Antiarrhythmics Classification (Vaughan Williams)

Epomedicine, May 27, 2024May 27, 2024

Understand the conducting system of heart, cardiac action potential and pacemaker action potential.

Physiology of Conducting System of Heart

Mnemonic to remember Vaughan Williams classification for anti-arrhythmic – Some Block Potassium Channel DAAM!

Mnemonic	Class	Mechanism of action	Comments	Example	Use
Some	IA	Sodium channel blocker (moderate) Intermediate action	Moderate ↓ phase 0 slope ↑ EFR & AP duration Additional class III action	Quinidine, Procainamide, Disopyramide	Ventricular arrhythmias, WPW (procainamide)
	IB	Sodium channel blocker (weak) Fast action	Small ↓ phase 0 slope ↓ EFR & AP duration	Lidocaine, Mexiletine	VT
	IC	Sodium channel blocker (strong) Slow action	Pronounced ↓ phase 0 slope = EFR & AP duration	Flecainide, Propafenone	Paroxysmal AF, recurrent SVT
Block	II	Beta blocker	↓ phase 4 slope in nodes (pacemaker potential) Prolong AV node repolarization	Atenolol, Bisoprolol, Carvedilol, Esmolol, Metoprolol, Propranolol, Sotalol	Recurrent tachyarrhythmias
Potassium	III	Potassium channel blocker	Delay phase 3 (repolarization)	Amiodarone (also class I, II & IV action), Sotalol (also class II action), Dofetilide, Ibutilide	Atrial fibrillation & flutter, Ventricular tachycardia
Channel	IV	Calcium channel blocker	Prolongs phase 2 ↓ slope phase 0 & 4 in node (pacemaker potential) Prolong AV node repolarization	Verapamil, Diltiazem	Paroxysmal SVT, AF with RVR
DAAM	V/Others	Direct nodal inhibition		Digoxin Atropine Adenosine Magensium sulphate	SVT (Adenosine), Torsades de pointes (Magnesium), Rate control in AF (Digoxin)

PGMEE, MRCS, USMLE, MBBS, MD/MS

Foot Drop : Differentials

Jun 8, 2023Jun 8, 2023

Foot drop can result from: L5 radiculopathy Lumbar plexopathy Sciatic neuropathy Peroneal neuropathy Causes Disc herniation, Spinal canal stenosis Pelvic surgery, hematoma, prolonged labor Hip surgery, Injection injury Compression/trauma Motor Weakness includes muscles and hip abductors Weakness includes hip abductors and anal sphincter Weakness includes tibial and hamstring muscles Weakness…

PGMEE, MRCS, USMLE, MBBS, MD/MS

Tendon Transfer Principles : Mnemonic

Mar 2, 2021Nov 2, 2022

Tendon transfer is the use of the power of a functioning muscle unit to activate a non-functioning nerve/muscle/tendon unit. The transferred tendon remains attached to its parent muscle with an intact neurovascular pedicle. Mnemonic: SEACOAST-1 a. Synergistic: act together to produce a single composite movement (facilitate each other). e.g. b….

PGMEE, MRCS, USMLE, MBBS, MD/MS

Parasympathetic ganglia of Head and Neck

Aug 25, 2023Aug 26, 2023

Important points: Mnemonics: 1. COPS 3977 2. C is 3rd letter hence related to cranial nerve III 3. S for Sphenopalatine and Submandibular and S for Seven and is related to Superior Salivatory nucleus 4. All postganglionic fibers are carried by trigeminal nerve (Cranial nerve V) Ganglion Nucleus Pre-ganglionic Post-ganglionic…

Related Posts

Leave a Reply Cancel reply