11 results
Torsades de Pointes 
•Precipitated by drugs that prolong the QT interval 
•Class IA antidysrhythmics (procainamide, quinidine)
that prolong the QT ... interval •Class ... hypomagnesemia, hypokalemia ... TorsadesDePointes #Diagnosis #Cardiology ... #ECG #EKG
Class I Antiarrhythmics and their Key Pharmacologic Properties

Class IA = Quinidine, Procainamide, Disopyramide ("Quarter PounDer")
Class IB
Class I Antiarrhythmics ... and their Key Pharmacologic ... results in prolonged QT ... #Class1 #Antiarrhythmics ... Agents #Cardiology
Antiarrhythmics - Vaughan Williams Classification
Class I (Ia, Ib, Ic) - Na+ Channel Blockade
 • Slows depolarization
Antiarrhythmics ... Classification Class ... potential • Prolongs QT ... EricsMedicalLectures/ #Antiarrhythmics ... #cardiology #pharmacology
Torsades de Pointes
• "Twisting of the pointes" 
• QRS axis swings from positive to negative direction
that prolong the QT ... interval Class ... Hypomagnesemia Hypokalemia ... TorsadesDePointes #Diagnosis #Cardiology ... #ECG #EKG
Recurrent Polymorphic VT/Torsades de Pointes - Management Algorithm
Drugs that prolong QT interval:
 • Class 1a (quinidine,
Torsades de Pointes - Management ... Drugs that prolong QT ... Congenital long QT ... Hypomagnesemia • Hypokalemia ... • Hypocalcemia
Classic EKG triad of long QT, ST-depression, and PVCs in Hypokalemia
Worry about hypokalemia; this patient had
Classic EKG triad ... of long QT, ST-depression ... , and PVCs in Hypokalemia ... Worry about hypokalemia ... #Cardiology #Clinical
Antiarrhythmics - Vaughan Williams Classification:
CLASS 1 - Sodium Channel Blockers:
 • MOA: Block fast Na+ channels
Antiarrhythmics ... Duration) - ↑ QT ... inotropy) ACCP Cardiology ... Vaughan #Williams #Pharmacology ... pathophysiology #cardiology
Antiarrhythmics Pharmacology Summary
Cardiac Conduction Phases:
Phase 0 - Ventricular Depolarization:
 • Na+ channels open leading to a
Antiarrhythmics ... Pharmacology Summary ... Duration) - ↑ QT ... inotropy) ACCP Cardiology ... #Pharmacology #
Checklist Approach to Hypokalemia

Consider risk factors for arrhythmia:
 - EKG changes (especially QT prolongation)
 - Digoxin
Checklist Approach to Hypokalemia ... arrhythmia: - EKG ... changes (especially QT ... route = severe hypokalemia ... #Management #CriticalCare
Clinically Significant Cardiovascular Drug-Drug Interactions With OTC Supplements and Herbal Products
Angiotensin-Converting Enzyme Inhibitors (ACEIs)
 • Night-blooming
Licorice - Causes hypokalemia ... wort - Increases QT ... I Antiarrhythmic ... wort - Increases QT ... #DDI #table #cardiology