Dataset Information

When Sinus Tachycardia Becomes Too Much: Negative Effects of Excessive Upright Tachycardia on Cardiac Output in Vasovagal Syncope, Postural Tachycardia Syndrome, and Inappropriate Sinus Tachycardia.

ABSTRACT:

Background

Upright posture reduces venous return, stroke volume, and cardiac output (CO) while causing reflex sinus rate (heart rate [HR]) increase. Yet, in inappropriate sinus tachycardia (IST), postural tachycardia syndrome (POTS), and vasovagal syncope (VVS), symptomatic excessive HR occurs. We hypothesized that CO reaches maximum as function of HR in all.

Methods

We recruited 12 healthy controls, 9 IST, 30 VVS, and 30 POTS patients (13-23years) selected randomly by disorder not by HR, each fulfilled appropriate diagnostic criteria. Subjects were instrumented for electrocardiography, beat-to-beat blood pressure, respiratory rate, CO-Modelflow algorithm, and central blood volume from impedance cardiography; 10-minute data were collected supine; subjects were tilted head-up for ?10 minutes. We computed phase differences, ??, between fluctuations of HR (?HR) and CO (?CO) tabulating data when phases were synchronized, determined by a squared nonlinear phase synchronization index >0.5, describing extent/validity of CO/HR coupling. We graphed results supine, 1-minute post-tilt-up, mid-tilt, and pre-tilt-down using polar coordinates (HR-radius, ??-angle) plotting cos(??) versus HR to determine if transition HR exists at which in-phase shifts to antiphase above which CO decreases when HR further increases.

Results

At baseline HR, diastolic and mean arterial pressures in IST and POTS were higher versus controls. Upright HR increased most in POTS then IST and VVS, with diverse changes in CO, SVR, and central blood volume. Each patient grouping was separately and collectively analyzed for HR change showing transition from in-phase to anti-phase (??) as HR increased: HR_transition=115±6 (IST), 123±8 (POTS), 124±7 (VVS), P=ns. Controls never reached transitional HR.

Conclusions

Excessive HR independently and equivalently reduces upright CO, in IST, POTS, and VVS.

SUBMITTER: Stewart JM

PROVIDER: S-EPMC7068217 | biostudies-literature | 2020 Feb

REPOSITORIES: biostudies-literature

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Publications

When Sinus Tachycardia Becomes Too Much: Negative Effects of Excessive Upright Tachycardia on Cardiac Output in Vasovagal Syncope, Postural Tachycardia Syndrome, and Inappropriate Sinus Tachycardia.

Stewart Julian M JM Medow Marvin S MS Visintainer Paul P Sutton Richard R

Circulation. Arrhythmia and electrophysiology 20200115 2

<h4>Background</h4>Upright posture reduces venous return, stroke volume, and cardiac output (CO) while causing reflex sinus rate (heart rate [HR]) increase. Yet, in inappropriate sinus tachycardia (IST), postural tachycardia syndrome (POTS), and vasovagal syncope (VVS), symptomatic excessive HR occurs. We hypothesized that CO reaches maximum as function of HR in all.<h4>Methods</h4>We recruited 12 healthy controls, 9 IST, 30 VVS, and 30 POTS patients (13-23years) selected randomly by disorder no ...[more]

PMID: 31941353

Similar Datasets

Project description:ObjectivesTo explore the role of the Poincaré plot derived from a 24-hour Holter recording in distinguishing vasovagal syncope (VVS) from postural tachycardia syndrome (POTS) in pediatric patients.Materials and methodsPediatric patients with VVS or POTS, hospitalized in Peking University First Hospital between January 2012 and December 2018, were included in a derivation study. The transverse axis (T), longitudinal axis (L), T/L ratio, product T × L, distance between the origin and the proximal end of the longitudinal axis (pro-D), and distance between the origin and distal end of the longitudinal axis (dis-D) of the Poincaré plot were compared between the VVS and POTS groups, and the differential diagnostic performance of the above-mentioned graphic parameters was evaluated using receiver operating characteristic curve analysis. A validation study was conducted in pediatric patients hospitalized between January 2019 and December 2020.ResultsIn school-aged children, the T, L, T/L, T × L, and dis-D values of patients with VVS were greater than those of patients with POTS; in adolescents, the T, T/L, T × L, and pro-D values of patients with VVS were greater than those of patients with POTS. Using a T/L cut-off value of 0.3 to distinguish between the two diseases, the sensitivity and specificity were 91.0 and 90.5%, respectively, for the total participants; 91.6 and 88.9%, respectively, for the school-aged children; and 82.1 and 95.7%, respectively, for the adolescents. In the validation study, a T/L cut-off value of 0.3 yielded an accuracy, sensitivity, and specificity of 81.8, 87.2, and 77.6%, respectively, in the total participants; 76.5, 82.6, and 71.4%, respectively, in the school-aged children; and 89.2, 93.8, and 85.7%, respectively, in the adolescents, in distinguishing VVS from POTS validated by clinical diagnosis.ConclusionsThe graphic parameters of the Poincaré plot are significantly different between VVS and POTS in pediatric patients, and the T/L of the Poincaré plot may be a useful measure to help differentiate VVS from POTS in children and adolescents.

Dataset Information

When Sinus Tachycardia Becomes Too Much: Negative Effects of Excessive Upright Tachycardia on Cardiac Output in Vasovagal Syncope, Postural Tachycardia Syndrome, and Inappropriate Sinus Tachycardia.

Background

Methods

Results

Conclusions

Publications

When Sinus Tachycardia Becomes Too Much: Negative Effects of Excessive Upright Tachycardia on Cardiac Output in Vasovagal Syncope, Postural Tachycardia Syndrome, and Inappropriate Sinus Tachycardia.

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