Flashcards in AFIB Deck (21):
Rates of atrial depolarization in a afib?
300 400 bpm
Chronic AFIB can lead to?
1. Rapid ventricular rate leading to myocardial ischemia or exacerbation of heart failure
2. Thrombus formation in the noncontractile atria leading to embolization
Two most common causes of atrial fibrillation?
Hypertension and coronary atherosclerosis
Medications that can cause atrial fibrillation?
Theophylline, caffeine, digitalis
Congenital heart diseases that can lead to atrial fibrillation?
Atrial septal defect, Ebstein anomaly
Causes of atrial fibrillation?
I SMART CHAP
Inflammatory disease (Pericarditis, myocarditis)
Atherosclerotic coronary artery disease
Rheumatic heart disease
Congenital heart disease
Hypertensive heart disease
In a patient in acute atrial fibrillation that is hemodynamically unstable(?), Tx?
Hemodynamically unstable = hypertensive, angina pectoris, or pulmonary edema
Use direct current cardioversion
If patient in acute Atrial fibrillation is hemodynamically stable, treatment?
Intravenous beta blockers, calcium channel blockers, or digoxin to control ventricular rate
If atrial fibrillation exceeds 48 hours, increased risk of what?
Intra-atrial thrombus formation
After 48 hours of atrial fibrillation what should be given prior to and after cardioversion? Alternatively? Can also treat with what drugs?
3 to 4 weeks of warfarin therapy. Alternatively, low-risk patients can undergo transesophageal echo to exclude the presence of atrial thrombus. Can try to treat with procainamide, sotalol, and amiodarone
Two factors that decrease the chance of successful cardioversion to sinus rhythm after AFIB?
Left atrial dilation (greater than 4.5 cm) and duration of atrial fibrillation
Treatment of chronic atrial fibrillation to reduce the risk of stroke? (By how much?)
Warfarin decreases risk of stroke by two-thirds
Goal INR with warfarin treatment and chronic atrial fibrillation (If atrial fibrillation is not caused by valvular disease)?
2 to 3
Lonely AFIB? Risk of stroke? Treatment?
Atrial fibrillation that develops in patients younger than 60 years without evidence of structural heart disease, hypertension, or other factors for stroke. Risk of stroke is very low. Anticoagulation with warfarin is not used. Use low-dose aspirin
If, with warfarin anticoagulation, INR is greater than 6, give?
Vitamin K without bleeding. Vitamin K and fresh frozen plasma if bleeding
AFIB can be life-threatening with this preexcitation syndrome
Mechanism of Wolff-Parkinson-White syndrome?
Accessory pathway provides an alternate route for electrical communication between the atria and ventricles leading to early ventricular depolarization that begins before AV node conduction
ECG sign for Wolff-Parkinson-White syndrome? Effect on QRS complex and PR interval?
Delta wave. Widens the QRS complex and shortens the PR interval
Avoid these drugs and Wolff-Parkinson-White patients with atrial fibrillation (why?)
Digoxin, verapamil And other AV node blocking agents. These Increased ventricular rate.
Tx for Wolff-Parkinson-White syndrome?
Procainamide or ibutilide to slow conduction and convert the rhythm to sinus