Approach to Common Cardiac Emergencies

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Approach to Common Cardiac Emergencies

• Agustin E. Rubio, MD
• Sibley Heart Center Cardiology
• Childrens Healthcare of Atlanta
• Emory School of Medicine

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Topics

• Cyanosis Ductal Dependent
• Emergency Room Diagnoses
• Tetralogy of Fallot
• Hypoplastic Left Heart Syndrome
• Coarctation of Aorta
• SVT
• Shunt Dependent vs Non-shunt Dependent

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Epidemiology

• Cardiac malformations
• 10 of infant mortality
• Incidence
• 4-6/1000 live births
• Most common lethal diagnosis
• Left ventricular outflow tract obstruction
• Hypoplastic left heart syndrome
• Coarctation of aorta
• Aortic stenosis

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Circulatory Transitions

• Conversion from right sided (placental
  oxygenation) to left sided circulation (pulmonary
  oxygenation)
• Progression is secondary
• Decreasing PVR
• Closure of ductal shunts
• Clinical presentations
• Cyanosis
• Respiratory failure
• Shock

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Cyanosis

• Typically, 2 g/dL of reduced hemoglobin
• 5g/dL of reduced Hb ? clinical cyanosis
• Hb 15 ? cyanosis at 75-80
• Hb 20 ? cyanosis at 80-85
• Hb 6 ? cyanosis at 45-50

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Ductal Dependent Lesions
Cyanosis CHF/Shock

• Lt Ventricular Outflow Tract Obstruction
• HLHS
• Coarctation of Aorta/ AS
• Truncus arteriosus
• TGA with VSD
• TAPVR

• Rt to Lt shunting
• Tricuspid atresia
• TOF/ Pulm atresia
• Ebsteins anomaly

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Left Ventricular Outflow Tract Obstruction

• Major source of neonatal MM from CHD
• Accounts for 12 of congenital cardiac disease
  in infancy
• 75 discharged from hospital w/o diagnosis
• 65 - normal newborn screen examination
• 6 died before diagnosis
• 96 symptoms by 3 wks of life

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Symptoms
Timeline of Clinical Diagnosis
Week 1 HLHS Coarctation of aorta TAPVR -
obstucted Week 2-6 Transposition of Great
Arteries Total Anomalous Venous
Return Truncus arteriosus
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Tetralogy of Fallot
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Tetralogy of Fallot

• Prevalence
• - 10 of CHD
• Most common cyanotic heart defect beyond infancy

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Tetralogy of Fallot

• /- Cyanosis
• Small to Nl cardiac silhouette
• pulmonary vasculature

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Tetralogy of Fallot

• Tet spell
• Hyperpnea
• Worsening cyanosis
• Disappearance of murmur
• RBBB pattern on ECG

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Tetralogy of Fallot

• Tet spell
• Treatment objectives
• Reverse the right-to-left shunt
• systemic vascular resistance (SVR)
• Correct potential acidosis with NaHCO3 volume
• Consider peripheral vasoconstriction
  (phenylephrine 0.02 mg/kg IV)
• Ketamine
• increase SVR and sedates 2 mg/kg over 1 min
• Morphine sulphate
• Oxygen

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Tetralogy of FallotSurgical Options

• Blalock-Taussig shunt
• Delayed repair

• Trans-annular patch
• VSD closure

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Tetralogy of FallotPost-operative Concerns

• Post-pericardiotomy syndrome
• 4 weeks post-op (25-30 of open heart pts)
• Fever, elevated ESR and CRP
• Increased work of breathing (? pericardial
  effusion)
• Cardiomegaly, pleural effusions
• ECG persistent ST segment elevation with flat
  or inverted T waves in limb left lateral limb
  leads
• Pericardiocentesis performed when tamponade
  physiology present

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Tetralogy of FallotPost-operative Concerns

• Endocarditis
• Dx after gt2 BCx or echo evidence
• Residual VSD
• Arrhythmias
• AV block, ventricular arrhythmias
• Remember
• Any incision in the ventricle produces a RBBB
  pattern (rSR in V1 wide complex QRS)

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Tetralogy of FallotPost-operative Concerns

• Arrhythmias
• TOF - 40 increased incidence of lethal
  arrhythmias
• Syncopal events- lethal ventricular arrhythmias ??

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Hypoplastic Left Heart Syndrome
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HLHS
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HLHS

• Uncommon form of cyanotic heart disease
• Most common cause of death in the first month of
  life
• Critically ill infant within the first 7 days
  with low O2 saturations

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HLHS

• Clinically
• Progressive cyanosis and hypoxemia
• Hx of poor feeding, tachypnea and poor weight
  gain
• Cardiovascular shock
• Severe acidosis
• Congestive heart failure

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Consequences and Complications

• Polycythemia (erythrocytosis)
• Clubbing (gt6 mos of age)
• Hypoxic spells
• CNS
• Cyanotic heart disease accounts for 5-10 of
  brain abscesses
• Cerebral venous thrombosis - lt2 yrs, cyanotic and
  microcytic anemia
• Dyscrasias

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HLHSPre-operative Resuscitation

• Medical management
• Intubation
• Ventilate and oxygen
• Intravenous access
• Central/ umbilical/ intra-osseos
• Glucose
• Na HCO3
• PGE1 (get that PDA open!!)
• PGE1 0.05 mcg/kg/min
• Volume NS/ 5 Albumin/ PRBCs
• NIRS probe

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HLHSNorwood/ Blalock-Taussig Shunt

