Basic Cardiovascular System and Pathological Abnormalities

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Approach to
Common Cardiac
Emergencies
Agustin E. Rubio, MD
Sibley Heart Center Cardiology
Children’s Healthcare of Atlanta
Emory School of Medicine
Topics
• Cyanosis & Ductal Dependent
• Emergency Room Diagnoses:
 Tetralogy of Fallot
 Hypoplastic Left Heart Syndrome
 Coarctation of Aorta
 SVT
• Shunt Dependent vs Non-shunt
Dependent
2
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
3
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
4
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%
5
Ductal Dependent Lesions
Cyanosis
CHF/Shock
Rt to Lt shunting:
Lt Ventricular Outflow
Tract Obstruction:
 Tricuspid atresia
 TOF/ Pulm atresia
 Ebstein’s anomaly
 HLHS
 Coarctation of Aorta/ AS
 Truncus arteriosus
 TGA with VSD
6
 TAPVR
Left Ventricular Outflow Tract
Obstruction
 Major source of neonatal M&M 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
7
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
8
Tetralogy of Fallot
Tetralogy of Fallot
 Prevalence:
- 10% of CHD
 Most common
cyanotic heart defect
beyond infancy
10
Tetralogy of Fallot
 +/- Cyanosis
 Small to Nl
cardiac silhouette

11
pulmonary
vasculature
Tetralogy of Fallot
“Tet spell”
• Hyperpnea
• Worsening
cyanosis
• Disappearance of
murmur
• RBBB pattern on
ECG
12
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
13
Tetralogy of Fallot
Surgical Options
14
 Blalock-Taussig shunt
 Trans-annular patch
 Delayed repair
 VSD closure
Tetralogy of Fallot
Post-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
15
Tetralogy of Fallot
Post-operative Concerns
• Endocarditis
 Dx after >2 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)
16
Tetralogy of Fallot
Post-operative Concerns
 Arrhythmias
• TOF - 40%
increased incidence
of lethal arrhythmias
• Syncopal eventslethal ventricular
arrhythmias ??
17
Hypoplastic Left Heart
Syndrome
HLHS
19
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
20
HLHS
Clinically:
• Progressive cyanosis and hypoxemia
• Hx of poor feeding, tachypnea and poor
weight gain
• Cardiovascular shock
• Severe acidosis
• Congestive heart failure
21
Consequences and Complications
 Polycythemia (erythrocytosis)
 Clubbing (>6 mos of age)
 Hypoxic spells
 CNS
• Cyanotic heart disease accounts for 5-10% of
brain abscesses
• Cerebral venous thrombosis - <2 yrs, cyanotic
and microcytic anemia
 Dyscrasias
22
HLHS
Pre-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/ PRBC’s
• NIRS probe
23
HLHS
Norwood/ Blalock-Taussig Shunt
 Post-operative changes
•
•
•
•
•
•
24
Uncontrolled PBF
Re-constructed aortic outflow tract
Fluid balance sensitive
Widened pulse pressures
Tenuous coronary circulation
Single ventricle for all circulation
HLHS
Norwood/ Sano shunt
 Post-operative changes
• Direct PA
communication with RV
• Uncontrolled PBF
• Neo-aortic
reconstruction
• Higher diastolic
pressures
• Better coronary
perfusion
25
HLHS
Post-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
26
Coarctation of Aorta
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
28
Coarctation of Aorta
Associations:
• HLHS
• Aortic stenosis
• TOF
• Truncus arteriosus
• VSD
• DORV
• Turner’s syndrome
29
Coarctation of Aorta
Clinical
• Poor feeding, dyspnea & poor weight gain
• Upper arm vs lower extremity BP
discrepancy
 >10-20 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
30
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
31
Coarctation of Aorta
Laboratory Evaluation:
• CBC & ABG/VBG
• CMP, Magnesium & Phos
• Lactate
• BNP level
• CXR & 12 lead ECG
• Blood cultures
• NIRS probe
32
Coarctation of Aorta
 Neonatal Coarctation
• rSR’ in the right precordial leads (V1 &
V2)
• Deep S waves in the lateral leads
• RAD
33
Coarctation of Aorta
 Infant Coarctation
• LVH apparent (left lateral leads)
• Deep S waves in the right chest
• Large R waves in lateral leads
34
Coarctation of Aorta
Surgical repairs
35
Coarctation of Aorta
Post-operative State
 Re-coarctation
• Occurs most commonly within the first 12
months
• Evaluated by 4 extremity BP’s
• Physical examination of upper & lower
extremity pulses
36
Tachyarrhythmia:
Sinus Tach vs. SVT
Clinical Signs of Tachyarrhythmia
38
Symptoms from History
 Neonate:
• Sudden onset of
irritability&
sudden relief
• Poor po intake &
somnolence
• Inconsolable
• “Rapid heart
beat”– felt by
parents
39
 Older Child:
• Stops activity
abruptly
• “Palpitations”/
“feels funny”
• Sudden relief with
vasovagal
manuever
• Chest pain - rare
ECG Findings
Sinus Tach
Sinus Tach
40
Rhythms
SVT
 Regular rhythm, narrow QRS, HR >200, p buried
in T wave
Sinus Tach
41
 Regular rhythm <200, distinct p waves, nl
intervals
Sinus Tachycardia vs. SVT
42
SVT – Hemodynamically Stable
43
SVT – Hemodynamically Unstable
** Cardioversion should be performed in a location which can provide
for continuous monitoring and potential complications of sedation.
44
Medications for SVT
45
Laboratory Evaluation
 Electrolytes
• Calcium, Magnesium & Phosphorus
 CBC with diff
 CXR & 12 lead EKG
• looking for pre-excitation – WPW
46
Shunt Dependent
vs. Non-dependent
What’s the big deal !!!
The Difference
 Shunt Dependent
• The only source of PBF = SHUNT
 Non-Dependent
• Two sources of PBF = Shunt + some
antegrade flow through diminuitive PV
48
Shunt Dependent
 Oxygen therapy
• Limit O2 therapy for cyanosis
• Maintain sats 75-85%
• Sats can drop significantly and quickly
• If sats >85%:

PVR 
PBF  Pulmonary edema
and circulatory shock
• Use blended O2 with range of up to FiO2 0.4
49
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
50
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
 H&P provide 90% of diagnoses
51
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
52
Miscellaneous
What information do we require?
• 4 extremity BP’s, weight %iles
• H&P
 Murmurs
 Organomegaly
 Pulses
 ECG
 Labs, CXR findings, saturations
53
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
54
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