Intrapulmonary distribution of blood flow during exercise in pulmonary hypertension assessed by a new combination technique
BackgroundHyperventilation and inadequate cardiac output (CO) increase are the main causes of exercise limitation in pulmonary hypertension (PH). Intrapulmonary blood flow partitioning between ventilated and unventilated lung zones is unknown. Thoracic impedance cardiography and inert gas rebreathin...
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| Format: | Article |
| Language: | English |
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Frontiers Media S.A.
2023-09-01
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| Series: | Frontiers in Cardiovascular Medicine |
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| Online Access: | https://www.frontiersin.org/articles/10.3389/fcvm.2023.1241379/full |
| _version_ | 1827822029753024512 |
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| author | Stefania Farina Beatrice Pezzuto Carlo Vignati Pierantonio Laveneziana Pierantonio Laveneziana Piergiuseppe Agostoni Piergiuseppe Agostoni |
| author_facet | Stefania Farina Beatrice Pezzuto Carlo Vignati Pierantonio Laveneziana Pierantonio Laveneziana Piergiuseppe Agostoni Piergiuseppe Agostoni |
| author_sort | Stefania Farina |
| collection | DOAJ |
| description | BackgroundHyperventilation and inadequate cardiac output (CO) increase are the main causes of exercise limitation in pulmonary hypertension (PH). Intrapulmonary blood flow partitioning between ventilated and unventilated lung zones is unknown. Thoracic impedance cardiography and inert gas rebreathing have been both validated in PH patients for non-invasive measurement of CO and pulmonary blood flow (PBF), respectively. This study sought to evaluate CO behaviour in PH patients during exercise and its partitioning between ventilated and unventilated lung areas, in parallel with ventilation partitioning between ventilated and unventilated lung zones.MethodsEighteen PH patients (group 1 or 4) underwent a cardiopulmonary exercise test (CPET) with a three-step loaded workload protocol. The steps occurred at 0%, 20%, 40%, and 60% of peak workload reached during a preliminary maximum CPET. Ventilatory parameters, arterial blood gases, CO, PBF, and intrapulmonary shunt (calculated as the difference between CO and PBF) were obtained at each step, combining thoracic impedance cardiography and an inert gas rebreathing technique.ResultsDead space ventilation observed throughout the exercise was about 40% of total ventilation. A progressive increase of CO from 4.86 ± 1.24 L/min (rest) to 9.41 ± 2.63 L/min (last step), PBF from 3.81 ± 1.41 L/min to 7.21 ± 2.93 L/min, and intrapulmonary shunt from 1.05 ± 0.96 L/min to 2.21 ± 2.28 L/min was observed. Intrapulmonary shunt was approximately 20% of CO at each exercise step.ConclusionsAlthough the study population was small, the combined non-invasive CO measurement seems a promising tool for deepening our knowledge of lung exercise haemodynamics in PH patients. This technique could be applied in future studies to evaluate PH treatment influences on CO partitioning, since a secondary increase of intrapulmonary shunt is undesirable. |
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| format | Article |
| id | doaj.art-792135842b464c94bff70cd12258fca1 |
| institution | Directory Open Access Journal |
| issn | 2297-055X |
| language | English |
| last_indexed | 2024-03-12T01:52:22Z |
| publishDate | 2023-09-01 |
| publisher | Frontiers Media S.A. |
| record_format | Article |
| series | Frontiers in Cardiovascular Medicine |
