AFIB Flashcards
Compare AFib vs A flutter
Most common cardiac arrythmia
AFIB
What is AFIB
A supraventricular arrhythmia (above the ventricles) which results from continuous and chaotic atrial activity
Risks of AFIB
Rarely life-threatening;
increases the risk of stroke (most severe)
left ventricular dysfunction (loss of ventricular ejection –> fatigue, exercise intolerance, light headed, palpitations)
Non-anticoagulated patients have 3-5 fold increased risk of stroke (generally severe)
W\hat is lost on an EKG during Afib?
P- wave is lost
Distance between p waves should be the same
What is afib classified as:
an irregularly, irregular rhythm
Prevalence Afib
Prevalence increases with age
The age adjusted prevalence is greater in men
10-30% of heart failure patients have AF (lost the atrial kick)
Common and undiagnosed
Sx Afib
Fatigue
Palpitations
Chest Pain
dyspnea
Dizziness
afib pathophys
ectopic foci that generate electrical impulses
Atria experience rapid irregular and uncoordinated contractions
Because electrical impulses reach the AV node erratically, the ventricular rhythm is irregular
Initiating event of AFIB
Factors which destabilize the myocardium such as electrolyte disturbances, ischemic and excessive sympathetic stimulation can contribute to the initiating event
How can afib be classified based on structural disease?
Valvular (Warfarin) –> Very significant valve disease (rheumatic fever, valve replacement, or mitral valve repair)
Non-Valvular (DOACS here only)
Absence of rheumatic mitral valve disease, a prosthetic heart valve, or mitral valve repair
“Lone” AF Young, no heart or pulmonary disease
Absence of clinical or echocardiographic findings of:
Other CVD (including hypertension)
Related pulmonary disease
Cardiac abnormalities; ex/ enlargement of the left atrium
Age under 60 years
Paraoxysmal AFib
lasting longer than 30 seconds and self-terminating within 7 days of recognized onset (jump in and jump out)
Persistent Afib
continuous AF episode lasting longer than 7 days but less than 1 year
Longstanding Afib
continuous AF equal or greater than 1 year in who rhythm control management is being pursued
Permenant Afib
continuous AF for which a therapeutic decision has been made not to pursue sinus rhythm restoration
What is a substrate?
a pre-existing condition that forms a prerequisite for the induction of an arrhythmia
Examples:
triggers
Stimulants
Alcohol
Sleep Depreivation
Emotional STress
Physical Exertiom
Sleep
Digestive
Risk factors
HTN
DM
Tobacco
Alcohol
Investigating AFib
12-lead ECG
Echocardiogram
LAb Investigations
Goals of tx and anticipated outcomes
Prevent stroke or systemic thromboembolism
Cardiovascular risk reduction
Improve symptoms, functional capacity and quality of life
Prevent complications (eg. LV dysfunction and falls)
Outcomes:
Improvement in survival
Reduction in healthcare utilization (ED visits or hospitalization)
Afib Diagnosus Scheme
Rate –> Let you be in AFIB but slow down the ventricular rhythym
Rhythym –> Put you back into sinus rhythym
CHad 65 Scores
Stroke Prevention ChadS 65
Anticoagulate AF in the presence of:
“Valvular AF”
–> Any mechanical heart valve
–> Moderate to severe mitral stenosis (rheumatic or non-rheumatic)
Hypertrophic cardiomyopathy
Hyperthyroidism
Amyloid cardiomyopathy
Non-Valvular AF
Stroke Prevention Obese
Higher BMI may be associated with lower stroke rates; higher bleeding rates (obesity paradox)
Standard DOAC dose is reasonable for BMI <40 kg/m2
DOAC Use Obese Guidelines
Dose Warfarin And DOACS
Apixaban when:
Consider Apixaban 2.5 mg po bid if 2 of
1) age 80 years or older,
2) body weight 60 kg or less
3) serum creatinine 133 𝜇mol/L or more;
DOAC D.I.
