Diagnosis and management of cyanotic congenital heart disease: part II

Single Ventricle-A Comprehensive Review

In this paper, the author enumerates cardiac defects with a functionally single ventricle, summarizes single ventricle physiology, presents a summary of management strategies to address the single ventricle defects, goes over the steps of staged total cavo-pulmonary connection, cites the prevalence of inter-stage mortality, names the causes of inter-stage mortality, discusses strategies to address the inter-stage mortality, reviews post-Fontan issues, and introduces alternative approaches to Fontan circulation.

The Author's Contributions to Echocardiography Literature (Part II-1991-2020)

The author's contribution up to 1990 was reviewed in part I and the echo contributions from 1991 to 2020 will be reviewed in part II. These include defining the relationship between the quantity of shunt across the atrial septal defect (ASD) and the diameter of ASD by echo and angio on the one side and the stretched diameter of the ASD on the other; echocardiographic assessment of balloon-stretched diameter of secundum ASDs; development of echocardiographic predictors of accomplishment of percutaneous closure of ASDs with the buttoned device, highlighting limitations of echocardiography in comprehensive assessment of mixed type of total anomalous pulmonary venous connection; description of follow-up echocardiographic results of transcatheter closure of ASD with buttoned device; review of ultrasound studies; depiction of collaborative echocardiographic and Doppler studies; echocardiographic appraisal of the outcome of balloon pulmonary valvuloplasty; editorials; ventricular septal aneurysm causing pulmonary outflow tract obstruction in the morphologic left ventricle in corrected transposition of the great arteries; dependability of echocardiographic assessment of angiographic minimal diameter of the ductus; occurrence of supravalvular pulmonary artery stenosis after a Nuss procedure; echocardiographic assessment of neonates who were suspected of having heart disease; role of echocardiographic studies in the appraisal of patent ductus arteriosus in the premature babies; and the role of pressure recovery in explaining differences between simultaneously measured Doppler and cardiac catheterization pressure gradients across outflow tract stenotic lesions.

Cross-sectional imaging of congenital pulmonary artery anomalies

Congenital pulmonary artery (PA) anomalies comprise a rare and heterogeneous spectrum of disease, ranging from abnormal origins to complete atresia. They may present in early infancy or more insidiously in adulthood, often in association with congenital heart disease such as tetralogy of Fallot or other syndromes. In recent years, cross-sectional imaging, including computed tomography (CT) and magnetic resonance imaging (MRI), has become widely utilized for the noninvasive assessment of congenital PA diseases, supplementing echocardiography and at times supplanting invasive angiography. In this article, modern CT and MRI techniques for imaging congenital PA disorders are summarized. The key clinical features, cross-sectional imaging findings, and treatment options for the most commonly encountered entities are then reviewed. Emphasis is placed on the ever-growing role of cross-sectional imaging options in facilitating early and accurate diagnosis and tailored treatment.

Management of Congenital Heart Disease: State of the Art-Part II-Cyanotic Heart Defects

In this review management of the most common cyanotic congenital heart defects (CHDs) was discussed; the management of acyanotic CHD was reviewed in Part I of this series. While the need for intervention in acyanotic CHD is by and large determined by the severity of the lesion, most cyanotic CHDs require intervention, mostly by surgery. Different types of tetralogy of Fallot require different types of total surgical corrective procedures, and some may require initial palliation, mainly by modified Blalock-Taussig shunts. Babies with transposition of the great arteries with an intact ventricular septum as well as those with ventricular septal defects (VSD) need an arterial switch (Jatene) procedure while those with both VSD and pulmonary stenosis should be addressed by Rastelli procedure. These procedures may need to be preceded by prostaglandin infusion and/or balloon atrial septostomy in some babies. Infants with tricuspid atresia require initial palliation either with a modified Blalock-Taussig shunt or banding of the pulmonary artery and subsequent staged Fontan (bidirectional Glenn and fenestrated Fontan with extra-cardiac conduit). Neonates with total anomalous pulmonary venous connection are managed by anastomosis of the common pulmonary vein with the left atrium either electively in non-obstructed types or as an emergency procedure in the obstructed types. Babies with truncus arteriosus are treated by surgical closure of VSD along with right ventricle to pulmonary artery conduit. The other defects, namely, hypoplastic left heart syndrome, pulmonary atresia with intact ventricular septum, double-outlet right ventricle, double-inlet left ventricle and univentricular hearts largely require multistage surgical correction. The currently existing medical, trans-catheter and surgical techniques to manage cyanotic CHD are safe and effective and can be performed at a relatively low risk.

Management of Congenital Heart Disease: State of the Art; Part I-ACYANOTIC Heart Defects

Since the description of surgery for patent ductus arteriosus in late 1930s, an innumerable number of advances have taken place in the management of congenital heart defects (CHDs). In this review the current status of treatment of seven of the most common acyanotic CHDs was reviewed. The discussion included indications for, and timing of, intervention and methods of intervention. The indications are, by and large, determined by the severity of the lesion. Pressure gradients in obstructive lesions and the magnitude of the shunt in left-to-right shunt lesions are used to assess the severity of the lesion. The timing of intervention is different for each lesion and largely dependent upon when the criteria for indications for intervention were met. Appropriate medical management is necessary in most patients. Trans-catheter methods are preferable in some defects while surgery is a better option in some other defects. The currently available medical, trans-catheter, and surgical methods to treat acyanotic CHD are feasible, safe, and effective.

