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Flashcards in AF Deck (16):
1

Definition

SV tachyarrhythmia. disorganised rapid atrial activation and uncoordinated atrial contraction.
structural or electrophysiological abnormality promotes abnormal impulse formation or propagation. Normal regular SAN impulses overwhelmed by disorganised impulses usually originating in PV roots. Irregular ventricular conduction.
Paroxysmal- more than one episode terminate spontaneously or with intervention in 7 days.
Persistent- episodes last over 7 days.
Long standing persistent- for over 1 year. Cardioversion failed or not tried.
Permanent- stop pursuing SR.

2

Aetiology

Loss atrial muscle mass and atrial fibrosis.
Re entrant and focal mechanisms cause multiple wandering waves usually originating from PVs.
Cardiomyopathy, CHF, HTN (most common)
Peri and myocarditis.
Atrial tachy and flutter, WPW.
HypoK and Mg.
Obesity
Drugs.
MITRAL HH-
MVD
IHD
Thyrotoxicosis, phaeochromocytoma
Rheumatic fever
Alcohol, caffeine
Lung- PE, COPD, apnoea, CO, CA
Hypertension
HypoK
Exercise of alcohol can trigger

3

Differentials

Multifocal atrial tachy, Flutter, WPW, MI
Alcohol
Rheumatic HD
Hyperthyroid
PE, COPD
Pericarditis
Anxiety
Systemic HTN
MVD
ASD

4

Symptoms

Often none
CP
Palpitations
Dyspnoea
Faint

5

Signs

Irregularly irregular pulse
Apical pulse rate greater than radial
1st heart sound variable intensity
LVF signs

6

Management

Heparin acute, warfarin long term (inhibits vit K reductase preventing CF activation in liver).
Rate control- BB eg atenolol, CCB eg varapimil, digoxin.
Rhythm control- amiodarone, flecainide.
Cardioversion.

7

Complications

Stroke due to turbulence= clot, to brain.
HF
Dilated cardiomyopathy

8

Diagnosis

Absent P
Irregular QRS
Echocardiogram for cause
Bloods- UE, cardiac enzymes, TFTs.

9

Class 2 BB

Inhibit heart beta 1 Rs. Less Ca IN.
Slow ventricular rate in AF and flutter.
AE- bronchospasm, hypotension.
DONT use in partial AV block or acute V failure unless pm in situ.

10

Class 3 K blocker eg amiodarone.

Increase ARP
Lot AE- proarrhythmic, pulmonary fibrosis, hepatic injury, increase LDL, thyroid disease, photosensitivity, optic neuritis.
Require high loading dose as long t1/2.
Give to central V to avoid thrombophlebitis.
DDI- digoxin, class 1's, warfarin.

11

Class 1c eg flecainide

VGNa blocker, use dependant. Slower binding offset than other class 1's.
AE- pro arrhythmic, sudden death chronic use, CNS, GI, metallic taste, headache. Increase ventricular response to SV arrhythmia.

12

Class 1a eg quinidine, procainamide.

Intermediate binding offset.
AE- hypotension, low CO, torsades increase QT. Dizzy, confusion, insomnia, seizure. GI. Lupus like syndrome.

13

Class 4 CCB eg verapimil, diltiazem

Decrease force and rate, some peripheral vasodilation.
Diltiazem for AF
Caution if partial AV block AND on BB- can=asystole.
Caution in hypotension as reduce CO.
Constipation.

14

Adenosine no class

Activates K current in nodes. Blocks conduction then restarts SR.
V short t1/2 (seconds)

15

Cardiac glycoside eg digoxin

Positive ionotrope
Blocks Na/K ATPase, reverses NCX, more Ca IN.
Also increases vagal activity (increase K current, decrease Ca=slows AV conduction and HR).

16

Explanation

-the heart normally beats in a systematic rhythmic way because an impulse start at the top and follows a set path. In AF the impulse starts from different places on the upper chamber walls and spreads to the lower chambers at all difffereent times. This means that the pumping action is not strong and regular like it should be. And your heart beats very fast.
-so the heart does not pump enough blood around the body which can cause dizziness and shortness of breath. Also because pumping is not normal, blood doesnt flow smoothly and quickly out the heart which can lead to clots. If these spreads to the brain they can cause strokes. Also the heart os working abnormally hard which in the long term can cause HF.
-lifestyle
-tx includes drugs to stop the blood clotting so easily to reduce the risk of stroke. Also drugs to slow the heart rate as well as to correct the abnormal rhythm. If that doesnt work we can reset the rhythm by applying electrical stimulation from the outside.