The Relationship Between Sinoatrial Conduction Time and Sinus Cycle Length Revisited |
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Authors: | JAMES A. REIFFEL M.D. J. THOMAS BIGGER JR. M.D. |
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Affiliation: | From the Department of Medicine, Columbia University and the Presbyterian Hospital, New York City, New York. |
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Abstract: | In 1974 we reported an inverse relationship between sinoatrial conduction time (SACT) and sinus cycle length (SCL) during sinus arrhythmia utilizing the indirect atrial premature stimulation technique for estimating SACT, However, this behavior seemed anomalous try analogy with the AV node. Subsequent to 1974, methodological considerations about and limitations of the indirect techniques for estimating SACT became apparent, making us question our former impression. When the capability to directly record sinus node electrograms was developed and established in the 1980s, we had the means to reevaluate the SACT/SCL relationship. This report presents our findings in 40 patients: the SACT/SCL relationship is direct, not inverse. Moreover, we also show that during the phasic fluctuations of sinus arrhythmia, the P-P alterations are initiated more frequently by changes in sinoatrial conduction time than by changes in sinus cycle length. |
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Keywords: | Sinus Node Sinus Arrhythmia Cardiac Conduction |
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