Atrial Fibrillation Clinical Features and Types
40 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What percentage of patients with atrial fibrillation (AF) are typically asymptomatic?

  • 25% (correct)
  • 50%
  • 75%
  • 10%

    • Which of the following is not a characteristic feature of symptomatic AF?

  • Hemodynamic stability (correct)
  • Lightheadedness
  • Dyspnea
  • Palpitations

    • Which tests are commonly used to evaluate patients with atrial fibrillation?

  • Ultrasound of the abdomen
  • Blood tests only
  • MRI and CT scan
  • Holter monitoring and chest radiograph (correct)

    • In patients with AF, which underlying condition is not considered reversible?

    <p>Age-related heart changes</p> Signup and view all the answers

    What is the main purpose of performing a transthoracic echocardiogram in atrial fibrillation patients?

    <p>To evaluate LV size and function</p> Signup and view all the answers

    How are patients with AF stratified for stroke risk?

    <p>Through a predictive index like CHADS2</p> Signup and view all the answers

    Which of the following arrhythmias would be investigated alongside AF using an electrocardiogram?

    <p>Bundle-branch block</p> Signup and view all the answers

    What characterizes the atrial rhythm in multifocal atrial tachycardia (MAT)?

    <p>At least three distinct P wave morphologies</p> Signup and view all the answers

    Which characteristic of paroxysmal AF typically differentiates it from persistent AF concerning embolism risk?

    <p>Similar embolism risk</p> Signup and view all the answers

    Which treatment option has limited success in managing multiple atrial tachycardia?

    <p>Calcium channel blockers</p> Signup and view all the answers

    What is a notable difference between atrial fibrillation (AF) and multifocal atrial tachycardia (MAT)?

    <p>MAT has an isoelectric baseline</p> Signup and view all the answers

    What distinguishes AV nodal reentrant tachycardia (AVNRT) from other tachycardias?

    <p>Regular R-R intervals with inverted P waves</p> Signup and view all the answers

    Which vagotonic maneuver is most commonly performed to terminate supraventricular tachycardia (SVT)?

    <p>Carotid sinus massage</p> Signup and view all the answers

    What is the typical heart rate range associated with atrial rhythm disturbances like MAT?

    <p>100 to 150 beats per minute</p> Signup and view all the answers

    Which statement accurately reflects the management of supraventricular tachycardia (SVT)?

    <p>Most SVT episodes resolve spontaneously without treatment</p> Signup and view all the answers

    Which condition is a potential cause of sinus tachycardia?

    <p>Hyperthyroidism</p> Signup and view all the answers

    What is the primary action of adenosine in managing SVT?

    <p>Blocking electrical impulses at the AV node</p> Signup and view all the answers

    Which treatment option is specifically contraindicated in patients with asthma?

    <p>IV Adenosine</p> Signup and view all the answers

    What is the typical initial dose of verapamil for managing SVT?

    <p>5 mg IV push</p> Signup and view all the answers

    For patients with infrequent recurrences of SVT, which approach is deemed reasonable?

    <p>Pill in the pocket approach with flecainide</p> Signup and view all the answers

    What is the reported cure rate of catheter ablation for patients with recurrent AVNRT?

    <p>95%</p> Signup and view all the answers

    What is a common symptom associated with episodes of tachycardia in AV reentrant tachycardia?

    <p>Syncope</p> Signup and view all the answers

    In the context of SVT management, which of the following agents is least effective for altering conduction in the antegrade slow pathway?

    <p>Amiodarone</p> Signup and view all the answers

    Which type of preexcitation occurs in the presence of a delta wave?

    <p>Orthodromic tachycardia</p> Signup and view all the answers

    What is the highest possible CHADS2 score for a patient who has experienced a stroke and is over the age of 75?

    <p>4</p> Signup and view all the answers

    In the CHADS2 VASc score, which risk factor contributes the most points?

    <p>Stroke/TIA</p> Signup and view all the answers

    Which of the following scenarios is most likely to favor rate control over rhythm control in atrial fibrillation management?

    <p>A patient aged 70 with persistent atrial fibrillation</p> Signup and view all the answers

    What might a HAS-BLED score indicate if a patient scores above 4?

    <p>High Risk of Bleeding</p> Signup and view all the answers

    Which anticoagulant is preferred over warfarin when oral anticoagulation therapy is indicated?

