Sinus Arrythmia Flashcards
What is a bradyarrhythmia?
A bradyarrhythmia is an abnormally slow heart rate, typically below 60 beats per minute.
What is the primary pacemaker of the heart?
The primary pacemaker of the heart is the sinoatrial (SA) node.
What happens when the sinoatrial (SA) node fails?
If the SA node fails, backup pacemakers, such as the atrioventricular (AV) node or the ventricles, take over.
At what rate does the AV node function as a pacemaker?
The AV node functions at a rate of 40-60 beats per minute.
What is the ventricular pacemaker rate when the AV node fails?
The ventricles act as the pacemaker with a rate of 20-40 beats per minute.
What is a junctional rhythm?
A junctional rhythm arises when the AV node takes over pacemaking, producing a heart rate of 40-60 beats per minute.
How does a junctional rhythm appear on ECG?
In junctional rhythm, P waves may be absent, inverted, or occur after the QRS complex, and the QRS complex is typically narrow.
What are the common causes of junctional rhythm?
Causes include SA node dysfunction, drug toxicity (e.g., digoxin), or myocardial ischemia.
What is a ventricular rhythm (idioventricular rhythm)?
A ventricular rhythm occurs when the ventricles take over as the pacemaker, typically with a rate of 20-40 beats per minute.
How does idioventricular rhythm appear on ECG?
Idioventricular rhythm presents with wide QRS complexes and no preceding P waves.
What conditions can cause idioventricular rhythm?
Idioventricular rhythm can occur in cases of complete heart block, severe bradycardia, or during reperfusion therapy after a heart attack.
What is a tachyarrhythmia?
A tachyarrhythmia is an abnormally fast heart rate, typically above 100 beats per minute.
What are ectopic beats?
Ectopic beats are premature beats that originate outside of the SA node.
How do atrial ectopic beats appear on ECG?
Atrial ectopic beats have abnormal P waves, occurring earlier than expected.
What are common causes of ectopic beats?
Causes include stress, caffeine, electrolyte imbalances, or heart disease.
What is atrial tachycardia?
Atrial tachycardia is a type of supraventricular tachycardia where the atria beat abnormally fast (150-250 bpm).
What does atrial tachycardia look like on ECG?
Atrial tachycardia shows a regular, fast rhythm with abnormal P waves and normal QRS complexes.
What are common triggers of atrial tachycardia?
Common triggers include structural heart disease, excessive caffeine, or medications.
What is multifocal atrial tachycardia?
MAT is an irregular form of atrial tachycardia where multiple atrial foci generate impulses, leading to varying P wave morphologies.
How does multifocal atrial tachycardia appear on ECG?
MAT shows at least three different P wave morphologies and an irregular rhythm with varying PR intervals.
What conditions are associated with multifocal atrial tachycardia?
MAT is often associated with chronic lung disease, electrolyte imbalances, and heart failure.
What is atrial flutter?
Atrial flutter is a rapid, regular atrial rhythm usually between 250-350 bpm, often due to a reentrant circuit.
How does atrial flutter appear on ECG?
Atrial flutter shows a “sawtooth” pattern of flutter waves, most prominent in leads II, III, and aVF.
What is the usual ventricular response in atrial flutter?
The ventricular rate is typically regular and can be 2:1, 3:1, or 4:1 atrioventricular conduction.
What is atrial fibrillation?
Atrial fibrillation is an irregular, rapid atrial rhythm with atrial rates often exceeding 350 bpm, causing ineffective atrial contraction.
How does atrial fibrillation appear on ECG?
Atrial fibrillation shows irregularly irregular QRS complexes with no distinct P waves.
What are the risk factors for atrial fibrillation?
Risk factors include hypertension, heart failure, valvular disease, and hyperthyroidism.
What is AV nodal reentrant tachycardia (AVNRT)?
AVNRT is a type of supraventricular tachycardia caused by a reentry circuit within the AV node.
How does AVNRT appear on ECG?
AVNRT shows a regular, fast rhythm with absent or retrograde P waves and narrow QRS complexes.
What are common triggers of AVNRT?
Triggers include stress, caffeine, and alcohol.
What is AV reentrant tachycardia (AVRT)?
AVRT is a type of supraventricular tachycardia caused by an accessory pathway between the atria and ventricles, such as in Wolff-Parkinson-White syndrome.
How does AVRT appear on ECG?
AVRT shows a regular tachycardia with narrow QRS complexes and often a retrograde P wave.
What is Wolff-Parkinson-White (WPW) syndrome?
WPW syndrome is a type of AVRT caused by an accessory pathway, presenting with a short PR interval and delta wave.
What is ventricular tachycardia (VT)?
VT is a rapid rhythm originating from the ventricles, usually with a rate of 100-250 bpm.
What is ventricular tachycardia (VT)?
VT is a rapid rhythm originating from the ventricles, usually with a rate of 100-250 bpm.
How does VT appear on ECG?
VT shows wide, regular QRS complexes with no associated P waves.
What are the common causes of ventricular tachycardia?
Causes include ischemic heart disease, electrolyte imbalances, structural heart disease, and prolonged QT syndrome.
What is polymorphic ventricular tachycardia?
Polymorphic VT is a type of ventricular tachycardia where the QRS complexes vary in shape and size.
How does polymorphic VT appear on ECG?
Polymorphic VT shows varying QRS complex morphology, with a twisting of points, as seen in torsades de pointes.
What conditions can lead to polymorphic VT?
Polymorphic VT can be caused by electrolyte imbalances, prolonged QT interval, and ischemia.
What is ventricular fibrillation (VF)?
VF is a life-threatening arrhythmia where the ventricles quiver instead of contracting effectively, leading to cardiac arrest.
How does ventricular fibrillation appear on ECG?
VF shows a chaotic, disorganized, and rapid waveform with no discernible QRS complexes.
What are the common causes of ventricular fibrillation?
VF is commonly caused by myocardial infarction, electrolyte imbalances, and severe ischemic heart disease.
What is the heart rate range typically seen with a ventricular escape rhythm?
Ventricular escape rhythms typically have rates between 20-40 bpm.
How does bradyarrhythmia affect cardiac output?
Bradyarrhythmia can decrease cardiac output by reducing heart rate, leading to symptoms such as dizziness and syncope.
What is the treatment for symptomatic bradyarrhythmia?
Treatment may include atropine, pacemaker insertion, or treating underlying causes such as electrolyte imbalances.
What are premature ventricular contractions (PVCs)?
PVCs are ectopic beats originating from the ventricles, presenting as wide QRS complexes.
How does a premature atrial contraction (PAC) differ from a PVC on ECG?
PACs have abnormal P waves followed by normal QRS complexes, while PVCs show wide QRS complexes without preceding P waves.
What is the typical heart rate range for atrial tachycardia?
The heart rate in atrial tachycardia typically ranges from 150 to 250 bpm.
What is the primary treatment for atrial tachycardia?
Treatment may include rate control medications (beta-blockers or calcium channel blockers) or antiarrhythmic drugs.
What are the common complications of atrial fibrillation?
Complications include an increased risk of stroke, heart failure, and thromboembolism.
