Related Experiment Video
Updated: Jun 12, 2026
Real-Time Cardiac Mapping with a Noninvasive Imageless Electrocardiographic Imaging System
Published on: April 11, 2025
Impact of moderate exercise workload on predicted optimal AV and VV delays determined by an intracardiac
Margit Strauss1, Torsten Becker, Thomas Kleemann
1Arrhythmia Center, Heart Center Ludwigshafen, Bremserstr 79, 67063 Ludwigshafen, Germany. straussm@klilu.de
Aims:
Aim of this study is to evaluate reproducibility, consistency and the impact of moderate exercise workload on optimized PV and VV delays as determined by the IEGM-based QuickOpt™ method (St. Jude Medical), that was shown to produce hemodynamic performance similar to that obtained by echo-guided aortic VTI maximization.
Methods:
Sixty patients with CRT-ICD (65 ± 9 years, 12% female, LVEF 28 ± 9%, 48% CAD and 52% DCM) were enrolled. IEGM-based PV/VV optimization was conducted six times: twice at rest, twice immediately after a 6-min walk test and twice following a 3-min recovery period. Timing cycle delays were programmed in accordance with the optimization results. Follow-up was performed after 1 year.
Results:
Although significant difference in heart rate was reached [68 ± 9 bpm (REST) vs. 79 ± 12 (6MWT), p < 0.001], differences were not observed between IEGM-based optimized PV/VV delays: PV(opt) = 128 ± 14 ms (REST) versus 130 ± 17 ms (6MWT) versus 129 ± 16 ms (RECOV); VV(opt) = 15 ± 24 ms (REST) versus 15 ± 22 ms (6MWT) versus 16 ± 24 ms (RECOV). During 1-year follow-up PV(opt) and VV(opt) remained stable (ΔPV(opt) = 10 ± 10 ms, ΔVV(opt) = 9 ± 11 ms).
Conclusion:
Optimized IEGM-based timing cycle delays are independent of moderate exercise status within a particular patient but varied between patients. This supports the use of PV/VV optimization in each CRT patient.
More Related Videos
12:45Benefits of Cardiac Resynchronization Therapy in an Asynchronous Heart Failure Model Induced by Left Bundle Branch Ablation and Rapid Pacing
Published on: December 11, 2017
08:12Calculating Heart Rate Variability from ECG Data from Youth with Cerebral Palsy During Active Video Game Sessions
Published on: June 5, 2019
Related Concept Videos
01:19Cardiac 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...
01:17Exercise and Cardiac Output
Sustained exercise increases the muscles' oxygen demand, which can be met...
01:22Cardiac 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...
01:26Imbalances 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...
01:25Correlation between ECG and Cardiac Cycle
A cardiac action potential originates in the SA node and spreads throughout the atria and the AV node in approximately 0.03 seconds. This results in the P wave in an ECG and triggers atrial contraction. The action potential is then briefly slowed at the AV node, allowing the atria to contract and fill the ventricles with blood before...
01:11Cardiac Output and Stroke Volume
In an average resting adult male, the typical cardiac output averages...