Paradoxical embolism causing fatal myocardial infarction in a newborn infant

Neonatal Myocardial Infarction: A Proposed Algorithm for Coronary Arterial Thrombus Management

BACKGROUND

Neonatal myocardial infarction is rare and is associated with a high mortality of 40% to 50%. We report our experience with neonatal myocardial infarction, including presentation, management, outcomes, and our current patient management algorithm.

METHODS

We reviewed all infants admitted with a diagnosis of coronary artery thrombosis, coronary ischemia, or myocardial infarction between January 2015 and May 2021.

RESULTS

We identified 21 patients (median age, 1 [interquartile range (IQR), 0.25-9.00] day; weight, 3.2 [IQR, 2.9-3.7] kg). Presentation included respiratory distress (16), shock (3), and murmur (2). Regional wall motion abnormalities by echocardiogram were a key criterion for diagnosis and were present in all 21 with varying degrees of depressed left ventricular function (severe [8], moderate [6], mild [2], and low normal [5]). Ejection fraction ranged from 20% to 54% (median, 43% [IQR, 34%-51%]). Mitral regurgitation was present in 19 (90%), left atrial dilation in 15 (71%), and pulmonary hypertension in 18 (86%). ECG was abnormal in 19 (90%). Median troponin I was 0.18 (IQR, 0.12-0.56) ng/mL. Median BNP (B-type natriuretic peptide) was 2100 (IQR, 924-2325) pg/mL. Seventeen had documented coronary thrombosis by cardiac catheterization. Seventeen (81%) were treated with intracoronary tPA (tissue-type plasminogen activator) followed by systemic heparin, AT (antithrombin), and intravenous nitroglycerin, and 4 (19%) were treated with systemic heparin, AT, and intravenous nitroglycerin alone. Nineteen of 21 recovered. One died (also had infradiaphragmatic total anomalous pulmonary venous return). One patient required a ventricular assist device and later underwent heart transplant; this patient was diagnosed late at 5 weeks of age and did not respond to tPA. Nineteen of 21 (90%) regained normal left ventricular function (ejection fraction, 60%-74%; mean, 65% [IQR, 61%-67%]) at latest follow-up (median, 6.8 [IQR, 3.58-14.72] months). Two of 21 (10%) had residual trivial mitral regurgitation. After analysis of these results, we present our current algorithm, which developed and matured over time, to manage neonatal myocardial infarction.

CONCLUSIONS

We experienced a lower mortality rate for infants with neonatal infarction than that reported in the literature. We propose a post hoc algorithm that may lead to improvement in patient outcomes following coronary artery thrombus.

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.

Massive perinatal left ventricle infarction treated with tissue plasminogen activator: No ECMO - A case report

Neonatal myocardial infarction due to coronary thrombus is a rare cause of acute heart failure and is associated with high morbidity and mortality. We present a rare case of a full-term newborn who developed coronary artery thrombus treated with intracoronary recombinant tissue plasminogen activator infusion while undergoing therapeutic hypothermia. Also, we describe a unique treatment strategy to support systemic circulation sparing the patient from neonatal extracorporeal membrane oxygenation and its complications. Neonatal myocardial infarction should be suspected and ruled out in sick newborns.

Abdominal aortic thrombus formation in a neonate with an interrupted aortic arch

We note the risk of paradoxical embolism in patients with congenital heart defects with a right-to-left shunt. These patients should be managed to ensure that abdominal aortic thrombi are not overlooked when their clinical conditions change.

Myocardial Infarction in Neonates: A Diagnostic and Therapeutic Challenge

Neonatal acute myocardial infarction is an uncommon entity. We describe the case of a 4-day-old term baby who presented with respiratory distress and distal acrocyanosis. The chest radiograph demonstrated cardiomegaly without pleural effusion, and examination revealed hepatomegaly. An electrocardiogram revealed QS pattern in leads I, aVL, and V6, suggestive of ischemia. Cardiac enzymes were elevated, and echocardiogram revealed moderate left ventricular dysfunction with a thrombus at the level of the left atrial appendage. The patient required hemodynamic stabilization, vasodilatation to avoid congestive heart failure, and anticoagulation with heparin and aspirin. In the context of this unusual diagnosis, we reviewed our experience over the last 17 years as well as the existing literature on neonatal myocardial infarction.

Early survival following in utero myocardial infarction

Intrauterine myocardial infarction is a rare and frequently fatal diagnosis. It has been presented in the literature only as case reports and short series. We present a case report of a coronary occlusive intrauterine myocardial infarction and survival and present a systematic review of the literature. This is the first summative description of current data on intrauterine and perinatal myocardial infarction. We performed the systematic review based on the guidelines established by the PRISMA statement. Our population of intrauterine and perinatal myocardial infarction included published cases who presented as a live birth within the first 28 postnatal days, and had a diagnosis of myocardial infarction. We conducted descriptive statistics and regression analysis on short-term mortality as the primary outcome. After applying exclusion criteria we described 84 individual cases of myocardial infarction from 63 full-text articles including our own case. Presentation within the first 12 hours was associated with mortality (OR 3.90, p=0.004). Treatment modalities were varied and inconsistently recorded. The aetiologies and comorbidities are varied in our systematic review. We would have a low threshold to perform viral testing, consider anticoagulation early and coronary imaging if feasible. The use of extracorporeal membranous oxygenation may serve as a bridge to cardiac recovery.

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.

Tissue plasminogen activator for neonatal coronary thrombosis presenting with mitral valve regurgitation and impaired ventricular function

OBJECTIVE

Neonatal coronary thrombosis is a rarely reported disorder, with variable outcomes described. This study assessed the feasibility and safety of an institutional protocol using tissue plasminogen activator (tPA) administration for the treatment of neonatal coronary artery thrombi.

