Myocardial Infarction in Neonates: A Review of an Entity with Significant Morbidity and Mortality.

Coronary artery disease is a global problem with high mortality rates and significant residual sequelae that affect long-term quality of life. Myocardial infarction (MI) in neonates is a recognized, uncommon entity, but the incidence and broad spectrum of the disease is unknown and likely underestimated due to limited reporting which in the majority is confined to acute ischemic events. The challenges involve clinical diagnosis which masquerades in the early phase as non-specific symptoms and signs that are commonly found in a host of neonatal disorders. Precise diagnostic criteria for neonatal MI are lacking, and management is driven by clinical presentation and hemodynamic stabilization rather than an attempt to rapidly establish the root cause of the condition. We conducted a review of the published reports of neonatal MI from 2000 to 2014, to establish an approach to the diagnosis and management based on the existing evidence. The overall evidence from 32 scientific articles stemmed from case reports and case series which were graded as low-to-very low quality. Neonatal MI resembles childhood and adult MI with features that involve characteristic ECG changes, raised biomarkers, and diagnostic imaging, but with lack of robust, standardized criteria to facilitate prompt diagnosis and timely intervention. The mortality rate of neonatal MI ranges from 40 to 50% based on inclusion criteria, but the short-term data reflect normal quality of life in survivors. An algorithm for the diagnosis and management of neonatal MI may optimize outcomes, but at the present time is based on limited evidence. Well-designed clinical studies focusing on the definition, diagnosis, and management of neonatal MI, backed by international consensus guidelines, are needed to alter the prognosis of this serious condition.

Incidence and Management of Thrombotic and Thromboembolic Complications Following the Norwood Procedure: A Systematic Review.

BACKGROUND: The stage 1 Norwood procedure and its variants represent the first step of palliation for hypoplastic left heart syndrome. Although appropriate postoperative thromboprophylaxis is integral, significant variance remains across institutional practices. The purpose of this systematic review is to estimate the incidence of thrombosis and thromboembolism following the Norwood or modified Blalock-Taussig shunt procedure and examine current thromboprophylaxis regimens. METHODS: Ovid MEDLINE and Embase were searched from January 2000 to June 2016 for primary studies explicitly reporting incidence of thrombosis, thromboembolism (strokes and pulmonary embolisms), or shunt occlusion in neonates, infants, and children undergoing the Norwood procedure or any variant. All-cause mortality was a secondary outcome of interest. RESULTS: Of 887 identified articles, 15 cohort studies were deemed eligible, the majority including modified Blalock-Taussig shunt patients. Reported incidence of thrombosis ranged from 0% to 40%; thromboembolic events were rarely reported. Overall mortality ranged from 4.5% to 31.3% across studies. Although most studies involved the long-term acetylsalicylic acid use, thromboprophylaxis strategies varied across studies. Due to substantial variability in event rates, no correlation was identified with thrombotic complications. DISCUSSION: Clinical practice guidelines recommend that patients receive intraoperative unfractionated heparin therapy and either aspirin or no antithrombotic therapy postoperatively. Our findings suggest a substantial risk of thrombosis and thromboembolism and demonstrate substantial variation in thromboprophylaxis practices. CONCLUSION: Although postoperative thromboprophylaxis seems optimal, it remains controversial whether the long-term aspirin use is most effective. Our findings highlight the lack of a gold-standard thromboprophylaxis strategy and emphasize the need for more consistency.

Patent foramen ovale and stroke in childhood: A systematic review of the literature.

BACKGROUND: Stroke in association with a patent foramen ovale (PFO) may be due to paradoxical embolization via a right to left intracardiac shunt but the exact contribution of PFO to stroke or stroke recurrence in childhood remains unclear. METHODS: To review the relationship of a PFO with stroke, and evaluate associated co-morbidities. An electronic database literature search of Pubmed, Cochrane and EMBASE was performed from January 2000-December 2014. RESULTS: 149 articles were retrieved, with overlap for diagnosis, management, treatment and outcome. 65 reports were utilized for the comprehensive review. Majority of childhood arterial ischemic stroke and transient ischemic attacks are associated with prothrombotic disorders or arteriopathy. Transthoracic echocardiography with a Valsalva maneuver is highly sensitive as a screening tool but may be falsely positive. Transthoracic echocardiography with color Doppler and a concurrent bubble contrast study are excellent for visualizing the atrial septum and PFO and identifying a right to left shunt. Current literature does not support PFO closure for cryptogenic stroke in young adults without an associated risk of thromboembolism. CONCLUSIONS: High quality research in the pediatric population is lacking and most of the data is extrapolated from adults. Paradoxical embolism from a PFO as a cause of transient ischemic attack or stroke is a diagnosis of exclusion. PFO closure should be individualized based on significant shunting and risk factors such that maximum benefit is derived from the procedure. A young person with a PFO and stroke should be thoroughly investigated to rule out other etiologies.

Postnatal Outcome of Fetal Left Ventricular Hypertrabeculation/Noncompaction.

