Ventricular Rhythms

Question 1

What is a PVC?`

Answer 1

ectopic beat originating in the ventricles

Question 2

Is there a P wave with a PVC?

Answer 2

NO

Question 3

Wide or narrow QRS with PVC?

Answer 3

wide

Question 4

T wave description with PVC?

Answer 4

T wave will be the opposite direction of the QRS complex

Question 5

What is the difference in ventricular bigeminy and ventricular trigeminy?

Answer 5

bigeminy is a PVC that occurs every other sinus impulse

trigeminy is a PVC that occurs after two sinus impulses

Question 6

What is the difference between uniform and multiformed PVCs? which are worse?

Answer 6

uniform come the the same site and have the smae form while multiformed come from multiple sites and have different forms

multiformed are worse becuase it means more sites are irritated increasing the chances of coverting to a dangerous rhythm

Question 7

What is the differnce between a couplet and triplet?

Answer 7

a couplet is two PVCs in a row and a triplet is 3 in a row and is considered a short run of v-tach

Question 8

Do PVCs occur in healthy people?

Answer 8

Yes, they are the most common of all ectopic beats

also can occur with presence of heart disease and myocardial irritability

Question 9

Because PVCs may be a sign of myocardial irritability in the ventricles, what can it they be a precursor to?

Answer 9

v-tach or v-fib

Question 10

what is the r-on-t phenomenon? Is this significant?

Answer 10

ventricles depolarize (R wave) again during the repolarization process (T wave)

It is significant because it may cause VF or sudden death

Question 11

How are PVCs treated?

Answer 11

infrequent and isolated PVCs require no treatment

repeated PVCs may be treated with antiarrhythmic agents, IV antiarrhythmics for emergency situations

potassium supplementation for possible hypokalemic cause

cessation of digoxin therapy if suspected toxicity

Question 12

Define ventricular tachycardia.

Answer 12

three or more PVCs in a row is considered v-tach.

Question 13

QRS with VT?

Answer 13

wide and bizarre, occurring fairly regularly with a minimum of 100 bpm

Question 14

P waves with VT?

Answer 14

Nope, not usually. unrelated to QRS if appearing.

Question 15

Can VT be short and nonsustained or long and sustained?

Answer 15

YES YES YES

Question 16

When can VT commonly occur?

Answer 16

MI

Question 17

Other causes of VT?

Answer 17

same as PVC

Question 18

what can VT lead to?

Answer 18

VF or hemodynamic compromise if rate is fast enough and sustained long enough

Question 19

If stable and wanting to convert from VT, what is the first-line therapy?

Answer 19

IV lidocaine

Question 20

If the patient becomes unstable while in VT, what is the next therapy used?

Answer 20

synchronized cardioversion

Question 21

If the unstable patient in VT still hasn’t converted and the situation becomes emergent, what is the next line of therapy?

Answer 21

an unsynchronized defibrillation may be indicated by this point

Question 22

what are some long-term treatments for VT?

Answer 22

ICD (implantable cardioverter defibrillator)

Question 23

What is torsades de pointes?

Answer 23

This is a type of VT where QRS complexes go from positive to negative or negative to positive

Question 24

QRS of torsades de pointes?

Answer 24

large, bizarre, polymorphous or multiformed of varying amplitude and direction. These vary from beat to beat and appear to be twisting around the isoelectric line

Question 25

What is the rate of torsades de pointes?

Answer 25

100-180 BPM usually… can reach 200-300

Question 26

When is torsades de pointes most likely to occur?

Answer 26

whenever the QT interval is prolonged

Question 27

What are some things that can prolong the QT interval?

Answer 27

severe bradycardia

Drugs - 1A antiarrhythmics

electrolyte disturbances - hypoK hypoCa hypoMg

Question 28

What are some treatment modalities for torsades de pointes?

Answer 28

focused on shortening the QT interval

Drug therapy - mag, isoproterenol

override pacing

discontinuing agents causing rhythm

correcting electrolyte imbalances

If it does not revert by itself to sinus, emergency cardioversion or defibrillation may be necessary

Question 29

What is the definition of v-fib?

Answer 29

rapid, irregular and noneffective depolarizations of the ventricle

Question 30

QRS in VF?

Answer 30

NOT DEFINEABLE

Question 31

When is VF seen?

Answer 31

myocardial ischemia and MI

catheter manipulation in ventricles

electrocution

prolonged QT interval

anything that causes circulatory failure

Question 32

Treatment for VF?

Answer 32

defibrillation

CPR

Drugs (if defibrillation doesnt produce response)

ICD for long-term management

Question 33

What is an AIVR?

Answer 33

Accelerated idioventricular rhythm - this is a wide QRS tachycardia that is caused by the acceleration of the rate of the ventricular pacemaker cells, beating as fast as 50-100 BPM.

Question 34

when is an AIVR typically seen?

Answer 34

acute MI after thrombolytic therapy to resume coronary perfusion

less commonly from ischemia or digoxin toxicity

Question 35

How is AIVR treated?

Answer 35

Often treatment is not necessary, deterioration to rapid VT is rare.

If hemodynamically compromised atropine may increase sinus rate, or atrial pacing.