Study of the Loss of AV Synchrony at Maximum Exercise

Author(s):  
2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
C Kourek ◽  
E Karatzanos ◽  
D Delis ◽  
M Alshamari ◽  
V Linardatou ◽  
...  

Abstract Background Chronic heart failure (CHF) remains a leading cause of morbidity and mortality and it is characterized by vascular endothelial dysfunction. During the last decades, endothelial progenitor cells (EPCs) are being used as an index of the endothelium restoration potential, therefore reflecting the vascular endothelial function. Exercise training has been shown to stimulate the mobilization of EPCs at rest in CHF patients. However, the effect of exercise training on the acute respond of EPCs after maximum exercise in CHF patients remains unknown. Purpose The purpose of the study was to assess the effect of a cardiac rehabilitation (CR) program on the acute respond of EPCs after maximum exercise in patients with CHF. Methods Forty-four consecutive patients (35 males) with stable CHF [mean±SD, Age (years): 56±10, BMI (kg/m2): 28.7±5.2, EF (%): 33±8, Peak VO2 (ml/kg/min): 18.4±4.4, Peak work rate (watts): 101±39] enrolled a 36-session CR program based on high-intensity interval exercise training. All patients underwent an initial symptom limited maximal cardiopulmonary exercise testing (CPET) on an ergometer before the CR program and a final maximal CPET after the CR program. Venous blood was drawn before and after each CPET. Five circulating endothelial populations were identified and quantified by flow cytometry; CD34+/CD45-/CD133+, CD34+/CD45-/CD133+/VEGFR2, CD34+/CD133+/VEGFR2, CD34+/CD45-/CD133- and CD34+/CD45-/CD133-/VEGFR2. EPCs values are expressed as cells/million enucleated cells in medians (25th-75th percentiles). Results The acute mobilization of EPCs after the final CPET was higher than after the initial CPET in 4 out of 5 circulating endothelial populations. Most specifically, difference of the acute mobilization of CD34+/CD45-/CD133+ cells [initial CPET: 25 (15–46) vs final CPET: 49 (26–71), p=0.002], CD34+/CD45-/CD133+/VEGFR2 cells [initial CPET: 3 (2–5) vs final CPET: 8 (5–12), p<0.001], CD34+/CD45-/CD133- cells [initial CPET: 129 (52–338) vs final CPET: 250 (129–518), p=0.03] and CD34+/CD45-/CD133-/VEGFR2 cells [initial CPET: 2 (1–4) vs final CPET: 6 (3–9), p<0.001] increased after the final CPET. The acute mobilization of CD34+/CD133+/VEGFR2 cells [initial CPET: 3 (−1–7) vs final CPET: 5 (0–15), p=0.441] did not differ between the 2 CPETS. Conclusion A 36-session cardiac rehabilitation program increases the acute respond of endothelial progenitor cells after maximum cardiopulmonary exercise training in patients with chronic heart failure, therefore indicating the beneficial effect of exercise training on the vascular endothelial function. Funding Acknowledgement Type of funding source: Public grant(s) – EU funding. Main funding source(s): Co-financed by Greece and the European Union (European Social Fund- ESF) through the Operational Programme “Human Resources Development, Education and Lifelong Learning” in the context of the project


CHEST Journal ◽  
2009 ◽  
Vol 135 (2) ◽  
pp. 425-433 ◽  
Author(s):  
Maurizio Bussotti ◽  
PierGiuseppe Agostoni ◽  
Alberto Durigato ◽  
Carlo Santoriello ◽  
Stefania Farina ◽  
...  

1988 ◽  
Vol 64 (6) ◽  
pp. 2482-2489 ◽  
Author(s):  
P. Leblanc ◽  
E. Summers ◽  
M. D. Inman ◽  
N. L. Jones ◽  
E. J. Campbell ◽  
...  

