…currents. It was also explained that the electrical currents are conducted all the way to the skin, because the tissues and fluids surrounding the heart…

…myocardium. The electrodes are also used to record electrical activity. This function of the pacemaker is referred to as sensing . Most pacemakers use two leads…

…it gives the most light and the best view. Irrigation: a 30–60 mL syringe with a soft irrigation catheter, or an electric ear irrigator…

…ecstasy) or amphetamines. In either scenario, there is sustained muscle activation, leading to marked heat generation, acidosis, and the subsequent development of hyperkalemia. This condition…

…contraction. The direction of the depolarization (and thus the electrical axis) is generally alongside the heart's longitudinal axis (to the left and downwards). Figure…

…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

…single heart vector [3]. The orientation and intensity of this vector fluctuate throughout the cardiac cycle as depolarization and repolarization progress [3]. The mean electrical…

…fibrillation prior to the cardiac arrest. Most of these have atherosclerotic heart disease (coronary artery disease) as the underlying cause. Other common causes are cardiomyopathy…

Referensvärden A child's ECG changes continuously with age: the heart rate, the electrical axis and the waveform in the newborn differ markedly from adult…

Myocardial ischemia and infarction ECG Posterior (posterolateral) acute myocardial infarction (STEMI) The heart is rotated 30° to the left in the thorax. This positions the…

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…

…and fluids surrounding the heart have an abundance of ions, enabling them to function as electrical conductors. As a result, the electrical currents produced by…

Arrhythmias and arrhythmology Emergency medicine Pharmacology & dosing Definition and Pathophysiology Bradycardia encompasses a spectrum of rhythm disturbances characterized by an inappropriately slow heart rate. Within…

…causes & management Definition of sinus bradycardia Sinus bradycardia fulfills the criteria for sinus rhythm but the heart rate is slower than 50 beats per minute…

…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…

…Beta blocker (metoprolol) First choice in most cases The IV dose is titrated slowly. Caution in acute heart failure and in obstructive airways disease Verapamil…

…heart rate, myocardial contractility and blood pressure. When coronary blood flow cannot increase adequately because of flow limiting disease, myocardial ischaemia may develop. The electrical…

Cardiology Atrial Fibrillation and Atrial Thromboembolism Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and a profound driver of global cardiovascular morbidity and…

…congenital heart disease (transposition of the great arteries, pulmonary valve stenosis, atrial septal defect, ventricular septal defect), tricuspid valve regurgitation are the most common causes…

…wave in lead II, but the heart rate exceeds 100 beats per minute. Although sinus tachycardia is the most common tachyarrhythmia, it may not always…

…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…

…macroscopic architectural abnormalities necessary for arrhythmogenesis. Ischemic heart disease (IHD), particularly prior myocardial infarction (MI), is the most prevalent etiology. The necrotic myocardium is replaced…

…by a sudden and random electrical event. An excerpt from the article follows: [...] Of every 10 such victims, the heart in 6 or 7 showed…

…in systolic blood pressure during inspiration; one of the most useful signs Low voltage on the ECG, electrical alternans Supportive; it does not exclude Diastolic…

…while awaiting the antidote and specific treatment. Bradyasystole during and after cardiac arrest with persisting electrical activity. Overdrive pacing in bradycardia dependent torsades de pointes…

…years 3–5 years 5–8 years 8–12 years 12–16 years 16 years Heart rate (beats per minute) 93–155 (122) 91–158 …

…ranges from symptom free presentation to persistent chest discomfort, cardiac arrest, electrical or haemodynamic instability, and cardiogenic shock. ACS is distinct from myocardial infarction (MI…

…coronary artery disease, arrhythmias, heart failure and alcohol related cardiomyopathy. The cardiovascular implications of lower alcohol intake remain controversial. Epidemiological studies have often described a…

…and hyperkalemia. When bradycardia occurs in the context of inflammatory heart disease, it often reflects myocardial pathology that may also reduce myocardial contractility and cause…

…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…

…into two broad categories: Electrical complications , particularly ventricular arrhythmias. Mechanical or pump failure complications , including heart failure and cardiogenic shock. Most out of hospital deaths…

