Mod VI: Congenital Heart Disease Part2 Flashcards
Cyanotic Heart Defects
Predominantly Right-to-Left Shunts/Mixing lesions include:
Tetralogy of Fallot
Transposition of the Great Arteries
Hypoplastic Left Heart Syndrome (HLHS)
Tricuspid valve abnormalities (Ebstein’s anomaly)
Truncus arteriosus
Total anomalous pulmonary venous connection
Cyanotic Heart Defects
Pathophysiologic changes a/w predominantly Right-to-Left Shunts/Mixing Lesions include:
Decreased pulmonary blood flow
leading to:
Hypoxemia
LV volume overload
LV dysfunction
Cyanotic Heart Defects
Hemodynamic goals for predominantly Right-to-Left Shunts/Mixing Lesions include:
Maintain SVR
(Squatting)
Decrease PVR
(via Hyperoxia - Hyperventilation - Avoiding lung hyperinflation)
Cyanotic Heart Defects
Cyanotic Heart Defects are complex lesions that produce
Ventricular outflow obstruction
Obstruction favors shunt towards unobstructed side
Intracardiac shunting
Affected by ratio SVR:PVR with mild obstruction
Direction and magnitude fixed with large obstructions
Atresia extreme form obstruction
Shunting occurs proximal to atretic valve
Survival depends on distal shunt (PDA, PFO, VSD) where blood flows in opposite direction
Cyanotic Heart Defects - Predominantly Right-to-Left Shunts/Mixing Lesions
Which Cyanotic Heart Defects are a/w decreased pulmonary blood flow?
TOF
Pulmonary atresia
Tricuspid atresia
Cyanotic Heart Defects - Predominantly Right-to-Left Shunts/Mixing Lesions
Which Cyanotic Heart Defects are a/w increased pulmonary blood flow?
Transposition of the great vessels
Truncus arteriosus
Hypoplastic left heart
Cyanotic (R→L) Heart Defects
The congenital heart condition that involves four abnormalities occurring together, including a defective septum between the ventricles and narrowing of the pulmonary artery, leading to cyanosis is also known as:
Tetralogy of Fallot
Cyanotic (R→L) Heart Defects
Most common CHD producing R to L shunt
Tetralogy of Fallot
Cyanotic (R→L) Heart Defects - Tetralogy of Fallot
What’s the prevalence of Tetralogy of Fallot in neonate?
3rd most prevalent CHD in the neonate
Cyanotic (R→L) Heart Defects - Tetralogy of Fallot
Anatomic defects associated with Tetralogy of Fallot:
VSD (R-to-L)
Aorta that overrides the pulmonary tract
Obstruction of pulmonary outflow tract
Right ventricular hypertrophy
Cyanotic (R→L) Heart Defects - Tetralogy of Fallot
Pathophysiologic characteristics seen with Tetralogy of Fallot:
R-to-L shunting
↓ Pulmonary blood flow
Polycythemia (>65%)
D/t body attempt to compensate for lack of O2 by producing more RBCs
Ductal dependent pulmonary blood flow (L-R shunt) in neonate with severe obstruction (PGE1)
Cyanotic (R→L) Heart Defects - Tetralogy of Fallot
Blood flow in Tetralogy of Fallot
Note:
VSD in TOF is with R=>L shunt
Misplaced aorta that overrides pulmonary tract
Stenosis of the pulmonary valve and pulm artery out of the RV
Thickening of the RV wall
Cyanotic (R→L) Heart Defects - Tetralogy of Fallot
Blood flow in Tetralogy of Fallot
See picture
Note “pulmonary atresia”
Cyanotic (R→L) Heart Defects - Tetralogy of Fallot
Manifestations Tetralogy of Fallot:
Hypoxemia/cyanosis
Clubbing
Squatting
(↑ SVR by reducing blood flow to femoral arteries)
Ejection murmur
Hypercyanotic attacks (“tet spells”), as evidenced by:
Infundibular “spasm” => worsen RV outflow tract obstruction
↓ SVR
Can occur w/o provocation but often associated with crying or exercise
Accompanied by hyperventilation & syncope
Cyanotic (R→L) Heart Defects - Tetralogy of Fallot
Treatment of Tetralogy of Fallot includes:
IV fluids
Knee-to-chest
Phenylephrine (↑ SVR)
Esmolol
MSO4
(caution w/ ↓ venous return and CO a/w MSO4 )
Cyanotic (R→L) Heart Defects - Tetralogy of Fallot
The surgical palliation to Tetralogy of Fallot in which the Left subclavian artery is shunted to the left pulmonary artery to increase pulmonary blood flow is known as:
Blalock-Taussig shunt
Cyanotic (R→L) Heart Defects - Tetralogy of Fallot
What’s the difference btw the Traditional and the Modified Blalock-Taussig shunts?