| spelling | doaj.art-792135842b464c94bff70cd12258fca12023-09-08T12:02:49ZengFrontiers Media S.A.Frontiers in Cardiovascular Medicine2297-055X2023-09-011010.3389/fcvm.2023.12413791241379Intrapulmonary distribution of blood flow during exercise in pulmonary hypertension assessed by a new combination techniqueStefania Farina0Beatrice Pezzuto1Carlo Vignati2Pierantonio Laveneziana3Pierantonio Laveneziana4Piergiuseppe Agostoni5Piergiuseppe Agostoni6Centro Cardiologico Monzino, IRCCS, Milan, ItalyCentro Cardiologico Monzino, IRCCS, Milan, ItalyCentro Cardiologico Monzino, IRCCS, Milan, ItalySorbonne Université, INSERM, UMRS1158 Neurophysiologie Respiratoire Expérimentale et Clinique, Paris, FranceAssistance Publique - Hôpitaux de Paris (AP-HP), Groupe Hospitalier Universitaire APHP-Sorbonne Université, sites Pitié-Salpêtrière, Saint-Antoine et Tenon, Service des Explorations Fonctionnelles de la Respiration, de l'Exercice et de la Dyspnée (Département R3S), Paris, FranceCentro Cardiologico Monzino, IRCCS, Milan, ItalyDepartment of Clinical Sciences and Community Health, Cardiovascular Section, University of Milan, Milan, ItalyBackgroundHyperventilation and inadequate cardiac output (CO) increase are the main causes of exercise limitation in pulmonary hypertension (PH). Intrapulmonary blood flow partitioning between ventilated and unventilated lung zones is unknown. Thoracic impedance cardiography and inert gas rebreathing have been both validated in PH patients for non-invasive measurement of CO and pulmonary blood flow (PBF), respectively. This study sought to evaluate CO behaviour in PH patients during exercise and its partitioning between ventilated and unventilated lung areas, in parallel with ventilation partitioning between ventilated and unventilated lung zones.MethodsEighteen PH patients (group 1 or 4) underwent a cardiopulmonary exercise test (CPET) with a three-step loaded workload protocol. The steps occurred at 0%, 20%, 40%, and 60% of peak workload reached during a preliminary maximum CPET. Ventilatory parameters, arterial blood gases, CO, PBF, and intrapulmonary shunt (calculated as the difference between CO and PBF) were obtained at each step, combining thoracic impedance cardiography and an inert gas rebreathing technique.ResultsDead space ventilation observed throughout the exercise was about 40% of total ventilation. A progressive increase of CO from 4.86 ± 1.24 L/min (rest) to 9.41 ± 2.63 L/min (last step), PBF from 3.81 ± 1.41 L/min to 7.21 ± 2.93 L/min, and intrapulmonary shunt from 1.05 ± 0.96 L/min to 2.21 ± 2.28 L/min was observed. Intrapulmonary shunt was approximately 20% of CO at each exercise step.ConclusionsAlthough the study population was small, the combined non-invasive CO measurement seems a promising tool for deepening our knowledge of lung exercise haemodynamics in PH patients. This technique could be applied in future studies to evaluate PH treatment influences on CO partitioning, since a secondary increase of intrapulmonary shunt is undesirable.https://www.frontiersin.org/articles/10.3389/fcvm.2023.1241379/fullpulmonary hypertensioncardiopulmonary exercise testcardiac outputshuntdead space |
| spellingShingle | Stefania Farina Beatrice Pezzuto Carlo Vignati Pierantonio Laveneziana Pierantonio Laveneziana Piergiuseppe Agostoni Piergiuseppe Agostoni Intrapulmonary distribution of blood flow during exercise in pulmonary hypertension assessed by a new combination technique Frontiers in Cardiovascular Medicine pulmonary hypertension cardiopulmonary exercise test cardiac output shunt dead space |
| title | Intrapulmonary distribution of blood flow during exercise in pulmonary hypertension assessed by a new combination technique |
| title_full | Intrapulmonary distribution of blood flow during exercise in pulmonary hypertension assessed by a new combination technique |
| title_fullStr | Intrapulmonary distribution of blood flow during exercise in pulmonary hypertension assessed by a new combination technique |
| title_full_unstemmed | Intrapulmonary distribution of blood flow during exercise in pulmonary hypertension assessed by a new combination technique |
| title_short | Intrapulmonary distribution of blood flow during exercise in pulmonary hypertension assessed by a new combination technique |
| title_sort | intrapulmonary distribution of blood flow during exercise in pulmonary hypertension assessed by a new combination technique |
| topic | pulmonary hypertension cardiopulmonary exercise test cardiac output shunt dead space |
| url | https://www.frontiersin.org/articles/10.3389/fcvm.2023.1241379/full |
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