Congenital Heart Disease
Commonest group of life threatening anomalies
8/1000 live births VSD 30-50%
AS 5%
PDA 10%
Tetralogy 5%
ASD 7%
TGA 5%
PS 7%
AVSD 3%
Coarctation of the Aorta 6%
Patent ductus arteriosus Atrial septal defect Ventricular septal defect Atrioventricular septal defect Aortopulmonary window Partial anomaly pulmonary venous drainge Aortic coarctation Interrupted aortic arch Congenital aortic stenosis Mitral stenosis Pulmonary stenosis Pulmonary atresia: With intact ventricular septum With ventricular septal defect Tricuspid atresia Ebstein’s anomaly Tetralogy of Fallot Transposition of the great arteries Truncus arteriosus Total anomalous pulmonary venous connection Hypoplastic left heart syndrome
Our Objective is to Understand
Normal Anatomy
Cardiac Chambers
Septa
Valves
Blood Vessels
Normal Circulation
Fetal Circulation
Fetal Physiology
Right-to-left shunting at atrial level (PFO) and at arterial level (ductus arteriosus)
High pulmonary vascular resistance
Little pulmonary blood flow
Ventricles work in parallel
Transition From Fetal Circulation
Pulmonary vascular resistance falls
Ductus venosus and ductus arteriosus close
Right-to-left shunting through foramen ovale ceases Timing of these events determines the timing of presentation of congenital heart defects
Congenital Heart Diseases Left Side Obstruction
Rt Side Obstruction
Shunting
Left to Right Shunting
Patent ductus arteriosus Atrial septal defect Ventricular septal defect Atrioventricular septal defect Aortopulmonary window PAPVC Aortic coarctation Interrupted aortic arch Congenital aortic stenosis Mitral stenosis Pulmonary stenosis Pulmonary atresia:
With intact ventricular septum With ventricular septal defect
Lt to Rt Shunting
Tricuspid atresia Ebstein’s anomaly Tetralogy of Fallot Transposition of the great arteries Truncus arteriosus Total anomalous pulmonary venous connection Hypoplastic left heart syndrome
Left Heart Obstruction
Patent ductus arteriosus Atrial septal defect Ventricular septal defect Atrioventricular septal defect Aortopulmonary window PAPVC Aortic coarctation Interrupted aortic arch Congenital aortic stenosis Mitral stenosis Pulmonary stenosis Pulmonary atresia:
With intact ventricular septum With ventricular septal defect
Lt to Rt Shunting Lt Heart Obstruction
Tricuspid atresia Ebstein’s anomaly Tetralogy of Fallot Transposition of the great arteries Truncus arteriosus Total anomalous pulmonary venous connection Hypoplastic left heart syndrome
Right Heart Obstruction
Patent ductus arteriosus Atrial septal defect Ventricular septal defect Atrioventricular septal defect Aortopulmonary window PAPVC Aortic coarctation Interrupted aortic arch Congenital aortic stenosis Mitral stenosis Pulmonary stenosis Pulmonary atresia:
With intact ventricular septum With ventricular septal defect
Lt to Rt Shunting Lt Heart Obstruction Rt Heart Obstruction Rt to Lt Shunting
Tricuspid atresia Ebstein’s anomaly Tetralogy of Fallot Transposition of the great arteries Truncus arteriosus Total anomalous pulmonary venous connection Hypoplastic left heart syndrome
Complex Congenital Heart Diseases
Tetralogy of Fallot (TOF) ANATOMY Infundibular Infundibular SubPulmonary SubPulmonary Stenosis Stenosis Overriding Overriding Aorta Aorta
Large LargeVSD VSD RV RV Hypertrophy Hypertrophy
Transposition of the Great Arteries (TGA)
Truncus Arteriosus
Total Anomalies Pulmonary Venous Drainage (TAPVD)
Hypoplastic Left Heart Syndrome (HLHS)
Patent ductus arteriosus Atrial septal defect Ventricular septal defect Atrioventricular septal defect Aortopulmonary window PAPVC Aortic coarctation Interrupted aortic arch Congenital aortic stenosis Mitral stenosis Pulmonary stenosis Pulmonary atresia:
With intact ventricular septum With ventricular septal defect
Tricuspid atresia Ebstein’s anomaly Tetralogy of Fallot Transposition of the great arteries Truncus arteriosus Total anomalous pulmonary venous Hypoplastic left heart syndrome
Lt to Rt Shunting
Acyanotic Lt Heart
Obstruction
Rt Heart Obstruction Rt to Lt Shunting Cyanotic Complex Lesions
Congenital Heart Diseases Cyanotic PBF
PBF
TGA Truncus A. TAPVR
TOF Tricusped A. Pulmonary A.
