SHA24/022002

Page 1

Saudi heart 2013 SHA 24


Tachycardia • Approach • Clinical • Mechanism • ECG analysis


Clinical • Stable vs unstable


Mechanism • Reentrant • Automatic (ectopic focus fire by its own) • Triggered automatic (needs stimlus )


ECG analysis • • • •

Narrow vs wide Fast vs slow Regular vs irregular Atrial and ventricular relationship (linked or not) • P wave axis and morphology


Two concepts • Sequential depolarization • ECG records Vector of electrical current • Positive • Negative • biphasic


Automatic • • • •

Ectopic atrial focus; abnormal automaticity Abnormal P-wave morphology/axis Structurally normal hearts Tachycardia-induced cardiomyopathy


Reentrant • Accessory Connection between atrium and ventricle


Types of AP • Manifested vs concealed • Bidirectional vs unidirectional • Fast conducting vs slow


Manifested pathway • Conduct Antegrade – From atrium to ventricle – recognized by presence of delta wave on ECG


Ventricular Pre-excitation depends on competition between AV node and AP


How serious is the AP ? • Depends on:

–Conduction velocity –Refractory period


Concealed pathway • Conduct retrograde – From the ventricle to atrium – No delta wave


Orthodromic


AVRT


Slow concealed pathway


Antidromic




AV Node Reentrant Tachycardia distinct pathways – “slow” and “fast” • Typical – Down slow, up fast • Atypical – Down fast, up slow



Atrial Tachycardia (Reentrant) • Atrial Flutter – rapid, regular flutter waves (“saw tooth”) – variable AV conduction • Atrial fibrillation – absence of discrete Pwaves – “irregularly irregular” ventricular response



Examples


Atrial tachycardia






AVRT


Thank you


Turn static files into dynamic content formats.

Create a flipbook
Issuu converts static files into: digital portfolios, online yearbooks, online catalogs, digital photo albums and more. Sign up and create your flipbook.