Intraventricular conduction delay laboratory findings

Intraventricular conduction delay Microchapters
Home
Overview
Anatomy and Physiology
Classification
Pathophysiology
Causes
Differentiating Intraventricular conduction delay from other Disorders
Epidemiology and Demographics
Natural History, Complications and Prognosis
Diagnosis
History and Symptoms
Physical Examination
Laboratory Findings
Electrocardiogram
EKG Examples
Chest X Ray
Echocardiography
Coronary Angiography
Treatment
Medical Therapy
Electrical Cardioversion
Ablation
Surgery
Primary Prevention
Secondary Prevention
Cost-Effectiveness of Therapy
Future or Investigational Therapies
Case Studies
Case #1
Intraventricular conduction delay laboratory findings On the Web
Most recent articles
Most cited articles
Review articles
CME Programs
Powerpoint slides
Images
Ongoing Trials at Clinical Trials.gov
US National Guidelines Clearinghouse
NICE Guidance
FDA on Intraventricular conduction delay laboratory findings
CDC onIntraventricular conduction delay laboratory findings
Intraventricular conduction delay laboratory findings in the news
Blogs on Intraventricular conduction delay laboratory findings
to Hospitals Treating Intraventricular conduction delay laboratory findings
Risk calculators and risk factors for Intraventricular conduction delay laboratory findings

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mugilan Poongkunran M.B.B.S [2]

Overview

Electrophysiological testing help localize the site of conduction delay or block within the conduction system of the ventricles.

Laboratory Findings

Electrophysiological Testing

• Electrophysiological testing help localize the site of conduction delay or block within the bundle of His by recording distal, middle, and proximal HB potentials using multipolar catheters to.
• His-ventricular HV interval longer than 70 milliseconds predicts a higher risk of AV block, especially in symptomatic patients.
• An HV interval exceeding 100 milliseconds identifies a group of patients at a very high risk of AV block.
• In the presence of RBBB with or without additional fascicular block, the HV interval should be normal as long as conduction is unimpaired in the remaining fascicle.

Procainamide Challenge Test

The administration of procainamide known to impair the HPS can unmask extraordinary sensitivity to the usual therapeutic doses of the drug, which can itself indicate poor HPS reserve. In normal procainamide typically produces a 10% to 20% increase in the HV interval. Abnormal HV interval responses to procainamide representing evidence of a higher risk for infra-Hisian AV block include any of the following:

• doubling of the HV interval
• prolongation of the HV interval to more than 100 milliseconds
• second- or third-degree infra-Hisian block