Flashcards in IHD + Ventricular Arrythmias Deck (22):
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
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
What is cardiac dyssynchrony?
disease of the Purkinje system
eg LBBB + diseased myocardium
What are indications to suppress VTs? What Rxs can be used for this?
sx of recurrent ventricular arryhthmias
Rx: Sotalol, Amiodarone, Catheter Ablation
What is a VT storm?
three or more VT events in a day
elevated mortality risk
What is the only intervention that has been shown to modify arrythmic risk of mortality?
What are causes of long QT?
genetic - abnormality in K+ or Na + channels - prolonged cellular repolarization
How can long QT lead to death
arrythmias --> syncope, palpitations, SCD
What exercise HR response might be seen in pts with congenital LQT?
QT interval fails to shorten with inc HR as it normally should
How is LQT treated?
avoid nonessential OTCs
sx pts should not participate in competitive sports
What are two primary mechanisms of ventricular arrythmias?
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)
What is required for reentrant ventricular arrythmias??**EXAM
slow conduction in one limb and unidirectional block in other limb
Lilly Figure 11.9
What is sustanined vs non sustained ventricular arrythmias?
sustained - > 30 s
nonsustained (self -terminating)
What is the prognosis of polymorphic VT?
not good! high risk of SCD
What is the prognosis of nonsustained VT in IHD with dec EF
inc risk of SCD
What is the prognosis of VT in a structurally normal heart?
What is the prognosis of sustaining VT in structural HD or red HF?
What are causes of polymorphic VT?
What are causes of sustained monomorphic VT in a structurally normal heart?
RVOT VT * most common
Belhassen's VT (re-entrant through conduction system)
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