Ekg Test 2

Question 0

Major cellular properties that distinguish cardiac cells from other tissues are their

Answer 0

• Contractility
• Conductivity
• Automaticity
• Rythmicity

Question 1

Conduction Systems

Answer 1

• SA node
• AV node
• bundle of his
• purkinjie fibers

Question 2

Contractility

Answer 2

Cardiac tissue can contract in response to electrical stimuli

Question 3

Conductivity

Answer 3

Myocardial cells conduct electricity after stimulation

Question 4

Automaticity

Answer 4

Ability to initiate its own beats

Question 5

Rythmicity

Answer 5

Capability if maintaining regularity of such pace making activity

Question 6

Bipolar leads

Answer 6

Basic leads proposed by William Einthoven was the Nobel Prize winner in 1924 for invention of practical electrocardiogram

He says the sum of heights of QRS in leads I and lll equals the height of QRS in lead II it’s called Einthovens law

Question 7

Normal sinus rhythm

Answer 7

Impulse originate in SA node to AV node to ventricles through normal pathways resulting in a normal P and QRS complex

rate- 60-100 bpm

Question 8

Sinus Arrhythmia

Answer 8

The heart rate stays within normal limits however the rhythm will be irregular.

It will have waxing and waning on heart rate in response to respiration
It’s the result of vagal control

Commonly seen in athletes, children, patients with sleep apnea

Rate- increases on inspiration decreases with expiration

There’s no treatment I

Question 9

Sinus Bradycardia

Answer 9

Characterized by sinus rhythm heart rate below 60bpm

Clinical significance- Can result in hemodynamic compromise and symptoms such as : syncope,chest pain, premature beats, ventricular tachycardia

No treatment is needs if patient is asymptomatic and rate stays close to 60 bpm. If patient becomes symptomatic administer Atropine

Question 10

Sinus tachycardia

Answer 10

Involves accelerated firing of SA node with a rate greater than 100 bpm

Clinical significance - Considered symptom of an underlying pathophysiologic process should find primary cause rather than treating it right away

Pharmacologic agents like beta blockers, calcium channel blockers, adenosine, or digoxin any be helpful

Question 11

Sinus Arrest

Answer 11

Normal sinus rhythm is interrupted by prolonged failure of SA node to initiate an impulse resulting on complete missing of PQRST complex

Rate- usually normal limits however length and frequency pauses may lead to bradycardia

Treatment same as sinus bradycardia administer Atropine

Etiology- ischemia affecting SA node, effect of SA nodal blocking drugs ex. Beta blockers and excessive vagal tone

Question 12

Premature Atrial Complexes (PAC)

Answer 12

Rate- usually within normal limits

Clinical significance -Occasional PACs are benign. Once become more frequent may cause subjective symptoms such as palpitations.
However frequent PACs sometimes prelude to atrial tachycardia of fibrillation.
Treatment - Recurrent PACs can be treated with digitalis

Question 13

First Degree Heart Block

Answer 13

Characterized by- elongated PR interval. It’s longer stretches everything out

Clinical significance- it’s benign. Causes by coronary artery disease causing AV nodal ischemia

Treatment - beta blockers, calcium channel , blockers, and digoxin

Question 14

Second Degree Heart Block (Wenckebach)

Answer 14

Periodic conduction failure within AV node causing PR interval to lengthen until a drop in QRS complex. After this dropped beat cycle repeats forming groups of beats called footprint of Wenckebach

clinical significance - has same causative factors as first degree heart block

Treatment- asymptomatic however symptomatic patients may need transcutaneous or transvenous pacing

Question 15

Mobitz Type II

Answer 15

More serious then Wenckebach. Location of block can be either AV node or bundle of branch level

Characteristics - regular rhythm with constant PR interval from beat to beat than sudden drop of QRS complex

Clinical significance- left untreated can progress into serious AV dissociation. Usually causes by hypoxia,myocardial infarction,conduction system disturbance

Treatment - Epinephrine

Question 16

Ventricular Fibrillation

Answer 16

Disorganized and chaotic ventricular rhythm has hemodynamic implications.
Completely irregular with fibrillatory waves

The only shockable rhythm

Clinical significance - does not generate cardiac output advanced life support measures and emergent defibrillation needed

Treatment - Amiodarone and Lidocaine

Question 17

Asystole

Answer 17

Ventricular standstill no cardiac output
Flat line appears means no pacemaker activity happening anywhere in the heart.

Clinical significance -terminal rhythm of the heart , seen after profound cardiac damage,severe hypoxia , multisystem failure

Treatment- aggressive resuscitative efforts with Epinephrine, Atropine, and CPR

Question 18

Corse V Fib

Answer 18

Does not generate cardiac output immediate basic and advanced life support and AED needed.

Treatment- Amiodarone and Lidocaine

Clinical Significance - causative factors same as that of ventricular tachycardia

Question 19

Torsadea de Pointes (TDP)

Answer 19

French term means - twisting of the points
Rate- 150-300 bpm

Ventricular tachycardia with a varying QRS morphology. May be produced by acute ischemia, myocarditis

Clinical significance- lethal arrhythmias can degrade into v fib

Treatment- intravenous administration of magnesium

Question 20

Monomorphic VT

Answer 20

Treated with immediate asynchronous DC cardioversion.

Intravenous Lidocaine or Amiodarone

Question 21

Agonal Rhythm

Answer 21

Worst possible cardiac rhythm second to asystole. Impending death

Rate - less than 20 bpm

Irregular occasional wide complex beats