The purpose of this study was to determine if
adenosine is equally effective in terminating
catecholamine-dependent and independent
supraventricular tachycardia (SVT). The effect of
adenosine on termination of SVT was studied in 21 patients: 12 with atrioventricular (AV)
reciprocating tachycardia, and 9 with AV node reentrant
tachycardia. Group 1 comprised 13 patients who had SVT induced in the absence of exogenous
catecholamines, whereas group 2 comprised 8 who needed
isoproterenol (1.6 +/- 0.4 micrograms/min) for induction. There was no statistical difference between the 2 groups regarding age, weight, mean arterial pressure during sinus rhythm and SVT, cycle length of SVT, or
norepinephrine and
epinephrine levels during sinus rhythm and SVT. Cycle length during sinus rhythm was significantly decreased in group 2. The mean dose of
adenosine needed to terminate SVT was 52 +/- 6 micrograms/kg of
body weight in group 1, and 61 +/- 12 micrograms/kg in group 2 (p > 0.05). In addition to
isoproterenol not altering the minimal dose of
adenosine necessary to terminate SVT, there was also no correlation between the dose of
adenosine (mean 55 +/- 6 micrograms/kg) of each patient, and the corresponding endogenous
epinephrine (273 +/- 59 pg/ml) (r = -0.19) and
norepinephrine (400 +/- 58 pg/ml) (r = 0.01) levels during SVT, or cycle length of SVT (323 +/- 9 ms) (r = -0.35). The results show that
adenosine is equally effective in terminating
catecholamine-dependent and independent SVT; higher
adenosine doses should not be needed to manage
catecholamine-dependent SVT.(ABSTRACT TRUNCATED AT 250 WORDS)