Transient bradycardia and subsequent sinus tachycardia produced by intravenous adenosine in healthy adult subjects.

Abstract

Adenosine was administered in increasing intravenous bolus doses to nine healthy volunteers. A transient decrease in heart rate was observed which occurred about 20 s after injection. This was due to a reduction in sinus rate and/or transient block of conduction through the atrioventricular node, and lasted less than 10 s. An increase in sinus rate which followed any transient bradycardia was also observed. The maximum bradycardia and maximum tachycardia were each significantly related to the logarithm of adenosine dose.

Evidence for a cooperation between adenosine A2 receptors and β1‐adrenoceptors on cardiac automaticity in the isolated right ventricle of the rat

“…However, some cardioexcitatory effects such as positive chronotropic effects as well as positive inotropic effects have been described (Burnstock & Meghji, 1983;Watt & Routledge, 1986). Recently it has been shown that both adenosine (La Orden et al, 1986) and its stable analogue, NECA (Hernandez et al, 1989), increased cardiac automaticity in the isolated right ventricle of the rat.…”

Adenosine causes transient dilatation of coronary arteries in man.

“…These findings are in accord with previous reports of negligible effects of adenosine on inotropic state in either direction (Buckley et al, 1961;Lammerant & Becsei, 1973;Urthaler et al, 1981;Burnstock & Meghji, 1983 (3.5 mg). This dose has been reported to cause minimal cardiac electrophysiological effects (Watt & Routledge, 1986b), suggesting a difference in the dose response with respect to these two effects of adenosine.…”

“…Left ventricular end diastolic pressure (LVEDP) and indices of contractility (peak LV dP/dt and peak LV dP/dt/P) were recorded using a Millar micromanometer-tipped catheter positioned in the left ventricle. Hearts were paced at 100 beats min-1, using a bipolar pacing electrode in the right ventricle, to prevent adenosineinduced alterations in heart rate (Watt & Routledge, 1986b).…”

Adenosine‐induced respiratory and heart rate changes in young and elderly adults.

“…Adenosine is an endogenous nucleoside with varied pharmacological actions (Lancet, 1985), which in man include dose-related respiratory stimulation (Watt & Routledge, 1985) and biphasic changes in heart rate (Watt & Routledge, 1986). There is some evidence of possible increases in adenosine sensitivity with increasing age.…”