Infants may present with tachypnea, sudden onset of cyanosis or pallor that may worsen with crying, sweating with feeds, lethargy, or failure to thrive. With the newborns first breath outside the uterus, pulmonary vascular resistance (PVR) decreases due to the increase in oxygen tension, leading to an increase in pulmonary blood flow. PVR continues to decrease and the right ventricle reaches adult pressures by day 10 of life.
Congenital heart disease lesions that present in the first two to three weeks of life are typically the ductal-dependent cardiac lesions. The patent ductus arteriosus had been sustaining blood flow for these infants and when the ductus closes after birth, these infants suddenly become ill. Depending upon the underlying structural abnormality, these neonates will present with either sudden cyanosis or signs of cardiovascular collapse. With certain lesions, the patent ductus arteriosus supplies the only adequate source of blood flow to the lungs (e.g. Tetralogy of Fallot or Tricuspid Atresia) – cyanotic congenital heart disease; in others, the newborn is dependent upon the PDA to allow adequate blood flow to the body if the aorta is severely underdeveloped. (e.g. coarctation of the aorta or hypoplastic left heart syndrome). For example, with coarctation of the aorta, right ventricular blood is ejected through the patent ductus to supply the descending aorta, as it does during fetal life. Perfusion of the lower body is then dependent on right ventricular output.
The cyanotic infant should be placed on 100% oxygen. If the oxygen saturation increases significantly, then the infant probably has pulmonary pathology. If the oxygen saturation does not increase, then consider a congenital heart disorder. The more accurate way to perform this test is to obtain a baseline ABG which is repeated after approximately 10 minutes of oxygen administration. An increase in the PAO2 of 30 torr or more or an increase in saturation of greater than 10% implies a pulmonary process.
If ductal-dependent congenital heart disease is suspected, then a prostaglandin E1 infusion (PGE1) should be initiated at a rate of 0.05-0.1ug/kg/minute. Prostaglandin is a very potent vasodilator and will have immediate effects on the ductus. Improvement is usually seen within fifteen minutes; however, the practitioner should be prepared to intubate since there is an approximately 12% incidence of apnea following PGE1 initiation. Other complications of prostaglandin use include fever, hypotension and seizures.
Always consider sepsis, and have a low threshold to empirically treat for it pending a more thorough work-up.
The differential diagnosis of congenital heart diseases that cause congestive heart failure include not only the left-to-right intracardiac shuns but also hypoplastic left ventricle, coarctation of the aorta, truncus arteriosus, endocardial cushion defect, patent ductus arteriosus (PDA), and aortic stenosis (6,7). Time of presentation of each lesion is listed in Table 5. If the patient has congestive heart failure furosemide (1 mg/kg) should be administered with the possible addition of digoxin, morphine, dobutamine and dopamine.
Presentations of CHD to EDs:
Infants with previously unrecognized CHD who present with acute and profound systemic hypoperfusion or cyanosis during the neonatal period often have a ductus arteriosus-dependent cardiac lesion . These patients may seem normal after birth, but are ductal-dependent for mixing of their systemic and pulmonary circulations or for providing pulmonary or systemic blood flow. When their ductus arteriosus closes, they develop varying degrees of systemic hypoperfusion and cyanosis. We had one such patient in our case series. This patient suffered from a complex coarctation of the aorta with ductal-dependent systemic blood flow and presented with systemic hypoperfusion at 1 week of age. The patient was initially treated with endotracheal intubation, fluid resuscitation, and prostaglandin E1 (PGE1) infusion. He subsequently underwent successful surgical repair of his underlying CHD. PGE1 infusion is vital for patients who are reliant on the patency of their ductus arteriosus for survival . PGE1 therapy should be instituted immediately in a critically ill infant presenting with acute cyanosis or severe systemic hypoperfusion in whom ductal-dependent CHD is suspected. If the patient’s condition and logistical considerations allow it, utilizing echocardiography to confirm CHD before PGE1 infusion is desirable. This strategy will reduce the frequency with which PGE-1 is used unnecessarily while ensuring that critically ill CHD patients receive this life-saving therapy. PGE1 infusion is typically started at .05 ug/kg/min. The most common serious side effect is dose-dependent hypotension [8 and 9]. Respiratory depression and fever are also known complications of therapy, but