…electrolyte disorders 1. Sodium Increased (hypernatremia) and decreased (hyponatremia) sodium levels do not have any effect on the ECG, nor cardiac rhythm, or impulse conduction…

Arrhythmias and arrhythmology Critical care Pharmacology & dosing Definition and Pathophysiology Bradycardia and conduction disorders arise from dysfunction within the sinus node, the atrioventricular node (AVN…

…electrolyte disorders. Because the rate (60–100 beats per minute) is on a par with the rate in sinus rhythm and there is atrioventricular conduction…

…cessation of prolonged and heavy alcohol intake. The condition can develop despite a measurable or high blood alcohol concentration, particularly in patients with marked tolerance…

…Myocardial ischemia and infarction Definition and pathophysiology Spontaneous coronary artery dissection (SCAD) is an acute coronary disorder caused by separation within the coronary arterial wall…

…ECG examples of each condition are presented below. The ECG in Brugada syndrome Brugada syndrome is a rare channelopathy (an electrical disorder caused by mutations…

…rise can cause osmotic demyelination syndrome [1,2]. Hyponatraemia is primarily a disorder of water balance. The plasma sodium reflects the ratio between the body…

…Medical conditions Category Condition Congenital conditions Jervell and Lange Nielsen syndrome Romano Ward syndrome Idiopathic congenital long QT syndrome (LQTS) Metabolic disorders Hypokalemia Hypomagnesemia Hypocalcemia…

…iron deficiency and anaemia, kidney dysfunction, sleep disordered breathing, cancer related disease and cardiac amyloidosis among the relevant clinical settings or comorbidities. HFrEF is distinguished…

…heritable aortopathies, selected congenital heart diseases, pulmonary arterial hypertension and thromboembolic disorders. Most recognised heritable cardiovascular conditions demonstrate autosomal dominant transmission, in which an affected…

…are other considerations when assessing chest pain [2]. Autoimmune/Malignancy: A history suggesting an autoimmune disorder or known malignancy may suggest specific, nonidiopathic etiologies [2]…

…OP are intended for apparently healthy people or for individuals with elevated BP who do not already have a condition conferring sufficiently high cardiovascular risk…

…abnormal amount of fluid in the pericardial space. It can be caused by numerous local and systemic disorders. Accumulation of fluid in the pericardial space…

…may coexist with mitral stenosis. Idiopathic degeneration (Barlow's disease), degeneration associated with connective tissue disorders (Marfan syndrome, Ehlers Danlos syndrome), osteogenesis imperfecta typically causes…

…are not apparent on conventional angiography. Coronary vasomotor disorders may involve epicardial spasm or abnormalities of the coronary microcirculation. Microvascular angina reflects myocardial ischaemia caused…

…efficiency of the pumping function. The primary ECG manifestations of conduction defects are prolonged QRS complexes and altered QRS appearance. These concepts will be discussed…

…participants with baseline ECG examinations. Individuals with nonspecific intraventricular conduction delays were at particularly high risk of death due to arrhythmias. Note that other causes…

…potential occurs. If any component of the ventricular conduction system has not fully repolarized by the time the next impulse reaches the ventricles, the impulse…

Drugs and electrolyte imbalance ECG Digoxin ECG changes: arrhythmias, conduction defects and waveform changes Digoxin may be used in patients with heart failure, atrial fibrillation…

…bundle branch block typically also have a fascicular block. This condition is referred to as bifascicular block. The anterior fascicle is most likely to be…

Conduction defects ECG Lathundar Left Bundle Branch Block (LBBB) Electrocardiographic Criteria and Characteristics Left bundle branch block is characterized by a significant reorganization of the…

Conduction defects ECG Fascicular block (hemiblock): left anterior fascicular block & left posterior fascicular block Fascicular blocks were previously referred to as hemiblocks, but the latter…

Conduction defects ECG First degree AV block: ECG criteria, clinical characteristics & management This chapter discusses first degree atrioventricular (AV) block, also referred to as 1st…

Conduction defects ECG Myocardial ischemia and infarction Left bundle branch block (LBBB) in acute myocardial infarction (AMI): clinical implications & Sgarbossa criteria Contrary to right bundle…

Conduction defects ECG Left bundle branch block (LBBB) Left bundle branch block (LBBB) results from anatomical or functional impairment of the left bundle branch (LBB…

Conduction defects ECG Management and treatment of AV blocks (AV block 1, 2 & 3) Evaluation of patients with suspected AV blocks requires a thorough medical…

Conduction defects ECG Atrioventricular block (AV block): definition, causes, diagnosis & management This article covers the fundamental principles of atrioventricular (AV) blocks, which are classified into…

Conduction defects ECG Right bundle branch block (RBBB) Right bundle branch block (RBBB) is due to an anatomical or functional dysfunction in the right bundle…

Conduction defects ECG Second degree AV block: ECG criteria, clinical characteristics & management In this chapter, the focus will be on second degree atrioventricular (AV) block…