The capacity of inspiratory muscles to generate esophageal pressure at several lung volumes from functional residual capacity (FRC) to total lung capacity (TLC) and several flow rates from zero to maximal flow was measured in five normal subjects. Static capacity was 126 +/- 14.6 cmH2O at FRC, remained unchanged between 30 and 55% TLC, and decreased to 40 +/- 6.8 cmH2O at TLC. Dynamic capacity declined by a further 5.0 +/- 0.35% from the static pressure at any given lung volume for every liter per second increase in inspiratory flow. The subjects underwent progressive incremental exercise to maximum power and achieved 1,800 +/- 45 kpm/min and maximum O2 uptake of 3,518 +/- 222 ml/min. During exercise peak esophageal pressure increased from 9.4 +/- 1.81 to 38.2 +/- 5.70 cmH2O and end-inspiratory esophageal pressure increased from 7.8 +/- 0.52 to 22.5 +/- 2.03 cmH2O from rest to maximum exercise. Because the estimated capacity available to meet these demands is critically dependent on end-inspiratory lung volume, the changes in lung volume during exercise were measured in three of the subjects using He dilution. End-expiratory volume was 52.3 +/- 2.42% TLC at rest and 38.5 +/- 0.79% TLC at maximum exercise.


1986 ◽  
Vol 60 (4) ◽  
pp. 1259-1267 ◽  
Author(s):  
E. A. Breisch ◽  
F. C. White ◽  
L. E. Nimmo ◽  
M. D. McKirnan ◽  
C. M. Bloor

The effects of exercise conditioning on the myocardium were studied in seven instrumented pigs strenuously exercised for 12 wk by treadmill running. Data were compared with eight instrumented untrained pigs. O2 consumption measured during maximum exercise effort was significantly elevated in the trained pigs (71.7 +/- 4.0 vs. 56.3 +/- 3.0 ml X ml-1 X kg-1). Absolute right and left ventricular mass increased by 20 and 13%, respectively, in response to exercise. Myocyte cross-sectional area increased by 21% in the trained hearts compared with the untrained hearts. Transmural left ventricular myocardial blood flow (ml X min-1 X g-1) was not significantly different at rest, during maximum exercise, or during exercise with adenosine infusion. However, training caused an elevation of the regional epicardial blood flow noted during exercise and exercise with adenosine. In the trained pigs mean aortic pressure during maximum exercise with adenosine infusion was not significantly different compared with untrained pigs. Coronary resistance during exercise with adenosine infusion was the same in both animal groups. In the trained group capillary numerical (no./mm2) and length (mm/mm3) densities were reduced, whereas arteriolar numerical and length densities were significantly increased compared with the untrained group. Measurements of capillary luminal surface density (mm2/mm3) in the trained group were unchanged compared with the untrained group. These results suggest that strenuous exercise does not stimulate the production of new capillaries, but this is modified by the ability of existing capillaries to increase their luminal surface area to parallel increases in myocyte growth. The arteriolar data suggest that exercise promotes the formation of new arterioles.(ABSTRACT TRUNCATED AT 250 WORDS)


1976 ◽  
Vol 40 (3) ◽  
pp. 287-292 ◽  
Author(s):  
G. L. Davis ◽  
C. F. Abildgaard ◽  
E. M. Bernauer ◽  
M. Britton

To evaluate changes in fibrinolytic activity, factor VIII and other hematological variables during and after a progressive step increment in work load, 10 healthy male subjects (22–27 yr of age) were exercised to exhaustion on an electromagnetic bicycle ergometer. Blood samples were drawn serially throughout the experiment. Little change in fibrinolytic activity was observed before 70–80% maximum heart rate (MHR) was achieved. Major changes occurred after 80% MHR. Peak values coincided with maximum exercise. In contrast major changes in factor VIII were observed between 95 and 100% MHR with peak values occurring 5–10 min postexercise. An increase in white blood cell count, platelet count, and retention was observed at maximum exercise. One individual failed to demonstrate an increase in either fibrinolytic or factor VIII activity. Relating the data to either the percent maximal oxygen uptake or percent maximal heart rate demonstrates the importance of the exercise protocol and exerting all subjects to the same relative level of physiological work.


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