    <p>Dabigatran</p> Signup and view all the answers

    In relation to rhythm control for atrial fibrillation, what does the AFFIRM trial primarily emphasize?

    <p>Improving quality of life rather than reducing mortality</p> Signup and view all the answers

    Which patient characteristic would most likely indicate a lower risk of complications from atrial fibrillation?

    <p>Ages 60-64 with hypertension and no previous stroke</p> Signup and view all the answers

    When indicating anticoagulation therapy with warfarin for a patient with mitral stenosis, what is the target INR?

    <p>2.5</p> Signup and view all the answers

    What is true about concealed WPW syndrome compared to typical WPW syndrome?

    <p>It has less risk of atrial fibrillation.</p> Signup and view all the answers

    In which type of AV reentrant tachycardia does the RP interval exceed the PR interval?

    <p>Atypical AVRT</p> Signup and view all the answers

    What is the treatment of choice for wide-complex tachycardias involving accessory pathways?

    <p>Class Ia antiarrhythmic agents</p> Signup and view all the answers

    What should be avoided in patients with AF and AFL who have antegrade conduction through an accessory pathway?

    <p>Digoxin and calcium channel blockers</p> Signup and view all the answers

    What does a success rate of 93% in catheter ablation refer to?

    <p>Curative ablation of accessory pathways</p> Signup and view all the answers

    Which characteristic does NOT describe asymptomatic individuals at high risk for sudden death?

    <p>Presence of a long refractory period</p> Signup and view all the answers

    In orthodromic AVRT, what is typically absent in the sinus rhythm?

    <p>P waves</p> Signup and view all the answers

    What indicates a narrow-complex reentry rhythm managed similarly to AVNRT?

    <p>Involvement of a bypass tract</p> Signup and view all the answers

    Study Notes

    Clinical Features

    • Patients with atrial fibrillation fall on a spectrum from asymptomatic to hemodynamically unstable.
    • 25% of patients with atrial fibrillation are asymptomatic, often in elderly patients and those with persistent atrial fibrillation.
    • Symptomatic atrial fibrillation can cause palpitations, fatigue, dyspnea, effort intolerance, lightheadedness and polyuria (post-pallpatory).

    Types

    • Atrial fibrillation can be acute or chronic (lasting longer than a month).
    • Chronic atrial fibrillation can be persistent, paroxysmal or permanent.
    • The risk of embolism is the same for persistent and paroxysmal atrial fibrillation (despite paroxysmal being less severe).

    Investigations-Electrocardiogram

    • An ECG can confirm the presence of atrial fibrillation, detect left ventricular hypertrophy, atrial fibrillation waves, pre-excitation, bundle branch block, prior MI, and other atrial arrhythmias.
    • ECG is used to follow changes in R-R, QRS and QT intervals with antiarrhythmic drug therapy.

    Transthoracic Echocardiogram

    • Can detect valvular heart disease and measure left and right atrial and ventricular sizes and function.
    • Can also detect peak right ventricular pressure to determine pulmonary hypertension.
    • A transthoracic echocardiogram can measure left ventricular hypertrophy and detect atrial thrombus as well as pericardial disease.

    Other Tests

    • Patients should have blood tests to determine thyroid, renal and hepatic function.
    • Holter monitoring and event recording are helpful investigations.
    • A transesophageal echocardiogram, chest radiograph, and a CHADS2 score for stroke risk and HAS-BLED score for bleeding risk are also recommended.

    CHADS2 Score

    • Designed to assess a patient's risk of a stroke.
    • Each risk factor has a score associated with it :
      • CHF = 1
      • Hypertension = 1
      • Age > 75 years = 1
      • Diabetes = 1
      • Stroke/TIA = 2

    CHADS2 Score and Stroke Risk

    • Higher CHADS2 scores correlate with a higher risk of stroke.

    CHADS2 VASC Score

    • VASC score is an extension of the CHADS2 score that includes :
      • Vascular disease (MI, PVD) = 1
      • Age 65-74 = 1
      • Sex Category Female = 1

    CHADS2 VASC Stroke Rate

    • CHADS2 VASC score is effective at predicting stroke risk.