Conduction defects ECG Third degree (complete) AV block: ECG criteria, clinical characteristics and management This chapter discusses third degree AV block, which is synonymous with…

…and calcium channel blockers on rhythm, conduction and ECG waveforms Although the purpose of antiarrhythmic drugs is to control arrhythmias, these medications may also cause…

…calcium channel blocker. Clevidipine is highly selective for vascular smooth muscle cells and has little or no effect on myocardial contractility or conduction. Clevidipine reduces…

…coronary syndromes, particularly ST elevation myocardial infarction (STEMI), ischemic injury can disrupt the conduction system at any level, producing atrioventricular (AV) or intraventricular blocks. Isolated…

…The atrial impulse must pass through the atrioventricular node, which delays the impulse due to its slow conduction, before the impulse may reach the ventricles…

…calcium channel blocker. Clevidipine is highly selective for vascular smooth muscle cells and has little or no effect on myocardial contractility or conduction. Clevidipine reduces…

…His Purkinje conduction is generally unaffected directly. Adenosine does not typically affect conduction in normal accessory pathways. However, conduction may be blocked in unusual accessory…

…artery disease. Proposed explanations in the source material include cardiac memory after abnormal ventricular activation, transient rate related conduction abnormalities, pacing related repolarization changes, and…

…superior vena cava. A critical area of slow conduction is consistently located in the posterolateral to posteromedial inferior region of the right atrium. This circuit…

…heart failure, atrial fibrillation, and other arrhythmias or conduction abnormalities. CKD also worsens the prognosis of established CVD. Mechanisms linking CKD to cardiovascular disease The…

…contraindication) . Irregular wide complex tachycardia is most often due to atrial fibrillation with wide QRS complexes due to bundle branch blocks or other conduction defects…

…action potential, it is activated and contracts. Figure 1 illustrates the relevant components of the conduction system, the heart and the classical ECG waveforms. Figure…

…As mentioned earlier, the electrical potentials of the conduction system are much too small to be detected by skin electrodes; the ECG presents the electrical…

…arrhythmias, conduction defects Cause of termination This article will discuss each of these six parameters in detail. Symptom during exercise stress testing Perceived exertion The…

…calcium channel blocker. Clevidipine is highly selective for vascular smooth muscle cells and has little or no effect on myocardial contractility or conduction. Clevidipine reduces…

…after the tachycardia episode. Under certain circumstances, bradycardia can actually reduce conduction through the AV node, resulting in increased AV block. Sinus node dysfunction can…

…lead tip is fixed in the septum, the impulse may actually enter the conduction system (His Purkinje network), which results in rapid impulse transmission and…

…Principles of myocardial excitability and the conduction system Achieving an effective pumping mechanism requires the atria and the ventricles to be activated rapidly and sequentially…

…into the following categories: Bradyarrhythmia s (bradycardia): arrhythmias commonly due to dysfunctional automaticity in pacemaker cells or blocking of impulses somewhere along the conduction system…

…originates in the atria it will pass through the bundle of His and therefore produce a normal QRS complex (provided that intraventricular conduction is normal)…

…discharged in the ventricles it will spread partly or entirely outside of the conduction system and thus produce a wide QRS complex (QRS duration ≥0…

…morphologically different from the sinus P wave, but the QRS complex is normal (provided that intraventricular conduction is normal). This rhythm may be referred to…

…the left ventricle. This type of bradycardia is due to diminished automaticity (pacemaker function) in the sinoatrial node or conduction defects (e.g. second degree…

…intermittent failures to discharge impulses). Sinoatrial block (delayed or blocked impulse conduction between the sinoatrial node and the atrium). All these conditions have been discussed…

…of ventricular activation (depolarization). The PR interval reflects whether impulse conduction from the atria to the ventricles is normal. The PR interval must not be…

…of tachyarrhythmia with wide QRS complexes (QRS duration ≥ 0.12 s): the commonest cause is ventricular tachycardia, which is a potentially life threatening condition. Note…

…no Magnesium Sulfate MAGNESIUM SULFATE MAGNESIUM SULFATE HEPTAHYDRATE NA sp ambiguous serious changes in cardiac conduction in digitalized patients(Drug Interactions) Premarin CONJUGATED ESTROGENS ESTROGENS…

…complex implies that the ventricles are depolarized rapidly, which in turn implies that the electrical conduction system functions normally. Wide (also referred to as broad…

…indicative of 'Ventricular pre excitation', and QRS duration ≥140 ms is considered 'Profound nonspecific intra ventricular conduction delay', both of which are not typical normal…

…ventricle. It extends the A H interval, which serves as an index of AV nodal conduction, but does not significantly alter the H V interval…

Cardiology Endocrinology & metabolism Definition and Pathophysiology Type 2 diabetes mellitus (T2DM) is a major cardiovascular risk condition. It is associated with a two to four…