Additional antiarrhythmics
So far, this module has covered high-yield antiarrhythmic medications by historical Singh Vaughan-Williams classification. There are other antiarrhythmics of note that will be covered now. Adenosine Adenosine binds to A1 adenosine receptors in the AV node (Gi‑coupled). Gi inhibits adenylyl cyclase → ↓ cAMP → reduced L‑type Ca²⁺ channel activity. This leads to: Slowed AV nodal conduction Increased […]
Class IV antiarrhythmic drugs
Class IV antiarrhythmics: Calcium channel blockers Drugs Verapamil Diltiazem Question Class IV antiarrhythmics are calcium channel blockers. Drugs from which other antiarrhythmics classes also reduce or blunt calcium’s effects? Select all that apply. Rationale Class II (beta‑blockers) antiarrhythmics do notblock Ca²⁺ channels directly, but reduce calcium influx by decreasing cAMP‑mediated activation of L‑type Ca²⁺ Amiodarone, a Class III […]
Class III antiarrhythmic drugs
Class III antiarrhythmics: Potassium channel blockers Class III drugs primarily target rapid (IKr) and slow (IKs) delayed rectifier K+ The main effects are increased action potential duration and refractoriness, which helps suppress atrial and ventricular arrhythmias caused by re-entry. Class III drugs can cause life-threatening proarrhythmia. Drugs Sotalol Amiodarone Ibutilide Dofetilide Dronedarone Memory aid A […]
Class II antiarrhythmic drugs
Class II antiarrhythmics: Beta-adrenergic receptor blockers Drugs Carvedilol Propranolol Atenolol Bisoprolol Metoprolol Esmolol Typically considered Class III, but also Class II is sotalol (sotalol will be discussed with Class III agents in this module) Memory aid Beta-blockers have the common drug stem -lol. Background required to understand mechanism We will cover more information regarding the […]
Class I antiarrhythmic drugs
Class I antiarrhythmics: Voltage-gated sodium channel blockers Class I drugs block Na+ channels, reduce excitability, and increase the threshold potential. The Class I antiarrhythmics are further broken down into 3 categories: Class IA, IB, and IC. Class Generic names Mnemonic device Image IA Disopyramide Quinidine Procainamide Double Quarter Pounder IB Lidocaine Mexiletine Lettuce Mayo IC […]
Antiarrhythmic drugs
There are several strategies to categorize antiarrhythmic drugs, each with their advantages and disadvantages. For the purposes of this learning module, we will use the Singh Vaughan-Williams classification system, which originally contained four classes, but was updated to include drugs that do not fit into those classes. The Singh Vaughan-Williams classification system now includes Class […]
Critical appraisal of a prospective cohort study
In this session, we will assess a paper that is a prospective cohort study about community burden and transmission of acute gastroenteritis caused by norovirus and rotavirus. We will also revisit the terms incidence, prevalence, and attack rate. Learning goals Learning activities Required reading Demonstrate respectful, constructive, adaptive interactions with peers and/or facilitators, including punctual […]
Observational study design
Learning Goals Resources Describe the design of case-control studies Discuss biases and confounds in case-control studies Discuss possible ways to deal with confounding in the design or analysis of an observational study Define and discuss the appropriate use of a cross-sectional study Differentiate between real and spurious associations in observational studies Describe a frequent sequence […]
Critical appraisal of a prospective cohort study (Facilitator)
In this session, we will assess a paper that is a prospective cohort study about community burden and transmission of acute gastroenteritis caused by norovirus and rotavirus. We will also revisit the terms incidence, prevalence, and attack rate. Learning goals Learning activities Required reading Demonstrate respectful, constructive, adaptive interactions with peers and/or facilitators, including punctual […]
Differential diagnosis of microangiopathic hemolytic anemia and thrombocytopenia
Feature HUS TTP Scleroderma Renal Crisis (SRC) HELLP Malignant HTN Typical setting Child after diarrheal illness (EHEC) Adults; autoimmune or idiopathic Systemic sclerosis (esp diffuse, early disease) Pregnancy (3rd trimester/postpartum) Long-standing uncontrolled HTN Key trigger Shiga toxin ↓ ADAMTS13 RAAS activation from endothelial injury Placental endothelial dysfunction Severe BP elevation Platelets ↓ ↓↓↓ ↓ ↓ […]