Phys 13 Flashcards

Digitalis toxicity can result in what cardiac arrythmia?

______ ______ ______ - results from spillover of signals from medullary respiratory center into adjacent vasomotor center during respiratory cycles

______ ______ ______ – rare, seen on ECG by P wave disappearance & slower impulse generation due to AV node taking over as pacemaker

ventricles spontaneously establish own signal

p-wave becomes dissociated from QRS-T complexs

atrial and ventricular rates are different

What pathology is shown above?

*hint - ventricles did not depolarize but atria did

2nd degree AV block – when AV bundle conduction is slowed enough where sometimes the AP doesn’t pass to the ventricles resulting in _____ _____ (P wave present, QRS complex absent)

can a premature/ectopic beat occur in normal healthy people?

What pathology is shown in the rhthym strip?

What pathology is shown above?

prolonged P-R interval, >0.20 sec; results in an incomplete block and typically originates in the AV node

Electrical ________

incomplete intraventricular block. can be due to confitions that depress heart such as ischemia, myocarditis, digitalis toxicity

In atrial fibrillaiton is the P wave present?

Is the rate regular or irregular?

What does a circus movement refer to in cardiac muscle?

A. Re-entry of an electrical impulse

B. Complete failure of conduction

C. Increased pacemaker firing

D. Simultaneous ventricular contraction

During a circus movement, an impulse re-enters what type of tissue?

A. Completely resting tissue

B. Previously excited muscle

C. Necrotic cardiac muscle

D. Unstimulated skeletal muscle

Which change can promote a circus movement by giving the impulse a greater distance to travel?

A. Shorter refractory period

B. Faster conduction

C. Longer conduction pathway

D. Increased contractility

Which cardiac condition can create a longer pathway and promote re-entry?

A. Hypertrophic heart

B. Bradycardic heart

C. Normal-sized heart

D. Dilated heart

Which change in electrical conduction can promote a circus movement?

A. Slowed conduction

B. Faster conduction

C. Increased automaticity

D. Increased contractility

Which condition can slow conduction and promote re-entry?

A. Hypokalemia

B. Purkinje block

C. Increased epinephrine

D. Shortened pathway

Which two conditions can slow cardiac conduction and promote circus movements?

A. Hypokalemia and exercise

B. Epinephrine and tachycardia

C. Ischemia and hyperkalemia

D. Hypertension and bradycardia

Which change in the refractory period can promote re-entry?

A. Prolonged refractory period

B. Absent refractory period

C. Unchanged refractory period

D. Shortened refractory period

Which substance can shorten the refractory period and promote circus movements?

A. Epinephrine

B. Acetylcholine

C. Adenosine

D. Insulin

Which set contains the three main conditions that promote circus movements?

A. Hypertrophy, fast conduction, long refractory period

B. Long pathway, slow conduction, short refractory period

C. Short pathway, slow rate, long refractory period

D. Fast conduction, short pathway, bradycardia

Supraventricular tachycardia includes which two paroxysmal conditions?

A. Atrial and AV nodal tachycardia

B. Ventricular and junctional tachycardia

C. Atrial and ventricular fibrillation

D. Sinus and ventricular tachycardia

Which condition is a type of supraventricular tachycardia?

A. Ventricular fibrillation

B. Atrial paroxysmal tachycardia

C. Torsades de pointes

D. Ventricular tachycardia

Which additional condition is included under supraventricular tachycardia?

A. Sinus bradycardia

B. Ventricular tachycardia

C. AV nodal paroxysmal tachycardia

D. Complete heart block

Due to AV node aberrant rhythm; causes normal QRS-T complexes but missing/obscured P waves

A. Sinus bradycardia

B. Ventricular tachycardia

C. AV nodal paroxysmal tachycardia

D. Complete heart block

Paroxysmal supraventricular tachycardia most commonly occurs in which population?

A. Elderly patients with heart failure

B. Adults with prior myocardial infarction

C. Patients with severe valve disease

D. Young, otherwise healthy people

What is the usual long-term outcome of this tachycardia predisposition in young patients?

A. Often resolves after adolescence

B. Causes permanent myocardial damage

C. Progresses to heart failure

D. Requires lifelong anticoagulation

Paroxysmal supraventricular tachycardia usually causes what degree of permanent cardiac harm?

