| abstract |
Using only ventricular and atrial rate criteria, there is ambiguity in the case of atrial tachycardia (AT) with anterograde conduction versus ventricular tachycardia (VT), with retrograde conduction. The introduction of dual chamber sensing in anti-tachycardia devices allows for computationally inexpensive measurements of VA intervals. The present invention addresses problems arising in tachycardia with confounding 1:1 relationships. According to the present invention, using atrial and ventricular rates only, all 1:1 tachycardia would be classified as VT, resulting in false shocks. Specificity of ambiguous 1:1 tachycardia can be potentially increased using VA interval measurements (82), at the cost of minimum loss in sensitivity for VT detection. The applied algorithm imposes little in additional computation for dual chamber sensing ICDs and greatly reduces the possibility of false shocks in 1:1 atrial tachycardia. |