Cardiac Rhythm Disturbances - Johnston

Question 1

Sinus arrhythmia

Answer 1

Rate changes based on respiration

Question 2

Wandering pacemaker

Answer 2

Multiple atrial foci, different P wave morphologies

Question 3

Atrial escape beat

Answer 3

Pause of unhealthy SA node –> ectopic focus fires (different shape P wave)

Question 4

Junctional escape beat

Answer 4

Pause of unhealthy SA node –> ectopic AV junction focus fires (giant QRS, no P wave)

Question 5

Atrial escape rhythm

Answer 5

Sinus arrest –> 60-80 beats/min, different P wave morphology than normal

Question 6

Junctional escape rhythm

Answer 6

Sinus arrest –> 40-60 beats/min, no P waves or inverted P waves AFTER QRS

Question 7

Ventricular escape rhythm

Answer 7

Sinus arrest –> 20-40 beats/min, no P waves

Question 8

A ventricular pacemaker focus may ultimately cause what phenomenon?

Answer 8

Stokes-Adams syndrome (transient syncope via insufficient cerebral perfusion)

Question 9

Premature atrial beat

Treatment?

Answer 9

EARLY, unique P wave –> normal, aberrant, or no QRS (depends on how early)

• IF symptomatic – Beta blocker (Metoprolol)

Question 10

How does the heart respond to a single premature atrial beat?

Answer 10

The SA node is depolarized, then starts again at the same rate as before (RE-SETS)

Question 11

Explain possible QRS’s after a premature atrial beat (3)

Answer 11

• TOO early = refractory ventricles = no QRS
• EARLY = 1 bundle branch refractory = ABERRANT QRS
• OK = normal QRS

Question 12

Ventricular beats appearing in groups of 2 or 3, with the last one early and a different P wave

Answer 12

Atrial Bigeminy or Trigeminy (ectopic focus tied to SA rhythm somehow)

Question 13

EKG sign of significant myocardial hypoxia/ischemia

Answer 13

Premature/Ectopic ventricular beats

Question 14

Premature ventricular contraction

Treatment?

Answer 14

WIDE QRS w/o a P wave, inverted T wave, pause afterward

IF symptomatic…Metoprolol (Amiodarone/Lidocaine if really unstable)

Question 15

Why is an ectopic ventricular QRS wider than a normal one?

Answer 15

Conduction in myocardium is slower than in the conduction system

Question 16

What to avoid administering w/ ectopic ventricular beats/rhythms?

Answer 16

SNS stimulants or K+ wasting drugs

Question 17

Ventricular beats appearing in groups of 2 or 3, with the last one wide, early, and without a P wave

Answer 17

Ventricular Bigeminy or Trigeminy

Question 18

Ventricular Parasystole

Answer 18

Dual QRS rhythms at once via 2 independent pacemakers (SA and ectopic)

Question 19

PVC falling immediately after a normal QRS (where T wave would be)

Significance?

Answer 19

“R on T” - HIGH RISK for ventricular tachy-arrhythmia

Question 20

Multiple different QRSs of different morphologies and varying rates

Risk?

Answer 20

Multifocal PVCs

RISK of V. FIB.

Question 21

Barlow Syndrome

Answer 21

Multifocal PVCs caused by MITRAL VALVE PROLAPSE

Question 22

Tachycardia, rate 150-250, same PQRS every time

Treatment?

Answer 22

Paroxysmal Atrial Tachycardia (PAT) - ectopic focus overrides SA node

• Magnesium sulfate + CCB (Verapamil), then Amiodarone/Adenosine instead of Magnesium

Question 23

Tachycardia (150-250), 2 P’s for every 1 QRS

Answer 23

PAT w/ AV Block - DIGITALIS TOXICITY + HYPO-K+

Question 24

Tachycardia (150-250), inverted Ps (or none), normal QRSs

Answer 24

Paroxysmal Junctional Tachycardia (PJT) - ectopic focus overrides SA node

Question 25

Tachycardia (150-250), no Ps, abnormal QRSs

Answer 25

Ventricular tachycardia

Question 26

What can often be seen occasionally w/ V. tach?

