apls cardiovascular system

Cardiovascular System I

Objectives• Present the clinical features and

emergency management of cardiovascular disorders, including:– Recognize congenital and acquired heart

disease.– Outline management of ductal dependent

lesions.– Identify patients with myocarditis.

Congenital Heart Disease: Recognition and Stabilization

• Rapid cardiopulmonary assessment to recognize and manage life-threatening illness caused by heart disease

• Understand the physiology of different conditions to optimize treatment plans.

Critical Concepts• Dysrhythmias can cause serious

cardiovascular compromise.• Structural congenital heart disease can

present in many different ways at many different ages.

• Acquired heart disease can be subtle yet life-threatening.

Case Study 1:“Rapid Breathing”

• 10-day-old infant is brought to ED by mother for rapid breathing and not eating well.

• Product of normal spontaneous vaginal delivery– Spent 2 days with mother in hospital– Uneventful course, including circumcision– Birth weight 3.2 kg

Case Study 1 (continued)

• Slow to breastfeed since birth• Would gasp and cry after sucking for a short

time. Difficulty feeding.• 3 to 4 wet diapers per day• No congestion, no fever• No vomiting with feedings• 2 yellow seedy stools since passing

meconium after birth

Initial Assessment (1 of 2)

PAT:– Abnormal appearance, abnormal

breathing, abnormal circulation

Vital signs:– HR 170, RR 70, BP 82/40, T 37°C (rectal),

Wt 3.4 kg, O2 sat 90% on room air

Initial Assessment (2 of 2)

A: No evidence of obstructionB: Elevated RR and laboredC: Pale, diaphoretic, tachycardia, weak

pulse, cyanosis D: GCS grossly normal but in distress and

inconsolableE: No signs of head injury, fractures, or

bruising

Detailed Physical Exam• Lung sounds equal bilaterally with rales in

both bases• Hyperactive precordium with a gallop rhythm• Pulses weak in distal and lower extremities• Distended abdomen with liver palpable 4 cm

below right costal margin

QuestionWhat is your general impression of this

patient?

General Impression• Impending cardiopulmonary failure

(compensated shock)– Cyanosis, diaphoresis– Pale, tachycardia

What are your initial management priorities?

Management Priorities (1 of 3)

• ABCs• Give 15L O2 by nonrebreather mask or

100% O2 by BMV, or perform endotracheal intubation.

• Start IV, obtain blood glucose.• ECG and monitor rhythm on cardiac monitor• CXR• Administer fluid challenge: 10 cc/kg NS

Management Priorities (2 of 3)

• Administer prostaglandin E1 (PGE1):– 0.05 to 0.1 mcg/kg/min– Intubate to protect against apnea and

relieve stress from work of breathing.• Consider furosemide (0.5 to 1 mg/kg).• Sepsis work-up and then antibiotics

– Defer lumbar puncture.

Management Priorities (3 of 3)

• Cardiology consultation or transfer to pediatric cardiology center emergently:– Echocardiogram

• If blood pressure and perfusion do not improve, add inotropic agent:– Dobutamine: 2 to 20 mcg/kg/min– Epinephrine: 0.1 to 1.5 mcg/kg/min

Case Discussion (1 of 2)

• This infant is in CHF.– Poor feeding and easy fatigability– Gallop rhythm and enlarged liver– Diminished pulses

• Shock:– Altered mental status, compensated shock

(tachycardia, diaphoresis, respiratory distress, normal BP in upper extremities)

Case Discussion (2 of 2)

• Possible ductal dependent lesion:– Right age for presentation of shock

triggered by closure of the ductus arteriosus

– Measure blood pressure in four extremities

– Assess oxygenation response to supplemental oxygen

Case Progression: Version 1• BP differential noted in lower extremities.• Oxygenation improves to 99% with

supplemental oxygen.• CXR shows cardiomegaly and pulmonary

edema.• Echocardiogram demonstrates coarctation of

the aorta.• Infant improves with PGE1 infusion, diuretics,

and inotropes.

Case Progression: Version 2• Oxygenation fails to improve with

supplemental oxygen (remains 90%).• Oxygenation declines further to <80%.• CXR is nonspecific.• Echocardiogram demonstrates transposition

of the great vessels. • Infant improves with PGE1 infusion.• Surgical intervention is scheduled.

