Showing posts with label Electrophysiology. Show all posts
Showing posts with label Electrophysiology. Show all posts

Tuesday, August 8, 2023

Lead impedance change threshold and cause

Low lead impedance 
< 200 ohms
Indicate insulation breach
Usually inner insulation in a bipolar coaxial lead

High lead impedance 
> 2000 ohms
Indicate open circuit
Lead fracture or loose set screw

Saturday, December 24, 2022

Hysteresis

In single chamber devices, for ventricular pacing, hysteresis allows a longer cycle length after a sensed event than after a paced beat. 

It helps maintain intrinsic rhythm and preserves battery. 

In summary: Hysteresis is a programmable feature that allows the pacemaker to begin ventricular pacing only if the spontaneous rate falls below a set rate (eg, 50 bpm); then pacing continues at the programmed base rate (60 bpm) unless intrinsic ventricular activity is sensed.

Thursday, July 7, 2022

Low voltage criteria on ECG mnemonic

Entire amplitude of the QRS (R + S wave) must be < 5mm in all limb leads or < 10mm in all precordial leads. How do I remember this? Mnemonic!​


- IkaN (Nakeya Dewaswala)

Wednesday, November 17, 2021

Monday, November 1, 2021

Normal P wave ECG notes and mnemonic

Here is the video:

 

Mnemonic:

Notes:
Sinus P waves
Axis: 0 and +75 degrees
Upright: Leads I, II, V5, V6
Inverted: aVR
Duration: <120ms or 3 small squares
Amplitude:
Limb leads: < 2.5 mm (0.25mV)
Precordial leads: < 1.5 mm (0.15mV)

-IkaN

Determining pacemaker type from EKG (RV pacing vs biventricular pacing)

 Hello, cardiowesomites!

Today we are going to learn how to determine pacemaker type from EKG (RV pacing vs biventricular pacing)


Notes:

Friday, April 24, 2020

Coronary artery dominance and EKG changes

Hello, hello!

Coronary arterial dominance is defined by the vessel which gives rise to the posterior descending artery (PDA).