Med Surg: Cardio alterations in rhythm and conduction

Question 1

What is the functional property of the cardiac muscle?

Answer 1

Automaticity: generate impluses spontaneously

Excitability: able to respond to cells that arent pacemaker

Conductivity

Contractility

Extensibility: stretch and ability to fill

Rhythmicity

Question 2

What is the confuction system?

Answer 2

SA node: greatest degree of automaticity

AV node: right atrium near the septum, as impulse travels from SA to AV nose

Bundle of His and bundle cranches located in the interventricular septum

Purkinje fibers: causes myocardial contration

Question 3

What is the normal impulse of ECG tracing?

Answer 3

Electrical activity converted to imaged on ECG paper

Not a recording of muscle contration, but of the electrical activity that precedes the contraction

Question 4

What are the different waves and intervals?

Answer 4

P wave: electrical activity of atrail depolarization

PR: isoelectric baseline time of delay for conduction at AV node

PR interval: beins at P wave and ends at next change of deflection

QRS: where goes straight up, represents ventricular depolarization and moving through bundle of His and Perkinje fibers

Question 5

What is the electrocardiographic rhythm analysis?

Answer 5

Determine the heart rate:

6 second method: count number of impulses in 6 seconds

R to R method: chose an R wave that falls on a vertical line, count the big boxes between that R wave and the next one, divide that number into 40, method can only be used if rhythm is regular

Question 6

What are the normal rhythms?

Answer 6

Normal sinus rhythm: most normal, everything within limits

Sinus arrhythmia: normal but when patient takes breath in there is pressure on pericardial to increase heart and deacrease a little when exhale

Question 7

What is sinus bradycardia?

Answer 7

Rate of sinus node discharge <60 beats/min

Question 8

What are the clinical manifestations of sinus bradycardia?

Answer 8

syncope

BP may decrease

SA node not firse as often

Question 9

What are interventions for sinus bradycardia?

Answer 9

Digoxin

Hyperkalemia

B-blockers

Dont treat unless symptoms Atropine-raise heart rate

Question 10

What is sinus tachycardia and its clinical manifestations?

Answer 10

rate of sinus node discharge >100 beats/minute

CM: still regular, all variables there caused by anxiety, pain, fever, nicotine, respiration meds recation to decrease CO and caffiene

Question 11

What is supraventricular tachycardia?

Answer 11

Rapid stimulation of atrial tissue occurs at a rate of 100-280 beat/min with a mean of 170 beats/min in adults

intermittent and terminated suddenly with or without intervention

Treat the underlying cause

Question 12

What is premature Atrial complexes?

Answer 12

Extopic focus on atrial tissue fires an impulse before the next sinus impulse is due

Question 13

What are clinical manifestations of premature atrial complexes?

Answer 13

irritability to atria

stress

fatigue

infection

caffiene

nicotine

alcohol

anesthesia

Question 14

What are the interventions of premature atrial complexes?

Answer 14

dont treat if occur too often

slow ventricular filling

Question 15

What is an Atrial flutter?

Answer 15

Rapid atrial depolarization occurring at a rate of 250 to 350 times per minute

Beating way to fast compared to ventricles

Question 16

What are clinical manifestations of atrial flutter?

Answer 16

ischemic heart disease

heart failure

alcoholism

open heart surgery

Question 17

What are interventions of atrial flutter?

Answer 17

Not life threatening

May have to slow down ventricles

Question 18

What is atrial fibrillation and its clinical manifestation?

Answer 18

chaotic firing of atria

cant be counted

CM: may feel irregular house, otherwise no symptoms same causes as flutter, electrolyte imbalance

Question 19

What is premature Ventricular Complexes?

Answer 19

A result of increased irritability of ventricular cells: early ventricular complexes followed by a pause

AV fires to soon

Question 20

What are the clinical manifestations of Premature ventricular complexes?

Answer 20

decrease CO

feel irregular heart rate

Dont perfuse

CAused by MI, ischemia, heart failure, anestesia, nicotine, caffeine, alcohol, stress

Question 21

Interventions for premature ventricular complexes?

Answer 21

improve or maintain CO

Meds to decrease ventricular irritability

Question 22

What is ventricular tachycardia?

Answer 22

repetitive firing of an irritable ventricular ectopic focus at a rate of 140-180 beats/minute

Question 23

What is ventricular fibrillation?

Answer 23

A result of electrical chaos in the ventricles

CM: no pulse

Interventions: CPR, catelcholamines, epinephrine, lidocaine, defibrilation

Question 24

What is ventricular asystole?

Answer 24

Complete absence of any ventricular rhythm

CM: hypoxia, hypothermia, drug toxicity, electrolyte, myocardial infarction

Intervention: defibrilation

Question 25

What are the different degrees of Atrioventricular block?

Answer 25

First: PR interval greater than 0.2 second prolonged

CM: MI, digoxin toxicity, ischemia to AV node

Second: progressive prolonged of the PR interval, followed by a dropped beat and a pause, each group has one more P way then QRS complex

CM: dropped beat from pattern, ventricular rate less then atrial, will feel inferior MI, DIG toxicity

Third: heart block is complete, none of the sinus impulses confuct to the ventricles

CM: dizzy, confusion, lightheaded, cardiac arrest