Proceedings of The Physiological Society

Europhysiology 2018 (London, UK) (2018) Proc Physiol Soc 41, PCB017

Poster Communications

Non-invasive evaluation of the systolic left ventricular load

N. Y. Belova1, R. D. Mileva-Popova1, N. A. Stoynev1

1. Physiology, Medical University of Sofia, Sofia, Bulgaria.

  • Time tension index (TTI) and augmentation index corrected for heart rate 75 bpm (AIx75) differ significantly between the two age groups.

  • Table 1<\#13>

    # p < 0.01 vs. 20yo, Mann-Whitney test

Impaired vascular-ventricular coupling might be an additional underlying factor for the development of imbalance between myocardial oxygen supply and oxygen demands (1, 2). The objective of our study was to assess non-invasively left ventricular load and its dependency on central arterial hemodynamics. Sixty-five healthy and gender-matched individuals were divided in two groups according to their age: 20y/o and 50y/o. Applanation tonometry was performed using the Sphygmocor device (AtCor Medical). Central pressures and the major indices of pulse wave analysis were computed using Sphygmocor software. Data are presented as means ± SEM. The general characteristics and the relevant central hemodynamic parameters of the studied subjects are presented in Table 1. Central systolic and pulse pressures as well as the augmentation index (AIx75), standardized for heart rate 75 beats per minute (bpm), were significantly higher in the 50y/o group as compared to the young individuals. All these parameters are relevant markers of arterial stiffness (3, 4) and evidenced the development of morphological and functional alterations of the central arterial wall in the middle aged group. The time-tension index (TTI) computed from the systolic pressure area under the pulse waveform is presumed to represent the left ventricular load and myocardial oxygen demand. TTI was significantly higher in the 50y/o subjects as compared to the 20y/o group (Fig. 1). Moreover, we have shown the presence of significant correlation between TTI and AIx75 (p<0.01) in both age groups. This finding confirmed the impact of arterial stiffness on the development of impaired vascular-ventricular coupling. In addition, negative correlation was shown between AIx75 and the subendocardial viability ratio (SEVR), a parameter associated with pressure and time for coronary perfusion. In conclusion, applanation tonometry might be utilized for non-invasive evaluation of the left ventricular load, which is an important parameter of cardiovascular risk.

Where applicable, experiments conform with Society ethical requirements