92649
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Atrioventricular conduction during long-term follow-up of patients with sick sinus syndrome . BACKGROUND It has been claimed that patients with sick sinus syndrome have an increased risk of developing AV block , but this has never been assessed prospectively . The aim of the present study was to evaluate in a prospective trial AV conduction during the long-term follow-up of patients with sick sinus syndrome . METHODS Two hundred twenty-five consecutive patients with sick sinus syndrome and intact AV conduction were randomized to undergo single-chamber atrial pacing ( 110 patients ) or single-chamber ventricular pacing ( 115 patients ) . Follow-up after 3 months and then yearly included measurement of the PQ interval and , in patients with atrial pacemakers , determination of the atrial stimulus-Q intervals at pacing rates of 100 and 120 bpm . The occurrence of AV block in the atrial group was recorded . During follow-up ( mean , 5.5+/-2.4 years ) , there was no change in PQ interval in either group and no change in atrial stimulus-Q intervals or Wenckebach block point in the atrial group . Four of 110 patients in the atrial group developed grade 2 to 3 AV block that required upgrading of the pacemaker ( 0.6 % per year ) . Two of these 4 patients had right bundle-branch block at pacemaker implantation . CONCLUSIONS AV conduction , estimated as PQ interval and atrial stimulus-Q interval at atrial pacing rates of 100 and 120 bpm and the Wenckebach block point , remains stable during long-term follow-up . Thus , treatment with single-chamber atrial pacing is safe and can be recommended to patients with sick sinus syndrome without bundle-branch block .
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Intervention_Surgical
single-chamber atrial pacing
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Intervention_Surgical
single-chamber ventricular pacing
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Intervention_Surgical
single-chamber atrial pacing
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Outcome_Physical
risk of developing AV block
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Outcome_Physical
PQ interval
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Outcome_Physical
atrial stimulus-Q intervals at pacing rates of 100 and 120 bpm
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Outcome_Physical
occurrence of AV block
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Outcome_Physical
PQ interval
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Outcome_Physical
atrial stimulus-Q intervals
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Outcome_Physical
Wenckebach block point
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Outcome_Physical
grade 2 to 3 AV block
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Outcome_Physical
right bundle-branch block
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Outcome_Physical
PQ interval
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Outcome_Physical
atrial stimulus-Q interval
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Outcome_Other
safe
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Participant_Condition
sick sinus syndrome
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Participant_Condition
sick sinus syndrome
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Participant_Condition
sick sinus syndrome
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Participant_Sample-size
Two hundred twenty-five
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Participant_Condition
sick sinus syndrome
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Participant_Condition
sick sinus syndrome