A. Severe permanent damage

B. No permanent harm

C. Progressive valve damage

D. Chronic ventricular failure

_____ _____ _____ – rapid HR with inverted P wave that is partially superimposed onto normal T wave of preceding beat

Premature contractions can lead to what phenomenon caused by the inability of the ventricles to fill with enough blood resulting in dec stroke volume?

_____ deficit

A _____ deficit is the difference between the heart rate counted at the apex (auscultation) and the pulse rate measured at a peripheral site (like the wrist).

Are p waves present in atrial flutter?

even tho afib is not ______, pts will have reduced overall ______ pumping ability

A patient that has Premature Ventricular Contractions is at increased risk for developing what potentially fatal arrthymia?

AV _____ is the only means by which impulses can pass from atria into the ventricles.

_____ = bunch of random impulses in several diff directions

_____ = single large impulse moving in one direction

increased body temp, increased sympathetic stimulation & toxic heart conditions can cause _______

increased vagal stimulation & in those with carotid sinus syndrome can cause _______

What are the 2 major drug options for Ventricular Tachycardia?

1. _______ (anti-arrythmic) - blocks ____ channels, reduces permeability, blocks rhythmical discharge of focal point

2. _______ (anti-arrythmic) - refractory period prolongation, slows AV conduction via blockage of ____ channels

_______ -_______ syndrome:

periodic fainting spells due to _______ block; the brain cannot remain active for more than 4-7 sec without blood - results in fainting. pumping does not occur until 5-30 secs when ventricles escape

What pathology is shown above?

Types of 2nd Degree AV Blocks

1. [...]– fixed number of nonconducted P waves for every QRS complex; caused by abnormality of the bundle of His-Purkinje system, may require pacemaker implantation

2. [...]– characterized by progressive PR interval prolongation until a ventricular beat is dropped & then followed by resetting of PR interval & repeating the abnormal cycle, no tx necessary; almost always caused by abnormality of the AV Node

_____ nodal/bundle _____ _____

P wave missing from premature contraction & is superimposed onto QRS-T complex; due to cardiac impulse traveling backwards into the atria as it traveled forwards into ventricles

During atrial flutter, one side of atria is _____ while other is _____ , amount of blood pumped by atria is _____.

What is the mainline treatment for acute Long QT Syndrome?

1. ______ Sulfate

2. ______ -Blockers

3. Cardiac ______ implant --> for long-term/chronic cases

______ ______ ______ = QRS shape changes due to premature beat, pause, then another beat occurs w/ long Q-T interval; triggers arrthymias, tachycardia, v fib

What electrolytes distrubances can result in Long QT syndromes?

1. Hypo________

2. Hypo________

3. Hypo________

*additionaly Anti-________ drugs (quinidine) can cause Long-QT syndrome

Rheumatic Fever and Diphtheria can result in what damage to the AV node/bundle?

a.) ischemia

b.) compression

c.) inflammation

________ ________ ________ – appearance of series of premature ventricular beats w/o any normal beats interspersed; serious condition and doesn't occur unless significant ________ damage is present in the ventricles

Premature ventricular contraction results in what 3 findings on an ECG?

1. QRS _____ - impulse is conducted thru slowly conducting muscles rather than the Purkinje system

2. _____ QRS (high voltage) - impulses travel in 1 direction (no neutralization)

3. _____ _____ opposite in polarity to QRS

What antibiotics (2) can result in the devlopment of Long QT syndrome (disorders that delay ventricular repolarization)?

1. _____

2. _____

How much time must elapse for AV node to pass impulse to ventricles during Atrial Fibrillation?

What is the most frequent cause of atrial fibrillation?

_____ enlargement

What is this?

What interval and/or complex measurement is useful in determing the severity of Rheumatic Heart Disease?

_____ interval

What is this?

What is this?

The heart rate usually increases about _____ beats/min for each degree (Fahrenheit) increase in body temperature

P-R interval usually _______ in length with a faster heartbeat and _______ with a slower heartbeat

second degree type I block is is _______ and no specific treatment is needed

Which treatment can stop ventricular fibrillation by briefly making all ventricular muscle refractory?

A. Electroshock defibrillation

B. Vagal stimulation

C. Adenosine infusion

D. Carotid massage

Defibrillation is usually delivered using which waveform?

A. Monophasic

B. Sinusoidal

C. Biphasic

D. Triphasic

A patient at high risk for recurrent ventricular fibrillation may receive which device?

