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Causality between the amplitude and frequency of cardiac oscillations

Research output: Contribution to journalJournal article

Published

Journal publication date06/2004
JournalCardiovascular Engineering
Journal number2
Volume4
Number of pages6
Pages127-132
Original languageEnglish

Abstract

Using an information-theoretic approach, causality between the systolic amplitude in blood pressure and the frequency of the heart beat was analyzed. Blood pressure and ECG were noninvasively recorded in young, healthy subjects. Three successive measurements were performed: during spontaneous breathing and during paced respiration—at frequencies both higher and lower than that of spontaneous respiration. We demonstrate that the amplitude and frequency of the cardiac rhythm are synchronized for most of the time. The synchronization is stronger during paced respiration at a frequency lower than that of spontaneous breathing. Episodes where the cardiac frequency was driven by the systolic pressure were also detected during slow, paced respiration.