AF Flashcards
Epidemiology – AF:
u Most common sustained cardiac arrhythmia
u Affects at least 1-2% of population (likely substantially
higher)
u Prevalence and incidence increases with age
u 4% at 65 years of age
u 12% at 80 years of age
u AF known to affect 200,000 to 250,000 Canadians
(estimated that actually up to 1 million affected)
u AF is associate with reduced quality of life,
functional status, cardiac performance and
survival
u AF is independently associated with a 1.5 to 4
fold increase risk of mortality, predominantly
due to thromboembolic risk (mainly stroke) and
ventricular dysfunction
Consequences of AF:
qivering
Atria: u Multiple re-entry loops causing disorganized atrial activity u Rate = 400-600 bpm u Ineffective atrial contraction leads to stasis of blood u Potential thrombosis in left atria or left atrial appendage
stasis of blood with not good contraction –> leads to clots
Virchow’s triad
Cardioembolic Stroke
u Thrombus may embolize from the heart and
travel to the brain to cause a cardioembolic
stroke
u Stroke presentation varies depending on
affected area of brain (80% affect the middle
cerebral artery or anterior cerebral artery)
u 70% of stroke with AF are either fatal or leave
severe residual deficits
Consequences of AF:
Loss of Atrial Kick:
Ventricular Response:
u Atria contract in a very rapid and irregular
rhythm impairing emptying of blood into ventricles
u Atrial kick can account for up to ~20% of cardiac
output in NSR
u Impulses from atria are irregular and reach the AV
node (gatekeeper) at varying times
u The impulses that pass through the AV node cause
the ventricles to contract at an irregular rhythm (faster than usual)
u Increased rate = up to 120 to 180 bpm
AV node is gatekeeper
heart pumping frequently
A) Short of breath
B) Heart pounding
C) Tired
B) They enlarge
Increased heart rate can cause the heart to work too hard and cause enlargement and damage. This is called tachycardia – induced cardiomyopathy
Symptoms of AF:
Patients with AF may be completely asymptomatic
to highly symptomatic
u Initial presentation of AF could be cardiac
symptoms, heart failure symptoms, cardioembolic
stroke or systemic embolism
Presentation of AF:
Thrombus
Formation:
•Cardioembolic Stroke
•Systemic Embolism
Rapid Heart Rate:
•Symptoms: palpitations, chest pain, hypotension
Loss of Atrial Kick:
•Heart Failure
Symptoms: Dyspnea, fatigue,
↓ exercise tolerance
Major Goals and Expected Outcomes:
Improve Survival
1. Thrombus Formation: • Prevention of Cardioembolic Stroke and Systemic Embolism
2. Rapid Heart Rate: • Improvement of Symptoms, Functional Capacity and Quality of Life
Reduce Health Care Utilization 1. Loss of Atrial Kick: • Prevent Complications such as LV Dysfunction
diagnosis of AF
slie 22
Risk Factors
AF-induced substrate
(e.g. electrical & structural remodeling)
Non-modifiable Substrate
(e.g. Age, Sex, Genetics)
Modifiable Substrate
(e.g. hypertension, obesity, sleep apnea)
HTN, diabetes, tobacco, alochol
Neurohormonal activation
• Structural, Electrical or
Autonomic Remodeling
• Inflammation and oxidative stress
2020 AF Guideline Recommendations:
u In patients with AF or high risk of AF:
u Systemic approach to identification of modifiable risk
factors/conditions associated with AF
u Strict Guideline adherent management of these risk
factors/conditions
Desired Outcomes: Prevent AF occurrence/recurrence and
decrease symptom burden
ole of Pharmacist in AF
qPrevention of AF qDetection of AF qAssessment of Patient with AF qManagement of Medications qMonitoring of Medications and of Patient
prevention
Sleep Apnea
- CPAP for moderate-severe OSA (AHI ≥ 15/hour)
Regular assessment of CPAP adherence (continuous pressure overnight, not holding breath)
Weight Loss
Target a weight loss of ≥10% to a
BMI of less than 27 kg/m2
Diabetes
Target a HbA1c of ≤7.0%
Blood Pressure
Target ≤ 130/80 mmHg at rest and ≤ 200/100 mmHg at peak exercise.