The traditional Blalock-Taussig shunt uses the actual subclavian artery, whereas
The Modified Blalock-Taussig shunt uses a graft to to divert some of the subclavian artery blood flow to the PA
Schematic drawing of original Blalock-Taussig shunt on patient’s right side and modified Blalock-Taussig shunt on left side
Cyanotic (R→L) Heart Defects - Tetralogy of Fallot
Complete correction of Tetralogy of Fallot involves:
Closure VSD
Removal obstructing infundibular muscle
Pulmonic valvulotomy
Cyanotic (R→L) Heart Defects - Tetralogy of Fallot
The main goal of Anesthetic management of Tetralogy of Fallot is to lessen the R-to-L shunt. How can this be accomplished?
Maintain intravascular volume
Maintain SVR/Avoid decreasing
Avoid ↑ PVR
(By avoiding acidosis, hypoxemia, excessive PIP)
Maintain higher FiO2 and lower ETCO2 to prevent PVR increase
Cyanotic (R→L) Heart Defects - Tetralogy of Fallot
Options for inducing Anesthesia in Tetralogy of Fallot
Inhalation with pink patients
Ketamine IV/IM with cyanotic patients
Cyanotic (R→L) Heart Defects - Tetralogy of Fallot
How does R-to-L shunting in Tetralogy of Fallot effect on rate of inhalational induction?
Slows inhalational induction
Slows uptake
(D/t to less blood flow to the lungs in general; Opposite of L-to-R shunts)
Dilutional effect
Cyanotic (R→L) Heart Defects - Tetralogy of Fallot
How does R-to-L shunting in Tetralogy of Fallot effect on rate of IV induction?
Accelerates onset in IV agents
Cyanotic (R→L) Heart Defects
A form of congenital heart disease whereby there is a complete absence of the tricuspid valve. Therefore, there is an absence of right atrioventricular connection. This leads to a hypoplastic (undersized) or absent right ventricle. This condition is also known as:
Tricuspid Atresia
Cyanotic (R→L) Heart Defects - Tricuspid Atresia
Anatomical defects/physiologic characteristics of Tricuspid Atresia:
Complete absence of right atrioventricular connection
Severe hypoplasia or absent RV
Pulmonary blood flow dependent on PDA (L-R shunting)
LA & LV handle both systemic and pulmonary circulations
Systemic venous return shunted from RA => LA via ASD or PFO
Mixing of O2 and deO2 in LA → LV → Aorta = CYANOSIS
90% associated with VSD allowing some blood to enter RV
Normal related great arteries or with transposition
Cyanotic (R→L) Heart Defects - Tricuspid Atresia
Clinical manifestations of Tricuspid Atresia:
Progressive cyanosis
Poor feeding
Tachypnea
CHF
Cyanotic (R→L) Heart Defects - Tricuspid Atresia
Treatment of Tricuspid Atresia:
PGE1 to maintain pulmonary flow
Balloon atrial septostomy if atrial defect not sufficient
Surgical interventions
Cyanotic (R→L) Heart Defects - Tricuspid Atresia
Which Surgical interventions are used in the Treatment of Tricuspid Atresia?
