Irregular Rhythms

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EKG #1

What’s the rhythm?

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EKG #2

Dude, what’s the rhythm?

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EKG #3

Home skillet, what’s the rhythm?

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BONUS QUESTION: What is a Lewis Lead?

EKG #1 - Atrial Fibrillation

·      Super irregular! This is probably the most common irregularly irregular rhythm we see

·      You may have confused this with atrial flutter because of the coarse fib waves in V1

o   First, you’re not alone: 1999 study showed high frequency of incorrect diagnosis, even by cardiologists: https://www.ncbi.nlm.nih.gov/pubmed/10549907

o   It may not matter, since aflutter and afib are treated same way in the ED

 

But since you’re all nerds like me, here’s how to differentiate…

1.     The waves in atrial flutter are much more uniform than the ones above.

2.     Flutter waves are classically sawtooth morphology

3.     Remember atrial flutter can be regular. It is only irregular when you have variable conduction.

I.e. when you have two flutter waves and a QRS, then three flutter waves and a QRS, then four, then two again…

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EKG #2 - Multifocal Atrial Tachycardia (MAT)

·      Multiple foci in the atria triggering the AV node. Look at all the different P wave shapes!

·      Three separate P wave morphologies = diagnostic of MAT

·      The slow version of MAT is a wandering pacemaker (MAT without the T)

·      Classically presents in a patient with COPD or CHF

·      Note that this EKG has R axis deviation, perhaps from cor pulmonale

EKG #3 - Premature Atrial Contractions, Normal Sinus Rhythm

·      So this is yet another irregularly irregular EKG, and at first glance you may call this atrial fibrillation.

·      However, note all the well defined p waves – this is sinus tach

·      So why is it irregular?

·      Before those irregularly occurring QRS complexes, there is a p wave, and it looks exactly the same as all the other p waves (in height, width, and axis)

·      The SA node is firing early, depolarizing the ventricles, and creating an irregular rhythm

What is a Lewis Lead?

Ohmygod, great question, so glad you asked!

From Wikipedia: “A Lewis Lead is a modified ECG lead used to detect atrial [activity] when [it] is suspected… but is not definitively demonstrated on the standard 12 lead ECG.”

So you think someone has atrial flutter (sustained HR of 145 perhaps?) but you can’t see any p waves or sawtooth activity. 

Maybe you’re trying to discern SVT from fast sinus tach?

How can you solve this conundrum?

Lewis Lead!

1. You can do this on the monitor, you don’t need a 12lead2. Arrange the leads as seen here. (The green one can go anywhere, it’s just an electrical ground)3. Check for atrial activity

1. You can do this on the monitor, you don’t need a 12lead

2. Arrange the leads as seen here. (The green one can go anywhere, it’s just an electrical ground)

3. Check for atrial activity

Before the Lewis Lead… (where the p waves at?)

After the Lewis Lead! (Retrograde p waves, mostly upright at the end of the QRS. No p waves prior to the QRS. This is SVT.)

Tachydysrhythmia Algorithm

Tachydysrhythmia Algorithm

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Ventriculoperitoneal  Shunt (Complications)

Background

  • Placed in the management of hydrocephalus

    • Hydrocephalus can be secondary to many disease processes, some included below:

      • Congenital

      • Spina bifida

      • Tumors

      • Post-meningitic

      • Dandy walker syndrome

      • Arachnoid cysts

      • Idiopathic Intracranial HTN

  • Location of the shunt is based on the location of blockage causing the hydrocephalus

    • Ventricular catheter can be placed in any brain ventricle (lateral, third, fourth)

      1. Valve portion then connects to distal end of the catheter/tubing, which can terminate in tissue that has epithelial cells capable of absorbing incoming CSF

        1. Most commonly in the abdominal peritoneal space, but can also be placed in the heart (right atrium, VA shunt), pleural cavity, etc. (see below images)

  • Most common neurosurgical procedure to cause complications

  • shunt failure occurs in 14% of children in the first month, 50% in first year

Symptoms of Complications

  • Adults: nausea/vomiting, lethargy, AMS, ataxia, CN palsies, paralysis of upward gaze (“sunset eyes”), seizures

  • Children: nausea/vomiting, irritability, lethargy, change in behavior, seizures, bradycardia, apnea, bulging fontanelle, prominent scalp veins,

 

Under-shunting

  • Obstruction of shunt flow

  • Develop high ICP and then aforementioned symptoms

  • Can be caused by extra-luminal obstruction or intraluminal obstruction

  • Extra-luminal obstruction

    • disconnection, kinking or fracture of the shunt system

  • Intra-luminal obstruction

    • Blockage caused by blood or CNS/inflammatory cells secondary to infection or tumor

