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Intravenous adenosine triphosphate during wide QRS complex tachycardia: Safety, therapeutic efficacy, and diagnostic utility
ABSTRACTS
safe and feasible to start t h r o m b o l y t i c s in the prehospital setting. However, no significant bencfit to this procedure was d e m o n s t r a t e d in this study.
Jeff Schafer, MD
myocardial infarction, prehospital
T h e p r e h o s p i t a l p h a s e of a c u t e m y o c a r d i a l i n f a r c t i o n in t h e e r a of t h r o m b o l y s i s Schmidt SB, Borsch MA Am J Cardiol 65:1411-1415 Jun 1990
setting or early in the emergency department visit enhances the effectiveness of thrombolytic therapy, especially when given less than four hours from onset of symptoms.] Lynn Keating, MD
adenosine triphosphate
T h r o m b o l y t i c t h e r a p y for acute m y o c a r d i a l i n f a r c t i o n (AMI) decreases m o r t a l i t y if t r e a t m e n t is begun w i t h i n six hours of s y m p t o m onset. Unfortunately, m a n y p a t i e n t s do n o t seek m e d i c a l care u n t i l after six hours. In order to identify those groups of patients m o s t likely to delay, a questionnaire was a d m i n i s t e r e d to 126 patients a d m i t t e d w i t h a confirmed out-of-hospital AMI. The questionnaire included questions designed to elicit information on various t i m e intervals, p s y c h o l o g i c a l factors, and feelings about control of personal health. T i m e intervals were defined as follows: precall t i m e was the i n t e r v a l b e t w e e n s y m p t o m onset and calling for transportation to the h o s p b tal; n o t i f i c a t i o n t i m e e x t e n d e d from s y m p t o m o n s e t to discussion of the p r o b l e m w i t h another person; dccision t i m e was that interval between notification and the decision to seek m e d i c a l care; delay t i m e was the t i m e between the decision to seek medical care and calling for transportation; wait t i m e was the period spent w a i t i n g for a r r i v a l of t r a n s p o r t a t i o n ; and t r a n s p o r t a t i o n t i m e was t i m e between leaving for and arrival at the hospital. Prehospital t i m e was the total period from s y m p t o m onset to hospital arrival. Psychological factors included questions on denial, suppression, and depression. One h u n d r e d patients (79%) were in the early arrival group (less t h a n six hours), and 26 (21%) were in the late arrival group (more than six hours). Significantly longer notification and decision times were found in the late arrival group, accounting for m o s t of the longer prehospital time. Those m o s t likely to delay were women, lower i n c o m e patients, older patients, and those w i t h a history of hypertension. Low i n t e n s i t y of i n i t i a l s y m p t o m s was found to be of borderline significance. Patients in the late group were more l i k e l y to h a v e called t h e i r p h y s i c i a n , and several were seen in their physician's office before going to the hospital. T h e r e was no significant difference in o u t c o m e between the two groups except for the greater use of throm-
180/1196
bolytic therapy. Identification of those groups at greatest risk for delay can help direct public education efforts. In this study, those groups included women, those w i t h slow s y m p t o m progression, l o w - i n c o m e p a t i e n t s , and e l d e r l y patients. /Editor's note: Rapid therapy in the prehospital
Intravenous adenosine triphosphate during w i d e Q R S c o m p l e x t a c h y c a r d i a : Safety, t h e r a p e u t i c e f f i c a c y , a n d d i a g n o s t i c utility Sharma AD, Klein GJ, Yee R Am J Med 88:337 343 Apr 1990
The authors studied a consecutive series of 34 patients w i t h sustained wide QRS complex tachycardia (duration of more than 120 ms) i n d u c e d during electrophysiologic testing. Adenosine was a d m i n i s t e r e d as a 20-mg peripheral IV bolus followed by rapid 10-mL flush of n o r m a l saline. In 14 patients w i t h ventricular tachycardia (VT), one was converted, and no significant change in cycle length was observed in the other 13. In ten patients w i t h atrial a r r h y t h m i a s , o n l y one was converted, and in the o t h c r n i n e t h e R-R i n t e r v a l was t r a n s i e n t l y s h o r t e n e d . In a group of ten patients w i t h re-entrant tachycardias involving the a t r i o v e n t r i c u l a r (AV) node, seven p a t i e n t s converted, with failure in two - one w i t h o r t h o d r o m i c AV reciprocating tachycardia associated w i t h a bundle branch block and one w i t h a second hidden AV accessory pathway. N o statistically significant change in blood pressure was observed, a l t h o u g h t h o s e p a t i e n t s w h o c o n v e r t e d were not included in the analysis. Three patients in VT and w i t h an initial systolic blood pressure of 80 to 90 m m Hg dropped their systolic blood pressure to 70 to 80 m m Hg for less than one m i n u t e . As a diagnostic test to indic a t e p a r t i c i p a t i o n of t h e AV node, t e r m i n a t i o n of t h e t a c h y c a r d i a w i t h a d e n o s i n e had a s e n s i t i v i t y of 70%, a specificity of 92%, and a positive predictive value of 85%. T h e authors concluded that adenosine triphosphate is useful for diagnosis and p r i m a r y therapy of wide QRS complex s u p r a v e n t r i c u l a r t a c h y c a r d i a and is safer t h a n verapamil in settings in w h i c h misdiagnosis m a y occur.
