When the electrical activity within the heart travels towards a lead, you get a positive deflection. Each deflection (a.k.a. wave) on the ECG represents the average direction of electrical travel (calculated using the ECG machine’s mathematical formulae). An easy to follow systematic approach, along with colour coding and inline links to a wealth of #FOAMed ECG resources, creates a simple and incredibly effective learning tool. If the R and S waves are of equal size, it means depolarisation is travelling at exactly 90° to that lead.

The ECG Made Easy - 9th Edition - Elsevier The ECG Made Easy - 9th Edition - Elsevier

Typically, the J point is raised with widespread ST elevation in multiple territories making ischaemia less likely.RAD is commonly associated with conditions such as pulmonary hypertension, as they cause right ventricular hypertrophy. RAD can, however, be a normal finding in very tall individuals. Right Axis Deviation Left axis deviation

ECG Made Easier • LITFL • ECG library - Life in the Fast Lane ECG Made Easier • LITFL • ECG library - Life in the Fast Lane

Right axis deviation (RAD) involves the direction of depolarisation being distorted to the right (between +90º and +180º). It represents the time taken for the ventricles to depolarise and then repolarise. The components of an ECGA single Q wave is not a cause for concern – look for Q waves in an entire territory (e.g. anterior/inferior) for evidence of previous myocardial infarction. An example of a pathological Q wave R and S waves If a patient’s heart rhythm is irregular, the first heart rate calculation method doesn’t work (as the R-R interval differs significantly throughout the ECG). As a result, you need to apply a different method:

How to Read an ECG | ECG Interpretation | EKG | Geeky Medics How to Read an ECG | ECG Interpretation | EKG | Geeky Medics

The ST segment is an isoelectric line representing the time between depolarisation and repolarisation of the ventricles (i.e. ventricular contraction). T waveThe cardiac axis gives us an idea of the overall direction of electrical activity. ECG leads Normal cardiac axis The data gathered from these electrodes allows the 12 leads of the ECG to be calculated (e.g. lead I is calculated using data from the electrodes on both the right and left arm). The presence of a delta wave does NOT diagnose Wolff-Parkinson-White syndrome. This requires evidence of tachyarrhythmias AND a delta wave. Delta wave Q-waves An ECG lead is a graphical representation of the heart’s electrical activity which is calculated by analysing data from several ECG electrodes.