Lecture 20: Approach to Dysrhythmias

Question 1

What are the 3 groups of dysrhythmias?

Answer 1

1. Premature/Ectopic/Escape beats/rhythms
2. Bradyarrhythmias
3. Tachyarrhythmias

Question 2

What are the 4 possible causes of palpitations?

Answer 2

1. Minor/transient arrhythmia
2. Significant CVD
3. Cardiac manifestation of a systemic condition (thyrotoxicosis)
4. Benign somatic symptom of psychosocial origin

Question 3

What are the risk factors that suggest a CV origin for palpitations?

Answer 3

• FMHx of arrhythmias
• FMHx of syncope or sudden death
• Hx of MI
• Structural HD
• Valvular diseases
• EKG abnormalities

Question 4

What should all patients get when evaluating for palpitations?

Answer 4

EKG

Question 5

What is a holter monitor?

Answer 5

1. 24-48 hour monitor placed on the chest to record cardiac rhythms.
2. Holter monitors include a diary for the patient.

Question 6

What is different about a loop recorder vs a holter monitor?

Answer 6

• Loop recorders are implantable but require no anesthesia or anything.
• Lasts 3-4 years
• Usually used if someone still has episodes but 30 day monitors were inconclusive
• Used for cryptogenic strokes

Question 7

What would suggest stress test vs echo for palpitation evaluation?

Answer 7

• Stress test: Exercise-induced palps or CAD
• Echo: structural abnormalities via EKG or decreased ventricular function

Question 8

When is cardioversion indicated?

Answer 8

• Unstable tachys: SVT, AF, VT, VF
• Afib/flutter
• SVT
• Vtach

Question 9

What is the joule range for cardioversion?

Answer 9

50-360 joules

Question 10

What kind of sedation is used in cardioversion?

Answer 10

Procedural sedation

Question 11

What is catheter ablation typically used for?

Answer 11

Reentrant circuits, specifically
1. AVNRT
2. Paroxysmal AT
3. AFlutter
4. Afib (Pulm veins)
5. PVCs
6. VT (difficult)

Question 12

What gets ablated generally in afib?

Answer 12

Pulmonary veins

Question 13

What are the potential complications of catheter ablation?

Answer 13

• Major vascular damage
• Perforation leading to tamponade
• AV node damage
• Atrio-esophageal fistula (if posterior LA is being ablated)

Question 14

What is the difference between an ICD and a pacemaker?

Answer 14

ICDs are for sudden death and include pacemakers.

Question 15

When are pacemakers indicated?

Answer 15

• Symptomatic bradycardia
• High-grade AV block
• Sinus pauses or afib pauses with symptoms
• No reversible cause identified

Mobitz 2 or CHB is high-grade

Question 16

When is an ICD indicated?

Answer 16

• Primary prevention of SCD (VT/VF)
• EF <= 35% or at-risk (Long QT, Brugada, HOCM)
• Secondary prevention of SCD

Question 17

What are most pacemakers placed in?

Answer 17

RA and RV (RV lead is always present)

Sometimes LV

RA + RV = dual chamber ICD
LV + RV = Bi-ventricular ICD (can be used for CRT)

Question 18

What is the main consideration with pacemakers/ICDs?

Answer 18

They are metal, and older ones are MRI-incompatible and set off metal detectors.

Question 19

If a patient has ventricular pacing, what EKG pattern will they have?

Answer 19

LBBB with a wide complex QRS

Since the RV is being paced, and then the signal goes to the left.