Myocardial infarction in a newborn heterozygous for the MTHFR C677T mutation

Neonatal Myocardial Ischemia-Reperfusion Injury: A Proposed Pathogenic Sequence in the Context of Maternal/Fetal Vascular Malperfusion and Paradoxical Embolism

BACKGROUND

Neonatal myocardial infarction (MI) in a structurally normal heart is frequently an obscure event that remains undiagnosed until autopsy. Causal attributions usually cite underlying maternal or fetal conditions. Refinement in understanding of pathogenic mechanisms underlying neonatal MI is key to advancements in diagnosis, prevention, treatments and prognosis.

OBJECTIVE

This study presents a 36-week gestational age female with perinatal asphyxia, congenital hemolytic anemia and umbilical vein thrombosis who sustained catastrophic MI with reperfusion injury; and it reviews pertinent literature.

RESULTS

We propose a pathogenic sequence that links maternal vascular malperfusion, fetal vascular malperfusion, hemolytic anemia, umbilical venous thrombosis, and paradoxical thromboemboli.

CONCLUSION

This case highlights the importance of placental examination in connecting complex neonatal events with adverse maternal/placental conditions. A high index of suspicion is essential for early diagnosis of neonatal MI.

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.

Erythrocytosis and severe asphyxia: two different causes of neonatal myocardial infarction

Neonatal acute myocardial infarction is a rare event that carries a high mortality rate. We describe the cases of two newborns who survived acute myocardial infarction and discuss the management. The first neonate was born with severe asphyxia and left ventricular myocardial infarction with ventricular tachycardia. In this patient, systemic flow was maintained by right-to-left shunting through the patent ductus arteriosus. The second neonate presented with a haematocrit of 80% and an inferolateral myocardial infarction. Intensive treatment of low cardiac output syndrome led to survival of both high-risk neonates. In the follow-up, at 48 and 4 months, respectively, ventricular function recovered in both patients.

Myocardial necrosis and infarction in newborns and infants

PURPOSE

This study aimed to investigate the incidence, and underlying associations, of myocardial necrosis occurring in infants undergoing autopsy.

METHODS

An autopsy database containing anonymized details of all infant autopsies conducted at Great Ormond Street Hospital between January 1996 and December 2010 was searched to identify all infants with myocardial necrosis. The characteristics of the necrosis and any underlying associations were reviewed.

RESULTS

Myocardial necrosis was recorded in 187 autopsies out of a total of 1,637 (11.4%), and was localized to the papillary muscles, subendocardial region, or trabeculae in 50.8% of cases. The most common associations were congenital heart disease, perinatal asphyxia, coronary artery abnormalities, or sepsis. Three cases of apparently idiopathic myocardial infarction were identified and are described in detail.

CONCLUSIONS

Myocardial necrosis is relatively common in infants who die and undergo autopsy, and is most commonly associated with congenital heart disease and perinatal asphyxia. Myocardial infarction can occur in infancy in the absence of any apparent underlying cause: the etiology of these cases is unclear.

Successful management of neonatal myocardial infarction with ECMO and intracoronary r-tPA lysis

Acute myocardial infarction (MI) is a life-threatening condition rarely encountered in neonates. The patients usually present with sudden cardiogenic shock. Clinical management in neonates is extremely challenging. If treatment is delayed, the prognosis is dismal. We report on a 4-day-old full-term male newborn presenting with acute MI and cardiogenic shock secondary to proximal thromboembolic occlusion of the left descending coronary artery. Hemodynamic stabilization could only be achieved after extracorporeal membrane oxygenation (ECMO) support. Coronary artery patency restoration was performed by selective intracoronary lysis with recombinant tissue plasminogen activator (r-tPA). ECMO support could be discontinued and myocardial function recovered within 6 weeks. We discuss the potential etiologies of acute perinatal MI and the role of ECMO support in the immediate post-MI period. Prompt recognition, timely referral to a cardiac center with availability of specialized advanced treatment options, and management in an orchestrated interdisciplinary approach are crucial for achieving a good outcome.