Ventricular Arrythmias and Sudden Cardiac Death

Question 1

main cause of sudden cardiac death

Answer 1

80% of SCD due to coronary artery disease/ACS, maybe scar related from prior MI). Many have a non-specific physician encounter days or weeks prior.

• dilated or hypertrophic cardiomyopahty (10%)

5-10% have structurally normal heart– long QT maybe.

Question 2

main types of arrhthmias that cause SCA(arrest) or SCD (death)

Answer 2

• usually caused by dysrhthmia.
• majority is VT/VF
• PEA and asystole is increaseing

Question 3

T/F Survival is lower for VF arrest compared to non-VF arrest/PEA

Answer 3

false. survival is lower for non-vf arrst. there is increasing proportion of PEA and asystole causing SCD. probably due to beta blocker use and cornary disease treatment.

Question 4

T/F SCD claims about the same number of lives per year as lung and breast cancer?

Answer 4

FALSE. larger! more than breast cancer, colon cancer, aids and stroke combined.

Question 5

natural history of untreated VT/VF

Answer 5

it goes down if you don’t address the underlying cardiomyopathy

Question 6

wide complex tachycardia ddx

Answer 6

1. ventricular tachycardia
2. supraventricular tachycardia with aberrant conduction (usually RBBB orLBBB)
   - possible atrial fibrillation.
   - pre-excited tachycardia (WPW)
   - pacemaker mediated
   - electrolyte abnormalities/toxicity

Question 7

____ is the most common cause of wide complex tachycardia. You may see ____ waves on the JVP.

Answer 7

ventricular tachycardia is the most common cause of WCT.

• cannon A waves maybe seen on JVP

Question 8

pathognomonic findings of ventricular tachycardia on ECG

Answer 8

1. AV dissociation
2. capture beats
3. fusion beats
   - other helpful clues include a past history of MI, very wide QRS, bizarre QRS, precordial concordance.

Question 9

• A) Pre-excited tachycardia (WPW)
• B) Pacemaker mediated tachycardia
• C) Vent r i c ul ar tachycardia
• D) Atrial fibrillation with aberrant conduction

Answer 9

B. pacemaker mediated tachycardia

Question 10

SCD Risk factors

Answer 10

• 80% of SCD is caused by CAD. thus, factors of coronary artery disease are factors of SCD.
• age
• obesity
• hypertension
• diabetes
• dyslipidemia
• smoking
• family history.
• structural/electrical heaert disease.

Question 12

non cardiac causes of sudden death

Answer 12

• aortic dissection or aneurysm
• CNS events- stroke, TBI
• pulmonary embolus

-

Question 13

inherited conditions that cause sudden cardiac death

Answer 13

HCM

• ARVC
• long QT
• Brugada
• CPVT
• syncope, palpitation, family history, genetic testing, abnormal ECG

Question 14

key questions to ask about a history if youre worried about sudden cardiac death

Answer 14

• Any history of syncope (“seizures, faints, blackouts”)?
• Any close family members (parents, siblings, children) died
suddenly under the age of 50?
• Include motor vehicle accidents
• Any unusual symptoms (pain, palpitations, syncope..) during
exercise?

Question 15

primary and secondary prevention of SCD

Answer 15

primary prevention: may lead to defibrillator implant or beta blockers if they have unheralded syncope, a concerning family history, significant cardiac structural abnormalities

secondary prevention: patient presenting with sustained VT/VF or cardiac arrest are usually implanted with a defibrillator.

Question 16

Class 1-IV anti-arrythmic medicatiosn

Answer 16

1. sodium channel blocker
2. beta blockers
3. potassium
4. calcium channel blockers

Question 17

T/F digoxin has been seen in being helpful for reducing sudden death

Answer 17

false. no benefit. the mechanism is that it increases cardiac contractility and can reduce heart rate in ppl with arrhthmia by decreasing AV node conduction

Question 18

which drugs have been shown to be beneficial in reducing sudden cardiac death

Answer 18

heart failure meds

• statin

ace inhibitors (prils)

• ARBs sartans
• aldosterone blockers
• entresto

Question 19

for every minute that passes from arrest to defibrillation, the survival decreases ____ without CPR and ____ with CPR

• Survival can be much higher (>70%) with early ___ for
VF (< 3min)
• AED and casino security officers study

Answer 19

7-10% without CPR and 2-4% with CPR

• Survival can be much higher (>70%) with early defibrillation for
VF (< 3min)
• AED and casino security officers study

Question 21

ICDs have monitors going to both the atria and ventricle for sensing and pacing of rhythm. what lead of an ICD actually does the cardioconversoin/defibrillation?

Answer 21

the ventricular lead

Question 22

ICD will reduce mortality and prevent arrhythmias?

Answer 22

false. won’t prevent anything, but can stop it once the arrythmia happens.

Question 23

an ICD implant for someone with severe LV dysfunction EF<35% is ___ prevention.

prior cardiac arrest or life threatening ventricular arrhthmia ICD implantation is ____prevention.

Answer 23

an ICD implant for someone with severe LV dysfunction EF<35% is PRIMARY prevention.

prior cardiac arrest or life threatening ventricular arrhthmia ICD implantation is SECONDARY prevention.

Question 24

___ ____ therapy

• Uses a specially designed lead placed usually on the
posterior-lateral wall of the LV via the Coronary Sinus
circulation • Provides RV and LV synchronous pacing

• With atrial lead can also provide AV synchrony
• Helps to improve symptoms of heart failure

Answer 24

cardiac resynchronization therapy

Question 25

note: CRT may provide an additional suden death reduction over an ICD

Question 26

treatment for sudden cardiac arrest-

Answer 26

ID individuals at risk

• rapid response- cpr and resuscitation
• post resuscitaiton management: COOLING IS NEUROPROTECTIVE
• medications: ssimilar meds to tx of cardiomyopathy/heart failure– ARB, ernetstro
• angioplast/bypass surfery.

Question 27