Interesting Case Rounds

Alyssa ReedR1 Emergency Medicine

CASE #1

• 16F presenting with 2 syncopal episodes over the last two days

• PMHx: chiari malformation, chronic back pain

• Meds: Naprosyn

• Vitals at Triage: 80 16 106-60 96% 5.5

Q: What else would you like to know?

Q: What is your approach to this patient?

Syncope DDx1.Focal Hypoperfusion of CNS Structures

• SAH

• Hyperventilation

2.Systemic Hypoperfusion Resulting in CNS Dysfunction

• Outflow Obstruction

- CHD

- valve stenosis

• Reduced Cardiac Output

1. WPW

- SVT

- Tachycardias

1. Bradycardias

- Long QT syndrome

- Aortic dissection

- Cardiomyopathy

• Vasomotor

3.Other CNS Dysfunction

• Hypoglycemia

• Seizure

1. Toxic

Findings

• O/E: AVSS, no significant findings

- N S1S2, no murmurs, no extra sounds, no JVD, no pulse delays, pressure same both arms, normal neuro exam

• Labs: CBC, Lytes, Ca, Mg, PO4 normal

• CXR: no cardiomegaly

• ECG........

Dx???

WPW

Definition: a preexcitation of the ventricles through an accessory pathway- the Bundle of Kent- which provides an abnormal pathway of electical communication between the atria and the ventricles

WPW Pattern: ECG abormalities

WPW Syndrome: ECG abnormalities and associated arrhythmia

AVRT (80%)

Atrial Fibrillation (15-30%)

Atrial Flutter (5%)

Prevalence• WPW Pattern

- 0.15-0.25% in general population

- 0.55% among first-degree relatives of affected patients

- in one large study it was 2x more prevalent in males

• WPW Syndrome

- approx 1% with pattern have arrhythmia

- review of 22500 showed .25% had pattern but only 1.8% of these had a documented arrhythmia

- sudden death: 0-.39% annually

CASE #2

• 8F presenting with several episodes of “black-outs” that she remembers dating back to when she was two. None witnessed.

• PMHx: healthy, no meds

• FHx: mom has some unknown heart condition- she was treated with something that ends in “lol”

• O/E: no significant findings

• Q: would you do an ECG?

Familial WPW

• WPW syndrome- 3.4% have 1st degree relative with preexcitation syndrome

- much lower than I expected

• Usually inherited as autosomal dominant trait

• Can also be associated with a familial hypertrophic cardiomyopathy

Pathophysiology/ECG

• Bundle of Kent is a muscle fiber accessory pathway that directly connects the atria and the ventricles

• conduction down this pathway is faster allowing ventricular activation earlier but occurs at a slower speed

• Q: What are the basic ECG findings in sinus WPW?

1. PR is short2. Delta wave3. Wide QRS

1. Short PRdue to rapid conduction through the accessory pathway and bypass of the AV node

2. Delta Waveupstroke slurred because of slow muscle fiber-to-muscle fiber conduction

3. Wide QRSfusion between early ventricular activation and the normal activation through the normal pathway

**the more rapid the conduction along the accessory pathway, the greater the amount of myocardium depolarized via the accessory pathway, resulting in a more prominent or wider delta wave, and longer QRS

50%

30%

10%

10%

Arrhythmias

1.PSVT/AVRT• Orthodromic AVRT*• Antidromic AVRT

2.Atrial Fibrillation3.Atrial Flutter

Irregular, Wide complex Tachycardia

Management

• Who to treat?

- patients with WPW syndrome

• Options for treatment?

- Pharmacologic‣ Antiarrhythmics

- Nonpharmacologic ‣ Radiofrequency ablation

Pharmacologic Mx

• Indications

- patients who are not candidates for ablation

- well-tolerated arrhythmias

• Choice depends on the ECG/electrophys testing and want it directed at the “weak link” in the conduction pathway

• Acute termination vs chronic prevention

OAVRT

• Weak link is the AV node (antegrade conduction)

• Acute Termination

1.Vagal maneuvers

2.IV verapamil (Class IV)

3.IV adenosine

• Chronic Prevention

1.Class IC (flecainide, propafenone)

2.Beta blockers

AAVRT

• Weak link is retrograde conduction through AV node

• BUT this should not be targeted unless you are 100% sure this is AAVRT

Q: Why?

Q: What drugs should be avoided?

Management WCT

• Avoid the ABCDs!

- Adenosine

- Beta Blockers

- Calcium Channel Blockers

- Digoxin

• Stable vs Unstable

- Unstable- cardiovert

- Stable- procainamide

DDX

1. VTach2. SVT with Aberrrancy - Antidromic WPW -WPW with AFib - MAT - A flutter - AVNRT

Non-Pharm Mx

• Ablation of Accessory Pathway

- Catheter

- Surgical

• Indications

- Symptomatic tachyarrhythmias

- Occupations in which development of Sxs would put themselves or others at risk

- Selected asymptomatic patients

QUESTIONS?