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document
The " SPEM " ( Studio Policentrico Elettrocateteri Membrane ) : a multicenter study on membrane leads . SPEM is a multicenter randomized double-blind study performed to test the acute and chronic electrophysiological behavior of three different ventricular leads : ( 1 ) an ion exchange membrane with 30-microgram dexamethasone elution in a contoured activated carbon tip lead ( Membrane 1400T , 30 patients ) ; ( 2 ) the same lead design without steroid ( Membrane 1401T , 24 patients ) ; and ( 3 ) the same lead design without steroid or membrane ( control group , 27 patients ) . Twenty-three of the 81 patients were women ; the mean age for all patients was 74 +/- 10 years . Parameters are calculated both in uni- and bipolar configuration at implant and at follow-up after 1 , 5 , 15 , 30 , 90 , 180 , and 360 days . Implant threshold ( chronaxie = 0.413 +/- 0.280 ms , rheobase = 0.264 +/- 0.099 V ) , signal amplitude ( 13.45 +/- 5.87 mV ) , and slew rate ( 2.05 +/- 1.38 V/s ) reveal no significant differences . Pacing impedance values both at implant ( unipolar 571 +/- 165 omega ; bipolar 605 +/- 123 omega ) and at follow-ups ( unipolar 480 +/- 72 omega ; bipolar 518 +/- 75 omega ) are slightly lower in the unipolar configuration . At 15 and 30-day follow-ups , control group and nonsteroid leads show a higher threshold value growth ( in unipolar from 0.16 +/- 0.11 to 1.19 +/- 0.85 microJ ; in bipolar from 0.18 +/- 0.13 to 1.24 +/- 0.88 microJ ) than the membrane steroid leads ( in unipolar from 0.13 +/- 0.11 to 0.70 +/- 0.39 microJ ; in bipolar from 0.23 +/- 0.32 to 0.76 +/- 0.36 microJ ) ; the threshold of nonsteroid leads decreases after 1-3 months and it settles at the same threshold level of the leads with membrane and steroid ( in unipolar 0.60 +/- 0.33 microJ ; in bipolar 0.55 +/- 0.26 microJ ) , which has been stable since the first month . The ion exchange membrane is effective in reducing the chronic pacing threshold like acute steroid elution at low doses , but membrane alone does not prevent an acute pacing threshold increase through the first month postimplant .
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Intervention_Physical
an ion exchange membrane with 30-microgram dexamethasone elution in a contoured activated carbon tip lead
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Intervention_Physical
same lead design without steroid
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Intervention_Physical
same lead design without steroid or membrane
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Intervention_Physical
ion exchange membrane
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Outcome_Physical
acute and chronic electrophysiological behavior
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Outcome_Other
Pacing impedance values
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Outcome_Other
threshold
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Outcome_Physical
threshold
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Outcome_Physical
threshold
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Outcome_Physical
chronic pacing threshold
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Outcome_Physical
acute pacing threshold
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Participant_Condition
membrane leads
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Participant_Condition
ventricular leads
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Participant_Sample-size
Twenty-three
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Participant_Sample-size
81
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Participant_Sex
women
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Participant_Age
74 +/- 10 years