Modified Blalock-Taussig shunt to maintain pulmonary blood flow
Cavopulmonary anastomosis (hemi-Fontan or bi-directional Glenn)
Cyanotic (R→L) Heart Defects - Tricuspid Atresia
What’s the goal of surgical interventions in the Treatment of Tricuspid Atresia?
Redirection of IVC and hepatic vein flow into pulmonary circulation
Cyanotic (R→L) Heart Defects
A form of heart disease in which the pulmonary valve does not form properly. It is present from birth (congenital heart disease). This heart defect is also known as:
Pulmonary Atresia
Cyanotic (R→L) Heart Defects - Pulmonary Atresia
Anatomical defect and physiologic effects a/w Pulmonary Atresia:
Absent pulmonary valve
RV hypoplasia
Tricuspid hypoplasia
Obligate atrial shunt from R to L
Ductal dependent pulmonary blood flow
Coronary artery-myocardial sinusoid communications
Myocardial infarction/death may occur with any palliative procedure that decompresses the RV if coronaries are RV dependent
Cyanotic (R→L) Heart Defects - Pulmonary Atresia
In Pulmonary Atresia, right heart is underdeveloped and cannot support the blood supply to the lungs. All the blood supply to the lungs is provided through which structure?
Ductus arteriosus
Cyanotic (R→L) Heart Defects - Pulmonary Atresia
Manifestations of Pulmonary Atresia:
Severe cyanosis immediately after birth
Tachypneic
Cyanotic (R→L) Heart Defects - Pulmonary Atresia
Pharmacological Treatment of Pulmonary Atresia:
PGE1
Cyanotic (R→L) Heart Defects - Pulmonary Atresia
Surgical Treatment of Pulmonary Atresia:
RV to PA conduit
(if coronary circulation is not RV dependent)
Blalock-Taussig shunt
Fontan palliation or heart transplant
(for RV-dependent coronary circulation)
Cyanotic (R→L) Heart Defects
The congenital (present at birth) heart defect in which the aorta is connected to the right ventricle, and the pulmonary artery is connected to the left ventricle is known as:
Transposition of the Great Vessels
Cyanotic (R→L) Heart Defects - Transposition of the Great Vessels
Prevalence of Transposition of the Great Vessels:
Accounts for 5% of all CHD
Cyanotic (R→L) Heart Defects - Transposition of the Great Vessels
Anatomical defect in Transposition of the Great Vessels:
Aorta arises from the RV => Deoxygenated blood returns back to systemic circulation
Pulmonary artery arises from the LV => Oxygenated blood returns back to lungs
Cyanotic (R→L) Heart Defects - Transposition of the Great Vessels
Survival in Transposition of the Great Vessels is possible only if:
Some form of intercirculatory mixing exists
ASD/VSD
Patent foramen ovale
PDA (PGE1 required)
Variable degrees of pulmonary blood flow occur dependent on types of lesions present
Cyanotic (R→L) Heart Defects - Transposition of the Great Vessels
What’s the immediate management of Transposition of the Great Vessels?
This is a Surgical emergency
Delivery takes places in OR
Neonate taken immediately for open heart surgery
The quicker the surgery, the better the outcomes
Cyanotic (R→L) Heart Defects - Transposition of the Great Vessels
Blood flow in Transposition of the Great Vessels
See picture
Cyanotic (R→L) Heart Defects - Transposition of the Great Vessels
Corrective surgical treatment for Transposition of the Great Vessels include:
Arterial switch with coronary artery reanastomosis
Atrial switch (Senning procedure)
Cyanotic (R→L) Heart Defects - Transposition of the Great Vessels
Anesthetic considerations for Transposition of the Great Vessels (TGV):
Maintain HR, contractility, preload, CO
Special considerations based on PBF
Cyanotic (R→L) Heart Defects - Transposition of the Great Vessels
What are Anesthetic considerations for TGV a/w ↓ PBF & minimal intracardiac mixing (ICM)?