should not prompt the discontinuation of the PGE1 infusion. Response to therapy is determined by assessing systemic perfusion (blood pressure, capillary refill, lactic acidosis) and pulmonary blood flow (mucosal color, pulse oximetry). PGE1 therapy in patients with TAPVR may be detrimental . Patients with TAPVR have limited systemic blood flow, and PGE1 may occasionally diminish this and result in worsening systemic perfusion. We had one patient with TAPVR of the infradiaphragmatic type who was surgically treated. Five of the eight patients without a pre-existing diagnosis of CHD in our study presented with pulmonary edema. Pulmonary edema in infancy is often the result of left to right heart shunt lesions. These lesions often go undetected in early infancy because high PVR precludes excessive PBF . Infants with previously subclinical left to right heart shunt lesions often develop symptoms between 2 and 6 months of age, when their PVR diminishes to the point where excessive PBF occurs. These infants typically present with progressive respiratory distress (tachypnea, wheezing, and feeding difficulties). Parents may mention decreased activity or excessive perspiration during feeding attempts and a shortened duration of feedings . Weight gain is poor as a result of their increased metabolic demands coupled with their diminished feeding capacity, and they often receive the diagnosis of failure to thrive . Increased pulmonary vascular markings and cardiomegaly are typically seen on chest radiographs . Three of our five patients with pulmonary edema had this presentation pattern; their ages ranged from 4 to 6 months. For the two remaining patients presenting with pulmonary edema, one suffered from critical aortic stenosis and the other with acute cardiogenic shock secondary to a myocardial infarction arising as a complication of an anomalous left coronary artery. Although acquired disorders were excluded from our study population, acute myocarditis and dysrhythmias are additional causes of infant pulmonary edema [15 and 16]. The new diagnosis of CHD as an incidental finding occurred only once in our series. This is the likely result of the inclusion criteria for our study, which required the presence of an acute serious illness resulting in hospital admission. One patient who underwent inpatient management of sepsis was noted to have a pathologic sounding murmur on physical examination. His murmur was ultimately attributed to increased pulmonary artery blood flow resulting from a moderate-sized atrial septal defect documented by echocardiography. The preponderance of pediatric CHD patients in our series (69/77) already had an established diagnosis of CHD at the time of their ED visit. These patients tended to have complex CHD. Despite being hospitalized, 9% (7/77) of the patients in this study died during their hospital course. Of note, all 7 deaths occurred in patients with a pre-existing history of complex CHD. The broad range of CHD-related and non-CHD-related illnesses bringing these patients to the ED precluded simple categorization. Despite the difficulty classifying all patient visits, several presentation patterns, each with its own distinct pathophysiologic basis, commonly occurred. Twenty-two percent (15/69) of our study patients had acute respiratory distress or worsening cyanosis due to acute decreases in PBF at the time of their ED presentation. Patients with baseline limited PBF are extremely sensitive to acute alterations in PVR. Simple respiratory infections (e.g., acute bronchiolitis) are potential life threats in this patient subset . These otherwise routine respiratory infections may lead to increased PVR and markedly decreased PBF, leading to profound hypoxemia . Accordingly, lower respiratory tract infections must be viewed as potentially life threatening to this patient subset. Management of these patients consists of intravascular volume repletion, treatment of underlying infections, and supportive respiratory care . Hypercyanotic spells (Tet spells) led to life-threatening alterations in PBF in four of our patients. A hypercyanotic spell is a hypoxic episode that results from a vicious cycle of increasing PVR, diminished PBF, and worsening cyanosis. These spells may be precipitated by agitation, crying, or hypotension. Originally described in Tetralogy of Fallot patients, other types of CHD patients with limited PBF resulting from dynamic subpulmonic stenoses suffer similar episodes . Initial treatment involves calming patients and placing them in a knee-to-chest position. Failing this, further measures include oxygen administration, intravenous fluid bolus administration, morphine injection, bicarbonate infusion, phenylephrine infusion, ketamine administration, propranolol infusion, or manual external compression of the abdominal aorta [21, 22, 23, 24 and 25]. The objectives of