An EGLN1 mutation may regulate hypoxic response in cyanotic congenital heart disease through the PHD2/HIF-1A pathway

Cyanotic congenital heart disease (CCHD), a term describing the most severe congenital heart diseases are characterized by the anatomic malformation of a right to left shunt. Although the incidence of CCHD are far less than the that of congenital heart diseases (CHD), patients with CCHD always present severe clinical features such as hypoxia, dyspnea, and heart failure. Chronic hypoxia induces hypoxemia that significantly contributes to poor prognosis in CCHD. Current studies have demonstrated that the prolyl-4-hydroxylase2 (PHD2, encoded by EGLN1)/hypoxia-inducible factor-1A (HIF-1A) pathway is a key regulator of hypoxic response. Thus, we aim to assess the associations of single polymorphisms (SNPs) of the EGLN1 gene and hypoxic response in CCHD. A missense variant of EGLN1 c.380G>C (rs1209790) was found in 46 patients (46/126), with lower hypoxia incidence and higher rate of collateral vessel formation, compared with the wild type (P < 0.05). In vitro experiments, during hypoxia, EGLN1 mutation reduced EGLN1 expression compared with the wild type, with higher HIF-1A, VEGF and EPO expression levels in the mutant. No difference in HK1 expression was observed between the mutant and wild type. CCHD patients with c.380G>C showed improved response to hypoxia compared with the wild-type counterparts. The EGLN1 c.380G>C mutation improves hypoxic response through the PHD2/HIF-1A pathway, which may provide a molecular mechanism for hypoxic response in CCHD. The effects of the EGLN1 c.380G>C mutation on CCHD prognosis deserve further investigation.

Multidetector Computed Tomography (CT) in Evaluation of Congenital Cyanotic Heart Diseases

Background

The aim of the study is to emphasize the role of 128 MSCT angiography in the diagnosis of congenital cyanotic heart diseases.

Material/Methods

This study included sixty patients and was conducted from December 2014 to July 2016 in the Multidetector CT unit of Zagazig University hospitals. All images included axial, MPR, MIP, and VRT and were interpreted in one session. Pulmonary veins were assessed for PAPVR or TAPVR, PDA, cardiac apex and heart chambers, interatrial or interventricular septal defects, pericardium, and site and size of the great veins (IVC and SVC).

Results

This study included 60 patients. Thirty-four were boys (56.7%), and 26 were girls (43.3%). The age ranged from nine months to five years, and the mean age was 34.5 months. We found the following anomalies: tetralogy of Fallot (15 patients, 25%), tricuspid atresia (12 patients, 20%), Ebstein's anomaly (4 patients, 6.5%), pulmonic atresia or stenosis (7 patients, 11.5%), truncus arteriosus (6 patients, 10%), TGA (10 patients, 17%), and TAPVR (6 patients, 10%).

Conclusions

MDCT proved to be an important modality for decision-making in patients with congenital cyanotic heart diseases.

A comparison of heart rate changes associated with levalbuterol and racemic albuterol in pediatric cardiology patients

BACKGROUND

To our knowledge, no data exist regarding the effect of levalbuterol and racemic albuterol on heart rate in pediatric cardiology patients.

OBJECTIVE

To compare heart rate change in pediatric cardiology patients receiving levalbuterol and/or racemic albuterol. The secondary objective was to identify characteristics associated with heart rate changes observed with these drugs.

METHODS

A review of electronic medical records at a pediatric academic hospital was conducted to determine the equivalence of heart rate change in patients receiving levalbuterol or racemic albuterol. Patients receiving at least 3 doses of levalbuterol and/or racemic albuterol during the study period were included if they were younger than 18 years and had a diagnosis of congenital heart disease (CHD), cardiomyopathy, or supraventricular tachycardia. Patients were excluded if they received a β-blocker or continuous racemic albuterol or did not have documented pre- and postdose heart rates.

RESULTS

One hundred ninety-two patients were included. One hundred forty-two received racemic albuterol, 40 received levalbuterol, and 10 received both racemic albuterol and levalbuterol. The mean increase in heart rate for patients receiving racemic albuterol and levalbuterol was 6.8 beats/min and 6.2 beats/min, respectively (p = 0.01). In patients with CHD, the racemic albuterol group experienced a mean heart rate increase of 6.6 beats/min compared to 6.3 beats/min in the levalbuterol group (p = 0.01). Equivalence was also determined in patients without surgical intervention and patients receiving concomitant cardiac and respiratory medications. Equivalence was not established in other analyzed subgroups secondary to insufficient sample sizes.

CONCLUSIONS

Racemic albuterol and levalbuterol were associated with increased heart rate in pediatric cardiology patients. This increase was found to be equivalent.

Diagnostic pediatric cardiac catheterization: Experience of a tertiary care pediatric cardiac centre

BACKGROUND

Cardiac catheterization was considered gold standard for confirmation of diagnosis and analyzing various management issues in congenital heart diseases. In spite of development of various non invasive tools for investigation of cardiac disorders diagnostic catheterization still holds an important place in pediatric patients.

METHODS

300 consecutive diagnostic cardiac catheterization performed since April 2007 were included in this study. The study was undertaken to evaluate the profile of patients undergoing diagnostic cardiac catheterization, its results, assess its safety and its contribution toward solving various management issues.

RESULT & CONCLUSION

Children who underwent cardiac catheterization ranged in weight from 1.6 kg to 35 kg, with their age range 0 day-12 years. The information obtained was of great importance for further management in over 90% cases. The procedure of cardiac cath is invasive, still it was proved to be quite safe even in smallest baby.