 

Over-shunting

  • Over-drainage of CSF

  • Develop intracranial hypotension aka low ICP

    • Siphoning effect of CSF fluid upon standing

    • Develop headache that’s relieved in recumbent position

  • Can lead to slit ventricles

    • Complete collapse of the ventricles

    • Most patients are asymptomatic

    • Few will develop Slit Ventricle Syndrome

      1. Pathophys not fully understood

  • Can cause subdural hematoma

    • Over-shuntingàbrain collapseà tearing of bridging veins

 

CSF Shunt Infection

  • Usually within 6 months of placement

  • Can have fever, but not mandatory

  • External Infection = subcutaneous tract around the shunt

    • Swelling, erythema, tenderness along area of shunt tubing

  • Internal Infection = shunt and CSF contained within the shunt

    • Symptoms above

  • Staph epidermidis (50%) > Staph aureus (20%) > gram-negative rods (15%) > Propionibacterium acnes

  • Require shunt tap, usually by neurosurgery . not LP!

  • AB = cephalasporin + vanc

 

Work up

  • Labs are not very helpful

    • Can get cbc, sed rate, blood cultures

  • CSF

    • Protein can be high

    • Glucose can be low

    • Cultures negative 40% of time

  • Shunt series

    • XRs along course of VP shunt

    • Useful to visualize fractures/disconnection/migration of tubing (see below images)

    • Compare to old series

vp5.png

    • Just because shunt series may show a disconnection doesn’t mean theres actually a malfunction.

      1. Shunt may still be draining csf through another tract

  • CT head (non-con)

    • Should be paired with shunt series to further asses for malfunction

      1. Should not obtain shunt series/CT alone, should always be paired with each other

  • MRI

    • Interestingly, shunt hardware difficult to evaluate on mri

  • VP shunt tap

    • Indications in chart below

    • Almost always done by neurosurgery

  • Medications

    • Symptomatic therapy (Zofran, pain control etc)

    • if suspect infxn, AB as stated above

    • Consult with neurosurgery about starting steroids/acetazolamide to reduce ICP

  • Dispo

    • If presentation/imaging concerning then admit for further neurosurgery follow up

https://wikem.org/wiki/Ventriculoperitoneal_shunt_problems

http://www.emdocs.net/complications-csf-shunts-ed-presentations-evaluation-management/

https://www.ncbi.nlm.nih.gov/books/NBK459351/


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Supracondylar Fractures

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Pediatric Supracondylar Fractures

Background

  • Defined by fracture of distal aspect of humerus above the epicondyles

  • Mechanism

    • Direct: blow to the elbow, fall onto flexed elbow

    • Indirect (more common): FOOSH, fall onto hyperextended UE

      1. 95% of these fractures are due to extension injury

  • Most common age: 5-8 year olds

    • Also more likely to be dislocated in this age group

  • Males>Females

Exam

  • Complain of pain/swelling/decreased ROM of elbow

  • “S shaped deformity”

    • when fracture is entirely displaced (distal humerus)

  • Need to perform neurovascular exam!

    • Median nerve: A-OK sign

      1. Mostly commonly affected

    • Radial nerve: thumbs up sign

    • Ulnar nerve: abduct/adduct fingers (try to remove paper they are holding in between adducted fingers)

  • Check for cap refill!

  • Evaluate brachial artery

    • Compromise of the artery can lead to permanent volkmans contracture, which is flexion at the wrist

Gartland Classification

  • Based on the integrity of the cortex and extent of displacement

  • Type 1: minimal to no displacement ; limited XR findings, look for occult signs of fx on xray (ie: fat pad)

  • Type 2: posterior hinge aka displaced anterior wall but intact posterior wall; anterior humeral line is anterior to capetellum

  • Type 3: complete displacement with no cortices in tact, neither anterior nor posterior wall in tact

  • Type 4: periosteal disruption with instability in extension AND flexion

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Imaging

  • Need AP and lateral films

  • Lines

    • Abnormality can indicate occult fracture

    • Radiocapitellar line (yellow): Line through central radius and central capitellum (middle third). Should be evaluated in both views

    • Anterior humeral line (blue): Line in front of the humerus and passes the anterior 1/3 of the capitellum.

  • Fat pads

    • Anterior: can be normal; elevation is abnormal

    • Posterior: always pathologic

  • These abnormalities without obvious sign of fracture along bones indicative of type 1 SC fx

Dispo:

  • Type 1: long arm posterior splint, ortho follow up

  • Type 2/3: OR with ortho for reduction (closed vs. open) and pinning


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