SMART pass will prevent inappropriate operation of S-ICD.BACKGROUND
 Newer algorithms have recently become available to reduce T-wave oversensing, such as SMART pass (SP). 
SMART pass
SMART pass will prevent inappropriate operation of S-ICD.BACKGROUND
 Compared to screening ECG before implantation of a subcutaneous implantable cardioverter-defibrillator (S-ICD), selectable vectors without T-wave oversensing increase after S-ICD implantation.  With this function, more selectable vectors are identified after S-ICD implantation.  We aimed to clarify S-ICD eligibility before and after S-ICD implantation with and without SP.


 Participants comprised 34 patients implanted with an S-ICD at Okayama University Hospital and its affiliated hospitals between February 2016 and August 2017.  A total of 102 S-ICD vectors were assessed for eligibility before and after S-ICD implantation, at rest and during exercise testing.  Vector availability was evaluated in the presence and absence of SP after S-ICD implantation.


 Subcutaneous implantable cardioverter-defibrillator eligibility was significantly better after implantation even without SP than S-ICD screening before S-ICD implantation, both at rest (before 65.7% vs after 95.1%, P < 0.01) and during exercise (before 59.3% vs after 90.6%, P < 0.01).  SP improved S-ICD eligibility during exercise (SP on 97.9% vs off 90.6%, P = 0.03).  Multivariate analysis showed the prevalence of S-ICD eligibility increased significantly after S-ICD implantation compared to screening before implantation.  Available vectors increased significantly after S-ICD implantation compared to preoperative vectors as assessed by S-ICD screening ECG.  T-wave oversensing during exercise has been an unresolved issue for S-ICD, but SP will help prevent inappropriate operation with S-ICD.
S-ICD
SMART pass will prevent inappropriate operation of S-ICD.BACKGROUND
 Compared to screening ECG before implantation of a subcutaneous implantable cardioverter-defibrillator (S-ICD), selectable vectors without T-wave oversensing increase after S-ICD implantation.  Newer algorithms have recently become available to reduce T-wave oversensing, such as SMART pass (SP).  With this function, more selectable vectors are identified after S-ICD implantation.  We aimed to clarify S-ICD eligibility before and after S-ICD implantation with and without SP.


 Participants comprised 34 patients implanted with an S-ICD at Okayama University Hospital and its affiliated hospitals between February 2016 and August 2017.  A total of 102 S-ICD vectors were assessed for eligibility before and after S-ICD implantation, at rest and during exercise testing.  Vector availability was evaluated in the presence and absence of SP after S-ICD implantation.


 Subcutaneous implantable cardioverter-defibrillator eligibility was significantly better after implantation even without SP than S-ICD screening before S-ICD implantation, both at rest (before 65.7% vs after 95.1%, P < 0.01) and during exercise (before 59.3% vs after 90.6%, P < 0.01).  SP improved S-ICD eligibility during exercise (SP on 97.9% vs off 90.6%, P = 0.03).  Multivariate analysis showed the prevalence of S-ICD eligibility increased significantly after S-ICD implantation compared to screening before implantation.  SP further increased selectable vectors in multivariate analysis.


 CONCLUSION
 Available vectors increased significantly after S-ICD implantation compared to preoperative vectors as assessed by S-ICD screening ECG.  T-wave oversensing during exercise has been an unresolved issue for S-ICD, but SP will help prevent inappropriate operation with S-ICD.
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