Avoid ↑ PVR relative to SVR
(↑ PVR will further reduce PBF and intracardiac mixing)
Adjust vent settings to ↓ PVR
(By: ↑ FiO2 & RR - ↓ ETCO2 - Maintain slight alkalosis)
Cyanotic (R→L) Heart Defects - Transposition of the Great Vessels
What are anesthetic considerations for TGV aw ↑ PBF & large ICM?
Maintain normal PVR, ETCO2, low FiO2
Adjusting PVR will only modestly improve saturations at the expense of systemic circulation
Cyanotic (R→L) Heart Defects
A birth defect that affects normal blood flow through the heart. As the baby develops during pregnancy, the left side of the heart does not form correctly. This condition is also known as:
Hypoplastic Left Heart Syndrome
Cyanotic (R→L) Heart Defects - Hypoplastic Left Heart Syndrome
Anatomical defects seen in Hypoplastic Left Heart Syndrome
Underdeveloped LV
Aortic valve stenosis or atresia
Mitral valve stenosis or atresia
Hypoplasia ascending aorta
Cyanotic (R→L) Heart Defects - Hypoplastic Left Heart Syndrome
Pathophysiologic effects of Hypoplastic Left Heart Syndrome:
Blood flow to left side heart eliminated or reduced => obligatory L-to-R shunt
Systemic blood flow completely ductal dependent (R-L shunt)
All blood entering aorta derived from PDA
PGE1 essential to keep PDA open
RV main pumping chamber for both pulmonary & systemic circulation
Cyanotic (R→L) Heart Defects - Hypoplastic Left Heart Syndrome
Surgical correction for Hypoplastic Left Heart Syndrome include:
Palliative
(Norwood, hemi-Fontan or bidirectional Glenn, completion Fontan)
Heart Transplantation
Cyanotic (R→L) Heart Defects - Hypoplastic Left Heart Syndrome
Normal heart vs Hypoplastic Left Heart Syndrome
See picture
Cyanotic (R→L) Heart Defects - Hypoplastic Left Heart Syndrome
Another view of Hypoplastic Left Heart Syndrome
See picture
Cyanotic (R→L) Heart Defects - Hypoplastic Left Heart Syndrome
In hypoplastic left heart syndrome, the left heart is underdeveloped and cannot support the blood supply to the body. All the blood supply to the body is provided through which structure?
Ductus arteriosus
Cyanotic (R→L) Heart Defects
Palliative surgical procedure used in children with univentricular hearts
Fontan Procedure
Cyanotic (R→L) Heart Defects - Fontan Procedure
Fontan” Physiology
All venous blood returning to heart bypasses the right heart and flows passively into the lungs
RV pumps oxygenated blood returning from lungs into systemic circulation
Cyanotic (R→L) Heart Defects - Fontan Procedure
Why is it important to avoid ↑ PVR w/ Fontan Procedure?
Blood is passively flowing into the PA
↑ PVR => ↓ PBF => hypoxemia
Cyanotic (R→L) Heart Defects - Fontan Procedure
Which Factors ↓ PVR/↑PBF and must be considered w/ Fontan Procedure?
Hyperoxia
Alkalosis
HTN/↑ SVR
Low mean airway pressures
Cyanotic (R→L) Heart Defects - Fontan Procedure
Which Factors↑ PVR/↓ PBF and must be considered w/ Fontan Procedure?
Hypoxemia
Acidosis
Hypotension/↓ SVR
PEEP
Congenital Heart Defects
Representation of the adult heart and incidence of congenital heart defects
See picture
Numbers in paranthesis represent incidence of heart defect for every 1,000 births
Congenital Heart Defects
Anesthesia providers will encounter patients with CHD for which types of procedures?
Elective or
Emergent noncardiac surgery and
during Pregnancy
Congenital Heart Defects
Unpalliated procedures are reserved for which Congenital Heart Defects?
