ABSTRACT
BACKGROUND: Sustained, stable wide QRS-complex tachycardia (WCT) remains a diagnostic challenge, because the treatment of supra-ventricular tachycardia (SVT) with aberrant conduction differs considerably from that of a ventricular tachycardia (VT). A usual recommendation for treating a case of a stable WCT is to manage it as if it were VT, in accordance with the consideration of "first do no harm". The aim of this study was to determine whether Board-certified emergency-physicians are able to differentiate VT from SVT with aberrant conduction in a high percentage of cases (> 90%), thus to assure more precise prehospital treatment." METHODS: Eight electrocardiograms with WCT (four with electrophysiologically proven VT or SVT, respectively) were evaluated in a blinded fashion by 64 Board-certified emergency-physicians (23 female, 41 male, mean age: 37,8 + 5,1 years). Initially, the diagnosis had to be made without any further information. Afterwards the same electrocardiograms were presented again, providing important additional information. RESULTS: 55% of the study population were able to establish the correct diagnosis merely by evaluating the electrocardiogram. Providing the above mentioned additional information, the number of correct diagnoses increased to 61%. These results were roughly similar in all subgroups, only the subgroup of cardiologists showed a trend to better results with correct diagnoses in 68% without and 73 % with additional information. None of the subgroups reached the pre-specified cut-off of > or = 90% correct diagnoses. Specialist status as well as experience in emergency medicine had no significant influence on the results, only the subgroup of emergency physicians with an experience of more than five years showed a trend towards a higher rate of correct diagnosis, compared with the subgroup with less than one year experience in emergency medicine. CONCLUSION: In cases of stable WCT the evaluation of the electrocardiogram without further information in prehospital emergency-medicine leads to unsatisfactory results. The correct diagnosis in WCT can be improved by using additional data but the diagnostic accuracy is still low. Therefore, the differential diagnosis of stable WCT in preclinical emergency-medicine cannot be recommended. Until proven otherwise, any stable WCT should be managed as if it were VT.
