Why the study?
Does coronary artery bypass grafting affect stroke volume variability in response to orthostatic maneuver in patients with coronary artery disease?
Does coronary artery bypass grafting affect stroke volume variability in response to orthostatic maneuver in patients with coronary artery disease?
CABG significantly alters the cardiovascular response to postural stress, as evidenced by decreased stroke volume variability spectral indices in the standing position 6 weeks post-surgery.
Post-CABG decline in standing stroke volume spectral power may indicate altered orthostatic response; hypothesis-generating and should not yet change practice.
The dynamics of cardiovascular responses to postural stress have not been fully recognized. To determine whether coronary artery bypass grafting (CABG) has any effect on stroke volume variability (SVV), the power spectrum components of SVV were measured in 60 patients before and at 6 weeks after CABG. Stroke volume was assessed by means of the thoracic bioimpedance method. The thoracic impedance cardiogram and ECG were recorded in the supine and standing positions with controlled breathing rate (0.25 Hz) during 10-minute periods. The analysis of SVV was done by means of the autoregressive method. The total power, the power in the low-frequency band LFSV (0.05-0.15 Hz), the power in the high-frequency band HFSV (0.15-0.5 Hz), and the LFSV/HFSV ratio were analyzed. Before CABG, we did not notice any significant changes in the stroke volume spectral power indices. After CABG, all spectral indices were significantly decreased in the standing position.
No takes yet. Share an insight, caveat, or question.
Siebert et al. (1999) studied this question.
Synapse has enriched 5 closely related papers on similar clinical questions. Consider them for comparative context: