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Non-invasive assessment of inspiratory muscle performance during exercise in patients with chronic heart failure.
Eur Heart J. 1998 May; 19(5):766-73.EH

Abstract

AIMS

The aim of this study was to assess inspiratory performance at rest and during exercise in patients with chronic heart failure in comparison with healthy controls using a non-invasive index: the tension-time index of inspiratory muscles (TTMUS).

METHODS

We studied 13 patients with chronic heart failure (57 +/- 7 years) and 10 control subjects (58 +/- 6 years) at rest and during an incremental maximal exercise test. Measurements included breathing pattern (inspiratory time, total time of respiratory cycle, minute ventilation, tidal volume and respiratory frequency), mouth occlusion pressure and mean inspiratory pressure (calculated as follows: 5 x mouth occlusion pressure x inspiratory time). The maximal inspiratory pressure was measured at rest. TTMUS was calculated from the equation: TTMUS = PI/PIMAX x TI/TTOT, where PI/PIMAX is the ratio of mean inspiratory pressure to maximal inspiratory pressure and TI/TTOT is the ratio of mean inspiratory time to total time of the respiratory cycle.

RESULTS

At rest, the results in patients showed non-significantly higher mouth occlusion pressure, lower maximal inspiratory pressure (P < 0.001), and a higher ratio of mean inspiratory pressure to maximal inspiratory pressure (P < 0.01). There was no difference in the breathing pattern. TTMUS was thus significantly higher in the patients with chronic heart failure (P < 0.001). At maximal exercise (77 +/- 16 W for patients with chronic heart failure vs 142 +/- 27 W for controls, P < 0.001), the ratio of mean inspiratory time to total time of respiratory cycle, the mouth occlusion pressure and the ratio of mean inspiratory pressure to maximal inspiratory pressure were not different. TTMUS was thus comparable in the two groups. During exercise, at comparable workloads (20, 40 and 60 W), the patients showed higher mouth occlusion pressure (P < 0.01) and a higher ratio of mean inspiratory pressure to maximal inspiratory pressure (P < 0.001), whereas the ratio of mean inspiratory time to total time of the respiratory cycle was similar. TTMUS was thus higher in the patients at each workload (P < 0.05).

CONCLUSION

This study shows that the determination of TTMUS at rest and during exercise allows the observation of alterations in inspiratory muscle performance as a result of both reduced inspiratory strength, as measured by the maximal inspiratory pressure, and increased ventilatory drive, as reflected by the mouth occlusion pressure in patients with chronic heart failure. The non-invasiveness of this new index is an additional argument for its use in a clinical setting.

Authors+Show Affiliations

Laboratoire de Physiologie des Interactions, Service Central de Physiologie Clinique, Unité d'Exploration Respiratoire, Montpellier, France.No affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info availableNo affiliation info available

Pub Type(s)

Journal Article
Research Support, Non-U.S. Gov't

Language

eng

PubMed ID

9717011

Citation

Vibarel, N, et al. "Non-invasive Assessment of Inspiratory Muscle Performance During Exercise in Patients With Chronic Heart Failure." European Heart Journal, vol. 19, no. 5, 1998, pp. 766-73.
Vibarel N, Hayot M, Pellenc PM, et al. Non-invasive assessment of inspiratory muscle performance during exercise in patients with chronic heart failure. Eur Heart J. 1998;19(5):766-73.
Vibarel, N., Hayot, M., Pellenc, P. M., Corret, J. L., Ramonatxo, M., Daures, J. P., Leclercq, F., Pons, M., & Prefaut, C. (1998). Non-invasive assessment of inspiratory muscle performance during exercise in patients with chronic heart failure. European Heart Journal, 19(5), 766-73.
Vibarel N, et al. Non-invasive Assessment of Inspiratory Muscle Performance During Exercise in Patients With Chronic Heart Failure. Eur Heart J. 1998;19(5):766-73. PubMed PMID: 9717011.
* Article titles in AMA citation format should be in sentence-case
TY - JOUR T1 - Non-invasive assessment of inspiratory muscle performance during exercise in patients with chronic heart failure. AU - Vibarel,N, AU - Hayot,M, AU - Pellenc,P M, AU - Corret,J L, AU - Ramonatxo,M, AU - Daures,J P, AU - Leclercq,F, AU - Pons,M, AU - Prefaut,C, PY - 1998/8/26/pubmed PY - 1998/8/26/medline PY - 1998/8/26/entrez SP - 766 EP - 73 JF - European heart journal JO - Eur. Heart J. VL - 19 IS - 5 N2 - AIMS: The aim of this study was to assess inspiratory performance at rest and during exercise in patients with chronic heart failure in comparison with healthy controls using a non-invasive index: the tension-time index of inspiratory muscles (TTMUS). METHODS: We studied 13 patients with chronic heart failure (57 +/- 7 years) and 10 control subjects (58 +/- 6 years) at rest and during an incremental maximal exercise test. Measurements included breathing pattern (inspiratory time, total time of respiratory cycle, minute ventilation, tidal volume and respiratory frequency), mouth occlusion pressure and mean inspiratory pressure (calculated as follows: 5 x mouth occlusion pressure x inspiratory time). The maximal inspiratory pressure was measured at rest. TTMUS was calculated from the equation: TTMUS = PI/PIMAX x TI/TTOT, where PI/PIMAX is the ratio of mean inspiratory pressure to maximal inspiratory pressure and TI/TTOT is the ratio of mean inspiratory time to total time of the respiratory cycle. RESULTS: At rest, the results in patients showed non-significantly higher mouth occlusion pressure, lower maximal inspiratory pressure (P < 0.001), and a higher ratio of mean inspiratory pressure to maximal inspiratory pressure (P < 0.01). There was no difference in the breathing pattern. TTMUS was thus significantly higher in the patients with chronic heart failure (P < 0.001). At maximal exercise (77 +/- 16 W for patients with chronic heart failure vs 142 +/- 27 W for controls, P < 0.001), the ratio of mean inspiratory time to total time of respiratory cycle, the mouth occlusion pressure and the ratio of mean inspiratory pressure to maximal inspiratory pressure were not different. TTMUS was thus comparable in the two groups. During exercise, at comparable workloads (20, 40 and 60 W), the patients showed higher mouth occlusion pressure (P < 0.01) and a higher ratio of mean inspiratory pressure to maximal inspiratory pressure (P < 0.001), whereas the ratio of mean inspiratory time to total time of the respiratory cycle was similar. TTMUS was thus higher in the patients at each workload (P < 0.05). CONCLUSION: This study shows that the determination of TTMUS at rest and during exercise allows the observation of alterations in inspiratory muscle performance as a result of both reduced inspiratory strength, as measured by the maximal inspiratory pressure, and increased ventilatory drive, as reflected by the mouth occlusion pressure in patients with chronic heart failure. The non-invasiveness of this new index is an additional argument for its use in a clinical setting. SN - 0195-668X UR - https://www.unboundmedicine.com/medline/citation/9717011/Non_invasive_assessment_of_inspiratory_muscle_performance_during_exercise_in_patients_with_chronic_heart_failure_ L2 - https://academic.oup.com/eurheartj/article-lookup/doi/10.1053/euhj.1997.0851 DB - PRIME DP - Unbound Medicine ER -