Annals of Emergency Medicine
Jeff Burgess, MD
19:10 October 1990
safe and feasible to start t h r o m b o l y t i c s in the prehospital setting. However, no significant bencfit to this procedure was d e m o n s t r a t e d in this study.
Jeff Schafer, MD
myocardial infarction, prehospital
T h e p r e h o s p i t a l p h a s e of a c u t e m y o c a r d i a l i n f a r c t i o n in t h e e r a of t h r o m b o l y s i s Schmidt SB, Borsch MA Am J Cardiol 65:1411-1415 Jun 1990
setting or early in the emergency department visit enhances the effectiveness of thrombolytic therapy, especially when given less than four hours from onset of symptoms.] Lynn Keating, MD
adenosine triphosphate
T h r o m b o l y t i c t h e r a p y for acute m y o c a r d i a l i n f a r c t i o n (AMI) decreases m o r t a l i t y if t r e a t m e n t is begun w i t h i n six hours of s y m p t o m onset. Unfortunately, m a n y p a t i e n t s do n o t seek m e d i c a l care u n t i l after six hours. In order to identify those groups of patients m o s t likely to delay, a questionnaire was a d m i n i s t e r e d to 126 patients a d m i t t e d w i t h a confirmed out-of-hospital AMI. The questionnaire included questions designed to elicit information on various t i m e intervals, p s y c h o l o g i c a l factors, and feelings about control of personal health. T i m e intervals were defined as follows: precall t i m e was the i n t e r v a l b e t w e e n s y m p t o m onset and calling for transportation to the h o s p b tal; n o t i f i c a t i o n t i m e e x t e n d e d from s y m p t o m o n s e t to discussion of the p r o b l e m w i t h another person; dccision t i m e was that interval between notification and the decision to seek m e d i c a l care; delay t i m e was the t i m e between the decision to seek medical care and calling for transportation; wait t i m e was the period spent w a i t i n g for a r r i v a l of t r a n s p o r t a t i o n ; and t r a n s p o r t a t i o n t i m e was t i m e between leaving for and arrival at the hospital. Prehospital t i m e was the total period from s y m p t o m onset to hospital arrival. Psychological factors included questions on denial, suppression, and depression. One h u n d r e d patients (79%) were in the early arrival group (less t h a n six hours), and 26 (21%) were in the late arrival group (more than six hours). Significantly longer notification and decision times were found in the late arrival group, accounting for m o s t of the longer prehospital time. Those m o s t likely to delay were women, lower i n c o m e patients, older patients, and those w i t h a history of hypertension. Low i n t e n s i t y of i n i t i a l s y m p t o m s was found to be of borderline significance. Patients in the late group were more l i k e l y to h a v e called t h e i r p h y s i c i a n , and several were seen in their physician's office before going to the hospital. T h e r e was no significant difference in o u t c o m e between the two groups except for the greater use of throm-
180/1196
bolytic therapy. Identification of those groups at greatest risk for delay can help direct public education efforts. In this study, those groups included women, those w i t h slow s y m p t o m progression, l o w - i n c o m e p a t i e n t s , and e l d e r l y patients. /Editor's note: Rapid therapy in the prehospital
Intravenous adenosine triphosphate during w i d e Q R S c o m p l e x t a c h y c a r d i a : Safety, t h e r a p e u t i c e f f i c a c y , a n d d i a g n o s t i c utility Sharma AD, Klein GJ, Yee R Am J Med 88:337 343 Apr 1990
The authors studied a consecutive series of 34 patients w i t h sustained wide QRS complex tachycardia (duration of more than 120 ms) i n d u c e d during electrophysiologic testing. Adenosine was a d m i n i s t e r e d as a 20-mg peripheral IV bolus followed by rapid 10-mL flush of n o r m a l saline. In 14 patients w i t h ventricular tachycardia (VT), one was converted, and no significant change in cycle length was observed in the other 13. In ten patients w i t h atrial a r r h y t h m i a s , o n l y one was converted, and in the o t h c r n i n e t h e R-R i n t e r v a l was t r a n s i e n t l y s h o r t e n e d . In a group of ten patients w i t h re-entrant tachycardias involving the a t r i o v e n t r i c u l a r (AV) node, seven p a t i e n t s converted, with failure in two - one w i t h o r t h o d r o m i c AV reciprocating tachycardia associated w i t h a bundle branch block and one w i t h a second hidden AV accessory pathway. N o statistically significant change in blood pressure was observed, a l t h o u g h t h o s e p a t i e n t s w h o c o n v e r t e d were not included in the analysis. Three patients in VT and w i t h an initial systolic blood pressure of 80 to 90 m m Hg dropped their systolic blood pressure to 70 to 80 m m Hg for less than one m i n u t e . As a diagnostic test to indic a t e p a r t i c i p a t i o n of t h e AV node, t e r m i n a t i o n of t h e t a c h y c a r d i a w i t h a d e n o s i n e had a s e n s i t i v i t y of 70%, a specificity of 92%, and a positive predictive value of 85%. T h e authors concluded that adenosine triphosphate is useful for diagnosis and p r i m a r y therapy of wide QRS complex s u p r a v e n t r i c u l a r t a c h y c a r d i a and is safer t h a n verapamil in settings in w h i c h misdiagnosis m a y occur.
Annals of Emergency Medicine
Jeff Burgess, MD
19:10 October 1990