A. External pacemaker

B. Holter monitor

C. Loop recorder

D. Implantable cardioverter-defibrillator

What is an important treatment for cardiac arrest?

A. Prolonged CPR

B. Carotid massage

C. Vagal stimulation

D. Exercise

Some patients with persistent loss of normal cardiac pacing may require which device?

A. ICD

B. Electronic cardiac pacemaker

C. Coronary stent

D. Prosthetic valve

After AV conduction suddenly stops, why may the ventricles remain silent for 5–30 seconds?

A. Ventricular fibrillation

B. Complete refractoriness

C. Overdrive suppression

D. Atrial flutter

What does overdrive suppression mean?

A. Atria stop firing permanently

B. Purkinje cells fire too rapidly

C. Ventricles become hyperexcitable

D. Ventricular automaticity is temporarily suppressed

Why are ventricular pacemaker cells initially suppressed after AV block?

A. Atria previously drove them faster

B. Ischemia destroys all Purkinje cells

C. Vagus stimulates the ventricles

D. Calcium channels permanently close

After several seconds of complete AV block, which fibers can begin pacing the ventricles?

A. SA nodal fibers

B. Purkinje fibers

C. Atrial muscle fibers

D. Mitral valve fibers

What is the ventricular rhythm produced by Purkinje fibers after AV block called?

A. Atrial escape

B. Sinus escape

C. Ventricular escape

D. Junctional flutter

A patient becomes markedly bradycardic when mild pressure is placed on the neck. What is the likely diagnosis?

A. Carotid sinus syndrome

B. Atrial flutter

C. Ventricular tachycardia

D. Sinus arrest

What causes the bradycardia in carotid sinus syndrome?

A. Sympathetic activation

B. Strong vagal response

C. Purkinje stimulation

D. Increased ventricular automaticity

Which neurotransmitter mediates the strong cardiac vagal effect in carotid sinus syndrome?

A. Norepinephrine

B. Dopamine

C. Acetylcholine

D. Epinephrine

Paroxysmal tachycardia is best described as what?

A. Persistent slow rhythm

B. Irregular lifelong rhythm

C. Gradual heart-rate increase

D. Sudden rapid rhythmic discharge

How does paroxysmal tachycardia often end?

A. Ventricles stop contracting

B. SA node regains pacing

C. AV node permanently blocks

D. Purkinje fibers stop working

What mechanism is thought to cause many episodes of paroxysmal tachycardia?

A. Valve stenosis

B. Sinus bradycardia

C. Re-entry circus movement

D. Complete AV block

Which maneuver can sometimes stop paroxysmal tachycardia?

A. Exercise

B. Defibrillation always

C. Hyperventilation

D. Vagal reflex

How can antiarrhythmic drugs help stop re-entry tachycardia?

A. Slow conduction and prolong refractoriness

B. Increase conduction and shorten refractoriness

C. Increase automaticity

D. Shorten action potentials

Why can ventricular fibrillation become harder to reverse if defibrillation is delayed?

A. Atria become hypertrophied

B. AV node becomes calcified

C. Coronary blood flow becomes inadequate

D. Vagus nerve becomes inactive

If immediate defibrillation fails because the heart has become too weak, what can help before another shock?

A. Carotid pressure

B. Vagal stimulation

C. Exercise

D. CPR

According to these notes, what is the main treatment for atrial fibrillation?

A. Electroshock

B. Pacemaker

C. Carotid massage

D. Beta stimulation

Which event can directly initiate cardiac fibrillation?

A. Mild exercise

B. Sudden electrical shock

C. Increased preload

D. Sinus bradycardia

Which cardiac problem can initiate fibrillation?

A. Hypertension

B. Valve prolapse

C. Myocardial ischemia

D. Mild tachycardia

When a depolarization wave encounters refractory tissue, what can it do?

A. Immediately disappear

B. Reverse through the SA node

C. Stop all atrial contraction

D. Travel around the refractory area

Inflammation of which structures can depress conduction from atria to ventricles?

A. SA node and atria

B. AV node or AV bundle

C. Ventricular walls

D. Papillary muscles

Simple weakening of the myocardium usually has what effect on heart rate?

A. Stops it

B. Decreases it

C. Increases it

D. Has no effect

A P wave without a following QRS-T complex in second-degree heart block represents what?