Background: Structural Congenital Heart Disease

• Congenital heart disease: 5 to 8 cases per 1,000 live births

• Child with congenital anomaly usually does not show cardiovascular problems in utero.

• Changes at birth place great stress on infant’s cardiovascular system.

• Some cyanotic heart conditions are highly dependent on shunting through ductus arteriosus. Closure can be terminal event.

Clinical Features: Your First Clue

• Age• Progressive deterioration (mild)

followed by suddenly progressing to critical condition

• Cyanosis• Congestive Heart Failure (CHF)• Consider concurrent sepsis

Diagnostic Studies (1 of 3)

• Radiology:– Pulmonary hypoperfusion: pulmonic stenosis,

TOF, TA– CHF (if large VSD present to allow high-output

failure, e.g., increased right-sided flow)– Some classic CXR appearances (more classic if

condition is permitted to worsen):• TGA: Egg on side• TAPVR: Snowman• TOF: Boot shaped

Diagnostic Studies (2 of 3)

• ECG:– Right axis (RVH): Normal for newborns– Left axis: Hypoplastic right heart, tricuspid

atresia, endocardial cushion defect (AV canal)– ST-T changes, strain, ischemia– Dysrhythmia– Prolonged QT– Low voltage

Diagnostic Studies (3 of 3)

• Laboratory:– Glucose: Any child in distress needs to have

hypoglycemia excluded.– CBC: Look for anemia, signs of sepsis.– Electrolytes: Congenital adrenal hyperplasia, salt-

wasting form – Arterial blood gas: Hyperoxia text

Fetal Circulation (1 of 2)

• Placenta oxygenates blood and returns to right atrium (RA) via IVC.

• Preferentially shunts across FO to LA.

• LV ejects most oxygenated blood to carotids and coronaries.

Fetal Circulation (2 of 2)

• Superior vena cava (SVC) returns deoxygenated blood to RA where it mixes with oxygenated blood from the placenta.

• Preferentially enters RV.• RV ejects into PA.• No pulmonary capillary flow, so PA is

shunted into the descending aorta via the ductus arteriosus.

Coarctation of the Aorta (1 of 2)

Coarctation of the Aorta

(2 of 2)

Transposition of the Great

Arteries

Differential Diagnosis: What Else? (1 of 2)

• Other cyanotic and acyanotic congenital structural heart disease

• Ductal dependent coarctation• Hypothermia• Sepsis• TORCH

Differential Diagnosis: What Else? (2 of 2)

• Congenital adrenal hyperplasia (CAH)• Hypoglycemia• Shaken baby syndrome/intracranial

lesion• Catastrophic gastrointestinal process,

e.g., volvulus

Normal CV System Function• Represented by vital signs (O2 sat included)• Factors affecting cardiac output (perfusion):

– Heart rate– Stroke volume– Contractility– Vascular resistance

• Children <8 years predominantly increase their HR to increase cardiac output (unable to increase stroke volume until >10 years).

Normal Vital Signs For Age HR RR BP (systolic)

Newborn 90-180 40-60 60-901 month 110-180 30-50 70-1043 months 110-180 30-45 70-1046 months 110-180 25-35 72-1101 year 80-160 20-30 72-1102 years 80-140 20-28 74-1104 years 80-120 20-26 78-1126 years 75-115 18-24 82-1158 years 70-110 18-22 86-11810 years 70-110 16-20 90-12112 years 60-110 16-20 90-12614 years 60-110 16-20 92-130

Transition from Fetal Circulation

• Placental circulation is interrupted at birth:– Increase in systemic arterial blood pressure– Spontaneous respirations

• Decreased pulmonary vascular resistance, increasing pulmonary blood flow

• Foramen ovale closes.• Ductus arteriosus closes. • This initial rapid change slows down over

first 24 hours of life.

Cyanotic Heart Disease (CHD)

• Cyanotic: Refractory to oxygen• Right to left shunting• Some lesions (e.g., TGA) are highly

dependent on a shunt (VSD, PDA)• Cyanosis usually presents shortly after

birth.

Cyanotic CHD• 5 Ts:

– Truncus arteriosus– Tetralogy of Fallot (TOF)– Transposition of the great arteries (TGA)– Tricuspid atresia– Total anomalous pulmonary venous return (TAPVR)

• Severe aortic stenosis• Hypoplastic left heart• Severe coarctation of the aorta

Tetralogy of Fallot (TOF)

• Pulmonic stenosis• Aortic override• VSD• RVH• Right-to-left

shunting through VSD dependent on severity of pulmonic stenosis

Tricuspid Atresia

• RV is hypoplastic.

