…resistance in the lead tip, the smaller the current used. Software settings The pacemaker software includes pre programmed algorithms and settings, which can be tailored…

…following types of pacemaker dysfunction: Failure to capture (FTC) , which means that the pacemaker stimulations do not result in myocardial activation. Failure to pace (FTP) …

…and ventricular myocardium. Propagation of the action potential is possible because all cardiac cells are electrically interconnected by gap junctions (Figure 1) . Gap junctions are…

…cells and ultimately depolarize all connected myocardium. This is the main principle behind artificial pacemakers; i.e applying an external electrical current that depolarizes cells…

…because it justifies their symptoms (treatment alternatives are discussed below). ECG in sinus tachycardia Sinus tachycardia fulfills all criteria for sinus rhythm but the heart…

…with implanting a permanent pacemaker and continuing the treatment. Commonly, patients with bradycardia have a strong indication for drugs that aggravate or cause bradycardia (e…

…and the ventricles are electrically disconnected. This condition is referred to as AV dissociation. Importantly, for the ventricles to exhibit any electrical—and consequently mechanical…

…genes encoding desmosomal proteins . The desmosome is a component of the intercalated disc that connects myocardial cells mechanically and electrically. Most mutations are inherited in…

…off. The defibrillator finds no stable R wave, and in sync mode no shock at all is then delivered while the patient deteriorates. Indications Emergency…

…of the normal heart axis. Figure 1. The electrical axis of the heart (heart axis). As evident from the figure, the normal heart axis is…

…range of normal heart axis. Figure 38. The electrical axis of the heart (heart axis). As evident from the figure, the normal heart axis is…

ECG Video lecture: Assessment of the electrical axis of the heart

…progress [3]. The mean electrical axis is typically calculated for ventricular activation in the frontal plane using the hexaxial reference system. This system is constructed…

…Treatment of ventricular fibrillation Ventricular fibrillation is treated according to the resuscitation algorithm. Cardiac arrest and sudden cardiac death For details regarding sudden cardiac arrest…

…isoproterenol, or transcutaneous pacing for post shock bradycardia, and use of biphasic defibrillators , which are standard due to superior efficacy over monophasic devices. Electrode position…

…the heart rate, the electrical axis and the waveform in the newborn differ markedly from adult reference values and normalise gradually through childhood. The interpretation…

…amplitude of the electrical signals generated in the myocardium. The same ECG grid is used in children and adult patients. Recommendations for ECG recording in…

…long has the fibrillation lasted, and does the patient need an anticoagulant? The unstable patient Immediate electrical cardioversion, without delay, in any of the following…

…typical flutter. Furthermore, typical flutter frequently emerges in patients undergoing pharmacological treatment for AF with class IC drugs or amiodarone. In these instances, the flutter…

…Pulmonary auscultation. Evaluation for heart failure. Assessment for circulatory compromise, haemodynamic instability, or electrical instability. Posterior infarction may occur in patients with a clinically unstable…

…evolved significantly; it is no longer viewed merely as an electrical anomaly but as a progressive, complex atrial myopathy. For the practicing cardiologist, mastering the…

…asystole. The tachyarrhythmias include ventricular fibrillation (VF) and pulseless ventricular tachycardia (VT). The bradyarrhythmias include all bradyarrhythmias, pulse less electrical activity (PEA), and asystole. Bradyarrhythmias…

…coughing before cardiac arrest also speak for anaphylaxis (airway obstruction caused by a foreign body is an important differential). Treatment of anaphylaxis and cardiac arrest…

…of all other cases aligns with the approach used for atrial fibrillation and atrial flutter. Beta blockers, digoxin, and calcium channel blockers may be used…

…seconds). ECG criteria for left anterior fascicular block (LAFB) Electrical axis between 45° to 90°. If the electrical axis is 30° to 45, probable LAFB…

…synchronized spread of depolarization, which is essential for coordinated and efficient atrial and ventricular activity. The conduction system includes the sinoatrial (SA) node, atrioventricular (AV…

…anatomical or functional dysfunction in the right bundle branch, such that the electrical impulse is blocked. Figure 1 illustrates the components of the ventricular conduction…

…LVH) and right ventricular hypertrophy (RVH). The electrical vector of the left ventricle is enhanced in LVH, which results in large R waves in left…

…any given instant during the cardiac cycle, all ECG leads analyze the same electrical events but from different angles. This means that ECG leads with…

…sequence, before mechanical dysfunction ( i.e. left ventricular systolic or diastolic dysfunction) or electrical changes (ST T changes on ECG) become apparent. In contrast, modalities…

…repolarisation: J point elevation ≥ 1 mm with notching or slurring in the inferolateral leads. See also the Calculators section for QTc formulas and risk scores.