METHODS

They reviewed the outcome of three neonates with clinical evidence of myocardial infarction secondary to coronary thrombosis. All three underwent the tPA treatment protocol.

RESULTS

The three described cases presented at 5 hours, 15 hours, and 10 days of life. The patients identified underwent the tPA protocol at least once. There was clinical evidence of improvement in coronary flow, as well as demonstration of increased left ventricular function and decreased mitral regurgitation. No major adverse events occurred.

CONCLUSION

Thrombolytic therapy with this tPA protocol may be safe and effective in treating neonates with coronary thrombosis.

Neonatal acute myocardial infarction of unknown etiology treated with surgical thrombectomy

Coronary artery thrombosis and resultant myocardial infarction in neonates are exceedingly rare. Seldom does a neonate survive this myocardial insult. Often there is an underlying predisposition to coronary artery thrombosis, such as thrombophilia, central line placement, or myocarditis. Treatment attempts have consisted of thrombolysis and supportive care. We present a case of acute left main coronary artery (LMCA) thrombosis of unknown etiology in a neonate, without ventricular dilatation. Flow into the LMCA was suggested echocardiographically, but a high clinical suspicion led to urgent cardiac catheterization. Once complete occlusion of the LMCA was demonstrated angiographically, emergent surgical thrombectomy was performed, which has never previously been reported.

Myocardial infarction in a newborn heterozygous for the MTHFR C677T mutation

Neonatal myocardial infarction secondary to congenital heart disease, anomalous coronary artery anatomy, thromboembolism, coagulopathy, birth asphyxia, and unknown causes has been previously reported. We now report an infant who suffered a massive myocardial infarction during birth, requiring extensive resuscitation and aggressive management. A thrombus, the origin of which was not detected on autopsy, was found occluding the proximal left coronary artery several hours after birth. Genetic studies revealed a single copy variant of the MTHFR C677T mutation that we speculate may have predisposed the infant to coronary thrombosis.

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.

Neonatal myocardial infarction or myocarditis?

We report a 29 week-gestation preterm infant who presented during his second week of life with cardiogenic shock. Clinical presentation and first diagnostics suggested myocardial infarction, but echocardiographic features during follow-up pointed to a diagnosis of enteroviral myocarditis. The child died of chronic heart failure at 9 months of age. Autopsy showed passed myocardial infarction. No signs for active myocarditis were found. We discuss the difficulties in differentiating between neonatal myocardial infarction and myocarditis. Recognizing enteroviral myocarditis as cause for cardiogenic shock is of importance because of the therapeutic options.

Staphylococcus aureus Septicemia with a fatal transmural myocardial infarction in a 27-week-gestation twin infant: a case study

Septicemia, one of the major causes of morbidity and mortality in the neonatal period, often has a rapid and fulminant course. Low-birth-weight infants with persistent Staphylococcus aureus septicemia, possibly associated with percutaneous central venous catheters, may develop metastatic infections including endocarditis with large vegetations. This article describes a neonate with S. aureus bacteremia that resolved with treatment who died secondary to decreased left ventricular function. At autopsy, organizing microthrombi were seen within both atria, the left ventricle, and the left coronary arterial system. Extensive infarcts were noted throughout the entire myocardium of the left ventricle. It was suspected, but not proven, that the thrombotic sequelae from septicemia caused this neonate's death.

Neonatal myocardial infarction due to thrombotic occlusion

Neonatal myocardial infarction is rare and its prognosis is poor. We describe the clinical course and autopsy findings of a newborn female with myocardial infarction. Her clinical course was rapidly progressive, becoming fatal before we could detect the cause. Autopsy demonstrated significant occlusion of the left coronary artery as well as evidence of new infarction, suggesting that the event occurred at birth. This case illustrates myocardial infarction as a possible cause of early neonatal death.

Instant percutaneous closure of patent foramen ovale in patients with acute myocardial infarction and normal coronary arteries

Two young women with angiographically normal coronary arteries suffered an acute myocardial infarction. Both were found to have a patent foramen ovale (PFO), the likely pathway of a paradoxical embolus causing the infarction. The PFOs were diagnosed and closed percutaneously with an Amplatzer PFO Occluder during the emergency coronary angiography.

Myocardial ischemia: atypical presentation of an atrial septal defect in childhood

We describe a 17-year-old male with a secundum atrial septal defect (ASD), who presented with acute myocardial ischemia. The presumptive diagnosis of a paradoxical coronary embolism was based on the demonstration of a large ASD in conjunction with normal coronary arteries, a negative endomyocardial biopsy, and a negative drug screen. After percutaneous closure with an Amplatzer device, there has been no recurrence for 2 years.

Acute myocardial infarction in a child: possible pathogenic role of patent foramen ovale associated with heritable thrombophilia

We report an 8-year-old girl who presented with clinical features of an acute myocardial infarction. The angiographic appearance of the coronary arteries was normal. A thrombophilic state caused by a homozygote genotype for the prothrombin G20210A mutation was detected, and a patent foramen ovale (PFO) with right-to-left shunting after Valsalva maneuver was demonstrated by transesophageal contrast echocardiography. No other embolic source was identified. We suggest that paradoxical embolization through a PFO resulted in a myocardial infarction in this young patient with hereditary thrombophilia. We closed the patient's PFO with a 25-mm PFO occluder. She was anticoagulated with warfarin for 6 months. After 6 months, a contrast echocardiogram showed no evidence of residual atrial shunt. There has been no evident recurrent paradoxical embolization.

Paradoxical embolism to the left main coronary artery: visualization by transesophageal echocardiography

A case of myocardial infarction is described with transesophageal echocardiography visualization of left main coronary artery thrombus arising from paradoxical embolism of mobile venous thrombus by patent foramen ovale.