Ventricular arrhythmias Flashcards
who are most prone to ventricular arrhythmia?
- those with structural heart disease (ACS (STEMI), CAD, LV dysfunction)
- may be precipitated by electrolytes inbalances (K, Mg), hypoxia, acidosis
- drugs that could cause it: digoxin, antiarrhythmatics
what ir premature ventricular contraction (PVC)?
ectopic beats due to premature depolarization
- knonw as VPD or VPB
what is ventricular tachycardia. difference between unsustained and sustained
a series of 3 or more PVC at a rate of more then 100 beats per minute
unsustained - last less then 30 seconds and end spontaneously
sustained - last more then 30 seconds and requires interventition( could lead to VF)
-40-80% of patients with heart failure
what is ventricular fibrillation?
absecne or organized beats, no cardiac output
- absence of pulse and palpable BP
PVC :
Symptoms
Prognosis
Treatment
Symptoms: asymptomatic
prognosis: little significance unless have CAD or a history of MI
Treament:
Asymtomatic benign
Symptomtaic: b-blocker
Avoid: Class 1c agents
VT:
Symptoms
Prognosis
Treatment
Prevention
Symptoms: depends on HR, SOB, palpitations, chest pain, syncope
Prognosis: could progress to VF
Treatment:
outlined in detail later however if hemo is unstable use DCCV ACLS
if hemostable - depends on the presence or absence of SHD
prevention:
Implantable cardioverter defibrillator (ICD) and use to anti-arrhythmic med ( beta blocker and amiodarone
VF:
Symptoms
Prognosis
Treatment
Prevention
Symptoms
- immediate lack of consciousness
Prognosis
- cardiac death if not defibrillated
Treatment
- defibrrillation and adjunt drug like ephinphrine, lidocaine, amiodarone
Prevention
- ICD
describe the detailed algorithm for VT management
hemo stable
- no - DCCV or ACLS
- yes - SHD
SHD
- no - verapamil or beta blocker - no termintion - Cardioversion
- yes - cardioversion, procainamide, IV amiodarone, and sotalol - no termination - reasses AAD drugs and repeat DCCV - no termination - ablation
what is meant but the term proarrhythmias and what does it include?
proarrhymthimas means that a cardaic or not cardia drig has the capacity to aggravte an arrhythmias or provoke a new arrhymtmia at therpautic or subthermitic levels
- this include: torsades de points and unsutained and sustained VT
what is torsade de pointes (TdP)? what HR? associated with what on a EKG
TdP- paroxysmal polymorphic Vt that can evolve into VF
HR: 160-240 bpm
EKG: delayed venticular repolarization causing prolonged QT interval, the longer the QT interval the higher the chance of TdP
what are some risk factors for TdP?
- QT interval greter then 500 ms
- female
- gentic predisposition
- hypomagnesia
- hypokalemia
- drugs that increase Qt interval
- HF with reduced ejection fracture
-diuretic use - bradycardia
-acute MI
drug that cause TdP categories
-known risk
- possible risk
- conditional risk
- drugs to avoid in congenital LQTS
what drugs are known to cause TdP?
- macorlides: clarithrmycin, erythromycin, azithromycin
-Quinolones: levofloxacin, moxifloxacin, ciprefloxacin
- antiarrythmics - All (espec sotalol)
- antiemeines
- methadone
- antidepressants
- antipsychotics
what do we use to determine the risk of tdp
risk csoring tool
pharamcist role in TdP
mod to severe contact and cosnult phsysicain
- normal K, Mg, Ca
- EKG
- consider alternte drug therpy
