Systolic Time Intervals at Rest and during Exercise

Cardús, D; Vera, Lauro B. De

doi:10.1159/000169672

Cited by 12 publications

(4 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…In several papers (5,9,35) large sample investigations have been published. However, the shape of the respective scatter diagrams between HR and STI is non-linear.…”

mentioning

confidence: 99%

Systolic time intervals—correction for heart rate

Wolf

Belz²,

Stauch

1978

Basic Res Cardiol

View full text Add to dashboard Cite

Shortening or prolongation of the systolic time intervals (STI) are frequently used as non-invasive measure of drug influence upon the left ventricular function of the heart. STI, however, are shortened by increasing heart rate (HR) alone.Because of the dependence on HR, STI may be changed though treatment did not influence the course of contraction.In this study dependence of STI on HR and the corrections of STI for HR have been reevaluated. The analysis of data gained from 82 subjects under strictly standardized conditions has shown:

show abstract

“…In several papers (5,9,35) large sample investigations have been published. However, the shape of the respective scatter diagrams between HR and STI is non-linear.…”

mentioning

confidence: 99%

Systolic time intervals—correction for heart rate

Wolf

Belz²,

Stauch

1978

Basic Res Cardiol

View full text Add to dashboard Cite

show abstract

“…Our results show that two thirds of the prolongation of PEP could be attributed to the QMVC component. Sim ilar results have been obtained using the Q-Si interval as a measure for the preisovolumic period [5]. Therefore, the effect of the upright position on the PEP would seem to predominate before mitral valve closure.…”

Section: Discussionmentioning

confidence: 99%

“…Furthermore, heart rate and peripheral resistance in crease due to baroceptor influence [3]. Therefore, in challenges which combine both positions, such as rest/exercise investigations, these factors must be taken into account.It has been shown that the upright position leads to changes in systolic time intervals [4][5][6]. These intervals are increasingly being complemented by diastolic time intervals, in particular the isovolumic relaxation time (IVR), in order to describe diastolic function [7][8][9].…”

mentioning

confidence: 99%

Effects of Posture on Cardiac Time Intervals

Leeuwen¹,

Kuemmell²

1991

Am J Noninvas Cardiol

View full text Add to dashboard Cite

The effect of posture on the duration of systolic and diastolic time intervals and their dependency on cycle length (R-R interval) was investigated in 20 healthy subjects using simultaneous electrocardiograms, phonocardiograms, carotid pulse tracings, and M mode echocardiograms. The dependency of left ventricular ejection time and left ventricular filling time on the R-R interval did not change between the sitting and the supine position. Preejection period, preisovolumic interval, isovolumic contraction time, and isovolumic relaxation time displayed either weak or no dependency. Preejection period, its component intervals preisovolumic interval and isovolumic contraction time, as well as isovolumic relaxation time were prolonged in the sitting position, whereas the corrected left ventricular ejection time was shortened, and the corrected left ventricular filling time showed no significant change. These changes in the duration of the intervals can be understood as a depression of cardiac function in the sitting position due to the pooling of blood in the lower extremities: reduced filling leads to a diminished contractile and relaxation response on the basis of reduced fiber length.

show abstract

“…In recent reviews, good correlations (mean r = 0.81‐0.88) of ICG‐derived measurements of left ventricular stroke volume (SV) and cardiac output (CO) in comparison to invasive standard techniques have been reported. 1‐3 Besides the evaluation of systolic time intervals in the early 1970s for noninvasive characterization of left ventricular systolic function 4‐7 and the evaluation of the Capan formula 8 and Judy formula 9 for calculation of the EF, the diagnostic value of other impedance‐derived parameters of systolic function derived from the ICG curves like the index of contractility (IC), acceleration index (ACI), and peak flow index (PFI) has not been extensively studied. Furthermore, no studies exist in which the clinical value of these parameters has been determined during cardiovascular stress testing.…”

Section: Introductionmentioning

confidence: 99%

Evaluation of Systolic Performance by Automated Impedance Cardiography

Scherhag¹,

Stastny²,

Pfleger

et al. 1999

Annals of the New York Academy of Sciences

View full text Add to dashboard Cite

Impedance cardiography (ICG) is a noninvasive method for evaluating cardiac function. Left ventricular stroke volume (SV) is the basic hemodynamic parameter derived from thoracic bioimpedance curves. Issues of our study were to investigate the diagnostic value of other indices of left ventricular systolic performance, such as ejection fraction (EF), index of contractility (IC), peak flow index (PFI), and acceleration index (ACI), which can also be calculated by ICG. Forty patients (PTS) with suspected coronary artery disease (CAD) were monitored by automated ICG during pharmacologic stress testing with dobutamine. All PTS underwent subsequent cardiac catheterization. In PTS with single vessel disease, the dobutamine-induced changes of SV, EF, IC, PFI, and ACI were comparable to those of PTS without CAD. In PTS with multivessel disease, the impaired systolic performance during dobutamine stimulation could be clearly demonstrated. We conclude that automated ICG is a useful method for monitoring SV and other indices of left ventricular systolic performance for detecting PTS with ischemic left ventricular dysfunction during cardiovascular stress.

show abstract

Systolic Time Intervals at Rest and during Exercise

Cited by 12 publications

References 23 publications

Systolic time intervals—correction for heart rate

Systolic time intervals—correction for heart rate

Effects of Posture on Cardiac Time Intervals

Evaluation of Systolic Performance by Automated Impedance Cardiography

Contact Info

Product

Resources

About