Myocardial infarction in the neonate with normal heart and coronary arteries

Acute myocardial infarction in a premature infant on the first day of life

Neonatal myocardial infarction (MI) is a very rare but potentially life-threatening condition with an approximated mortality rate of 80%. Congenital heart disease, anomalous coronary artery anatomy, thromboembolism, coagulopathy, birth asphyxia or myocarditis have been suggested as possible causes of MI. Here we report the case of a premature infant who died at about 40 h of life from a massive MI. Autopsy revealed an occlusive thrombus in the right coronary artery. An isolated prothrombotic status, characterized by a double copy variant of the MTHFR A1298C mutation, was identified at the postmortem genetic studies as a possible explanation for the coronary artery thrombosis. No other risk factors were detected.

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.

Neonatal myocardial infarction secondary to umbilical venous catheterization: A case report and review of the literature

Neonatal acute myocardial infarction (MI) is a rare event, with a high mortality rate. Early recognition and intensive care management can be successful, and it requires a high index of suspicion in cases of unknown cardiogenic shock. The lack of access to cardiac catheterization should not delay management. Furthermore, there is great potential for myocardial regeneration to occur in surviving neonates with MI, emphasizing the importance of early recognition and management. The present report describes a neonate with an anatomically normal heart and coronary arteries who developed clinical, laboratory and electrocardiographic features of MI, and was managed successfully with fluid resuscitation, inotropic drugs and vasodilators.

Role of ECMO in neonatal myocardial infarction

A neonate with myocardial infarction who failed to respond to conventional treatment was supported by extracorporeal membrane oxygenation (ECMO). Severe mitral valve regurgitation necessitated mitral valve replacement while receiving ECMO following which the infant was successfully weaned. ECMO should be considered for potentially treatable causes of catastrophic heart failure.

Survival of a neonate after myocardial infarction complicated by late mitral regurgitation

A neonate born with a normal heart developed acute myocardial infarction at 12 days of age. Trivial mitral regurgitation secondary to fibrosis of posteromedial papillary muscle progressed to heart failure at 6 months of age. Mitral valve annuloplasty improved her condition.

Myocardial infarction in childhood: clinical analysis of 17 cases and medium term follow up of survivors

Between 1979 and 1989 17 patients aged two months to 12 years with acute myocardial infarction of any cause (other than after cardiac surgery) were seen at a children's hospital. Eight died from three days to three years after diagnosis (overall mortality 47%). The nine survivors, now aged 2-17 years, have been followed for one to 10 years (mean follow up five years) after infarction. The commonest causes of myocardial infarction in this series were anomalous origin of left coronary artery from the pulmonary artery (six patients (35%] and Kawasaki disease (five patients (27%]. The main symptoms of acute myocardial infarction were dyspnoea, vomiting, and difficulty feeding. Diagnosis was made in all patients by electrocardiography and confirmed by echocardiography, cardiac catheterisation, or at operation. All survivors were symptom free with excellent exercise capacity. The left ventricular ejection fraction in survivors ranged from 21% to 66%, and only one child was on regular cardiac medications. There were no cases of late sudden death. Twenty four hour Holter monitoring performed on survivors was normal (seven) or showed minor abnormalities only (one), suggesting that serious arrhythmia is rare after paediatric myocardial infarction. Myocardial infarction in children had a high early mortality; however, the incidence of serious arrhythmia was low in the survivors, who had a good exercise tolerance even when the left ventricular ejection fraction was low.