Redifining SVT entrainment criteria for differentiating AVNRT from

Redifining SVT entrainment criteria for differentiating AVNRT from AVRT R. Vadivelu 1, Eduardo Back Sternick 2, Raghav Bansal 3, Yash Lokhandwala 4 1 - Velammal Medical College and Hospital Madurai, India, 2 -Biocor Institute, Brazil , 3 -AIIMS, Delhi, India, 4 - Holy Family Hospital, Mumbai, India • Background: Entrainment during SVT is used to differentiate between different types of SVT. Aims and Method: In this study (n=306 patients) we evaluated the PPI-TCL, c. PPI-TCL and Delta VA (VA in tachycardia-VA during RV pacing) values to differentiate between AVNRT (both typical and atypical) and orthodromic AVRT (including PJRT) and compared our estimated cut off values with the reported literature values. Sensitivities, specificities and predictive values were obtained for the tests. Performances of the tests were assessed by the Receiver Operating Characteristic (ROC) curve and respective area under the curve (AUC). • Results: Totally patients were 306 (70% were typical AVNRT, 22% orthodromic AVRT, 4% atypical AVNRT and 3% PJRT). Table 1: Sensitivity, specificity, PPV and NPV of Table 2: AUC characteristics of various post-entrainment different cut-off points. parameters. Tachycardias Cut-off points Sensitivity Specificity PPV AVNRT AVRT NPV PPI-TCL ≥ 128. 5 78. 8% 74. 3% 82. 6% 69. 3% c. PPI-TCL ≥ 106. 5 88. 4% 87. 5% 91. 6% 82. 9% Delta VA ≥ 100. 5 85. 5% 84. 8% 89. 7% 79. 0% PPI-TCL < 126. 5 79. 8% 78. 4% 65. 2% 88. 5 c. PPI-TCL < 101 91. 4% 90. 8% 83. 4% 95. 4% Delta VA <93. 5 92. 6% 92. 1% 85. 6% 96. 1% Tachycardia Tests PPI-TCL AVNRT AVRT ( 0. 799 - 0. 900) c. PPI-TCL 0. 906 (0. 859 - 0. 952) Delta VA 0. 904 (0. 859 - 0. 950) PPI-TCL 0. 882 ( 0. 839 - 0. 926) c. PPI-TCL 0. 906 (0. 859 - 0. 952) 0. 904 Curves Comparisons PPI c. PPI Delta VA - NS NS - - <0. 05 - (0. 859 - 0. 950) <0. 05 NS - Figure 2. ROC curves of PPI-TCL, c. PPI-TCL, Delta VA tests for AVNRT (a) 95 % CI AUC 0. 850 Delta VA Figure 1. ROC curves of PPI-TCL, c. PPI-TCL, Delta VA tests AUC for AVRT (b) (a) (b) • Conclusions: Ø The significant estimated cut off point for PPI-TCL to discriminate AVNRT from AVRT was >128 ms (median sensitivity specificity was 76. 6%) as compared to literature reported cut off point of >115 ms (median sensitivity specificity was 77. 4%), p>0. 05. Similarly our estimated c. PPI-TCL for AVNRT was > 106 ms (median sensitivity specificity was 88%) as compared to literature reported cut off point of >110 ms (median sensitivity specificity was 87. 5%), p>0. 05. Ø Regarding Delta VA, our estimated value for AVNRT was > 100. 5 ms (median sensitivity specificity was 85. 2%) as compared to literature reported cut off point of >85 ms (median sensitivity specificity was 87. 8%), p>0. 05. Ø To simplify the applicability of our findings, newer values of 125 ms for PPI-TCL, 105 ms for c. PPI-TCL and 100 ms for delta VA are recommended. Ø Our study differs from several previously reported studies since it has included atypical AVNRT and PJRT patients also.