• Right-to-left shunt through VSD

Total Anomalous Pulmonary

Venous Return

(TAPVR)

Cyanosis• Respiratory disorder• Hemoglobin disorder• Acrocyanosis (normal newborns): Cold

stress and peripheral vasoconstriction• Generalized or central cyanosis often

due to cyanotic congenital heart disease. Often worsened by crying.

Central Cyanosis vs. Acrocyanosis

Hyperoxia Test• Administer 100% oxygen.• Significant increase in PaO2 seen with

pulmonary and hemoglobin disorders.• In CHD, PaO2 will not increase or it will

increase slightly.– Deoxygenated blood bypasses lungs and goes

directly to left side of heart, diluting the fully oxygenated blood coming from lungs with deoxygenated blood.

CHD• Increased pulmonary vascularity:

– Total anomalous pulmonary venous return– Truncus arteriosus– Transposition of the great arteries– Other complex lesions without pulmonic stenosis

• Decreased pulmonary vascularity:– Tetralogy of Fallot– Ebstein’s anomaly– Hypoplastic right heart, tricuspid atresia– Complex lesions with pulmonic stenosis

Prostaglandin E1

• Keeps the ductus open• 0.05 to 0.1 mcg/kg/min with an

increase to 0.2 mcg/kg/min over several minutes

• Side effects: Apnea, pulmonary congestion, fever, hypotension, seizures, and diarrhea

• Consider elective intubation.

Noncyanotic CHD• May present with CHF or heart

murmurs heard during physical exam• Left-to-right shunts

– Excess pulmonary vascularity– ASD, VSD, PDA

• Obstructive lesions– Aortic stenosis, coarctation of the aorta,

mitral stenosis, pulmonic stenosis

Clinical Features• CHF: Tachypnea, tachycardia,

diaphoresis, decreased feeding, hepatomegaly, murmurs, gallop rhythms, pulmonary edema

• Decreased activity or poor sleeping with respiratory distress

Diagnostic Studies• CXR: Cardiomegaly, pulmonary

vascular congestion• ECG: Abnormal axis, ST segment

changes• Echocardiogram: Definitive anatomic

diagnosis, degree of congestive heart failure (chamber sizes, contractility)

Management of CHF• Give oxygen, assisted ventilation if needed.• Elevate head and shoulders 45 degrees.• Monitors, pulse oximetry• Obtain IV access.• Send laboratories.• CXR and ECG• Furosemide, nitroglycerin, digoxin• Inotropes (dobutamine) for signs of shock

Case Study 2:“Chest Pain, SOB”

• 10-year-old boy presents with chief complaint of chest pain and shortness of breath.

• 5 days of cold and cough symptoms• He has been lying around a lot and has

missed 1 week of school.– Usually a very active child but complains

that he is “just too tired” to play

Initial AssessmentPAT:

– Abnormal appearance, abnormal breathing, abnormal circulation

Vital signs:– HR 130, RR 44, BP 90/65, T 37.8°C, O2

sat 90% on room air, increases to 100% on O2

Initial AssessmentA: PatentB: Intermittently shallow and deep;

rapid respiratory rateC: Pale; pulse rapid, thready, and

weak D: No focal deficits, GCS 15E: No signs of injury

Focused HistoryO: Chest hurts for several days.P: Provoked by cough and exertion; short

of breath whenever he gets up and walksQ: Burning, pressureR: Substernal, some radiation to shouldersS: 3 to 8 out of 10T: Pressure and SOB last almost all day,

exacerbations with exertion last 15 to 30 min.

Detailed Physical Exam• Neck: Jugular venous distention supine• Lungs: Diminished breath sounds with

occasional end expiratory wheeze with deep breaths

• Cardiac: Distant heart sounds, no murmurs, S3 gallop rhythm

• Abdomen: Distended with palpable spleen and liver

• Neuro: No focal deficits

QuestionWhat is your general impression of this

patient?

What are your initial management priorities?

General Impression• Child is in respiratory distress and in

cardiogenic shock. – Demonstrates abnormal appearance with

increased work of breathing and signs of shock.

