Jane E. Crosson, MDDirector, Pediatric Electrophysiology and Adult Congenital Heart Disease Program

◦Characterized by only one usable ventricle

◦Final common pathway: Fontan procedure Surgical palliation that relies on “downhill”

flow from veins to pulmonary arteries, with no pump to the lungs

◦Long-term complications are numerous

Tricuspid atresia◦ Variable presentation at birth◦ Eventual palliation Fontan procedure◦ Best long-term survival of all single ventricles,

due to systemic left ventricle Hypoplastic left heart syndrome

◦ Includes aortic and mitral atresia, most severe form of HLHS

◦ Need multiple surgeries◦ Survival rate has improved over time◦ Relies on systemic right ventricle

RV failure, tricuspid regurgitation common

• Also called Hypoplastic Right Heart Syndrome

• Atretic tricuspid valve• Small right ventricle

fed via a VSD• Obligate right to left

flow across atrial septum

• Normal or malposed great arteries

• +/- PS, AS, coarctation

Aortic atresia/severe stenosis

Mitral atresia/stenosis

Hypoplastic LV Arch obstruction Ductal and PFO

dependent

Pulmonary atresia with intact ventricular septum◦ Some can undergo 2 ventricular repair, if RV large

enough, and no coronary arteries are dependent on the high pressure RV

◦ Those with very small RV, and RV dependent coronary circulation, require Fontan palliation Major risk: ischemia with sudden death

Double-inlet single left ventricle Unbalanced AV canal Primitive heart with single atrium and

ventricle (“frog heart”)

Replaced lateral tunnel by late ‘90s in most centers

• Advantages:• Can be done without circ

arrest (or even CPB)• Best fluid dynamics• No intra-atrial suture line

• Disadvantages:• Fixed conduit size• Epicardial pacing only

AV valve regurgitation

Aortic regurgitation Sub-aortic

obstruction Arch obstruction

PA hypoplasia, obstruction, compression by aorta

Pulmonary venous obstruction

Baffle leaks

Surgical re-intervention in ~25% of Fontan patients

Arrhythmias◦ Heart block◦ Sinus node dysfunction◦ Atrial arrhythmias◦ Ventricular arrhythmia

Ventricular dysfunction◦ Right ventricle

especially vulnerable◦ Causes: chronic

cyanosis, chronic volume overload, dyssynchrony

Thrombus, PE AP collaterals Pulmonary AVMs Chronic effusions Protein-losing

enteropathy ‘Cirrhosis’

 Actuarial survival in hypoplastic left heart syndrome.

McGuirk S P et al. Heart 2006;92:364-370

©2006 by BMJ Publishing Group Ltd and British Cardiovascular Society

 Improved early survival in HLHS

McGuirk S P et al. Heart 2006;92:364-370

©2006 by BMJ Publishing Group Ltd and British Cardiovascular Society

Copyright ©2000 American Academy of Pediatrics

Mahle, W. T. et al. Pediatrics 2000;105:1082-1089

Neurodevelopmental Outcome in HLHS

Health Excellent 52 (45.2%)    Good 40 (34.8%)    Fair 14 (12.2%)    Poor 10 (8.7%) Limitations to activity    None 59 (51.3%)    Slight 43 (37.4%)    Significant 12 (10.4%)    Severe 2 (1.7%)

Copyright ©2000 American Academy of Pediatrics

Mahle, W. T. et al. Pediatrics 2000;105:1082-1089

Number of cardiac medications required in children with HLHS

Harrison

Top-notch medical care Early school readiness intervention Life-long access to Adult Congenital Heart

Disease experts Funds for pacemakers, repeat surgeries Job training Option for heart transplantAdult patients with single ventricle are

the most poorly insured and most in need of services

Almost all arrhythmias can be well-controlled with medication, catheter ablation of the arrhythmia focus, pacemaker and/or defibrillator (ICD)

No limitations to work or school for most patients

Those with pacemakers and ICDs have some limitations regarding work environment◦ No extremely physical work◦ No close exposure to high-voltage

Rare in children as compared to adults◦ 1.3 to 8.5 per 100,000 patient-years

Often 2ndary to hypertrophic cardiomyopathy, myocarditis or congenital heart disease

SIDS/airway most common cause in infants Most common primary arrhythmias with risk of

SCD are:◦ Long QT syndrome◦ Catecholaminergic polymorphic ventricular tachycardia◦ Arrhythmogenic right ventricular cardiomyopathy◦ Brugada syndrome

Overall survival rate for out-of hospital cardiac arrest is low, ~10%, including SIDS

As with adults, witnessed arrest has better outcome; unwitnessed arrest survival rate ~0%

If successfully resuscitated, cognitive sequelae can be significant, including lifelong need for complete support.

Access to medication, catheter techniques and devices as needed

Time off from work/school to see physicians/ have procedures

Rare need for disability unless associated with co-morbidities such as congenital heart disease (not uncommon association), or sequelae from SCD resuscitation