Atrial Fibrilation, HF, QTc Prolongation Flashcards
AFib is caused by…
Abnormal electrical conduction in atria, resulting in chaotic, uncoordinated contraction of atrial chambers
Patients with AFib may experience…
SOB, fatigue, palpitations
Chest discomfort
Anxiety, sweating
Or may be asymptomatic - patients can flip in + out of AFib
Two key clinical issues with AFib are…
Significant increased risk of ischemic stroke
Increased heart rate increases risk of heart failure
Stroke risk in AFib is managed via…
Anticoagulation with warfarin or DOAC’s
The dilemna of age with AFib and anticoagulation is…
Incidence of AFib increases with age, but advanced age increases risk for both stroke + major bleeds
Advanced age is a deterrent to anticoagulation due to…
Bleed risk
Adherence/INR monitoring with warfarin
Underestimation of benefit
Evidence for anticoagulation in Afib was shown via…
BAFTA trial - warfarin vs. ASA; anticoagulation significantly reduced strokes with no significant difference in major bleed rates
If individuals with AFib are unsuitable for anticoagulation, we could try…
ASA + clopidogrel to decrease stroke risk
However, did increase risk of major bleeding
Advantages of DOAC’s over warfarin include…
Equal/superior efficacy
Less ICH
No INR monitoring, fewer drug/food interactions
Disadvantages of DOAC’s over warfarin include…
More GI bleeds
Less long-term safety data
Caution in renal impairment/CI in severe renal impairment
Not indicated with mechanical heart valves
Some are $$$
Warfarin may be preferable over a DOAC when…
Someone has labile INR’s
Severe renal dysfunction
Unique points of dabigatran include…
Most GI upsetting
Most highly renally eliminated
BID dosing
Unique points of rivaroxaban include…
Needs to be taken with food for adequate absorption
OD dosing
Unique points of edoxaban include…
Has more DI’s
OD dosing
Unique points of apixaban include…
Best safety data so far
Shows superior efficacy compared to warfarin
BID dosing
Best choice when renal function is borderline
To determine risk of bleeding, we can use…
HAS-BLED criteria
Caution if score is 3+
Does anticoagulation contribute to fall risk?
Overall benefit with stroke prevention heavily outweighs risk of falls
Anticoagulation + Antiplatelet therapy combined may be warranted for…
Post-PCI with high risk features for thrombotic CV events
Adherence with DOAC’s is important due to…
Rapid onset/offset - unreliable adherence will cause periods of no anticoagulation
Warfarin should be avoided in individuals with cognitive impairment, due to…
Frequent INR monitoring - likely will not have ability to self-manage dosage adjustments
Factors to consider when deciding between rate vs. rhythm control include…
Duration of AFib
Bothersome AFib symptoms
Comorbid heart failure
Likelihood of successful rhythm control decreases as Afib duration increases. Therefore, with persistent Afib we would focus on…
Rate control
A trial that explored rhythm control in patients with early AFib (<1 year) found that…
Risks > Benfits - serious AE’s related to antiarrhythmic treatment
Abalation is often less desirable for older adults due to…
Increased risk of procedural AE’s, and increased likelihood of Afib recurrence post-ablation
____ remains important whether a patient is rate/rhythm controlled.
Anticoagulation
Amiodarone AE’s are quite severe and include…
Optic neuropathy, neuritis, photosensitivity
Pulmonary + hepatic toxicity
Thyroid issues
Blue-grey skin discoloration
Always check for DI’s - common ones include warfarin, digoxin, BB/Non-DHP CCB’s
Medications for rate-control include…
Beta-blockers
Non-DHP CCB’s
Digoxin
Beta-blockers are preferred for rate control with…
Concurrent CAD, Heart failure
If asthma/COPD, aim for cardioselective BB
Non-DHP CCB’s are preferred for rate control with…
Severe/poorly controlled asthma or COPD, sensitive to BB’s
Add on to BB’s if rate control not achieved
Digoxin is usually used as ____ therapy because…
Add-on - less effective, does not control HR during exercise
Digoxin may be benefician with…
Concurrent, symptomatic HF
Target heart rate in AFib is…
Below 100 bpm at rest
Digoxin efficacy is monitored via…
Target HR
NOT serum digoxin levels
Digoxin toxicity is monitored via…
Serum levels - ideally maintain trough level below 1 nmol/L
Digoxin AE’s often manifest as…
GI issues (N/V/D, decreased appetite), then develops into cognitive issues + vision (delirium, blurred vision, ocular haloes)
CAUTION with renal impairment
Severity of heart failure symptoms can be classified by…
NYHA functional capacity; class 1 (no limitation) to class 4 (inability to carry on any physical activity without discomfort)
The 4 standard drug therapies for HFrEF include…
ARNI (or ACEI/ARB)
Beta-blocker
MRA
SGLT2 inhibitor
This can be used to relieve symptoms in heart failure
Diuretics - furosemide
Help manage SOB, fluid retention, increased weight
Titrated to minimum effective dose, to maintain euvolemia
Which drug classes should be initiated first for HFrEF treatment?
Based on clinical characteristics of patient, such as…
Hemodynamic status
Renal function, BP
AE/tolerability
Cost + Adherence
Evidence of ARNI vs. ACEI for HFrEF showed that…
ARNI showed a decrease in CV mortality and HF hospitalizations - however, increase in symptomatic hypotension
Switching from ACEI to ARNI requires…
A 36 hour washout period - risk of angioedema
With ACEI/ARB/ARNI’s, we should monitor…
SCr + Electrolytes within 1-2 weeks of initiation or titration
Sitting + standing BP
Frail older adults more susceptible to hypotension with ARNI
Monitoring with beta-blockers includes…
HR, BP, fatigue
Monitoring with MRA’s includes…
Electrolytes - potassium
Avoid if CrCl is low
SGLT2 inhibitors in HF demonstrated…
Benefit in reducing hospitalizations or CV death
Notable monitoring with SGLT2 inhibitors include…
Decrease in GFR ~15% upon initiation
May cause hypovolemia
Sick day management - SADMANS
Tolerability of SGLT2 inhibitors…
Fairly well tolerated. May see increased risk of yeast infection, UTI, diabetic ketoacidosis
Digoxin could be used in heart failure if…
Symptoms despite optimized 1st + 2nd line medications
Remember that blood levels are only used to measure toxicity
Regarding dosing of quadruple HF therapy, we should try to…
Titrate to target doses as tolerated
Can space doses if orthostatic hypotension/low BP is limiting titration
Dosing of furosemide should be…
The lowest effective dose to mainatain euvolemia
This could be used for HFpEF…
Empagliflozin - showed a decrease in HF hospitalizations.
QT prolongation may lead to ____, which is dangerous because…
Torsades de Pointes (TdP) - arrythmia may lead to sudden cardiac death
Risks of TdP include…
Older, female
Electrolyte abnormalities
Chronic diseases - liver, kidney, HTN
Smoking
Drugs
Pharmacist role in QT prolongation + TdP involves…
Identifying risk factors (RISQ-PATH score) - if high risk, can try alternative medication, or recommend baseline + follow-up ECG
Watch for drug interactions
