Junctional tachycardia causes

A tachycardia made up of three or more Premature Junctional Beats. Junctional Tachycardia is usually caused by the AV node taking over as the dominant pacemaker due to enhanced automaticity. As in junctional escape beats the atria are retrogradely depolarized, resulting in inverted P waves that can occur after the QRS complex. 

Vomiting is common in patients with digitalis overdose. Hyperkalemia may be caused by acute digitalis overdose or severe poisoning, whereas hypokalemia may be present in patients as a result of long-term diuretic treatment. (Digitalis does not cause hypokalemia.) A variety of cardiac rhythm disturbances may occur, including sinus bradycardia, AV block, atrial tachycardia with block, accelerated junctional rhythm, premature ventricular beats, bidirectional ventricular tachycardia, and other ventricular arrhythmias. 

Nitrous oxide causes drowsiness and headache. Anesthesia with nitrous oxide as the sole anesthetic in normal humans for periods of 7.-A h has induced tachypnea, tachycardia, increased systemic blood pressure, atrioventricular junctional rhythm, acute cardiovascular failure, mydriasis, diaphoresis, and occasional clonus and opisthotonus. 

Peripheral Pharmacological Actions of Nicotine. Nicotine effects on the cardiovascular system include tachycardia and peripheral vasoconstriction, which leads to elevated blood pressure. Because the cardiovascular effects are mainly caused by elevated levels of catecholamines and cortisol, tolerance to these effects does not occur. Other pharmacological actions of nicotine include increased gastrointestinal motility caused by parasympathetic ganglionic stimulation and skeletal muscle contraction caused by the effect on nicotinic receptors in the neuromuscular junction (184). 

The changes in the degree of blockade are not understood but the interaction appears to occur at the neuromuscular junction. It has been seen in animal studies. The bradycardia and hypotension (c) were probably due to the combined depressant effects on the heart of the anaesthetics and the beta blocker not bdng offset by atracurium, which has little or no effect on the vagus nerve at doses within the recommended range. Note that neuromuscular blockers with vagolytic activity can cause tachycardia and hypotension. 

RED FLAG At toxic levels, digoxin may cause numerous arrhythmias, including paroxysmal atrial tachycardia with block, AV block, atrial and junctional tachyarrhythmias, and ventricular arrhythmias. 

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