Bradycardia, supraventricular

Lidocaine can cause dysrhythmias and hypotension. The dysrhythmias that have been reported include sinus bradycardia, supraventricular tachycardia (11), and rarely torsade de pointes (12). There have also been rare reports of cardiac arrest (2) and worsening heart failure (13). Lidocaine can also cause an increased risk of asystole after repeated attempts at defibrillation (14). Lidocaine may increase mortality after acute myocardial infarction, and it should be used only in patients with specific so-called warning dysrhythmias (that is frequent or multifocal ventricular extra beats, or salvos) (15). 

Phenylephrine. Phenylephrine hydrochloride is an a -adrenoceptor agonist. Phenylephrine produces powerful vasoconstrictor and hypertensive responses. This results in baroreceptor activation of a reflex bradycardia and thus is useful in the treatment of supraventricular tachyarrhythmias. Unlike epinephrine [51-43-4] the actions of which are relatively transient, phenylephrine responses are more sustained (20 min after iv dosing and 50 min after subcutaneous dosing) (86). 

Supraventricular bradycardia is treated by implantation of a pacemaker device or has been treated pharmacologically with atropine. Supraventricular paroxysmal tachycardia is treated with aj marine or praj marine. Supraventricular tachyarrhythmias or AV reentrant arrhythmia typically can be terminated using adenosine. 

Compare and contrast the risk factors for and the features, mechanisms, etiologies, symptoms, and goals of therapy of (1) sinus bradycardia (2) atrioventricular (AV) nodal blockade (3) atrial fibrillation (AF) (4) paroxysmal supraventricular tachycardia (PSVT) ... 

Indications. Verapamil is used as an antiarrhythmic drug in supraventricular tachyarrhythmias. In atrial flutter or fibrillation, it is effective in reducing ventricular rate by virtue of inhibiting AV-conduction. Verapamil is also employed in the prophylaxis of angina pectoris attacks (p. 308) and the treatment of hypertension (p. 312). Adverse effects Because of verapamil s effects on the sinus node, a drop in blood pressure fails to evoke a reflex tachycardia Heart rate hardly changes bradycardia may even develop. AV-block and myocardial insufficiency can occur. Patients frequently complain of constipation. 

Cardiovascular effects Drugs that increase cholinergic activity may have vagotonic effects on heart rates (eg, bradycardia). The potential for this action may be particularly important in patients with sick sinus syndrome or other supraventricular cardiac conduction conditions. 

Cardiovascular conditions - Cholinesterase inhibitors have vagotonic effects on the sinoatrial and atrioventricular nodes, leading to bradycardia and AV block. These actions may be particularly important to patients with supraventricular cardiac conduction disorders or to patients taking other drugs concomitantly that significantly slow heart rate. Consider all patients to be at risk for adverse effects on cardiac conduction. 

Inappropriate sinus bradycardia, sinoatrial block, and bradycardia-tachycardia syndrome (bradycardia followed by supraventricular tachyarrhythmias such as atrial fibrillation) are included in this syndrome. Treatment of sick sinus syndrome is generally based upon the patients symptoms. In general, bradycardia... 

It is a vasopressor agent with some structural similarity to adrenaline and has a powerful alpha receptor stimulant action. The pressor response is accompanied by reflex bradycardia. It is used as a nasal decongestant and mydriatic agent and also in the treatment of paroxysmal supraventricular tachycardia. 

SA node Digitalis sensitizes the SA node to normal vagal impulse resulting in bradycardia. In a patient suffering from paroxysmal supraventricular tachycardia, it decreases the heart rate due to vagal action on SA node which is associated with decrease in the slope of slow diastolic depolarisation and increase in the transmembrane negativity and, also lower the SA rate by antiadrenergic action. 

It includes anorexia, vomiting which may be of central origin. Headache, visual disturbance, xanthopsia (yellow vision), white vision, diplopia, drowsiness, disorientation, delirium and psychotic behaviour. Cardiac related effects include cardiac arrhythmias e.g. tachyarrhythmias, ventricular arrhythmias, supraventricular arrhythmia, AV block and bradycardia. 

Amiodarone Blocks IKr, JNa/ Ica-L channels, adrenoceptors Prolongs action potential duration and QT interval slows heart rate and AV node conduction low incidence of torsade de pointes Serious ventricular arrhythmias and supraventricular arrhythmias Oral, IV variable absorption and tissue accumulation hepatic metabolism, elimination complex and slow Toxicity Bradycardia and heart block in diseased heart, peripheral vasodilation, pulmonary and hepatic toxicity hyper- or hypothyroidism. Interactions Many, based on CYP metabolism... 

