Congenital Heart Disease

OVERVIEW

  • multiple types of Congenital Heart Disease
  • classified as acyanotic or cyanotic; and according to the presence of shunt

CLASSIFICATION

Acyanotic

Left -> right shunt

  • ventricular septal defect (VSD)
  • atrial septal defect (ASD)
  • atrioventricular septal defect
  • patent ductus arteriosus (PDA)

No shunt

  • bicuspid aortic valve, aortic stenosis
  • pulmonary stenosis
  • tricuspid stenosis
  • coarctation
  • dextrocardia

Cyanotic

  • Tetralogy of Fallot (TOF)
  • transposition of great vessels
  • hypoplastic left heart
  • pulmonary atresia
  • Eisenmenger syndrome (later in life -> pulmonary hypertension with right to left shunt)
  • truncus arteriosus
  • tricuspid atresia
  • total anomalous pulmonary venous drainage
  • Ebstein anomaly (inferior displacement of tricuspid valve into right ventricle with right to left shunt through ASD)

OPERATIONS

Blalock-Taussig shunt placement

  • palliative care procedure where subclavian artery connected to the pulmonary artery

Fontan circulation:

1. SVC anastamosed to the right pulmonary artery
2. homograft valve insertion in the IVC
3. closure of ASD
4. connection of RA and PA by a valved homograft conduit.

Bidirectional Glenn Shunt

  • for hypoplastic left heart syndrome where SVC is anastamosed to the PA (usually used as a staging procedure to a Fontans circulation)

Tetralogy of Fallot Repair:

1. large VSD
2. RV outflow tract obstruction
3. RV hypertrophy
4. Overriding aorta

-> complete correction undertaking during infancy

VSD repair

  • surgical closure and percutaneous closure options (both are associated with problems with ventricular arrhythmias post op)

ASD repair

  • percutaneously closed

HISTORY

  • diagnosis (when, how, age)
  • treatment (corrective, palliative or untreated)
  • symptoms (cyanosis, heart failure symptoms, pulmonary hypertension symptoms,
  • functional capacity
  • history of stroke or thrombosis (hyperviscosity)

EXAMINATION

  • SpO2
  • CHF signs

INVESTIGATIONS

  • FBC: HCT (high), platelets (low)
  • U+E: renal dysfunction from chronic hypoxia
  • Coags: coagulation factor deficiencies common in cyanotic heart disease
  • ECHO: diastolic dysfunction, decreased ejection fraction, nature and size of lesion, flow reversal,

MANAGEMENT

Preoperative

  • identification of seriously effected patients with transfer to regional unit
  • premedication (decrease O2 consumption and sympathetic tone)

Intraoperative

  • all IV induction agent safe (rate of delivery and dose important not actual drug)
  • good analgesia (decrease sympathetic activation)
  • 100% FiO2 can be used in simple cardiac anomalies with left to right shunt (but caution with complex lesions with right to left shunt)
  • controlled ventilation
  • invasive monitoring
  • TOE helpful (PAC not so much)
  • capnography underestimates in patient with right to left shunt
  • pulmonary hypertension management (to decrease PVR; increase FiO2, hypocarbia, akalaemia, SV, normal lung volumes, avoid sympathetic stimulation, isoprenaline, milrinone, prostaglandins, NO, sudenafil)
  • endocarditis; see guidelines below

Postoperative

  • HDU/ICU
  • management of pulmonary hypertension and systemic haemodynamics
  • hypoxaemia; from either inadequate pulmonary blood flow (avoid dehydration, maintain SVR, control PVR, minimise oxygen consumption) OR pulmonary hyperperfusion (minimise cardiac work)

Eisenmenger syndrome

= high pulmonary vascular resistance with reversed or bidirectional shunt flow

  • can be caused by a number of defects
  • definitive treatment = to close defect
  • goal when managing is not to decrease SVR and cause -> increase in right to left shunt, worsening cyanosis and death
  • arrhythmias, hypovolaemia and large fluid shifts not tolerated well
  • no air bubbles
  • invasive monitoring with anticipation and treatment of haemodynamic changes

Infective Endocarditis Prophylaxis

  • more conservative approach as risks of adverse effects from antibiotics higher than risks of developing IE from dental, GI or GU tract procedure
  • high risk patients or procedures that require antibiotics;
    1. any prosthetic material in heart
    2. previous IE
    3. unrepaired congenital cyanotic heart disease
    4. cardiac transplant patients with valvulopathy
    5. all dental procedures that involve manipulation of gingival tissue or periapical region of teeth or perforation of oral mucosa (thus only check ups and simple fillings that don’t involve gingiva don’t need antibiotic prophylaxis)

ASD VERSUS VSD VERSUS PDA

  • auscultation and right heart catheterisation oxygenation findings
ASDVSDPDA
Fixed split of second heart soundHarsh pansystolic murmur confined to the left sternal edgeA continuous murmur heard over the pulmonary area
Mid diastolic flow murmur over tricuspid area if significant shuntMid diastolic flow murmur over mitral area if significant shuntMid diastolic flow murmur over mitral area if significant shunt
Step up in oxygen saturation at atrial levelStep up in oxygen saturation at ventricular levelStep up in oxygen saturation at pulmonary artery level

References and Links

  • Burns, J et al (2002) “Anaesthesia for non-cardiac surgery in patients with congenital heart disease” BJA CEPD Reviews, Vol 2, Number 6, pages 165-169
  • AHA/ACC Guidelines: Prevention of Infective Endocarditis (2007) – Summary Statements
  • Lovell, A.T. (2004) “Anaesthetic implications of grown-up congenital heart disease” BJA 93 (1) pages 129-139

CCC 700 6

Critical Care

Compendium

Chris is an Intensivist and ECMO specialist at the Alfred ICU in Melbourne. He is also the Innovation Lead for the Australian Centre for Health Innovation at Alfred Health and Clinical Adjunct Associate Professor at Monash University. He is a co-founder of the Australia and New Zealand Clinician Educator Network (ANZCEN) and is the Lead for the ANZCEN Clinician Educator Incubator programme. He is on the Board of Directors for the Intensive Care Foundation and is a First Part Examiner for the College of Intensive Care Medicine. He is an internationally recognised Clinician Educator with a passion for helping clinicians learn and for improving the clinical performance of individuals and collectives.

After finishing his medical degree at the University of Auckland, he continued post-graduate training in New Zealand as well as Australia’s Northern Territory, Perth and Melbourne. He has completed fellowship training in both intensive care medicine and emergency medicine, as well as post-graduate training in biochemistry, clinical toxicology, clinical epidemiology, and health professional education.

He is actively involved in in using translational simulation to improve patient care and the design of processes and systems at Alfred Health. He coordinates the Alfred ICU’s education and simulation programmes and runs the unit’s education website, INTENSIVE.  He created the ‘Critically Ill Airway’ course and teaches on numerous courses around the world. He is one of the founders of the FOAM movement (Free Open-Access Medical education) and is co-creator of litfl.com, the RAGE podcast, the Resuscitology course, and the SMACC conference.

His one great achievement is being the father of two amazing children.

On Twitter, he is @precordialthump.

| INTENSIVE | RAGE | Resuscitology | SMACC

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