Sunday, 5 July 2020

Published Articles

https://www.magonlinelibrary.com/doi/abs/10.12968/bjca.2017.12.2.77


Monday, 4 December 2017

Sgarbossa criteria




Tuesday, 3 October 2017

right ventricular wall infarction






Basic ecg rhythm strips


Einthoven's triangle

Einthoven's triangle is an imaginary formation of three limb leads in a triangle used in electrocardiography, formed by the two shoulders and the pubis. The shape forms an inverted equilateral triangle with the heart at the center that produces zero potential when the voltages are summed. It is named after Willem Einthoven, who theorized its existence.
Einthoven used these measuring points, by immersing the hands and foot in pails of salt water, as the contacts for his string galvanometer, the first practical ECG machine.

Electrodes may be placed distally or proximally on the limb without affecting the recording. The leg electrode acts as a grounding lead, and either the right or left leg can be used as a grounding lead without an effect on the ECG results.
Each lead measures the electric field created by the heart during the depolarization and repolarization of myocytes. The electric field can be represented as a vector that changes continuously and can be measured by recording the voltage difference between electrodes.

Though Einthoven's triangle is no longer used in contemporary ECGs, Einthoven's triangle can be helpful in the identification in incorrect placement of leads. (Incorrect placement of leads can lead to error in the recording, which can ultimately lead to misdiagnosis.) If the arm electrodes are reversed, lead I changes polarity, causing lead II and lead III to switch. If the right arm electrode is reversed with the leg's electrode, lead II changes polarity, causing lead I to become lead III, and vice versa. Reversal of the left arm and leg causes a change in polarity of lead III and switching of leads I and II.



Wednesday, 16 November 2016

Pericarditis




Acute pericarditis is a type of pericarditis (inflammation of the sac surrounding the heart, the pericardium) usually lasting less than 6 weeks. It is by far the most common condition affecting the pericardium.

Typical ECG changes in acute pericarditis includes:
  • stage 1 - diffuse, positive, ST elevations with reciprocal ST depression in aVR and V1. Elevation of PR segment in aVR and depression of PR in other leads especially left heart V5, V6 leads indicates atrial injury.
  • stage 2 - normalization of ST and PR deviations
  • stage 3 - diffuse T wave inversions (may not be present in all patients)
  • stage 4 - ECG becomes normal OR T waves may be indefinitely inverted
The two most common clinical conditions where ECG findings may mimic pericarditis are acute myocardial infarction (AMI) and generalized early repolarization.