    Predicting Bleeding Risk using HAS-BLED Score

    • Designed to assess a patient's risk of bleeding.
    • Scores are assigned for different risk factors:
      • Hypertension (>160 mmHg systolic) = 1
      • Abnormal Renal/Hepatic function = 1 - 2
      • Stroke = 1
      • Bleeding history or anemia = 1
      • Labile INR (TTR <60%) = 1
      • Elderly (age > 75 years) = 1
      • Drugs/Alcohol (antiplatelet/NSAIDs) = 1 - 2

    HAS-BLED Score and Bleeding Risk

    • Higher HAS-BLED Scores are associated with an increased risk of bleeding.
      • High Risk: >4% per year = >4
      • Moderate Risk: 2-4% per year = 2-3
      • Low Risk: <2% per year = 0-1

    INR (International Normalized Ratio)

    • INR is a common measurement to asses the effectiveness of oral anticoagulation therapy.

    Warfarin vs DOAC

    • DOACs are the preferred oral anticoagulant over Warfarin.

    Rate Control vs Rhythm Control

    • Rate Control
      • Favored in persistent atrial fibrillation
      • Favored in patients over 65 years old
      • Favored in patients with hypertension, no history of heart failure, and previous antiarrhythmic drug failure.
    • Rhythm Control
      • Favored in paroxysmal atrial fibrillation
      • Favored in newly diagnosed atrial fibrillation.
      • Favored in patients under 65 years old, no hypertension, with heart failure exacerbated by atrial fibrillation, and no prior antiarrhythmic drug failure.

    AFFIRM Trial

    • Found no improvement in mortality for rhythm control vs rate control.

    Rhythm Control of Atrial Fibrillation

    • The goal of rhythm control is to improve the patient's quality of life. It is not necessary to eliminate all episodes of atrial fibrillation.

    Atrial Fibrillation Burden (Ablation)

    • Ablation may be helpful for patients with atrial fibrillation or atrial flutter who remain symptomatic despite rate control therapy.
    • Ablation does not always eliminate all episodes of atrial fibrillation but can improve patient symptoms and clinical outcomes

    Multifocal Atrial Tachycardia (MAT)

    • This rhythm is characterized by at least three distinct P-wave morphologies and at least three different PR intervals.
    • The heart rate is typically between 100 and 150 beats per minute.
    • An isoelectric line distinguishes MAT from atrial fibrillation.
    • MAT is distinct from normal sinus rhythm with frequent multifocal atrial premature complexes.

    Treatment

    • MAT is treated by correcting the underlying pulmonary problem.
    • Cardioversion is ineffective.
    • Calcium channel blockers have limited success.
    • In selected patients, beta-blockers may be helpful, but use is limited by bronchospasm.

    Sinus Tachycardia

    • This rhythm is caused by rapid impulse formation from the sinoatrial node.
    • It can be caused by fever, exercise, emotion, pain, anemia, heart failure, shock, thyrotoxicosis, and various drugs.

    AV Nodal Reentrant Tachycardia (AVNRT)

    • Patients may be asymptomatic but also experience mild chest pain or shortness of breath.

    AVNRT ECG Findings

    • A narrow complex tachycardia with regular R-R intervals and no visible P-waves.
    • P-waves are retrograde and inverted in Leads II, III, and avF.
    • If P-waves are not visible, a pseudo-S wave in inferior leads and pseudo-R’ wave in lead V1 are characteristic.
    • P-waves may be farther away from the QRS complex distorting the ST segment.

    Vagotonic Maneuvers

    • Carotid sinus massage
    • Valsalva maneuver
    • Facial ice pack
    • Mueller maneuvers, gagging
    • These maneuvers induce vagal tone via the baroreceptor reflex, impacting the sinoatrial and atrioventricular nodes.

    Termination of Supraventricular Tachycardia (SVT) by Vagotonic Maneuver

    • Carotid sinus massage effectively terminates SVT in many cases by stimulating the vagal reflex.

    Supraventricular Tachycardia (SVT) Treatment

    • Many SVT Episodes are self-limiting and require no treatment.
    • Symptomatic SVT lasting longer than 1 hour or severe cases usually require hospital admission and treatment.
    • IV adenosine is commonly used to treat SVT but should be avoided in people with asthma.
    • Verapamil is an alternative if adenosine is not advised.
    • Electric shock treatment rarely is needed to stop SVT.

