Ventricular Arrhythmias Flashcards Preview

CardioPulm II > Ventricular Arrhythmias > Flashcards

Flashcards in Ventricular Arrhythmias Deck (32):

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



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 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***


Myocardial Ischemia


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

TdP and hemodynamic significance


First line agent

Resolve underlying cause

1. Remove and correct underlying causes (i.e. medications which increasing QT interval)

2. Treat electrolyte abnormalities (i.e. magnesium


Treatment of TdP

TdP and patient is hemodynamically stable

Magnesium sulfate IV

Magnesium Sulfate IV- Drug of Choice (DOC)
At least 1-2 grams IV


IV push
Dilute in 10 mL of D5W and give over 5- 20 minutes
Can give IV push in an emergent situation

1st line

- only give when patient has TdP or if patient is hypomagnesemic


Treatment of TdP

TdP and patient is hemodynamically unstable

Direct cardiac cardioversion
Magnesium sulfate IV

Magnesium Sulfate IV- Drug of Choice (DOC)
At least 1-2 grams IV


IV push
Dilute in 10 mL of D5W and give over 5- 20 minutes
Can give IV push in an emergent situation

Direct current cardioversion- 1st line therapy

If the patient is significantly hemodynamically compromised
Frequently associated with ventricular rate > 150 beats/minute and unconscious


Chronic Treatment of TdP:

Unnecessary in most patients

Avoid medications which can prolong QT interval


Ventricular Fibrillation (VF)

VT can also cause the heart to beat irregularly, causing the ventricles to “quiver.”
VF is considered a MEDICAL EMERGENCY

No cardiac output (no blood flow)

Cardiovascular collapse= sudden cardiac death (SCD)

Occurs most commonly in patients with ischemic heart disease, coronary artery disease, or LV dysfunction

ACUTE management of VF (ACLS algorithm)

PROMPT and EFFECTIVE cardiopulmonary resuscitation (CPR)
Delivery of defibrillation (for shockable rhythms


Diagnosis of VF

Hemodynamic instability

Electrical disorganization in ventricular myocardium
No distinct wave forms


Acute VF Treatment

Advanced cardiac life support (ACLS)


Chronic VF Treatment


Assess underlying cause if reversible (i.e. s/p MI within 48 hours of VF arrest) long term treatment is NOT necessary

Implantable Cardioverter Defibrillator (ICD) for all survivors of VF arrest (if no reversible causes are found)


Chronic VF Treatment

Antiarrhythmic therapy

If patient refuses an ICD

If patient experiences frequent shocks with ICD

Drug of choice: AMIODARONE IV

-->Convert to PO therapy when possible

-->May require higher maintenance dose compared to atrial fibrillation (400- 600 mg PO daily)


Sustained VT (SuVT)

Lasts > 30 seconds

May require intervention to restore a stable rhythm because of hemodynamic compromise

Can degenerate into Pulseless VT/ Ventricular Fibrillation (VF)

TdP is a form of polymorphic VT

Hemodynamically stable
(Magnesium Sulfate IV)

Hemodynamically unstable
(Direct Cardiac Cardioversion)
(Magnesium Sulfate IV)


Non- Sustained VT (NSVT)

Spontaneously self terminates after short duration

VT with a pulse

Pulseless VT (cardiac arrest)


Premature Ventricular Complexes

Healthy patients without structural heart disease

No treatment is necessary


Premature Ventricular Complexes

Symptomatic patients without structural heart disease

β- blockers can be used in patients to suppress symptomatic PVCs


Premature Ventricular Complexes

Patients with MI
(or other structural heart disease)

Antiarrhythmic empiric therapy is NOT recommended
*ONLY β- blockers have been proven to prevent arrhythmias and overall mortality in patients s/p MI


CAST trial (Cardiac Arrhythmia Suppression Trial)

Trial ended early due to excess mortality in the encainide and flecainide arm

PVCs during MI are not predictive of VF

PVCs after MI infarction increase risk of sudden death

Empiric pharmacologic therapy (Class IC agents) is NOT
effective and is associated with INCREASED mortality and death due to arrhythmias


VT Assessment

FIRST assess patient status and symptoms to determine hemodynamic stability
-->Mental Status
==>Blood pressure

Assess and treat underlying causes
Ischemia (i.e. Myocardial Infarction)
Drug-induced (i.e. digoxin toxicity, antiarrhythmics)
Electrolyte abnormalities (i.e. hypomagnesemia, hypokalemia)


Electrocardiogram Evaluation

Holter Monitoring
Continuous Electrocardiogram (ECG or EKG) monitoring (Ambulatory setting)


Invasive electrophysiology study (EP study)

If arrhythmia can be reproduced it is called “Inducible”
Patient elgible for inplantable cardiac device.

Must D/C all meds antiarrhythmic


Ventricular Tachycardia (VT)


Myocardial scarring from a previous myocardial infarction (MI)
---=> Can occur within 48 hours of an acute MI

Metabolic or electrolyte abnormalities (i.e. hypoxemia, hypomagnesemia, hypokalemia)

Medications (i.e. digoxin toxicity) + Amiodoarine