Ventricular Arrhythmias Flashcards
Premature Ventricular Complexes (PVCs)
Asymptomatic or causes mild palpitations
warning arrhythmias
Can occur in patients with or without structural heart disease
non life threating
CAST trial (Cardiac Arrhythmia Suppression Trial):Empiric pharmacologic therapy (Class IC agents) is NOT effective and is associated with INCREASED mortality and death due to arrhythmias–>but stops symptoms
In normal healthy patients (no heart disease) little prognostic implications
In patients with history of MI (or other structural disease) some forms of PVCs are associated with a higher risk of sudden cardiac death (SCD) and may be predictive of future risk of ventricular fibrillation
Ventricular Tachycardia (VT)
Duration of VT
Wide QRS tachycardia that is ≥ 3 or more consecutive PVCs occurring at a rate > 100 beats/minute
Asymptomatic (VT with a pulse) or life-threatening (pulseless VT) associated with pulseless, hemodynamic collapse*
Torsades de Pointes (TdP)
≥ 3 consecutive PVCs occurring at a rate >100 beats/ minute
Can either be asymptomatic (i.e. asymptomatic VT with a pulse) or can result in hemodynamic collapse (i.e. pulseless VT)
Ventricular Fibrillation (VF)
Acute medical emergency resulting in hemodynamic collapse*, syncope, and cardiac arrest
Results in hemodynamic collapse, syncope, and cardiac arrest. Cardiac output and BP are not recordable
Considered a medical emergency requiring CPR
Cardiac Arrest
Unexpected loss of cardiac function
Loss of pulse and blood pressure resulting in a loss of oxygen delivery to vital organs, including the heart and brain
If not treated IMMEDIATELY can lead to Sudden Cardiac Death (SCD)
Sudden Cardiac Death (SCD)
Unexpected cardiac death occurring in a patient within one hour of experiencing symptoms
Hemodynamic collapse of hemodynamic instability
BP (SBP
Acute Episode of VT Treatment
Hemodynamically stable
Amiodarone IV
β- blockers IV (if associated with MI)
Always have DCC available
Acute VT and hemodynamic significance
Hemodynamically unstable
Direct cardiac cardioversion (DCC)
ACLS algorithm
Can add IV amiodarone
Acute Episode of VT Treatment
48 hours
If VT occurs during the first 48 hours of an acute MI, it will probably not reappear on a chronic basis after the infarcted area has been reperfused or healed with scar formation
Acute Episode of VT Treatment
correction
Correction of the underlying precipitating factors will usually prevent further recurrences of VT
i.e. electrolyte abnormalities (hypomagnesemia, hypokalemia), digoxin toxicity, ischemia (MI)
VT Chronic Treatment
Non-pharmacologic Management
Correct acute episode
Depends on risk factors (i.e. LV function, s/p MI, ECG findings)
Implantable Cardioverter Defibrillator (ICD):( musst wait 40 days post-MI
Recurrent or inducible VT on EP study
High-risk characteristics (i.e. EF
VT Chronic Treatment
pharmacologic Management
Prevention with β-blockers only or addition of antiarrhythmic therapy (i.e. amiodarone
Torsades de Pointes (TdP)
Torsade de Pointes (TdP) is a polymorphic rhythm which is a form of ventricular tachycardia (VT)
Associated with prolonged QT interval or QTc interval and prolonged repolarization
Electrolyte disturbances (hypomagnesemia, hypokalemia)**
Female gender (have prolonged QT interval)z***
Medications**
Myocardial Ischemia
HF
Bradycardia
Torsades de Pointes (TdP)
Drug induced
methadone, haloperidol, trimethoprim/sulfamethaxazole, voriconazole, amiodarone)
Antiarrhythmic agents (Type IA (quinidine, procainamide), Type III (sotalol, dofetilide, ibutilide)
Treatment of TdP
ALL
TdP and hemodynamic significance
and
First line agent
Resolve underlying cause
- Remove and correct underlying causes (i.e. medications which increasing QT interval)
- Treat electrolyte abnormalities (i.e. magnesium
