Tachycardia sinus

Arrhythmias Originating in the Sinus Node Sinus bradycardia Sick sinus syndrome Sinus tachycardia Disorders of Impulseformation ... 

Abnormal initiation of electrical impulses occurs as a result of abnormal automaticity. If the automaticity of the SA node increases, this results in an increased rate of generation of impulses and a rapid heart rate (sinus tachycardia). If other cardiac fibers become abnormally automatic, such that the rate of initiation of spontaneous impulses exceeds that of the SA node, other types of tachyarrhythmias may occur. Many cardiac fibers possess the capability for automaticity, including the atrial tissue, the AV node, the Purkinje fibers, and the ventricular tissue. In addition, fibers with the capability of initiating and conducting electrical impulses are present in the pulmonary veins. Abnormal atrial automaticity may result in premature atrial contractions or may precipitate atrial tachycardia or atrial fibrillation (AF) abnormal AV nodal automaticity may result in junctional tachycardia (the AV node is also sometimes referred to as the AV junction). Abnormal automaticity in the ventricles may result in ventricular premature depolarizations (VPDs) or may precipitate ventricular tachycardia (VT) or ventricular fibrillation (VF). In addition, abnormal automaticity originating from the pulmonary veins is a precipitant of AF. 

Pulmonary Normal breath sounds, undergoing tracheal intubation for mechanical ventilation CV ECG shows sinus tachycardia, otherwise normal Abd Within normal limits... 

A 76-year-old female with an eight-year history of CHF that has been well controlled with digoxin and furosemide develops recurrence of dyspnea on exertion. On physical examination, she has sinus tachycardia, rales at the base of both lungs, and 4+ pitting edema of the lower extremities Which agent could be added to her therapeutic regimen ... 

Common supraventricular tachycardias requiring drug treatment are atrial fibrillation (AF) or atrial flutter, paroxysmal supraventricular tachycardia (PSVT), and automatic atrial tachycardias. Other common supraventricular arrhythmias that usually do not require drug therapy are not discussed in this chapter (e.g., premature atrial complexes, wandering atrial pacemaker, sinus arrhythmia, sinus tachycardia). 

Hypotension, tachycardia, tachypnea, confusion, and oliguria are common symptoms. Myocardial and cerebral ischemia, pulmonary edema (cardiogenic shock), and multisystem organ failure often follow. Significant hypotension (systolic blood pressure [SBP] less than 90mmHg) with reflex sinus tachycardia (greater than 120 beats/min) and increased... 

P-Blockers also serve to lower cardiac rate (sinus tachycardia, p. 134) and elevated blood pressure due to high cardiac output (p. 312). The mechanism underlying their antihypertensive action via reduction of peripheral resistance is unclear. 

Sinus tachycardia (resting rate >100 beats/min). p-Blockers eliminate sympathoexcitation and decrease cardiac rate. 

Electrophysiology-The ECG may show slight sinus tachycardia and widened... 

Cardiovascular disorders Use with extreme caution in patients with cardiovascular disorders because of the possibility of conduction defects, arrhythmias, CHF, sinus tachycardia. Ml, strokes, and tachycardia. These patients require cardiac surveillance at all dose levels of the drug. In high doses, TCAs may produce arrhythmias, sinus tachycardia, conduction defects, and prolonged conduction time. Tachycardia and postural hypotension may occur more frequently with protriptyline. Hyperthyroid patients Hyperthyroid patients or those receiving thyroid medication require close supervision because of the possibility of cardiovascular toxicity, including arrhythmias. 

Cardiac dysrhythmias Exercise caution in patients prone to cardiac dysrhythmias. In a study comparing pergolide and placebo, patients on pergolide had significantly more episodes of atrial premature contractions and sinus tachycardia. 

Propranolol is indicated in the management of a variety of cardiac rhythm abnormalities that are totally or partially due to enhanced adrenergic stimulation. In selected cases of sinus tachycardia caused by anxiety, pheochromocytoma, or thyrotoxicosis, (3-blockade will reduce the spontaneous heart rate. 

