**Author details**

Munir Zaqqa\*

*Author Year N* **Comment**

*Marchlinski et al* [54] 1988 33 Patients with low DFT (n=19) had 100% success rate of clinical

threshold group *Pires et al* [22] 2006 835 Long term survival was lower in the no DFT testing group (n=203) in

*Hall et al* [55] 2007 112 Higher mortality seen in patients who did not have DFT testing

*Epstein et al* [26] 1992 1946 There was improved mortality among patients with high DFT who

*Russo et al* [30] 2005 1139 No difference in mortality among patients with high DFT who had

*Blatt et al* [56] 2008 717 No difference in mortality between lower (< or =10 J) (n=547) versus higher (n=170) DFT groups *Bianchi et al* [57] 2009 291 No difference in mortality between Italian centers that perform DFT

testing (n=154) *Michowitz et al* [58] 2011 256 No difference in mortality between CRT-D patient who had DFT

*Codner et al* [59] 2012 213 No difference in mortality between DFT testing (n=80) and no DFT testing (n=133) groups *Brignole et al* [60] 2012 2120 Prospective but non randomized evaluation of DFT testing (n=836)

The approach to DFT testing has changed since ICD's were first introduced. It has changed from being an essential part performed in all the patients to being done in less than one third of the patients at current time. The need for DFT testing is a balance between benefit and risk with studies showing conflicting results. Most recent studies show equal benefit risk ratio for DFT testing. A prospective randomized study is needed to resolve the issue and there is currently one being performed. When this study is finished it should give a

arrhythmia termination as compared to 73% (n=14) in the high

because of contraindication (n=55) as compared to a random sample

received ICD (n=71) versus those who did not receive ICD (n=16)

intervention (n=34) versus who did not have intervention (n=37)

testing routinely (n=137) versus centers that do not perform DFT

versus no DFT testing (n=1284) showed no difference in mortality

testing (n=204) versus who did not have DFT testing (n=52)

comparison to DFT and safety margin testing (n=632)

who had DFT testing performed (n=57)

Favor DFT testing

128 Cardiac Defibrillation

Against DFT testing

**Table 5.** Studies favoring and against DFT testing.

more clear answer regarding this issue.

**6. Conclusion**

Address all correspondence to: munirzaqqa@yahoo.com

Jordan University Hospital, Jordan