Left ventricular hypertrabeculation/noncompaction (LVHT) is a cardiac abnormality of unknown etiology. Prenatal diagnosis of LVHT can be established by fetal echocardiography. A review of 106 published cases showed that 46 cases with prenatally diagnosed LVHT were alive 0.5-120 months after birth. Since the course of cases with prenatally LVHT after publication is unknown, we aimed to collect follow-up-information. Information regarding vital status, cardiac and extracardiac morbidity was gathered by contacting the authors of the 46 cases. Fourteen of the 28 authors answered and gave information about 18 cases (six females, seven males, five gender-unknown, age 18 months to 10 years, mean follow-up 60 months). No differences were found between the 18 cases with follow-up and the 28 cases without follow-up regarding age, gender, cardiac or extracardiac comorbidities, and interventions. Three of the 18 cases had died subsequently from heart failure, osteosarcoma, and enterocolitis, respectively. Mutations or chromosomal abnormalities were found in six of the seven examined patients, extracardiac abnormalities in nine patients. Three patients received a pacemaker because of complete AV block, and two patients underwent heart transplantation. Cardiac surgical or interventional procedures were carried out in four patients. None suffered from malignant arrhythmias or had a cardioverter-defibrillator implanted. Based on the limited information, there are indications that cases with fetal diagnosis of LVHT have a continuing morbidity and mortality, even if they receive appropriate care. Since fetal LVHT is frequently associated with genetic abnormalities, further research about survival and underlying genetic causes is needed.

Acquired unilateral pulmonary vein atresia in a 3-year-old boy.

While unilateral pulmonary venous atresia (UPVA) most commonly presents as an extremely rare late embryological defect resulting in complete occlusion or absence of the PV pathway, it may also be an acquired pathology. We present a 3-year-old boy who presented with mild respiratory distress. Neonatal echocardiographic investigations revealed normal mediastinal anatomy and pulmonary vasculature with a bicuspid aortic valve. However, follow-up Doppler investigation revealed a pulmonary artery size difference with minimal forward flow and reverse flow during diastole. Absence of the left pulmonary veins and the presence of collaterals draining to the innominate vein confirmed the diagnosis of acquired UPVA. Our case represents the first case of acquired UPVA in conjunction with a normally functioning bicuspid aortic valve. The Doppler flow patterns discussed might be of significant interest to pediatricians, cardiologists and imaging specialists. These findings suggest that acquired UPVA should be considered in the differential diagnosis of such patients when radiographic and echocardiographic findings may rule out other more common diagnoses. While the management of such a condition remains unclear and conservative management was agreed upon for our patient, the vulnerability of such cases warrants timely diagnosis and routine monitoring.

Upcoming biomarkers for the diagnosis of Kawasaki disease: A review.

Kawasaki disease (KD) is a major cause of acquired heart disease among children and increases the risk of myocardial infarction. While the biochemical basis of the disease is unclear, the evidence suggests interplay between a microbial infection and a genetic predisposition in the development of the disease. Diagnosis of KD based on clinical observation is not completely reliable and is problematic due to the time-sensitive nature of the disease. Hence, identification of inflammatory, proteomic, and genetic biomarkers may assist in earlier and more effective diagnosis and treatment. This review of observational studies and clinical trials analyzes biomarkers in recent research that may be used to establish a gold standard test for KD diagnosis. 65 articles in the literature are assessed to investigate these new biomarkers in addition to biomarkers presently in use. ESR≥40mm/h, leukocyte count ≥16∗10(9)/L and increased WBC count are together suggestive of the presence of KD. Among proteomic biomarkers, elevated NT-proBNP and differing levels of several other proteomic biomarkers such as iNOS in monocytes and neutrophils have been observed in KD patients. Genetic polymorphisms of six HLA class I genes have also been linked with the disease, alongside MICA alleles A4 and A5.1. The results suggest that NT-proBNP is currently a very promising biomarker for future investigation; further research is warranted to allow for accurate and early detection of the disease using this biomarker.

Anomalous systemic vessel to the lung with hypoplastic left heart syndrome in a fetus.

We report a case of a fetus with hypoplastic left heart syndrome in addition to an anomalous vessel extending from the descending thoracic aorta to the basal segments of the lower left lung without sequestration. The concurrence of these 2 congenital abnormalities is extremely rare and unreported in the existing literature. The anomalous vessel to the left lung may cause increased pulmonary vascular resistance, which has implications for the long-term management of hypoplastic left heart syndrome via the Fontan procedure.

Thrombosis and embolism in pediatric cardiomyopathy.

The management of cardiomyopathy in pediatric patients is complicated by the risk of cardiac-associated embolism. This review examines the incidence, risk factors, and treatment of embolism in dilated cardiomyopathy (DCM), restrictive cardiomyopathy (RCM), and noncompaction of the left ventricular myocardium (NLVM) in children. The reported incidence of embolism for DCM ranges from 1 to 16%. Left ventricular ejection fraction below 25% or fractional shortening below 15% are major risk factors for intracardiac thrombus formation in this group. The risk of embolism for RCM ranges from 12 to 33%. Atrial dilation is considered the major risk factor. The reported incidence of embolism for NLVM ranges from 0 to 38%, with most studies indicating an absence of detectable thrombus or embolus. Severe systolic dysfunction exacerbates the risk of embolism in this group. On the basis of these risk factors, we propose an algorithm for the management of embolism in these groups of patients.