• Post-operative changes
• Uncontrolled PBF
• Re-constructed aortic outflow tract
• Fluid balance sensitive
• Widened pulse pressures
• Tenuous coronary circulation
• Single ventricle for all circulation

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HLHSNorwood/ Sano shunt

• Post-operative changes
• Direct PA communication with RV
• Uncontrolled PBF
• Neo-aortic reconstruction
• Higher diastolic pressures
• Better coronary perfusion

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HLHSPost-Operative Resuscitation

• Limit oxygen (remember relative uncontrolled
  PBF)
• Hemoglobin
• Auscultate for murmur
• Continuous murmur at RUSB (? BT shunt)
• Systolic murmur at RLSB/ LUSB (Sano shunt)
• Fluid balance
• Palpate liver
• /- rales and CXR to evaluate for CHF
• Reverse dehydration
• Reverse acidosis

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Coarctation of Aorta
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Coarctation of Aorta

• Common cause of left sided heart failure
• 95 located in juxtaductal region
• Associated with other congenital anomalies
• May be short segments or long segments

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Coarctation of Aorta

• Associations
• HLHS
• Aortic stenosis
• TOF
• Truncus arteriosus
• VSD
• DORV
• Turners syndrome

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Coarctation of Aorta

• Clinical
• Poor feeding, dyspnea poor weight gain
• Upper arm vs lower extremity BP discrepancy
• gt10-20 mmHg systolic upper vs. lower
• 20-30 develop CHF by 2-3 months
• Hx of lower extremity weakness or pain after
  exercise
• 50 will have no murmur

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Coarctation of Aorta

• Acute clinical presentation
• Cardiovascular shock
• Somnolent lethargic
• Poor po intake/ dehydrated, poor U/O
• Cold, clammy diaphoretic
• Poor pulses
• /- organomegaly
• Bradycardia/ tachycardia

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Coarctation of Aorta

• Laboratory Evaluation
• CBC ABG/VBG
• CMP, Magnesium Phos
• Lactate
• BNP level
• CXR 12 lead ECG
• Blood cultures
• NIRS probe

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Coarctation of Aorta

• Neonatal Coarctation
• rSR in the right precordial leads (V1 V2)
• Deep S waves in the lateral leads
• RAD

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Coarctation of Aorta

• Infant Coarctation
• LVH apparent (left lateral leads)
• Deep S waves in the right chest
• Large R waves in lateral leads

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Coarctation of AortaSurgical repairs
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Coarctation of AortaPost-operative State

• Re-coarctation
• Occurs most commonly within the first 12 months
• Evaluated by 4 extremity BPs
• Physical examination of upper lower extremity
  pulses

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TachyarrhythmiaSinus Tach vs. SVT
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Clinical Signs of Tachyarrhythmia
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Symptoms from History

• Neonate
• Sudden onset of irritability sudden relief
• Poor po intake somnolence
• Inconsolable
• Rapid heart beat felt by parents

• Older Child
• Stops activity abruptly
• Palpitations/ feels funny
• Sudden relief with vasovagal manuever
• Chest pain - rare

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ECG Findings
Sinus Tach
Sinus Tach
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Rhythms
SVT

• Regular rhythm, narrow QRS, HR gt200, p buried in
  T wave

Sinus Tach

• Regular rhythm lt200, distinct p waves, nl
  intervals

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Sinus Tachycardia vs. SVT
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SVT Hemodynamically Stable
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SVT Hemodynamically Unstable
Cardioversion should be performed in a
location which can provide for continuous
monitoring and potential complications of
sedation.
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Medications for SVT
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Laboratory Evaluation

• Electrolytes
• Calcium, Magnesium Phosphorus
• CBC with diff
• CXR 12 lead EKG
• looking for pre-excitation WPW

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Shunt Dependent vs. Non-dependent

• Whats the big deal !!!

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The Difference

• Shunt Dependent
• The only source of PBF SHUNT
• Non-Dependent
• Two sources of PBF Shunt some antegrade flow
  through diminuitive PV

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Shunt Dependent

• Oxygen therapy
• Limit O2 therapy for cyanosis
• Maintain sats 75-85
• Sats can drop significantly and quickly
• If sats gt85
• PVR ? PBF ? Pulmonary edema and
  circulatory shock
• Use blended O2 with range of up to FiO2 0.4

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Non-Dependent

• Oxygen therapy
• Two sources of PBF
• One with fixed obstruction and the other is
  uncontrolled
• If BT shunt present
• Limit O2
• O2 saturations should not drop as far nor as
  quickly

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Summary

• CHD /or arrhythmias should be suspected neonates
  with cardiovascular shock
• Evaluation should include
• CBC, cultures, electrolytes, lactate levels,
  Blood gases
• CXR, 12 Lead EKG
• HP provide 90 of diagnoses

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Medical Management

• Airway, Breathing, Circulation
• What disease and what was the repair?
• Prostaglandins
• 0.03 to 0.1 mcg/kg/min
• Side effects
• Hyperpyrexia
• Apnea
• Flushing

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Miscellaneous

• What information do we require?
• 4 extremity BPs, weight iles
• HP
• Murmurs
• Organomegaly
• Pulses
• ECG
• Labs, CXR findings, saturations

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Sources

• Internet websites
• www.childrenshospital.org
• www.cincinattichildrens.org
• www.ucsfhealth.org/childrens/
• Pediatric Cardiology for the Practioners. MK Park
  4th ed.
• Congenital Heart Disease - Moss and Adams