    Supraventricular Tachycardia (SVT) Prevention

    • Drugs that slow conduction in the antegrade slow pathway, such as digitalis, beta blockers, and calcium channel blockers can help to prevent SVT.
    • Beta blockers can help prevent exercise-precipitated AVNRT
    • Patients who don’t respond to drug therapy directed at the antegrade slow pathway may benefit from Class IA and Class Ic agents.

    Pill in the Pocket Approach:

    • A "pill in the pocket" approach is an option for patients with infrequent but sustained, well-tolerated SVT.
    • Patients with a single SVT episode may benefit from this approach.
    • The approach involves the patient carrying a specific medication to take at the onset of an SVT episode.
    • Flecainide, verapamil, beta blockers, and propafenone are all possible medications.

    Catheter Ablation

    • Catheter ablation of SVT, targeting the elimination or modification of the slow pathway conduction, can permanently eliminate AVNRT.
    • It is effective in over 95% of patients.
    • Patients with symptomatic recurrent SVT, significant symptoms, or heart rates over 200 beats per minute may be candidates for ablation.

    Wolff Parkinson White (WPW) Syndrome - Atrial Preexcitation

    • Pre-excitation occurs in 1.5/1000 people, and 50-60% of these cases are symptomatic.
    • Symptoms can range from palpitations to syncope.
    • Episodes of tachycardia may be associated with dyspnea, chest pain, decreased exercise tolerance, anxiety, dizziness, or syncope.
    • WPW can precipitate atrial fibrillation and ventricular fibrillation on use of AV-nodal blockers.

    Wolff Parkinson White (WPW) Syndrome Types

    • Orthodromic - This is the more common type.
    • Antidromic - This subtype presents as a wide complex tachycardia with a delta wave on the ECG.
    • Concealed WPW - This subtype lacks a delta wave on the ECG and is less likely to cause atrial fibrillation.

    Manifest vs Concealed WPW

    • Manifest WPW Syndrome - is characterized by a delta wave on the ECG demonstrating the presence of an accessory pathway.
    • Concealed WPW Syndrome - is characterized by having the accessory pathway present without a delta wave on the ECG.

    Accessory Pathway with Ventricular Preexcitation (Wolff Parkinson White Syndrome)

    • Delta Wave - A slurring of the first part of the QRS complex.
    • Fusion activation of the ventricles - The accessory pathway activation occurs after normal activation by the AV node, with a "hybrid" QRS morphology.
    • PR Interval < 0.12 seconds
    • QRS Duration > 0.12 seconds

    AV Reentrant Tachycardia (AVRT)

    • AVRT is characterized by the presence of an accessory pathway and reentrant tachycardia.
    • AVRT is classified into typical and atypical subtypes.
    • Typical - The RP interval is less than the PR interval, and the RP interval is greater than 80 msec.
    • Atypical - The RP interval is greater than the PR interval.

    Orthodromic AV Reentrant Tachycardia

    • Orthodromic AVRT is when impulses travel forward through the AV node and go backward through the accessory pathway.
    • Retrograde P waves are often buried within the ST segment and are not always visible.

    Catheter Ablation of Accessory Pathways

    • Effective for the treatment of AVRT.
    • Success rates reach 93%.
    • Patients with an asymptomatic RR cycle length less than 220 ms, indicating a short refractory period, are at increased risk of sudden death and should consider prophylactic ablation.

    Pharmacologic Therapy

    • Many common medications used to treat reentrant rhythms involving an accessory pathway can be used for AVNRT treatment.
    • Drugs to avoid - Digoxin, calcium channel blockers, and beta blockers may reduce the refractoriness of the accessory pathway leading to faster ventricular rates.
    • Effective Medications - Class 1A (procainamide), Class 1C (flecainide, propafenone), and Class III agents are appropriate for wide-complex tachycardias and increase bypass-tract refractoriness.
    • Electric Cardioversion - Indicated in cases of hemodynamic compromise.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Related Documents

    Narrow Complex Tachyarrhythmias PDF

    Description

    Explore the clinical features and classifications of atrial fibrillation in this quiz. Understand the differences between acute and chronic forms, as well as the various symptoms and investigations used for diagnosis, such as the role of ECG. Perfect for students and healthcare professionals alike.

    More Like This

    Use Quizgecko on...
    Browser
    Open
    Browser
    Browser