The most profound effect of adenosine is the induction of an A-V block within 10 to 20 seconds of administration. Mild sinus slowing may be observed initially followed by sinus tachycardia. There is no effect on the QRS duration or QT interval. Rarely, an adenosine bolus injection is accompanied by atrial fibrillation or ventricular tachyarrhythmias. 

In overdose, the antihistamines cause convulsions, hallucinations, excitement, ataxia, incoordination, and athetosis. On exam patients may exhibit fixed, dilated pupils with a flushed face, sinus tachycardia, urinary retention, dry mouth, and fever. At high doses the patient can become comatose, which is often followed by cardiorespiratory collapse and death within 2 to 18 hours (Babe and Serafin, 1996). Treatment of overdose is mainly supportive, with efforts to manage the anti-colinergic effects. 

In other cases, somnolence, mild sinus tachycardia, and generalized convulsions were noted. Recommended treatment includes general supportive and symptomatic measures. In severe cases, dialysis should be considered. 

Much more is known about overdose with the immediate-release formulation of bupropion than with the newer, SR and XL formulations. Reported reactions to overdose with the immediate-release form include seizures, hallucinations, loss of consciousness, and sinus tachycardia. Treatment of overdose should include induction of vomiting, administration of activated charcoal, and electrocardiographic and electroencephalographic monitoring. For seizures, an intravenous benzodiazepine preparation is recommended. 

Nausea and vomiting because of CTZ stimulation, which can be minimized by starting with a lower dose. It also causes confusion, hallucinations, delusions and other behavioural effects. Certain cardiovascular effects such as palpitation, postural hypoten-sion, sinus tachycardia and ventricular arrhythmias have also been reported. 

The antiarrhythmic action is due to cardiac adrenergic blockade. It decreases the slope of phase 4 depolarization and automaticity in SA node, Purkinje fibres and other ectopic foci. It also prolongs the effective refractory period of AV node and impedes AV conduction. ECG shows prolonged PR interval. It is useful in sinus tachycardia, atrial and nodal extrasystoles. It is also useful in sympathetically mediated arrhythmias in pheochromocytoma and halothane anaesthesia. 

Class II drugs are the p-adrenoceptor antagonists that suppress the sympathetic modulation of the heart action. They are used in the therapy of sinus tachycardia, supraventricular paroxysmal tachycardia and ventricular extra-systoles. Because of its rapid onset and short duration of action, esmolol is the preferred drug in this class for intra-operative use. 

Class IV drugs are calcium-entry blockers of the phenylalkylamine (verapamil) and benzothiazepine (diltiazem) type. They slow atrioventricular conduction, and are used to treat supraventricular and sinus tachycardia. 

Sympathomimetic effects (from NA re-uptake inhibition) and antimuscarinic effects can cause a sinus tachycardia. Postural hypotension may occur as a result of sympatholytic al-adrenoceptor antagonism. With overdoses of these drugs, there is a reduced re-uptake of catecholamines, resulting in arrhythmias and hypertension. Tricyclic compounds have a high... 

The classic anticholinergic (technically, "antimuscarinic") syndrome is remembered as "red as a beet" (skin flushed), "hot as a hare" (hyperthermia), "dry as a bone" (dry mucous membranes, no sweating), "blind as a bat" (blurred vision, cycloplegia), and "mad as a hatter" (confusion, delirium). Patients usually have sinus tachycardia, and the pupils are usually dilated (see Chapter 8). Agitated delirium or coma may be present. Muscle twitching is common, but seizures are unusual unless the patient has ingested an antihistamine or a tricyclic antidepressant. Urinary retention is common, especially in older men. 

In addition to sinus tachycardia and tremor, vomiting is common after overdose. Hypotension, tachycardia, hypokalemia, and hyperglycemia may occur, probably owing to B2-adrenergic activation. The cause of this activation is not fully... 

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