A. Dropped ventricular beat

B. Premature ventricular beat

C. Atrial fibrillation

D. Ventricular escape

What happens to the QRS complex during a premature ventricular contraction?

A. Becomes shorter

B. Becomes prolonged

C. Disappears

D. Becomes normal

Amiodarone has what effect on the cardiac action potential?

A. Shortens it

B. Eliminates it

C. Prolongs it

D. Does not affect it

Amiodarone has what effect on the refractory period?

A. Shortens it

B. Eliminates it

C. Leaves it unchanged

D. Prolongs it

Amiodarone also slows conduction through which structure?

A. AV node

B. Aortic valve

C. SA artery

D. Coronary sinus

In atrial flutter, approximately how many atrial beats occur for each ventricular beat?

A. One

B. Two to three

C. Five to six

D. Eight to ten

Which form of paroxysmal tachycardia is usually considered particularly serious?

A. Atrial

B. AV nodal

C. Ventricular

D. Sinus

Premature contractions can commonly be mechanically triggered during which procedure?

A. Bronchoscopy

B. Colonoscopy

C. Lumbar puncture

D. Cardiac catheterization

Which condition can create an ectopic focus and cause premature beats?

A. Local ischemia

B. Increased sleep

C. Mild exercise

D. Increased vagal tone

How can small calcified plaques promote premature beats?

A. Block all blood flow

B. Irritate nearby cardiac fibers

C. Increase refractory periods

D. Suppress all pacemakers

Which type of irritation can create ectopic foci in the AV node, Purkinje system, or myocardium?

A. Mechanical exercise

B. Increased oxygen delivery

C. Toxic irritation

D. Decreased preload

Which group contains possible causes of toxic ectopic irritation?

A. Exercise, sleep, water

B. Hypotension, anemia, fever

C. Calcium, sodium, potassium

D. Infection, drugs, nicotine, caffeine

Most patients with Stokes-Adams attacks are treated with what?

A. Artificial pacemaker

B. Defibrillation every day

C. Vagal stimulation

D. Carotid massage

During ventricular fibrillation, despite massive movement of stimulatory signals throughout the ventricles, the ventricular chambers neither _____ nor _____ but remain in an indeterminate stage of partial contraction, pumping either no blood or negligible amounts

Atrial flutter causes fast _____ signals, but the A-V node blocks many of them so the ventricles do not beat too fast.

when the P-R interval increases to greater than ______ second, the P-R interval is said to be prolonged and the patient is said to have ______-degree incomplete heart block

What is this?

people at risk for ventricular fibrillation will have a _____ implanted

second degree type I block is characterized by progressive ______ of the PR interval until a ventricular beat is dropped and is then followed by resetting of the PR and repeating of the abnormal cycle

during rapid stimulation of the heart, the velocity of conduction through the heart muscle ______, which allows a longer time interval for the impulses to travel around the heart

When the heart contracts ahead of schedule, the ventricles will not have filled with blood normally, and the stroke volume output during that contraction is depressed or almost absent.

Therefore, the ______ may be so weak that it cannot be felt in the radial artery

what does this EKG show?

The paroxysm usually ends as suddenly as it began, with the pacemaker of the heart instantly shifting back to the ______ node

What can compress the AV bundle and block conduction from the atria to the ventricles?

A. Scar tissue or calcification

B. Increased vagal tone

C. High cardiac output

D. Atrial dilation

Which area of the neck can be pressed to trigger a vagal reflex that may stop paroxysmal tachycardia?

A. Jugular veins

B. Carotid sinuses

C. Thyroid cartilage

D. Supraclavicular fossa

What does a cardiotachometer measure from the ECG?

A. P-wave amplitude

B. QRS width

C. Time between QRS complexes

D. ST-segment elevation

After a premature atrial contraction, the next normal beat is slightly delayed. What is this called?

A. Ventricular escape

B. Heart block

C. Overdrive suppression

D. Compensatory pause

Coronary insufficiency can impair conduction by causing ischemia of which structures?

A. AV node and bundle

B. SA node and atria

C. Papillary muscles

D. Ventricular septum

Why can cardiac arrest occur during deep anesthesia?

A. Excessive coronary blood flow

B. Severe hypoxia from poor breathing

C. Increased ventricular filling

D. Increased sympathetic stimulation

During fibrillation, what happens when an impulse reaches another refractory area?

A. It always stops

B. It returns to SA node

C. It splits into more impulses

D. It causes AV block