ACE-I or ARB may be preferred.
Exercise
1. Moderate intensity aerobic exercise ≥ 30
minutes a day at least 3-5 days per week
(target ≥ 200 minutes weekly).
2. Resistance exercise 2-3 days per week.
3. Flexibility exercises at least 10 minutes
per day at least 2 days per week in those
>65 years of age
Alcohol and Tobacco Limit to ≤ 1 standard drink1 per day. Complete abstinence from alcohol may be preferred in selected patients. Target complete abstinence from tobacco-related products.
Diagnosis:
• Diagnosis of AF is based upon ECG
1) Irregular Absence of P waves ( hard to find P waves)
2) Irregular intervals of QRS complexes (ventricles is not beating properly )
3) Irregularly, irregular supraventricular tachyarrhythmia (no regular QRS intervals)
Patterns/Duration of AF:
AF can be self-terminating and may be difficult to detect
paroxysmal af
AF Diagnosis: Holter Monit
u Patients may have NSR as their predominant rhythm with brief bouts of AF u Holter monitor allows for > 24 hour monitoring of ECG
hard to order >24 hrs
AF Diagnosis: Implantable Device
implantable loop recorder
can last p to 2 years
can record the arrhthmia
Other Ways to Detect AF:
pulse palpitation, bp monitor, non 12 lead ECG
smartphone
2020 AF Guideline Recommendations:
Opportunistic screening for AF should be conducted in people >65 years of age at the time of medical
encounters
u Practical Tip: Screening can be efficiently and costeffectively performed using pulse checks during
u Desired Outcomes: Early detection and treatment of
AF can prevent adverse events
Opportunistic AF screening for individuals
≥ 65 years at time of medical encounter
Pulse-based Screening
• Pulse palpation
• Blood Pressure monitors
• Plethysmograph
Rhythm-based Screening
• Single-lead ECG devices
Atrial Fibrillation Suspected
Perform 12-lead ECG
No AF confirmed:
Perform additional
rhythm-based monitoring
diagnosis of AF:
Stroke Prevention
Management of arrhythmia
Assessment of Risk factors
Other Investigations for AF (2)
u Echocardiogram
u Transthoracic Echocardiogram (TTE) recommended in all patients
u Identify LA size, LV hypertrophy or dysfunction, valvular heart
disease, and possibly LAA thrombus (usually need
Transesophageal Echo - TEE)
u Blood work
u CBC, coagulation profile, electrolytes, renal, thyroid, and liver function tests
uDetermine if underlying cause
uPrepare for possible therapy
AF Classification
Classification of AF
guides treatment
decisions
Structure of AF
uValvular AF
uNon-Valvular AF
Duration uParoxysmal uPersistent u“Longstanding” persistent uPermanent
Structural Classification CLOT RISK ASSESSMENT DETERMINES TREATMENT SELECTION
Valvular AF: AF in the presence of any mechanical heart valve or in the presence of moderate to severe mitral stenosis
risk of stroke = 17%/yr
NonValvular AF:
AF without mechanical heart valve of moderate to severe mitral stenosis
Risk of stroke ~4.5%/yr
Duration of AF
Paroxysmal AF: Continuous AF episode lasting >30
seconds but terminating within 7 days of
onset
- rate of stroke = 2.1
Persistent AF: Continuous AF episode lasting >7 days
but terminating within 1 year of onset
- rate of stroke = 3.1
“Longstanding” Persistent AF: Continuous AF > 1 year for which rhythm control is being pursued
Permanent AF Continuous: AF for which therapeutic
decision has been made to not pursue
rhythm restoration (high chance it wont go back normal)
- rate of stroke = 4.2% (increases the longer you have it)
CLOT RISK IS SIGNFICANT IN ALL PATTERNS OF AF
most common thromotic consequence of af
type of clot that forms w/ stasis of blood:
best option for tx of red clots
cardioembolic stroke
red clot
- endothelial injury -> white clot (atherosclerosis, cholesterol) -> use antiplatelets (platelets and strans of fibrin)
- DVT due to stasis -> red clot
- red clot tx -> anticoagulants (erythrocytes in fibrin matrix)
