ABSTRACT
The authors investigated the effect of adenosine or ATP on narrow QRS tachycardia in 56 pts, 3 pts with wide QRS tachycardia 9 pts with suspected latent preexcitation and 10 pts with PVC suspected to be ventricular parasystole. After the bolus iv. administration of adenosine or ATP every SVT was stopped related to AV node (44 pts), but in the rest twelve related to atrial origin of SVT only one automatic atrial tachycardia could be stopped. From the 9 patient suspected to have concealed WPW 2 pts had delta wave during the effect of adenosine, and in four pts parasystole was demonstrated among the pts had varying coupling interval PVC. None of the pts who had wide QRS tachycardia was the tachycardia stopped, but in two cases the supraventricular origin--atrial flutter and tachycardia--was discovered. The authors emphasize the favourable effect of adenosine in narrow complex tachycardia and suggest that it can given safely in wide QRS tachycardia of unknown origin either. The diagnostic effect of adenosine can be used in sinus rhythm too if latent preexcitation or ventricular parasystole is suspected.
Subject(s)
Adenosine Triphosphate/therapeutic use , Arrhythmia, Sinus/drug therapy , Arrhythmias, Cardiac/drug therapy , Tachycardia, Sinoatrial Nodal Reentry/drug therapy , Tachycardia/drug therapy , Adolescent , Adult , Aged , Arrhythmia, Sinus/diagnosis , Arrhythmias, Cardiac/diagnosis , Electrocardiography , Female , Humans , Male , Middle Aged , Parasystole/diagnosis , Parasystole/drug therapy , Tachycardia/classification , Tachycardia/diagnosis , Tachycardia, Sinoatrial Nodal Reentry/diagnosisABSTRACT
The cases of two patients with ventricular parasystole revealed a new depressive effect of adenosine on ventricular parasystolic activity. To the authors' knowledge, this is the first report that clearly demonstrates the disappearance of "true" parasystole.
Subject(s)
Adenosine/therapeutic use , Anti-Arrhythmia Agents/therapeutic use , Heart Ventricles/drug effects , Parasystole/drug therapy , Adolescent , Adult , Electrocardiography , Female , Heart Ventricles/physiopathology , Humans , Male , Parasystole/physiopathologyABSTRACT
An arrhythmogenic mechanism has been investigated pharmacologically by acute drug tests (ADT) and alternate block of slow calcium channels and fast sodium channels of the cellular membranes. ADT with verapamil reduced extrasystoles by 60% in 44% of patients demonstrating the predominance of calcium-dependent arrhythmogenesis. An antiarrhythmic efficacy of fast sodium channels blockers was ascertained in 33% of the patients. ADT with rhythmilen and verapamil produced a satisfactory antiarrhythmic effect in 18% of the examinees. These patients seem to have parallel activation of both fast sodium and slow calcium channels. They received courses of both drugs. It is stated that a pharmacological analysis of extrasystolic arrhythmia allows inference on pathogenesis of myocytic electrolyte disturbances which serves the basis for adequate corrective therapy.
