Atrial Dysrhythmias

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Questions and Answers

What is the typical atrial fibrillation rate range?

150 - 300

300 - 400

400 - 600

350 - 600 (correct)

In atrial fibrillation, the P wave is usually present and can be clearly identified.

False

Name one possible cause of atrial fibrillation.

Mitral valve disease

Atrial fibrillation can lead to blood clots that may cause a __________ if they travel to cerebral arteries.

stroke Signup and view all the answers

Match the following aspects of atrial fibrillation with their descriptions:

Irregularly irregular = Regularity of rhythm Absent = P wave in atrial fibrillation Normal = QRS complexes 150 - 600 = Typical rate range for atrial fibrillation Signup and view all the answers

What is a Premature Atrial Complex (PAC)?

A premature impulse arising from an ectopic focus in the atria Signup and view all the answers

The P wave during a PAC is often normal and does not exhibit any changes.

False Signup and view all the answers

What is the conduction ratio in a PAC?

1:1 Signup and view all the answers

The impulse during a Wandering Atrial Pacemaker occurs at various points in the ______.

atria Signup and view all the answers

Match the following atrial conditions with their descriptions:

Atrial bigeminy = 1:1 ratio of normal and PAC Atrial trigeminy = 2:1 ratio of normal, normal, and PAC Atrial quadgeminy = 3:1 ratio of normal, normal, normal, and PAC Wandering Atrial Pacemaker = Impulse at various points in the atria Signup and view all the answers

Which of the following can be a cause of PACs?

Caffeine consumption Signup and view all the answers

A premature atrial contraction results in a compensatory pause following the early PQRST complex.

False Signup and view all the answers

What is one underlying condition that may lead to the development of PACs?

Hypoxia Signup and view all the answers

What is the typical rate of Atrial Tachycardia?

160 - 240 bpm Signup and view all the answers

In Multifocal Atrial Tachycardia, the P waves are identical.

False Signup and view all the answers

What is the normal range for heart rate?

60-100 bpm Signup and view all the answers

Atrial Flutter involves a series of __________ waves.

F Signup and view all the answers

Match the following conditions with their associated symptoms:

Atrial Tachycardia = Rate of 160 - 240 bpm Multifocal Atrial Tachycardia = Abnormal and variable P waves Atrial Flutter = Sawtooth F waves ECG Conduction Ratio = Conduction ratio is half of atrial rate Signup and view all the answers

What is a common cause of Atrial Flutter?

Acute coronary syndrome Signup and view all the answers

The PR interval is typically variable in Multifocal Atrial Tachycardia.

True Signup and view all the answers

What does a high ventricular rate in Atrial Flutter indicate?

Higher myocardial demand Signup and view all the answers

Electrolyte imbalances can lead to __________ conditions in the heart.

tachycardia Signup and view all the answers

Match the following ECG characteristics with their associated conditions:

Atrial Tachycardia = Abnormal P waves Multifocal Atrial Tachycardia = Rate of 100 - 150 bpm Atrial Flutter = Regular F waves Signup and view all the answers

Which of the following best describes the characteristics of the P wave in Atrial Tachycardia?

Inconsistent size and direction Signup and view all the answers

Rapid depolarisation during Atrial Tachycardia results in increased cardiac output.

False Signup and view all the answers

What can trigger Atrial Tachycardia?

PAC (Premature Atrial Contractions) Signup and view all the answers

In Atrial Flutter, the conduction ratio is typically ________ of the atrial rate.

half Signup and view all the answers

Match the condition with its notable characteristic:

Atrial Flutter = 240 - 360 bpm Atrial Tachycardia = 160 - 240 bpm Multifocal Atrial Tachycardia = 100 - 150 bpm Normal Heart Rate = 60 - 100 bpm Signup and view all the answers

Study Notes

Premature Atrial Complex (PAC)

An ectopic focus in the atria causes an early PQRST complex followed by a non-compensatory pause.
On ECG, the P wave will be abnormal, inverted if the pacemaker is low in the atria, and the PR interval may be shorter than usual.
The QRS complex will be narrow and sharp with a 1:1 conduction ratio.
The PP and RR intervals will be early due to the premature complex.
PACs can be caused by increased sympathetic tone, autonomic nervous system infections, sympathetic emetic drugs, caffeine, nicotine, hypoxia, cardiovascular disease, atrial hypertrophy, valve problems, increased automaticity, and re-entry.
Clinical significance depends on the underlying cause.
For example, if the PAC is a result of a pathological process in the atria it could be clinically significant.

