…Importantly, the vast majority of recommended ECG criteria (e.g. criteria for acute myocardial infarction) have been derived and validated using the 12 lead ECG…

…12 lead ECGs (e.g EASI, Frank's leads etc). Note that in some situations it is appropriate to connect additional electrodes in order to…

Arrhythmias and arrhythmology ECG Pacemaker mediated tachycardia (PMT) Pacemaker mediated tachycardia may arise if the pacemaker records a rapid atrial rate (e.g. during a…

…If the left atrium encounters increased resistance (e.g due to mitral valve stenosis) it becomes enlarged (hypertrophy) which amplifies its contribution to the P…

…safely restore sinus rhythm, obviating slow drug titration and rendering the supraventricular versus ventricular distinction less critical. Performance involves sedation (e.g., intravenous midazolam, propofol…

…blocks. Importantly, first degree sinoatrial block and third degree sinoatrial block cannot be diagnosed using surface ECG (i.e. ECG recorded on the body surface)…

…ultrasound imaging and echocardiography. Piezoelectric crystals The ultrasound waves are generated by ceramic crystals exhibiting piezoelectric properties (i.e piezoelectric crystals ). Thousands of piezoelectric crystals…

…main principle behind artificial pacemakers; i.e applying an external electrical current that depolarizes cells in contact with the lead tip, and thus generate an…

…field repolarization currents (T waves), as well as far field currents (i.e currents generated by tissues that the electrode is not connected to). Also…

…often for practical than for medical reasons: the cuff is in the wrong place, the electrodes come off, the patient has not kept a diary…

…the myocardium are transmitted through the body to the skin, where they can be detected using electrodes. The electrocardiograph (ECG machine) records and processes these…

…Figure 2. Placement of chest leads in children Placement of chest electrodes (precordial leads) in children V1: placed in the fourth intercostal space, to the…

…directed towards the back, where there is no exploring electrode (in the 12 lead ECG) that can present the ST segment elevations ( Figure 1 ). Thus…

…Lateral ventricular infarction. Pre excitation. Switched arm electrodes (negative P and QRS T in lead I). Situs inversus. Left posterior fascicular block is diagnosed when…

…Lateral ventricular infarction. Pre excitation. Switched arm electrodes (negative P and QRS T in lead I). Situs inversus. Left posterior fascicular block is diagnosed when…

…about increased QRS amplitudes. This is because large chambers may be positioned closer to the electrodes (chest leads) which therefore observe stronger electrical potentials. However…

…atrium. An electrode placed in the oesophagus at the right level therefore records atrial depolarisation with an amplitude the surface ECG can never achieve, and…

…and defibrillation according to adult recommendations. Electrode pads should be positioned as standard, and defibrillation energy levels should remain consistent with those used for non…

…in the report. Shaving and careful skin preparation at the electrode sites — movement artefact ruins an exercise test more often than anything else. Record a…

…explained in this article). An isolated QS complex is allowed in lead V1 (due to missing r wave or misplaced electrode). Lead III occasionally displays…

…directed towards the back, where there is no exploring electrode (in the 12 lead ECG) that can present the ST segment elevations ( Figure 1 ). Thus…