Single Ventricle Physiology
General Principle Q = P/R Where:
Q=
Blood flow (CO)
P=
Pressure within a chamber or vessel
R = Vascular resistance of pulmonary or systemic vasculature Ability to alter above relationship is the basic tenet of anesthetic management in children with CHD
Control of PVR PVR, PBF
PVR, PBF
Hypoxia
Hypercarbia
Acidosis High mean airway pressures Sympathetic stimulation
Hypovolemia
Pain/agitation
Oxygen Hypocarbia Alkalosis Nitric oxide Vasodilators (milrinone) Adequate Anesthesia: Hypnosis Analgesia Muscle relaxation
Control of SVR SVR
SVR
High dose dopamine
Milrinone
Epinephrine
Dobutamine
Norepinephrine
GTN
Pain
Nitroprusside
Agitation
Adequate analgesia
Negative intrathoracic pressure
Adequate anesthesia Positive pressure ventilation
Left to Right Shunting
In patients with L to R shunt:
May have normal oxygen saturation
Pulmonary overcirculation
Pulmonary congestion & heart failure
Avoid
Excessive fluids is not advocated
PVR &
SVR
Lt Side Obstruction
May have normal oxygen saturation
Diminished systemic flow
Maintain adequate tissue perfusion
Organ protection is mandatory
SVR &
PVR is advocated
Volume loading is useful
Rt Side Obstruction In
patients with severe RVOT obstruction:
R to L shunt
Peripheral oxygen desaturation
Intense cyanosis
Polycythemia & clubbing
Diminished pulmonary flow
SVR &
PVR is advocated
Volume loading may be useful
Treatment of Hypoxic Spells
100 % oxygenation
Assure adequate level of anesthesia
Enhancing preload (15-30 ml/kg crystalloid)
Treat metabolic acidosis
Phenylephrine: 5-10 ug/kg IV bolus or 2-5 ug/kg/min IV infusion
Propranolol (0.1 mg/kg) or esmolol (0.5 mg/kg followed by IV infusion of 50-300 ug/kg/min)
Beta-adrenergic agonists are contraindicated
Preoperative Evaluation History
Examination
Investigations
Illness
General
Hematological
Medications
Cardiac
Chemistry
Chest
Chest X- ray
Neurologic
ECG
Hepatic / GIT
Cardiac MRI
Renal
Cardiac Cath.
Allergy Exercise Capacity Hospitalization
Monitoring
Anesthetic Management
Adequate volume expansion before induction
IV induction is desirable
Ketamine is a useful induction agent
Inhalational induction is well tolerated
Systemic hypotension should be avoided
Maintenance of anesthesia with fentanyl, a muscle relaxant, and inhalational agent is appropriate
Anesthetic Management Preload Adequate tissue perfusion Normal temperature
Anesthetic Management Afterload Na Nitroprusside Nitroglycerine Phentolamine
Anesthetic Management Contractility Milrinone Epinephrine Dopamine
Anesthetic Management
Phosphodiesterase Inhibitors:
Improve contractility
Diastolic relaxation
Afterload reduction
Improve CI & lowering LV pressure after Bypass
Treating low cardiac output due to pulmonary hypertension