Lecture on AV Blocks and Sinus Node Dysfunction

Introduction

• Apology for time shift due to urgent issues.
• Next session scheduled for 6 PM West African Time.
• Speaker: Dr. Caro, Associate Professor in Cardiac Electrophysiology at the University of Texas.

Objectives

• Discuss sinus node function and AV blocks.
• Explore the implications of pacemaker placement.
• Review conduction system and heart block management.

Key Concepts

Sinus Node and Pacemaker Indications

• Normal sinus node function and when pacemakers are needed.
• Sinus node dysfunction can lead to pacemaker consideration.

AV Blocks Overview

• Types of AV Blocks: First-degree, second-degree (Type 1 and Type 2), and third-degree.
• Key differences in block locations: Superhisian (in AV node), intra-hisian (within the His bundle), and infra-hisian (below the His bundle).

Sinoatrial Blocks

• Types: First-degree (not visible on EKG), second-degree (Type 1 and Type 2), and third-degree blocks.
• Importance of recognizing sinoatrial blocks, as they may necessitate pacemaker placement.

Detailed Discussion

Conduction System Overview

• Includes the sinus node, interatrial conduction system, AV node, bundle of His, and Purkinje fibers.
• Function of each component explained.

EKG Interpretation

• PR interval, QRS complex, ST segment, and T wave explained.
• Significance of sinus node and AV node conduction on EKG.

Electrophysiology Study (EP Study)

• Gold standard for diagnosing arrhythmic causes of syncope.
• Usefulness in determining block locations for AV and sinoatrial blocks.

Management of Bradycardia

• Focus on determining the cause (e.g., underlying conditions, medication) before intervention.
• Indications for pacemaker placement based on symptoms and conduction study results.

Questions and Case Studies

• Three clinical scenarios discussed to apply lecture content.
  • Focus on interpreting EKGs and deciding management steps.

Conclusion

• Importance of understanding conduction block locations and symptoms for management.
• Use of pacemakers in different block scenarios guided by guidelines and clinical judgment.

Guidelines and Recommendations

• Reference to 2018 guidelines for pacemaker placement.
• Emphasis on treating reversible causes and observing asymptomatic patients before considering pacemaker.

Questions and Discussions

• Addressed queries on AV blocks, sinoatrial block identification, and pacemaker dependency.
• Clarified concepts like decremental conduction and the role of EP studies.

Note: The session was recorded and available for review on YouTube for detailed revisiting of complex topics.