Chapter 2: Cardiovascular Flashcards
(214 cards)
Classes of Anti-arrhythmic drugs ?
CLASS 1 - membrane stabilising drugs; Na+ blockers
CLASS 2 - Beta-blocker
CLASS 3 - K+ channel blockers
CLASS 4 - Calcium Channel blockers (rate limiting)
OTHER
- adenoside
- digoxin (effective in sedentary patients with non-paroxysmal AF and in patients with associative CHF)
What is included in the CLASS 1 antiarrhthmic drugs?
MEMBRANE STABILISING DRUGS ; Na+ blockers
- disopyramide
- lidocaine
- flecainide/propafenone (c/i in asthma/ severe COPD. Avoid in structural ischameic heart disease)
What is flecainide/propafenone c/i in?
c/i in asthma/ severe COPD. Avoid in structural ischameic heart disease
What is CLASS 2 antiarrhythmic drugs?
BETA-BLOCKERS
- propanolol, bisoprolol etc
What is included in CLASS 3 antiarrhythmic drugs?
K+ CHANNEL BLOCKERS
- amiodarone (4 weeks before and 12 months after electrical cardioversion to increase success)
- sotalol
- dronedarone (hepatotoxicity and heart failure side effects)
What is included in CLASS 4 antiarrhthmic drugs?
CALCIUM CHANNEL BLOCKERS (rate limiting)
- verapamil
- diltiazem (unlicensed)
OTHER antiarrhythmic drugs?
- adenosine
- digoxin (effective in sedentary patients with non-paroxysmal AF and in patients with associative CHF)
What is AF?
- abnormal, disorganised electrical signals fired caused the atria to quiver or fibrillate = rapid and irregular heartbeat
Symptoms of AF?
- heart palpitations = pounding/fluttering
- dizziness, SOB, tiredness
Complications of AF?
stroke and heart failure
Classifications of AF?
LONE
- Single self limiting episode of AF in ‘normal’ patients i.e. those that are defined by a normal clinical history and examination, ECG, chest x ray and echocardiogram
CHRONIC: recurring episodes of AF
- Paroxysmal: when symptoms stop spontaneously without treatment within 2-7 days
- Persistent: when AF is persistently occurring and does not terminate spontaneously, therefore requiring either electrical or pharmacological cardioversion to stop it (> 7 days)
- Permanent: if the cardioversion is not successful or not indicated for that particular patient (present all the time)
POST-OP
- Occurs in a third of patients who have cardiothoracic surgery. This type is associated with greater morbidity, mortality and risks of complications
2 types of control in AF?
RATE CONTROL (controls ventricular rate)
RHYTHM CONTROL (restores and maintains sinus rhythm) - Cardioversion : restores sinus rhythm
Explain cardioversion process
CARDIOVERSION; restores sinus rhythm (RHYTHM CONTROL)
- electrical = direct current
- pharmacological = anti-arrhythmic
- cannot give if symptoms > 48 hours; increased risk of stroke
- electrical preffered if > 48 hours, but should wait until fully anticoagulated for 3 weeks before cardioversion and continue 4 weeks after
- if haemodynamically unstable (perfusion/heart failure) = electrical cardioversion; give parenteral anticoagulant and rule our left atrial thrombus immediately before procedure
For an acute new-onset presentation of AF what would you do?
- life threatening haemodynamic instability: electrical cardiversion
- without life threatening haemodynamic instability:
- <48 hours = rate or rhythm control (electrical or amiodarone/flecainide)
- > 48 hours = rate control (verapamil, beta blocker)
Maintenance drug treatment for AF?
First line = rate control
- betablockers (NOT sotalol)*
- rate limiting CCBs (verapamil, dlitiazem)
- Digoxin
monotherapy –> dual therapy –> rhythm control
Second line = rhythm control
- bbs or oral anti-arrhythmic drug
e.g. sotalol, amiodarone, flecainide, propafenone, dronedarone
(also given if rhythm control is stil required post-cardioversion
Treatment for paroxysmal and symptomatic AF?
- rate or rhythm control = standard bb or oral antiarrhtymic drug
- “pill in pocket” if infrequent episodes - self treatment = flecainide or propafenone restores sinus rhythm if episode occurs
Treatment for atrial flutter?
Similar treatment as AF but catheter ablation more suitable
*A catheter ablation involves passing thin, flexible tubes, called catheters, through the blood vessels to the heart. The catheters record the heart’s electrical activity and can pinpoint where the arrhythmia is coming from. The area of heart muscle at the affected site is then destroyed using either heat (radiofrequency ablation) or by freezing (cryoablation). This creates scar tissue, which doesn’t conduct electricity and so knocks out a trouble spot or acts as a fence around the problem area to prevent the electrical signals from reaching the rest of the heart and causing the arrhythmia.
Stroke prevention: when to give anticoagulant ?
Give if risk of thromboembolic stroke > risk of bleeding (HAS-BLED)
Risk of stroke CHAD2=DS2-VASc
C = chronic heart failure or left ventricular dysfunction
H = hypertension
A2 = age 75+
D = diabetes mellitus
S2 = stroke/TIA/venous thromboembolism history
V = vascular history
A = age 65-74 yrs
Sc = sex i.e. female
Give anticoagulant is 2 or more
male= 0 and female = 1
What anticoagulant given in new onset AF?
parenteral anticoagulant
What anticoagulant given in diagnosed AF?
Warfarin OR NOAC
*NOAC in non-valvular AF with 1 or more rusj factors
What is ventricular tachycardia ?
Ventricular tachycardia (VT) is a fast, abnormal heart rate. It starts in your heart’s lower chambers, called the ventricles. VT is defined as 3 or more heartbeats in a row, at a rate of more than 100 beats a minute. If VT lasts for more than a few seconds at a time, it can become life-threatening.
How should pulseless VT be treated?
immediate defibrillation + CP; IV amiodarone is given refractory to defibrillation
How should patients with unstable sustained VT be treated?
direct current cardioversion. If this fails give IV amiodarone and repeat direct current. If this fails, IV amiodraone should be administered and dc cardioversion repeated
How should stable sustained VT be treated?
IV antiarrhythmic drug (amiodarone preferred). Flecainide, propafenone and lidocaine (less effective) can be used.
If sinus rhythm is not restored, direct current cardioversion or pacing should be considered. Catheter ablation is an alternative if cessation of arrhythmia is not urgent