Wandering Atrial Pacemaker

The impulse occurs at various different points in the atria.
The rhythm is associated with multiple orderly pacemaker sites from the SA node to the AV junction.
It is generally associated with increased automaticity in conduction cells.
On ECG, the rate is typically 60-100/min and variable, the rhythm can be slightly irregular, and the P waves will be inconsistent as they are coming from different pacemakers.
The PR interval will be normal but can be shorter if the ectopic focus is closer to the AV node.
The QRS complex is normal.
The origin of the wandering pacemaker is variable and depends on where it is firing from.
While not typically significant in the immediate term, the wandering atrial pacemaker can be caused by aging and medications.

Atrial Tachycardia

A single ectopic focus produces the rhythm, which can be triggered by a PAC.
On ECG, the rate is 160-240/min, the rhythm is typically regular, the P wave will be abnormal, identical, and inconsistent, and the PR interval will be fairly regular.
The QRS complex will be narrow and sharply pointed with a normal time and can be dropped (2:1 ratio).
The PP and RR interval should be regular.
Causes of atrial tachycardia include electrolyte imbalances, hypoxia, chronic lung disease, coronary heart disease, acute coronary syndromes, rheumatic heart disease, and acute alcohol toxicity.
Clinical significance depends on the underlying cause.
For example, if the atrial tachycardia is associated with acute coronary syndrome, it could be clinically significant.
Rapid depolarization transferred to the ventricles can lead to poor ventricular filling, decreased cardiac output, and increased oxygen demand.

Multifocal Atrial Tachycardia (MAT)

Multiple foci depolarizing (more than three) create the rhythm.
On ECG, the rate is 100-150/min, the rhythm is typically regular, the P waves are abnormal and variable, and the PR interval will be variable depending on the ectopic focus location relative to the AV node.
The QRS complex is narrow and sharply pointed.
The PP and RR interval can potentially vary.
The causes of MAT are similar to those of atrial tachycardia.
Clinical significance depends on the underlying cause. For example, MAT associated with acute coronary syndrome is clinically significant.
Similar to atrial tachycardia, MAT leads to rapid depolarization to the ventricles, poor ventricular filling, decreased cardiac output, and increased oxygen demand.

Atrial Flutter

Increased atrial automaticity or re-entry circuit causes atrial ectopic pacemaker to create flutter waves (f waves).
On ECG, the atrial rate is 240-360/min and the ventricular rate is half the atrial rate.
The rhythm is typically regular but may be irregular if the conduction ratio changes.
The P wave is called an F wave and exhibits a sawtooth pattern.
The PR interval (now the FR interval) is difficult to measure.
The QRS complexes should be regular, but consistently irregular if the number of F waves changes.
Causes of atrial flutter can be either paroxysmal (occurs transiently) or chronic.
Clinical significance depends on the ventricular rate, with higher rates increasing the risk of new or exacerbating preexisting conditions.

Atrial Fibrillation

Increased automaticity or re-entry in the atria causes chaotic f waves with an irregular ventricular response.
On ECG, the atrial rate is 350-600/min. The ventricular rate can be under 60/min.
The rhythm is irregularly irregular.
The P wave is an f wave, and the PR interval is essentially absent.
The QRS complexes are normal, but the conduction ratio is random.
Common causes include mitral valve disease, coronary heart disease, hypertension, hyperthyroidism, congestive cardiac failure, acute myocarditis and pericarditis, lung disease, excessive alcohol and caffeine consumption, emotional distress and certain medications.
Clinically significant due to the risk of clot formation, which can lead to embolism (a clot blockage of a blood vessel).
An embolism in a cerebral artery can result in stroke.