…VF) and pulseless ventricular tachycardia (VT). The bradyarrhythmias include all bradyarrhythmias, pulse less electrical activity (PEA), and asystole. Bradyarrhythmias are discussed in the chapter Management…

…for up to 20% of sudden cardiac deaths in patients without structural heart disease and is the leading cause of SCD in men under the…

…air is substantial enough to compress the superior and inferior vena cava, impeding or halting venous return to the heart. In instances of tension pneumothorax…

…coordinate these two tasks, the heart has an electrical conduction system composed of specialized myocardial cells (henceforth referred to as conduction cells). These cells form…

…and rhythm This is arguably one of the most important chapters throughout this course. At the heart of ECG interpretation lies the ability to determine…

…fashion which is rather easy to spot. The hallmark of fascicular blocks is the deviation of the electrical axis. The QRS duration is slightly prolonged…

…two tasks, the heart has an intrinsic pacemaker–i.e. the sinus node–and an electrical conduction system composed of specialized myocardial cells. Conduction cells…

…years 3–5 years 5–8 years 8–12 years 12–16 years 16 years Heart rate (beats per minute) 93–155 (122) 91–158 …

…Chamber dimensions constitute key parameters of most echocardiographic examinations. For example, left ventricular size, measured as its inner diameter, is strongly related to heart failure…

…Table 1). Phase Period Optimal treatment Electrical phase 0 to 4 minutes Defibrillation Circulatory phase 4 to 10 minutes Compressions and ventilation, followed by defibrillation…

…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…

…tachycardia almost invariably have significant underlying heart disease. The most common causes are coronary heart disease (acute coronary syndromes or ischemic heart disease), heart failure …

…arteries or in heart muscle. In other words, the heart today is anatomically the same as it was yesterday except that an electrical charge developed…

…drug induced arrhythmias in patients receiving agents known to alter the electrical properties of the heart (inducing QRS or QT prolongation) or causing electrolyte abnormalities…

…most dramatic changes occur during the first year of life. The electrocardiogram (ECG) evolves in parallel with the changing anatomy and physiology of the heart…

…exercise tolerance Acute coronary syndrome Silent ischaemia Heart failure, particularly when left ventricular function is impaired Haemodynamic or electrical instability in advanced or acute presentations…

…deterioration, heart failure, malignant arrhythmias, or mechanical complications. Risk assessment is intended to identify patients most likely to benefit from early coronary angiography and revascularization…

…Its relationship with cardiovascular risk is nonlinear: even light smoking carries a substantial proportion of the excess ischaemic heart disease risk associated with heavy smoking…

…blood supply. Stress increases myocardial oxygen requirements, principally through increased heart rate and contractility. In the presence of a flow limiting coronary stenosis, supply cannot…

…associated with roughly one in five strokes. Thrombus formation is most commonly related to the left atrial appendage, although competing mechanisms such as large artery…

…can cause tamponade. Post operative Complications : Post surgical complications following thoracic procedures can cause tamponade. Tamponade with swinging heart of the pericardium. Source. Rapid diagnosis…

…or other trauma. Drowning Cardiac arrest due to drowning Electrocution Cardiac arrest due to electrical current through the heart. Asphyxia Asphyxia as a result of…

…to beat variation i electrical amplitude – is the ECG hallmark of cardiac tamponade. Causes of pericardial effusion and cardiac tamponade The most common cause of…

…In the United States, more than 500,000 individuals (adults and children) experience a cardiac arrest (Heart Disease and Stroke Statistics). The CARES registry reported…

…most dramatic changes occur during the first year of life. The electrocardiogram (ECG) evolves in parallel with the changing anatomy and physiology of the heart…

…the AV node and the His Purkinje system, which transmit electrical impulses from the atria to the ventricles. Conduction through the AV node is intentionally…

…particularly with continuing ischaemia, heart failure, electrical instability or a large area of myocardium at risk. Over 48 hours: urgent PCI is still indicated with…

…of the QRS complex around the isoelectric line. Most patients display QTc 500 ms during sinus rhythm. TdP is typically initiated by a long short…