Atrial Fibrillation

Question 1

Atrial Fibrillation

Answer 1

Irregularly Irregular

Multiple ectopic atrial foci produce fibrillation waves

Atria do not contract,
Beware of CLOTS!!! (common in the appendages– procedures like the lariat and the watchman can close these off or exclude them)

AV node gates entry to the ventricles

The most common cardiac arrhythmia
The RR interval follows no repetitive pattern
No distinct “P” waves, undulation of the baseline, atrial rate 300-600 beats/minute

Question 2

Atrial Fibrillation with Rapid Ventricular Response

Answer 2

CAD, Valvular heart disease, Pulmonary disease, Hyperthyroidism
Can be temporary in normal individual
- Exercise
- EtOH

f waves in fibrillation
F waves in Flutter

Question 3

when you raise heart rate, which time interval is most affected?

Answer 3

diastole

you decrease filling rate –> decreased stroke volume

Question 4

atrial contribution to ventricular filling– what heart sound?

Answer 4

S4

Question 5

What should S3 in adults make you think of?

Answer 5

heart failure

Question 6

what percent of the ventricular filling comes from the atrial kick in people without heart failure?

Answer 6

5% or less, you wouldn’t notice it being gone

but in heart failure it can be as much as 40%

Question 7

AF - who gets it?

Answer 7

More common in men
Increases with age
AF reduces cardiac output by decreasing filling from increased rate encroaching on diastolic filling time and loss of atrial contribution to ventricular filling

Question 8

AF Etiology

Answer 8

1. Hypertensive Heart Disease
2. CHD
3. RF in underdeveloped countries
4. Hyperthyroidism- drives the heart nuts (palpitations)
5. Genetic (likely most common)

Question 9

underlying details of AF

Answer 9

Changes in the refractory period of the underlying atrial musculature
PAC (APBs) often precipitate atrial fib of all kinds
AF may be valvular or non-valvular

Question 10

treating AF

Answer 10

Always address underlying cause

ie; postop cardiac surgery, hyperthyroidism, mitral valve disease, pulmonary disease, etc.

Question 11

AF Classification

Answer 11

1. Paroxysmal-AF that terminates spontaneously or with intervention within 7 days of onset. Episodes may recur with variable frequency.
2. Persistent-AF that fails to self-terminate within 7 days. Episodes often require pharmacologic or electrical cardioversion to restore NSR (Normal Sinus Rhythm). AF generally progresses.
3. Long standing persistent-AF that has lasted for more than 12 months.

Permanent AF- patients with persistent AF where a joint decision has been made by the patient and clinician to no longer pursue a rhythm control strategy.

Question 12

Low Risk AF

Answer 12

Used to be called “Lone” AF.
15-30% of AF
Younger male patients
Frequently familial, low risk of thrombo-embolus (CHA2DS2-VASc score of 0).

Question 13

Recurrent AF

Answer 13

90% of AF patients have asymptomatic recurrent episodes lasting up to 48 hours

Question 14

Subclinical AF

Answer 14

AF detected in asymptomatic patients without a prior diagnosis. Many of these patients have paroxysmal AF.

Question 15

Evaluation of the Patient 1. H&P

Answer 15

History of palps, syncope, dyspnea, fatigue. Precipitating causes include exercise, emotion, alcohol- Holiday Heart.
PE-mitral valve disease, especially MS, CHF findings, etc.

Question 16

Anti Coagulation: CHA2DS2-VASc:

Answer 16

This is becoming the most useful tool for deciding risk of stroke to determine whether to anti-coagulate

C=Congestive Heart Failure
H=Hypertension
A2=Age>=75 (2 points)
D=Diabetes Mellitus
S2=Stroke, TIA or Thromboembolus (2 points)
V=Vascular Disease (prior MI, PAD, aortic plaque)
A=Age (65-74) 1 point
Sc= Sex category, Female (1 point)

Question 17

CHA2DS2-VASc score and stroke risk/year

Answer 17

Score Risk
0 0.2%
1 0.6%
2 2.2%
3 3.2%
4 4.8%
5 7.2%
6 9.7%
7 11.2%
8 10.8%
9 12.2%

Question 18

when do you anticoagulate for sure?

Answer 18

absolutely at 2 points, consider at 1

Question 19

Warfarin

Answer 19

1954 FDA approval
“WARF”=Wisconsin Alumni Research Foundation
Derived from “sweet clover animal feed” spoiled with a fungus, discovered at the University of Wisconsin.

First oral anti coagulant
Measured by INR (International Normalized Ratio)
Therapeutic range 2.0-3.0 for atrial fibrillation stroke prevention

Question 20

AF Anticoagulants

Answer 20

NOAC (Novel Oral Anti Coagulants) are replacing warfarin in many patients
No blood testing necessary
These drugs interfere very little with other drugs and virtually no foods
As of this date there are 3 available
One Direct Thrombin Inhibitor, Pradaxa, dabigitran

Question 21

NOAC

Answer 21

2 Factor Xa inhibitors
Xarelto (rivaroxaban)
Eliquis (apixaban)

Question 22

Evaluation

Answer 22

EKG-rhythm, rate, other abnormal findings, LVH, ST changes, QRS width, QT interval, PR interval.
Echocardiogram-chamber sizes and function, valvular function, pulmonary artery pressures (Pulmonary Hypertension).

Question 23

Treatment, Tale of 2 Cities

Answer 23

1. Rate Control- patient is appropriately anti-coagulated and the rate is controlled by AV blockers.
2. Rhythm Control- effort is made to anti-coagulate and restore NSR by meds or electrical cardioversion. A TEE may be used to rule out LA thrombus prior to cardioversion.