Related Experiment Video
Updated: Oct 9, 2026

A Method for Tracking the Time Evolution of Steady-State Evoked Potentials
Published on: May 25, 2019
The effects of orthostasis on the ventricular-evoked response
F Saborowski1, G Krahé-Fritsch, M Krakau
1Medizinische Klinik, Krankenhaus Holweide, Köln, Germany.
Aims:
The effects of orthostasis on the morphology of the ventricular-evoked response were investigated.
Methods And Results:
Seven patients (five females; 74.9 +/- 4.6 years) with second- or third-degree atrioventricular block received DDD pacemakers Physios CTM 01 with fractal-coated ventricular leads (both Biotronik, Germany). At their 3-month follow-up sessions, these patients underwent tilt-table tests. Heart rate, mean arterial blood pressure and ventricular-evoked response were measured continuously. Signals were averaged over 15 consecutive beats. Coefficients of correlation between selected ventricular-evoked response parameters and heart rate or mean arterial blood pressure were calculated. Tilt upwards affected heart rate, mean arterial blood pressure and ventricular-evoked response extremes showed non-uniform, patient-specific changes that were not related directly to other parameters. Heart rates significantly increased in six patients following tilt upwards. For all patients, ventricular-evoked response plateau amplitudes immediately increased with tilt upwards. Furthermore, repolarization times correlated with changes in heart rates (r = -0.78).
Conclusions:
Monitoring of the ventricular-evoked response during tilt-table testing revealed that the plateau amplitude of the ventricular-evoked response depends on the patient's position; ventricular-evoked response increased in the upright position and decreased in the supine position. Furthermore, repolarization time and heart rate correlated inversely; higher heart rates resulted in a shortening of the ventricular-evoked response.
Related Concept Videos
Disturbances in Heart Rhythm
Arrhythmias are categorized by their speed, rhythm, and origin. A slow heart...
Dysrhythmias V: Evaluating Dysrhythmias
Cardiac Output II: Effect of Stroke Volume on Cardiac Output
Preload
Preload refers to the initial elongation of the cardiac myocytes before contraction and is related to the volume of blood filling the heart at the end of diastole, or end-diastolic volume. The...
Dysrhythmias IV: Characteristics of Bradyarrhythmias
Imbalances in Cardiac Output
CHF can occur due to the failure of either side of the heart. Left-side failure leads to pulmonary congestion—the right side continues to send blood...
Cardiac Output I:Effect of Heart Rate on Cardiac Output
Cardiac output (CO) refers to the total amount of blood ejected by one of the ventricles in liters per minute (L/min). In a resting adult, CO ranges from 5 to 6 L/min, adjusting according to the body's metabolic requirements.
Effect of Heart Rate on Cardiac Output
Cardiac output adapts to metabolic demands during stress, physical activity, or illness. The autonomic nervous system regulates heart rate via the sinoatrial node. The parasympathetic nervous system decreases heart rate...