these interventions are to maximize SVR, restore intravascular volume, and minimize PVR. This will maximize the PBF and resultant blood oxygenation in these patients. Left untreated, these episodes may lead to cerebral hypoperfusion, syncope, and death [26, 27, 28 and 29]. CHD patients with markedly limited pulmonary or systemic blood flow are extremely intolerant of hypovolemia. Illnesses causing intravascular volume loss, such as gastroenteritis, must be treated aggressively, because hypovolemia may lead to hypoxemia or systemic hypoperfusion. Twenty percent (14/69) of patients with known CHD in our study had this presentation. Management of these patients involves intravenous rehydration (e.g., 10 ml/kg NS fluid boluses) until volume repletion is achieved. In addition, dehydration may predispose palliative shunts (e.g., Blalock-Taussig shunt) to thrombosis. Shunt thrombosis may precipitate a rapid decline in a patient’s clinical status . It is often characterized by a loss of a shunt murmur and varying degrees of hypoxemia and cyanosis. One patient in our series developed refractory cardiac arrest due to a thrombosed Blalock-Taussig shunt. Shunt obstruction may be confirmed by echocardiography and therapies include anticoagulation, thrombolytics, or emergent surgical revision . The presentation pattern of 64% (44/69) of our patients with a pre-existing history of CHD fell into the miscellaneous presentation category (Table 2). Heart failure was the diagnosis in 30% (13/44) of these patients. Heart failure was defined as the inability of a patient’s heart to provide appropriate systemic and pulmonary blood flow to satisfy the patient’s baseline physiologic needs. The spectrum of conditions leading to heart failure was diverse. It included simple CHD conditions with excessive left to right heart shunting of blood with resultant excessive PBF as well as complex CHD conditions such as patients with a single ventricle that was failing to provide adequate pulmonary and systemic blood flow. Although chest radiography was helpful in the former condition, the latter condition often required more extensive confirmatory diagnostic testing (e.g., cardiac catheterization). Respiratory tract infections were the most common non-CHD-related diagnoses and were documented in 36% (16/44) of CHD patients in the miscellaneous category. (JEM April 2003)
Hemodynamically Unstable Patients
Maintain ABCs. Fluid Bolus
Shunt-Dependant Congenital Lesions
PGE1 0.05 to 0.1 ug/kg/min increasing to 0.2 if no improvement
Cardiogenic Shock from Acquired Cardiomyopathies
Most cases are idiopathic
If there is an identified cause, coxsackie enterovirus will be the most common agent. CPK will be elevated.
Keep the infant in quiet comfortable environment. Administer O2
Lasix 1 mg/kg can be administered.
Can cause sudden death, dysrhythmia, and ischemia.
Autosomal dominant inheritance
Irregular left ventricular hypertrophy or septal hypertrophy.
Problems are caused by diastolic dysfunction, hence the goal is to improve L ventricular diastolic filling. Reducing heart rate allows more time for filling. Decreasing muscle tension also allows easier filling. B and calcium channel blockers achieve these goals.
Normal Newborn HR is 85-205. Sinus tach should not exceed 220 bpm.
Age HR BP Neonate 85-205 60-80 SBP by palp 1 yr 100-130 80/40-105/70 5 yr 80-110 80/50-110/80 10 yr 70-100 90/55-130/85 15 yr 60-80 95/60-140/90 Adult 60-80 100/60-140/90
Medication vs. shock @ 0.5-1 J/kg
Adenosine 0.05 mg/kg increasing to 0.1 or 0.15 mg/kg (max 12 mg/dose)
hypoxemia and vagal stimulation are the most common causes
epi 0.01 mg/kg 1:10000 dilution. If epi is not effective, atropine 0.02 mg/kg, minimum .1 mg
Stable Symptomatic Patients
>5 g/dl of deoxygenated hemoglobin. Acrocyanosis (confined to hands and feet) is a normal variant in newborns. Central cyanosis is a sign of systemic hypoxemia. May need hyperoxia test to evaluate for cardiac disorder. Get baseline ABG then place on 100% O2 and repeat the ABG. It is positive if < 100 mm Hg. Get c-xr and 12 lead.
Congestive Heart Failure
Sweating during feeding is equivalent to dyspnea on exertion.
Acute Rheumatic Fever
<45o in infants, 440 in children, and 430 in adolescents.
Problems in Children with Known Heart Disease
Hypoxemic (Tet) Spells
cyanosis, rapid respirations, floppy, decreased mental status,
Calm the child, administer 100% O2, place in knee to chest position
If the spell continues, give morphine 0.1 mg/kg and fluid bolus. If they still persist, give esmolol 0.5 to 0.6 mg/kg over 1 minute followed by an infusion at 0.2 mg/kg/min
Suspect if murmur disappears
Pulmonary Hypertensive Crisis
Alkalinization and 100 O2.
Subacute Bacterial Endocarditis
Get at least 2 sets of cultures before antibiotics.
Most often presents in children with bradycardia.
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