…waves. The transducer is held with one hand and its position and angle are adjusted to send ultrasound waves through structures to be visualized. Ultrasound…

…obtained by combining two or three electrodes. At any given instant during the cardiac cycle, all ECG leads analyze the same electrical events but from…

…instilled 15–30 minutes before the procedure, or over a few days at home for a hard plug. Have the patient lie with the ear…

…to second hand smoke. Use of cannabis, electronic cigarettes or other inhaled products. Readiness to attempt cessation. Depression, schizophrenia, schizoaffective disorder, HIV infection or other…

…despite medical treatment. Diagnostic drainage in suspected purulent pericarditis, tuberculosis or malignancy. Tamponade is a clinical diagnosis supported by echocardiography: Finding Comment : : Hypotension, distended neck…

…yields a positive P wave in lead II ( Figure 2 , right hand side). The P wave is always positive in lead II during sinus rhythm…

…but it may also be referred to as the posterior wall, or the inferobasal wall. Transmural ischemia located in this area yields an injury current…

…and overall mortality. Ventricular dimensions are measured using an electronic caliper, with the tips positioned at the interface between the compacted myocardium and the noncompacted…

…study, PET, SPECT, genetic profiling — add information but are too costly or invasive to screen a population. The surface ECG is the obvious cheap, standardized…

…had no myocardial disease or acute coronary syndrome. Indeed, the majority of the victims were healthy and tragically killed by a sudden and random electrical…

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

…chapters (see The 3 Phase Model of Cardiac Arrest). Both chest compressions and defibrillation are paramount in restoring cardiac electrical activity, hence rhythm and contractility…

…of the vena cava can be accomplished using a wedge board (or any hard material) to tilt the body 15 to 30° to the left…

…a battery , and one or two leads . The pulse generator generates the electric current needed to stimulate the myocardium. The current is delivered to the…

…ventricular fibrillation) or cardioversion (ventricular tachycardia). Non shockable rhythm : Cardiac rhythm that cannot be defibrillated or cardioverted. These rhythms include pulse less electrical activity (PEA…

…metal, or tissue and fluids in the human body. Sound waves arise when a sound source generates mechanical vibrations in the particles of the medium…

…because the vibrations in the piezoelectric crystals, and thus the electric current they send back to the machine, vary with the amplitude of the reflected…

…the procedure is routine. Synchronised cardioversion or unsynchronised defibrillation Synchronised cardioversion Unsynchronised defibrillation : : : Rhythm An organised rhythm with discernible QRS complexes: atrial fibrillation, atrial flutter…

…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…

…of these have atherosclerotic heart disease (coronary artery disease) as the underlying cause. Other common causes are cardiomyopathy (hypertrophic or dilated), arrhythmogenic right ventricular cardiomyopathy…

…stability. Define the operative electrical environment The surgical team should establish: Whether electrosurgery or diathermy will be used. Whether monopolar or bipolar electrocautery is planned…

…required. The rationale for electrical therapy over drugs is that, under monitored conditions, a controlled "dose" of electricity can immediately and safely restore sinus rhythm…

…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…

ECG Stimulation threshold As previously discussed, myocardium may be excited by external electrical stimuli that drive the cells to threshold. Stimulation threshold is the minimum…

…action potential, automaticity and electrical vectors Video lecture The following video lecture summarises this chapter. The action potential includes a depolarization (activation) followed by a…

…lead anatomy and electrical vectors have been discussed in the chapter The ECG Leads. Acquisition of ECGs in pediatric patients is slightly different from adults…

…1 Cardioversion (electrical or pharmacological) can be performed directly. An anticoagulant is then given according to CHA₂DS₂ VA 24–48 hours, or risk factors present…

…which manifests on the electrocardiogram (ECG) as organized, continuous atrial electrical activity. This activity most commonly presents as a characteristic saw tooth pattern at rates…

…or electrical instability. Posterior infarction may occur in patients with a clinically unstable acute coronary syndrome, but the examination does not reliably establish or exclude…

…The contemporary understanding of AF has evolved significantly; it is no longer viewed merely as an electrical anomaly but as a progressive, complex atrial myopathy…

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

…anaphylactic cardiac arrests present with pulseless electrical activity (PEA) as the initial rhythm, while the remainder manifest ventricular fibrillation (VF) or asystole ( Ebo et al…

…instead as an ectopic atrial rhythm (EAR) . Ectopic atrial tachycardia (EAT) most commonly occurs in individuals with underlying structural or electrical heart disease. Less frequently…

…which delivers the electrical impulse to the posterior and inferior walls of the left ventricle. Anatomical or functional block in the anterior fascicle leads to…

…from the right ventricle. The electrical impulse will propagate through the left ventricle partially or entirely outside the specialized conduction system. This slower conduction results…

…In PET (Positron Emission Tomography), radiotracers emit positrons. When a positron collides with an electron, they annihilate each other, producing two gamma photons emitted in…

…right ventricle relies on electrical impulses originating from the left ventricle. However, these impulses propagate slowly as they travel partially or entirely outside the specialized…

…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…

…automaticity) in the sinoatrial node. This simply means that the sinoatrial node discharges electrical impulses at a higher frequency than normal. Similar to sinus rhythm…

…In contrast, modalities like echocardiography and ECG typically identify ischemia at later stages, when functional or electrical alterations are evident. Subjective symptoms (i.e. chest…

…usually II or V5, and the U wave must not be included. Electrical axis Electrical axis Interpretation : : −30° to +90° Normal −30° to −90° Left…

…Asystole with no electrical activity at all — pacing has no documented benefit there. Transcutaneous pacing: burns or wounds in the area where the pads would…

…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…

…with or without an acute rise in cardiac troponin. The spectrum ranges from symptom free presentation to persistent chest discomfort, cardiac arrest, electrical or haemodynamic…

…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…

…myocardial ischaemia may develop. The electrical manifestation may be horizontal or downsloping ST segment depression, reflecting an abnormal repolarization response to exercise induced myocardial oxygen…

…to establish a working diagnosis of STEMI rapidly, identify haemodynamic or electrical instability and determine the appropriate reperfusion pathway. Important early clinical priorities include: Recognition…

…wave. Because of the long duration of the plateau phase most contractile cells are in this phase at the same time (more or less). Moreover…

…features characteristic of biventricular hypertrophy. Biventricular hypertrophy ECG In case the ECG or other examinations suggest left ventricular hypertrophy (LVH), one should suspect concomitant right…

…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…

…resulting in obstruction. Central nervous system (CNS) injuries might cause apnea or hypoventilation. Respiratory conditions : Tension pneumothorax Drowning Airway obstruction Hanging Pneumonia High altitude sickness…

…and can guide resuscitative efforts. If the patient presents with hypotension or has a lactate level exceeding 4 mmol/l, commence an intravenous fluid resuscitation…

…when cells in the sinoatrial node discharge an action potential that spreads as an electrical impulse through the atria and – via the atrioventricular node – to…

…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…

…The ECG in Brugada syndrome Brugada syndrome is a rare channelopathy (an electrical disorder caused by mutations in cardiac ion channels) which predisposes the individual…

…diminish the QRS amplitudes. Electrical alternans: The amplitude of the QRS complexes vary from one beat to another (in the same lead). This is due…