THERAPEUTICS EX3 L(?) (VENTRICULAR ARRHYTHMIAS) (MIRANDA)

Define non-sustained VT

Series of 3 or more consecutive PVCs at a rate of > 100 bpm

Last 30 seconds or less and terminates spontaneously

May be asymptomatic, but can be symptomatic if HR is fast enough

What happens if sustained VT is left untreated?

Potential progression to VFib, then asystole

Define sustained VT

Last > 30 seconds or requires termination before 30 seconds because of hemodynamic instability

Monomorphic VT?

Consistent QRS complexes; usually initiates from a single origin

Polymorphic VT?

Varying QRS complexes; initiates from multiple sides in the ventricles

Describe VF/Pulseless VT?

VF = absence of organized ventricular rhythm

Chaotic electrical activity = irregular undulation and lack of recognizable QRS complexes -> no CO = absence of pulse and palpable BP

T/F: Pulseless VT is associated with immediate loss of consciousness and death within minutes if not resuscitated.

True

3 deadly types of ventricular arrhythmias?

1. VF/pulseless VT

2. Sudden cardiac death

3. Sudden cardiac arrest

Cardiac causes of VT?

Ischemic heart disease, cardiomyopathy

Electrolyte imbalances which can cause VT?

Hypokalemia

Hypocalcemia

Hypomagnesemia

Sympathomimetic drugs which can contribute to VT?

Cocaine, methamphetamines

T/F: Digoxin toxicity is a contributor to VT development.

True

Symptoms of VT (when symptomatic) can include?

Palpitations

Light-headedness

Syncope

Chest pain

Anxiety

3 management goals in VT?

Restore hemodynamic stability

Terminate arrhythmia

Eliminate reversible cause or manage irreversible cause

T/F: If a patient is hemodynamically unstable, they should undergo cardioversion for VT management.

True

T/F: Hemodynamically stable patients with VT usually are treated long-term with beta-blockers.

True

Describe premature ventricular complexes (PVC)

Premature ventricular contraction; often described as an uncomfortable heart beat; usually asymptomatic, not requiring drug treatment

What drug do we use if treatment is necessary for PVCs?

Low-dose beta blocker usually

If not tolerated, CCB

T/F: Ventricular tachycardias (VT) are monomorphic.

True

When is therapy indicated in NSVT?

If symptoms are present, a BB is indicated unless there are contraindications

When is therapy not indicated in NSVT?

Patient EF > 40%, no symptoms

Alternatives to BBs in NSVT therapy?

Sotalol, amiodarone

Is preserved LV function in SVT, what do we use? Alternatives?

Procainamide first line

Alternatives: amiodarone, lidocaine

If LF dysfunction in SVT, what do we use?

BB or ICD

T/F: Torsades de Pointe is a monomorphic VT.

False; polymorphic.

Drug of choice for treatment of Torsades de Pointe?

Magnesium sulfate IV

Drugs we use in ventricular arrhythmias? (four big ones)

Procainamide

Lidocaine

Amiodarone

Sotalol

How is dosing renally adjusted in patients needing procainamide for ventricular arrhythmia?

1/3 in patients with moderate renal impairment

2/3 in patients with severe renal impairment

Adverse effects associated with procainamide?

Hypotension, positive ANA

Contraindications associated with procainamide?

Hypersensitivity to procainamide or any other ester-type local anesthetic

Procainamide is ___________ eliminated

A. Renally

B. Hepatically

A. Renally

How often do we take lidocaine levels to prevent adverse effect/CNS toxicity?

After 12 hours; after 24 hours, clearance may be decreased

What therapeutic range do we want to see when we take a lidocaine plasma conc.?

1.5 - 5 mcg/mL

Adverse effects associated with lidocaine?

CNS toxicity (agitation, disorientation, headache, lightheadedness)

Contraindication for lidocaine?

Hypersensitivity to lidocaine, any other amide-type anesthetic

Heart block

Contraindications for amiodarone?

Hypersensitivity to amiodarone or iodine, severe-sinus node dysfunction causing marked sinus bradycardia, 2nd/3rd degree heart block, cardiogenic shock

T/F: Amiodarone highly lipophilic, accumulates in adipose and cell membranes.

True

VFib, first thing you do is

SHock

Sotalol CrCl contraindication cutoff?

40 mL/min

Dosing for sotalol?

80 mg BID; may be increased gradually to 160-320 mg

From which sotalol isomer does B-blocking effect come from?

A. S-sotalol

B. R-sotalol

B. R-sotalol

Contraindications for sotalol?

Hypersensitivity to sotalol, bronchial asthma, severe bradycardia, 2nd/3rd degree heart block, congenital or acquired long QT syndrome, cardiogenic shock, uncontrolled HF

Ventricular fibrillation is a what

TRUE EMERGENCY

T/F: 40-70% of patients with an ICD will require concurrent AAD therapy.

True

Why do we add an AAD to AICD?

Decrease number of inappropriate firings

Reduce number of high voltage shocks, inappropriate shocks provoked by supraventricular arrhythmias

Prolong the battery life