Cardiac anomaly does not cause hemodynamic compromise
(ASD/VSD/Mild valvular stenosis)
Surgical emergencies
(CDH, Intestinal instruction)
where lesion may be more complex
(TOF)
and infant waiting for palliative surgery
These procedures do not cause hemodynamic compromise
Congenital Heart Defects
Partially palliated anomalies and procedures include:
Staged repairs
Congenital Heart Defects
Completely palliated procedures include:
Fontan
Blalock-Taussig
Congenital Heart Defects
Complete familiarization with the anatomic and hemodynamic function of the CHD is essential to formulating and managing a safe anesthetic plan. How can this be achieved?
Categorize the anomaly
(Cyanotic vs acyanotic, direction of shunt, reduced blood flow vs obstruction, etc.)
Develop ideal anesthetic plan to keep pt safe during the procedure
Be familiar with common sequelae after repair
Management of anesthesia for patients with CHD requires thorough knowledge of the pathophysiology of each cardiac defect
You may have a pt that had a Fontain procedure 10 years ago and you must be able to care for them
This may help you care for that pt when they are undergoing other procedures if you are familiar w/ their blood flow as a result of their past cardiac hx
Ideal to discuss case with child’s pediatric cardiologist prior to surgery
Congenital Heart Defects
Understanding the impact of anesthesia management on the ratio of systemic to pulmonary blood flow is also vital when formulating the anesthetic plan. What questions must you be able to answer once you categorize where the Congenital Heart Defect sits?
What events ↑ SVR?
What events ↓ SVR?
What events ↑ PVR?
What events ↑ SVR?
Review M & M: page 521-524
Congenital Heart Defects - Atrial Septal Defect (ASD)
What are the three anatomical varieties of ASD?
See picture
Congenital Heart Defects - Atrial Septal Defect (ASD)
What are the pathophysiological changes a/w ASD?
See picture
Congenital Heart Defects - Atrial Septal Defect (ASD)
Which surgical corrections are used to correct ASD?
See picture
Congenital Heart Defects - Atrial Septal Defect (ASD)
What are anesthetic considerations for ASD?
See picture
Congenital Heart Defects - Ventricular Septal Defect (VSD)
What are anatomical findings in VSD?
See picture
Congenital Heart Defects - Ventricular Septal Defect (VSD)
What are the pathophysiological changes a/w VSD?
See picture
Congenital Heart Defects - Ventricular Septal Defect (VSD)
What are anatomical findings in VSD?
What are the pathophysiological changes a/w VSD?
What are the surgical correction for VSD?
What are anesthetic considerations for VSD?
See Picture
Congenital Heart Defects - Co-arctation of the Aorta
What are anatomical findings, pathophysiological changes, surgical correction, and anesthetic considerations in Co-arctation of the Aorta?
See picture
Congenital Heart Defects - Co-arctation of the Aorta
What are anatomical findings, pathophysiological changes, surgical correction, and anesthetic considerations in Patent Ductus Arteriosus (PDA)?
See picture
Congenital Heart Defects - Co-arctation of the Aorta
What are anatomical findings, pathophysiological changes, surgical correction, and anesthetic considerations in Tetralogy of Fallot?
See picture
Congenital Heart Defects - Co-arctation of the Aorta
What are anatomical findings, pathophysiological changes, surgical correction, and anesthetic considerations in Transposition of the Great arteries?
See picture
Congenital Heart Defects - Co-arctation of the Aorta
What are anatomical findings, pathophysiological changes, surgical correction, and anesthetic considerations in Truncus Arteriosus?
See Picture
Congenital Heart Defects - Co-arctation of the Aorta
What are anatomical findings, pathophysiological changes, surgical correction, and anesthetic considerations in Atrioventricular Canal Defect?
See picture
Congenital Heart Defects - Co-arctation of the Aorta
What are anatomical findings, pathophysiological changes, surgical correction, and anesthetic considerations in Hypoplastic left heart syndrome?
See picture
