<HTML><BODY style="word-wrap: break-word; -khtml-nbsp-mode: space; -khtml-line-break: after-white-space; "><DIV><DIV><DIV class="MsoNormal"><FONT class="Apple-style-span" face="Arial">Dr. Ariel Szyszko from Argentina asks</FONT></DIV><DIV class="MsoNormal"><FONT class="Apple-style-span" face="Arial"><BR class="khtml-block-placeholder"></FONT></DIV><DIV class="MsoNormal"><FONT class="Apple-style-span" face="Arial">- Is it necessary to conduct a defibrillation threshold test as a routine in cardioverter defibrillator implants, or are there patients in whom the test's risk/benefit would not be justified?</FONT></DIV></DIV><DIV><P class="MsoNormal"><FONT class="Apple-style-span" face="Arial">Dr. Alfred Buxton from U.S.A. answers</FONT></P><P class="MsoNormal"><FONT class="Apple-style-span" face="Arial">- The risk of performing defibrillation threshold testing is extremely low, and we perform it routinely. We defer performing the test in patients in atrial fibrillation who have not been adequately anticoagulated. One situation in which we do consider deferring the test is in patients with nonischemic dilated cardiomyopathy in whom we have questions about their hemodynamic stability, but in general ICD implants should not be performed in unstable individuals. We repeat the defibrillation test yearly in patients whose threshold at previous tests was >20 joules. We also repast the defibrillation test in patients whose receiving new antiarrhythmic medication such as amiodarone, that can elevate the DFT.</FONT></P><DIV class="MsoNormal"><FONT class="Apple-style-span" face="Arial">Alfred E. Buxton, M.D.</FONT></DIV><DIV class="MsoNormal"><FONT class="Apple-style-span" face="Arial">Ruth and Paul Levinger Professor of Medicine</FONT></DIV><DIV class="MsoNormal"><FONT class="Apple-style-span" face="Arial">Director, Division of Cardiology</FONT></DIV><DIV class="MsoNormal"><FONT class="Apple-style-span" face="Arial">Director, Arrhythmia Services and Electrophysiology Laboratory</FONT></DIV><DIV class="MsoNormal"><FONT class="Apple-style-span" face="Arial">Brown Medical School</FONT></DIV><DIV class="MsoNormal"><FONT class="Apple-style-span" face="Arial">Cardiology Division</FONT></DIV><DIV class="MsoNormal"><FONT class="Apple-style-span" face="Arial">2 Dudley Street, Suite 360</FONT></DIV><DIV class="MsoNormal"><FONT class="Apple-style-span" face="Arial">Providence, RI 02905</FONT></DIV><DIV class="MsoNormal"><FONT class="Apple-style-span" face="Arial"><A href="mailto:Alfred_Buxton@Brown.edu">Alfred_Buxton@Brown.edu</A></FONT></DIV></DIV></DIV><FONT class="Apple-style-span" face="Arial"><BR></FONT><DIV><DIV><FONT class="Apple-style-span" face="Arial">--</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">Dr. Sergio Dubner</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">President of Scientific Committee</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"><BR></FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">Dr. Edgardo Schapachnik</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial">President of Steering Committee</FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"><BR class="khtml-block-placeholder"></FONT></DIV><DIV><FONT class="Apple-style-span" face="Arial"><BR class="khtml-block-placeholder"></FONT></DIV><FONT class="Apple-style-span" face="Arial"><BR class="Apple-interchange-newline"></FONT></DIV><FONT class="Apple-style-span" face="Arial" size="3"><SPAN class="Apple-style-span" style="font-size: 13px;"><BR></SPAN></FONT></BODY></HTML>