac gating. This was subsequently modified to a prospective gated, targeted protocol to decrease the radiation dose. The images were interpreted by an experienced radiologist and a pediatric cardiologist. Continuous variables were expressed as mean and standard deviation or range, and the two imaging protocols were compared. A comparison of exposure rates with those from other pediatric studies that had used the 64-slice CT angiography also was performed. For the first group of patients, with nongated CT examinations, the mean effective whole-body radiation dose was 1.8 ± 0.71 millisieverts (mSv) (range, 0.96-3.2 mSv). For the second group, the mean was 0.8 ± 0.39 mSv (range, 0.4-1.5 mSv). Although the radiation dose was reduced dramatically, clinicians must be vigilant about the cumulative risk of radiation exposure.