A 41-year-old man who took risperidone 270 mg developed a prolonged QTC interval (480 ms) and sinus bradycardia (44/minute), without hemodynamic compromise. After 9 hours, he had episodes of asymptomatic supraventricular tachycardia with a maximum frequency of 150/minute. After 30 hours he was in sinus rhythm with a normal QTC interval (360 ms). 

DIPYRIDAMOLE ANTIARRHYTHMICS t effect of adenosine 1 doses needed to terminate supraventricular tachycardias case report of profound bradycardia when adenosine infusion was given for myocardial stress testing Dipyridamole inhibits adenosine uptake into cells l bolus doses of adenosine by up to fourfold when administering it to treat supraventricular tachycardias. Some recommend avoiding adenosine for patients taking dipyridamole. Advise patients to stop dipyridamole for 24 hours before using adenosine infusions... 

In 33 patients with sjmptomatic and inducible supraventricular tachycardias single doses of placebo, flecainide 3 mg/kg, or dUtiazem 120 mg plus propranolol 80 mg were used to terminate the dysrhythmia (5). Conversion to sinus rhythm was achieved within 2 hours in 17 patients with placebo, in 20 with flecainide, and in 31 with diltiazem plus propranolol. Time to conversion was shorter with diltiazem plus propranolol (32 minutes) than with flecainide (74 minutes) or placebo (77 minutes). Of those who were given flecainide, two had hypotension and one had sinus bradycardia. 

A 74-year-old man was to receive a combined sciatic nerve and psoas compartment block for a total hip arthroplasty the classic Labat s approach was used and 30 ml of 0.75% ropivacaine was injected over 1.5 minutes, after which he suddenly became unresponsive and developed tonic-clonic movements. Propofol was administered and the seizure resolved, but he developed sinus bradycardia with progressive lengthening of the QRS interval, which converted to nodal bradycardia. A ventricular escape rhythm at 20/minute with T wave inversion was treated with ephedrine 10 mg and adrenahne 0.1 mg, resulting in supraventricular tachycardia with transient atrial fibrillation. 

Supraventricular extra beats have rarely been reported after low doses of ropinirole and have also been reported after pergolide and levodopa (1). Symptomatic postural hypotension has occurred after even low oral doses of ropinirole (2-5), related to peripheral dopaminergic activity. Hypotensive effects occur within 3 minutes of standing, usually between 2 and 4 hours after an oral dose, associated with nonspecific malaise (2). Dizziness occurred in up to 40% of patients in clinical trials. Related symptoms include faintness, malaise, and yawning (2). Bradycardia has occasionally accompanied postural hypotension (4). Syncope has been reported. 

Arrhythmias (VT, supraventricular tachycardia), AV block headache, hypotension, bradycardia... 

In addition to drugs in these classes, others may be used for certain arrhythmias. Digoxin may be used for treatment of atrial fibrillation, adrenaline for asystolic cardiac arrest, atropine for sinus bradycardia, methacholine (rarely) for supraventricular tachycardia, magnesium salts for ventricular arrhythmias, and calcium salts for ventricular arrhythmia due to hyperkalaemia. 

Hypersensitivity to amide-type local anesthetics, Adams-Stoke syndrome, supraventricular arrhythmias, Wolf-Parkinson-White syndrome. Spinal anesthesia contraindicated in septicemia. Caution Dosage should be reduced for elderly, debilitated, acutely ill safety in children has not been established. Severe renal/hepatic disease, hypovolemia, CHF, shock, heart block, marked hypoxia, severe respiratory depression, bradycardia, incomplete heart block. Anesthetic solutions containing epinephrine should be used with caution in peripheral or hypertensive vascular disease and during or following potent general anesthesia. Sulfite sensitivity or asthma for some local and topical anesthetic preparations. Tartrazine or aspirin sensitivity with some topical preparations. Anxiety, insomnia, apprehension, blurred vision, loss of hearing acuity, and nausea CNS depression, convulsion and respiratory depression... 

M2 receptor antagonists may also be used for the treatment of Alzheimer s disease, furthermore in the therapy of supraventricular bradycardia and for quantifying M2 receptors in the CNS with PET imaging. In the search for antagonists which clearly differentiate M2 from other muscarinic receptors, we investigated the two enantiomers of the widely used Hj-anti-histaminic drug dimethindene. (S)-Dimethindene proved to be a potent M2-selective antagonist with lower affinities for the Mj, M3 and M4 receptors. In addition, the (S)-enantiomer... 

M2 receptor antagonists may be applied also for the treatment of Alzheimer s disease [9, 14-16], fiirthermore in the therapy of supraventricular bradycardia [17-19] and for quantifying M2 receptors in the CNS with PET imaging [20]. 

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