IHD + Ventricular Arrythmias Flashcards Preview

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Flashcards in IHD + Ventricular Arrythmias Deck (22):
1

What types of drugs can be life threatening in long QT?

drugs that block the K+ channel
eg, antiarryhthmics, antihistamines, antimicrobial/antifungal, psychotropits, epinephrine, diuretics, cisapride, bepridil, ketanserin
avoid nonessential OTC meds

2

How is catheter ablation used to Rx VT?

catheter ablation of scar-related VT
attempt to identify areas of slow conduction critical to VT reentry circuit
heat tissue and destroy it

3

What is cardiac dyssynchrony?

disease of the Purkinje system
eg LBBB + diseased myocardium

4

What are indications to suppress VTs? What Rxs can be used for this?

sx of recurrent ventricular arryhthmias
VT storm
ICD shocks
Rx: Sotalol, Amiodarone, Catheter Ablation

5

What is a VT storm?

three or more VT events in a day
elevated mortality risk

6

What is the only intervention that has been shown to modify arrythmic risk of mortality?

defibrillators

7

What are causes of long QT?

genetic - abnormality in K+ or Na + channels - prolonged cellular repolarization
drugs
hypokalemia
hypocalcemia

8

How can long QT lead to death

arrythmias --> syncope, palpitations, SCD

9

What exercise HR response might be seen in pts with congenital LQT?

QT interval fails to shorten with inc HR as it normally should

10

How is LQT treated?

avoid nonessential OTCs
med review
BB
ICD
sx pts should not participate in competitive sports

11

What are two primary mechanisms of ventricular arrythmias?

focal arrythmia
reentrant arrythmia

12

What are three mechanisms of focal arrythmias causing ventricular arrythmias?

focal ventricular tachycardia
accelerated idioventricular rhythm (post-MI - ventricles take on herat beat)
PVCs and nonsustained VT

diseases cells can leak Ca2+ and start firing abnormally --> abnormal automaticity and triggered activity (delayed afterdepolarizations)

13

What is required for reentrant ventricular arrythmias??**EXAM

two limbs
slow conduction in one limb and unidirectional block in other limb

Lilly Figure 11.9

14

What is sustanined vs non sustained ventricular arrythmias?

sustained - > 30 s
nonsustained (self -terminating)

15

What is the prognosis of polymorphic VT?

not good! high risk of SCD

16

What is the prognosis of nonsustained VT in IHD with dec EF

inc risk of SCD

17

What is the prognosis of VT in a structurally normal heart?

good

18

What is the prognosis of sustaining VT in structural HD or red HF?

not good

19

What are causes of polymorphic VT?

ischemia
DCM, HCM
myocarditis
sasrcoid
valvular HD
electrolyte abn
channelopathies
drugs

20

What are causes of sustained monomorphic VT in a structurally normal heart?

RVOT VT * most common
LVOT VT
Belhassen's VT (re-entrant through conduction system)
focal VTs

21

What are causes of sustained monomorphic VT in a structurally abnormal heart?

DCM (reentry through scarred myocardium or bundle branch reentry), sarcoid, scars, repaired CHD (often reentry through scar), IHD (reentry through scarred myocardium), ARVC

22

How are PVCs or PACs affected by exertion?

Generally, go away with exertion - are noticeable at rest.