We have over 12,000 students, from over 100 countries, within one of the safest campuses in the UK


97% of Lancaster students go into work or further study within six months of graduating

Home > Research > Publications & Outputs > Causality between the amplitude and frequency o...
View graph of relations

« Back

Causality between the amplitude and frequency of cardiac oscillations

Research output: Contribution to journalJournal article


<mark>Journal publication date</mark>06/2004
<mark>Journal</mark>Cardiovascular Engineering
Number of pages6
<mark>Original language</mark>English


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.