…mm), loculated or purely posterior effusion with no safe route for puncture — surgical drainage or pericardiotomy instead. Relative: uncorrected coagulopathy, thrombocytopenia and ongoing anticoagulant treatment…

…only monitoring and preparedness. Asystole with no electrical activity at all — pacing has no documented benefit there. Transcutaneous pacing: burns or wounds in the area…

…137 (108) 65–133 (100) 63–129 (92) 66–120 (86) 50 – 120 Electrical axis (degrees) 58–168 ( 135) 65–171 ( 134) 76–168 ( 133…

…and an accelerating pattern. An accelerating pattern includes increasingly frequent or severe episodes, longer episodes, a lower threshold for provocation, or symptoms that awaken the…

…organ hypoperfusion. In severe cases, bradycardia may progress to bradyarrhythmic arrest or pulseless electrical activity (PEA), presenting as cardiovascular collapse and cardiac arrest. Evaluation and…

…additional information concerning cardiovascular reserve and electrical stability. Clinical indications Suspected chronic coronary syndrome Exercise ECG may be used in selected patients with suspected chronic…

…pacing for haemodynamic stability. In patients with resynchronization devices, maintaining CRT during surgery is recommended to provide better haemodynamic stability. Define the operative electrical environment…

…communities. Late presentation is clinically important: Within 12 hours of symptom onset: reperfusion therapy is recommended for all patients with a working diagnosis of STEMI…

…point depression). The reason for such electrical potential difference is that not all ventricular myocardial cells will finish their action potential simultaneously. Myocardial cells which…

…has low sensitivity with respect to detecting biventricular hypertrophy. This is because the strong and oppositely directed forces tend to cancel each other out. However…

…presentation is notoriously heterogeneous, ranging from lifelong asymptomatic ECG anomalies to electrical storm and sudden cardiac arrest (SCA) as the index presentation. Over the past…

…finding in acute coronary syndromes). Between 3 8 minutes, pulseless electrical activity (PEA) develops. PEA progresses to asystole within minutes, as outlined in the studies…

…followed. Moreover, for optimal management in the context of sepsis induced cardiac arrest, consider the following recommendations: Administer 100% oxygen at the maximum flow rate …

…which has much stronger electrical potentials. Cell types in electrocardiology For the purpose of this discussion it is important to distinguish between two main types…

…35 mm or R aVL 11 mm Sokolow Lyon's index is the most used index, despite having the lowest sensitivity (20%) of all indexes…

…occurs in 5% to 10% of all males. It is less common among women (prevalence 2% to 4%). The condition has been recognized for decades…

…or sudden cardiac death. The resulting extensive ischemia causes immediate myocardial stunning (akinesia) and electrical instability. Fewer than 1% of patients with ST elevation myocardial…

ECG Genetic and miscellaneous conditions Eletrical alternans: an ECG sign of pericardial effusion and cardiac tamponade The pericardial space (cavity) always contains a small amount…

…There is no consensus regarding the criteria for ECMO initiation. However, frequently used criteria include the following: A witnessed cardiac arrest attended by immediate bystander…

…Click to zoom. ECG criteria for first degree AV block PR interval ≥0,22 s. All P waves are followed by QRS complexes. First degree…

…Sudden unexpected cardiac arrest is the mechanism of death for about half of all individuals with heart failure ( Packer et al ) and 30% of people…

…1930s, to a routine, safe, and sophisticated treatment used worldwide. Artificial pacemakers have benefitted immensely from advances in engineering, notably with the advent of transistors…

…137 (108) 65–133 (100) 63–129 (92) 66–120 (86) 50 – 120 Electrical axis (degrees) 58–168 ( 135) 65–171 ( 134) 76–168 ( 133…

…surface). This is because the electrical potentials generated by the sinoatrial node are much too small to be detected on the surface ECG. Intracardiac electrodes…

…be initiated. Agonal breathing is interpreted as manifest cardiac arrest. Defibrillation : Use of non synchronized electric shock (i.e. a shock delivered randomly, without considering…

…Myocardial oxygen demand Myocardium can only function under aerobic conditions (oxygen is required for ATP synthesis [ATP is the primary energy source in all cells])…

…pathway). This is associated with a delta wave. For further details on the PR interval and the PR segment, refer to The normal electrocardiogram (ECG).

…Importantly, for the ventricles to have any electrical (and thus pumping) activity at all, an escape rhythm must arise in an ectopic focus (located distal…