DOAC antidote
Dosing DOAC differences
Dual Tx Doses
1 antiplatlet (P12Y or ASA)
Triple Therapy
ASA + P12Y +
Do Not use DOACS if:
Mechanical heart valves and significant mitral valve stenosis
Use of strong P-gp and 3A4 inhibitors or inducers* (check current product monographs)
Pregnancy and lactation (no safety – more heparin product here)
Expert bodies indicate need for clinical judgement in extremes of body weight (<50kg; >120kg)**
Pediatrics
Caution when combined with dual antiplatelets – triple therapy**
Monitoring of anticoag
Adherence
Frequency of adverse effects (affects adherence)
Signs and symptoms of bleeding and bleeding risk factors
Regular SCr, CrCl, Hgb
Acute Management
Determine if AF is the primary concern or secondary to another acute medical illness
Consider hemodynamic stability (blood pressure)
Determine whether rate vs rhythm control is appropriate
In newly diagnosed AF – rhythm control has been associated with reduced CV death and stroke
Determine need for hospitalization
Determine need for OAC – start as soon as possible (in ED) if required – CCS algorithm
Early follow up
Define Rate Control
allow the patient to remain in Atrial Fibrillation, however ensure that the ventricular rate is slowed sufficiently to minimize negative outcomes
Benefit of Rhthym COntrol
used in stable patients with recent-onset AF with the decision made on the basis of patient symptoms and goals of care, recognizing that early rhythm control has been associated with a lower risk of stroke and CV death
Rhythym control in who:
Recently diagnosed (<1 year)
Highly asymptomatic
Multiple recurrences
Difficulty to achieve rate control
Arrthymia-induced cardiomyopathy
(Rhythym has more anti death)
Acute rate control:
Goal of rate control
Reduction in HR of greater than 20% with control of symptoms
ND-CCB Examples
Verapamil
Diltazem
Targets of Rate Control
Resting heart rate < 100 bpm at rest
B-blockers or ND-CCBs first line agents
Selection of BB vs CCB should be on the basis of patient comorbidities, contraindications and side effects
Achieved goal at rest/exercise
Ventricular Rate control Choice
Hemodynamic instability
–> Digoxin is a poor choice – delayed onset
AF associated with exercise, thyrotoxicosis, fever etc.
–> ß-blockers are first line
–> CCBs are more effective than digoxin
Age
CCB preferentially used in the young
Long term RAte Control
Cardioversion and AFIB ANticoagulation
AFIB for more than 48 hours –> need to anticoagulated for 3 weeks before put back into sinus rhthym
Do not want to push the clot to the brain
Transesophageal ECHO see if blood clot in atria
Risky Rhythym Control
increased the risk of systemic embolism, it is important to start appropriate anticoagulation as time allows for all patients
Rhythym COntrol Objectives
Relief of symptoms such as palpitations, fatigue and dyspnea
Improve CO and exercise tolerance
Prevention of tachycardia-induced myocardial remodeling and heart failure
Hemodynamic improvements may take days to weeks
Ways to achieve Sinus Rhthym
Rate Control & Await Spontaneous Conversion
Electrical (Direct Current) Cardioversion
–> Treatment of choice with ventricular rate >150 bpm who are hemodynamically unstable or have serious signs/symptoms
i.e., chest pain, pulmonary edema
Chemical (pharmacologic) Cardioversion
Cardioversion Risk
Must anticoagulate if AF>48 hours (therapeutic INR for 3 weeks before and 4 weeks post conversion to NSR)
Patients most likelky to maintain normal sinus rhthym after cardioversion?
Short duration of AF and absence of left atrial dilation
Patients who NSR should be attempted?
Recent onset of AF
Heart failure
Angina
Hypotension
Cardioversion benefit and risk vs Pharm Conversion
Electrical cardioversion is more effective than pharmacologic cardioversion especially for more prolonged AF episode durations
Pharmacologic has the advantage of being immediately feasible in a nonfasting patient as well as avoiding the delays and risks associated with procedural sedation
Treatment Indications
Before and after cardioversion
OAC for 3 weeks before and 4 weeks after for patients with valvular AF or NVAF >48h
Cardioversion acute management Guide
Drugs used for pharmacological conversion
Sodium Channel Blockers (Class I agents) and amiodarone are superior to placebo in acute and chronic AF
Digoxin, ß-Blockers or CCBs are NOT effective for the conversion of AF to sinus rhythm (Not effective)
Side effects pharmacologic conversion
GI related
Left Ventricular Depression
Negative inotropic effects with many agents
Pro-Arrhythmia (life-threatening) ~1-2%
Accelerated ventricular response can be seen if converted to atrial flutter
Slowing of atrial rate & vagolytic effects of some agents can lead to 1:1 AV conduction
Recommendation managing s/e
Concurrent rate control agent
Drugs used for Achieveing sinus rhthym
In Paris, friends party
Long Term Rhthym Control