Management Priorities• ABCs• Give O2 by nonrebreather mask.• Obtain IV access.• Check rhythm on cardiac monitor.• Obtain blood glucose, lab studies.• Consider reducing preload and afterload with

nitrates.• Consider diuretic therapy.• May need inotropic support.

Case Discussion:Differential Diagnosis

• Acquired cardiac problem:– Respiratory illness during winter months

causing secondary myocarditis• Congenital heart lesion that had been

asymptomatic until this illness:– Anomalous coronary artery or valvular

disease• Pericarditis

Clinical Features: Your First Clue

• Consider myocarditis in any child with: – Weakness– SOB– Chest pain– Especially if associated with preceding

prodromal viral illness– Distant heart sounds: “Silent Chest”– Enlarged heart on CXR

Diagnostic Studies: Myocarditis• Radiology:

– CXR will reveal cardiomegaly and prominent vasculature, perhaps even pulmonary edema

– Laboratory:• May not add

much• Not specific

Differential Diagnosis: What Else?• Pericarditis• Hypertensive crisis• Anomalous coronary artery and myocardial

ischemia/infarction• Valvular disease• Structural cardiac disease (e.g., VSD, ASD)• Renal failure (e.g., glomerulonephritis)• Rheumatic fever

Management: Myocarditis• Gentle diuretic therapy• Afterload reduction• Possibly inotropic support• Echocardiogram

– Intrinsic cardiac lesion?– Muscle hypertrophy?– Pericardial effusion?– Decreased contractility?

Case Progression: Version 1• CXR: Cardiomegaly• Echocardiogram: Poor cardiac contractility• Diagnosis: Myocarditis• Maintained on inotropes and pressor agents• Recovered to a point that he could be

discharged 2 weeks later• Will be followed closely to assess the degree

to which he regains cardiac function

Case Progression: Version 2• CXR: Cardiomegaly• Echocardiogram: Poor cardiac contractility• Diagnosis: Myocarditis• Deteriorates in ED:

– Progressive shock– Requires inotropic support– Develops V-tach and V-fib– Extracorporeal membrane oxygenation (ECMO)

Myocarditis• Inflammatory disease of the myocardium:

– Direct infection of the myocardium (e.g., viral myocarditis)

– Toxin production (e.g., diphtheria)– Immune response as a delayed sequela of an

infection (postviral or postinfectious myocarditis) – A common type of myocarditis is acute rheumatic

fever (ARF).

Acute Rheumatic Fever:Jones Criteria

• Major criteria:– Carditis: Most commonly valvulitis– Migratory polyarthritis– Chorea, erythema marginatum,

subcutaneous nodules• Minor criteria:

– Fever, elevated CRP or ESR, prolonged PR interval, arthralgia

Pericarditis• Pericardial inflammation• Viral versus bacterial• Bacterial causes include

pneumococcus, S. aureus, H. influenzae type B

• Cardiac tamponade possibly requiring pericardiocentesis

Pericarditis: Clinical Features• Chest pain• Respiratory distress, CHF, or tamponade• Precordial "knock" or rub (like the sound of

shoes walking on snow)• The classic signs include exercise

intolerance, fatigue, jugular distension, lower extremity edema, hepatomegaly, poor distal pulses, diminished heart tones, and pulsus paradoxus.

Endocarditis• An infection of the endothelial surface of the

heart, with a propensity for the valves• Increased risk in children with artificial valves

and patches, and patients with central lines• 90% of cases are caused by gram-positive

cocci. – Alpha strep, Staph aureus, pneumococcus, group

A ß hemolytic streptococci

Endocarditis Clinical Features• Fever• Tachycardia, CHF, dysrhythmia, cardiogenic

shock• History of recent cardiac surgery or

indwelling vascular catheter• Heart murmur• Petechiae, septic emboli, or splenomegaly

Kawasaki Disease• Vasculitis: Propensity for coronary

aneurysms• Aneurysms may subsequently scar,

resulting in coronary stenosis (early onset coronary artery disease).

• Coronary artery thrombosis and myocardial infarction

• Myocarditis, dysrhythmia

Kawasaki Disease: Clinical Features

• High fever• Conjunctivitis• Cervical lymphadenopathy• Gingivostomatitis• Polymorphous rash• Swelling of the hands with erythema of

the palms

The Bottom Line• Assessment of congenital heart

disease can be challenging; however, applying assessment skills with an understanding of normal physiology as well as pathophysiology of cardiovascular disorders in children will assist the clinician in management.