1. All I need is a cast… Shawn Dowling, PGY-4

2. Case • 11 yoa M. Seen in ED last week after fall during Lacrosse game. • Dx with a Distal Radius Buckle # • Discharged with a removable brace. • Returns to ED today to get a cast because his “friends” are hitting his broken arm in the splint

3. Physical Exam • BP – 116/70, • HR – 42, RR-20, SpO2-97% • Tender at distal radius • Wrist/elbow shoulder normal

4. Normal Vital Signs

5. Your options • Describe to him the Buckle Fracture study in detail and keep him in the splint • Cast him and avoid the hassle • 1 or 2 + have a discussion about what “friends” are • 3 + ECG

6. Diagnosis?

8. QRS’s map out P’s map out Where is the escape rhythm coming from?

9. Complete heart block • No atrial impulses reach the ventricle through the AV conduction system • AV Dissociation • :. Always more atrial beats than ventricular • Escape rhythm can occur anywhere below site of block • The more distal, the slower the HR • The higher the block the more likely to respond to atropine/catecholamines • Proximal to/at bundle of His; narrow QRS, HR>40 • Distal to bundle of His; wide QRS, HR<40

11. Patient had presyncope and SOB with exertion in the past Saw pediatrician a few years ago Did iron studies -> normal, told there is nothing to be concerned about Over past few months increasing Sx Made appt with FP for two wks from now PMHx – ADD Meds - Concerta, FHX – no SCD, no premature deaths, no pacemakers Further history

12. Idiopathic progressive cardiac conduction dz Ischemic heart disease Drugs (many, MC are…) Amiodarone B-blocker CaCB Digitalis Concerta NOT one Valvular Heart disease Calcification extend to AVN Hyperkalemia Infiltrative dz – lymphomas, tumours Familial disease Congenital Complete heart block Infectious/Post-infectious Myocarditis Rheumatic fever Lyme carditis DDx

13. Incidence – 1 in 15,000 – 22,000 Diagnosed: In utero/Neonatal Later in childhood Etiology: NEONATAL Neonatal Lupus (95%) LATER IN CHILDHOOD Myocarditis AV discordance Corrected TGA Polysplenia with AV defect Hereditary disorders Congenital Complete Heart Block

14. Pathophysiology – Neonatal • With neonatal lupus the problem is maternal lupus AB • These AB bind to AV nodal tissue leading to autoimmune injury and fibrosis of the AV node and surrounding tissue

15. Pathophysiology – older children • With most other causes, the problem is fibrous tissue that either replaces the AV node/surrounding tissue or there is a disconnect between the atrial myocardium and the AV node

16. In Utero/Neonatal presentation • Bradycardia is the MC presentation • IN UTERO • Significant number have IUFD (7-21%) • Other presentations include hydrops fetalis, PCE • NEONATAL • High neonatal MR (9-27%), • Worse Px when fast atrial rate (>150bpm) and slow ventricular rate (<50bpm) • Better PX when Dx as neonate (rather than in utero)

17. Childhood presentation • Up to 40% may not present until older (mean age 5-6 yoa) • 5% had unrecognized neonatal lupus • Can be intermittent initially – becomes persistent with advancing age • Age at presentation likely dependent on VR • Usu present w/ bradycardia related Sx • Exertional SOB • Presyncope/syncope

18. Treatment • In utero/perinatal • Steroids (if associated with neonatal lupus) • Isoproterenol • Childhood • Pacemaker (type based on MD preference) • Ventricular (VVI) • Dual Chamber(DDD): MC since more physiologic, • 90% by age 60

20. Class I conditions Symptomatic bradycardia (syncope or presyncope) Moderate to marked exercise intolerance Heart failure thought related to the bradycardia Left ventricular dysfunction or low cardiac output A wide QRS escape rhythm or block below the His bundle [33] Complex ventricular arrhythmias [31,37] . In an infant, <50 to 55 bpm or <70 bpm w/SHD Sustained VT 2 or 3 ºAVB >7 post cardiac Sx Cardiomegaly Prolonged QT Ventricular arrhythmias related to a slow rate or abolished by a more rapid heart rate. Class II conditions 2 or 3 ºAVB within the bundle of His in an asymptomatic patient. Prolonged subsidiary pacemaker recovery time with a pause greater than three seconds Transient post Sx 2 or 3 ºAVB that reverts to bifascicular block. 2 or 3 ºAVB and a ventricular rate below 50 bpm when awake beyond the first year of life Complete AV block with double or triple rest cycle length pauses or minimal heart rate variability. Asymptomatic neonate with congenital complete heart block and bradycardia in relation to age [3] . Long QT syndrome. CHD and impaired hemodynamics due to sinus bradycardia or loss of AV synchrony. Neuromuscular disease with any degree of AV block Pacemaker Indications

21. Prognosis • Neonatal CHB • 17% die prior to 3 months (usually from fetal hydrops/premature delivery) • Childhood CHB • Higher likelihood of poor outcome in patients with HR <50 and with unstable jxn escape • Study of 102 patients followed up between 7-30 years • 27 patients had syncopal episode • 8 of these were fatal, 6/8 were first syncopal episodes • 44 of the remaining patients received a pacemaker

22. HR decreased with age from 46bpm at age 15 to 39 bpm at 40 yoa • Everyone with a prolonged QTc had a syncopal attack • Without PM: • Many develop cardiomegaly (compensatory for low CO) and CHF • Risk of SCD increases with age

23. Px Post-Pacemaker • Px is excellent with pacemaker • 5-11% develop CHF • Related to myocardial fibrosis, ventricular asynchrony • Will require • Most live normal productive life