Cross-Talk between the Heart and Arteries in Older 65+ Adults

Tomasz H. Wierzba1, Stanislaw Zajaczkowski2, Robert A Olek3, Artur Polinski4
1Medical University of Gdansk, 2Department of Physiology, Medical University of Gdansk, 3Department of Bioenergetics and Nutrition, Gdansk University of Physical Education and Sport, Gdansk, 4Department of Biological Engineering, Faculty of Electronics Telecommunications and Informatics, Gdansk University of Technology, Gdansk


Abstract

Introduction: Regulatory interactions between heart and arterial tree is essential for optimal oxygen delivery to tissues at a possibly low energetic cost. Desynchronization between blood ejection from the left ventricle and pulse wave propagation in big arteries is likely to result in the left ventricle overload with an increased risk of fatal complications. Aim: We aimed to investigate functional coherence between heart rhythm and aortic wall compliance in senescent volunteers. Methods: 29 volunteers aged 65 -80 were recruited to the study. One lead ECG (AdInstruments, Australia) and pulse wave were simultaneously recorded for 5 min. Plethysmography sensors (MLT1020PPG, AdInstrument, Australia) were placed onto the left carotid artery and right iliac artery. ECG and pulse wave signals were digitized at 2 kHz. Peaks of R waves were identified. Following estimation of the individual carotid to femoral arterial distance (cfD) carotid-femoral pulsewave transit time (cfTT) was assessed using the intersecting tangent algorithm at time-point of the maximal upstroke of the second derivative of the filtered pulse signal. Pulse wave velocity (PWV), that is a major index of aortic compliance, was calculated by dividing cfTT by cfD. Time-series of 256 subsequent RRi were used for heart rate variability (HRV) analysis (Kubios Pro software, Finland). HRV and cfTT variability (CfTT) spectra were calculated using Fast Fourier Analysis. Magnitude square coherence between the both spectra was estimated with use of MATLAB software. Results and Conclusion: We found selected frequency spectra of high coherence (above 0.5) between HRV and cfTT in almost all volunteers. cfPWV ranged from 5.5 to 12,8 m/s. In volunteers exceeding the reference cfPWV range (10 m/s) the cardio-aortic coherence was significantly reduced comparing to those with cfPWV below 8 m/s. Our data indicate dysfunctional cross-talk between heart and big arteries of increased stiffness.