Download All I need is a cast…

All I need is a cast…
Shawn Dowling, PGY-4
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
Physical Exam
• BP – 116/70,
• HR – 42, RR-20,
SpO2-97%
• Tender at distal radius
• Wrist/elbow shoulder
normal
Normal Vital Signs
Your options
1. Describe to him the Buckle Fracture
study in detail and keep him in the splint
2. Cast him and avoid the hassle
3. 1 or 2 + have a discussion about what
“friends” are
4. 3 + ECG
Diagnosis?
QRS’s map out
P’s map out
Where is the escape rhythm coming from?
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
Further history
• 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
DDx
• 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
Congenital Complete Heart Block
• 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
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
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
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)
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
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
Pacemaker Indications
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
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
– 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
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