Answer 26

Capture (normal QRS btwn VT) or Fusion beats (1/2 and 1/2)

Question 27

What is Supraventricular Tachycardia? Treatment?

Answer 27

Any tachycardia arrhythmia (not normal) that originates above the ventricular tissue (PAT or PJT or AVNRT) -- Tx = Adenosine

Question 28

When suspecting VT, what MUST you rule out?

Answer 28

SVT + BBB/aberrant conduction --> wide QRS's like VT | - NOT TREATED THE SAME AS VT

Question 29

How to distinguish VT from Wide QRS SVT?

Answer 29

Wide SVT = no RAD or coronary disease | VT = coronary disease, captures and fusions, EXTREME RAD

Question 30

Cause of Torsades de Pointes

Answer 30

- Low K+, K+ blockers, and/or long QT (syndrome or drug)

Question 31

Good Dx tool for atrial flutter Best leads to see it?

Answer 31

Vagal Maneuver (help slow AV node to show more flutter waves) 2, 3, AVF

Question 32

Ventricular flutter

Answer 32

Smooth, sine-wave appearance (as opposed to wide QRSs), same size every time

Question 33

Problem with V. flutter if not treated

Answer 33

PROGRESS to V. FIB due to coronary blood insufficiency

Question 34

Flutter rate

Answer 34

250-350 beats/min

Question 35

Fibrillation appearance

Answer 35

Random, super-fast, jagged beats w/ changing amplitudes and no recognizable pattern

Question 36

What will be seen on long-term EKG w/ untreated V. FIB?

Answer 36

Diminished amplitude over time as heart dies

Question 37

Immediate treatment for V. FIB

Answer 37

Defibrillation + CPR

Question 38

Upward-curving R waves ("delta waves")

Answer 38

Wolff-Parkinson-White Syndrome (via Bundle of Kent)

Question 39

V1-V3...RBBB (RSR') w/ ST elevation Treatment?

Answer 39

Brugada Syndrome (congenital) ICD placement

Question 40

T wave inversion in V2 and V3 (upward) Cause? Treatment

Answer 40

Wellens Syndrome (congenital) LAD stenosis (stent or bypass)

Question 41

QT interval greater than 1/2 the length of the cycle

Answer 41

Long QT syndrome (congenital)

Question 42

COPD - EKG findings

Answer 42

- Low voltage - RAD - MAT (multiple p wave morphologies, abnormal rates)

Question 43

Pulmonary embolus - EKG findings

Answer 43

``` S1 Q3 T3 - Large S in lead 1 - Large Q in lead 3 - Inverted T in lead 3 RAD ST depression in lead 2 T wave inversion in leads V1 - V4 ```

Question 44

Flatter, wider P wave Wide QRS Peaked T waves

Answer 44

Hyperkalemia

Question 45

``` Flat or inverted T waves U waves (if severe) ```

Answer 45

Hypokalemia

Question 46

Hypercalcemia

Answer 46

Short QT

Question 47

Hypocalcemia

Answer 47

Long QT

Question 48

Sinus tachycardia Causes? Treatment?

Answer 48

Elevated HR, normal PQRST - Emotion, anxiety, fear, drugs, hyperthyroid, pregnancy, anemia, CHF, hypovolemia - Treat underlying cause

Question 49

Sinus bradycardia

Answer 49

Slow HR, normal PQRST (

Question 50

Tachycardia, followed by bradycardia (cycle)

Answer 50

Sick Sinus Syndrome

Question 51

When to treat sinus bradycardia? How to treat? (preferred)

Answer 51

HR

Question 52

SVT vs. VT

Answer 52

SVT - normal narrow QRSs | VT - wide QRSs