Purpose: Flattening of oxygen pulse curve during incremental cardiopulmonary exercise testing has been proposed for the improvement of diagnostic accuracy of exercise-induced myocardial ischemia. In this study, we compare the oxygen pulse response to incremental treadmill exercise in patients with and without ischemia as detected by myocardial perfusion scintigraphy.

Methods: Eighty-seven patients referred to exercise myocardial perfusion scintigraphy were also evaluated with incremental treadmill cardiopulmonary exercise testing. One investigator prospectively identified patients who presented transient exercise-induced perfusion defects on 99mTc sestamibi myocardial scintigraphies. Another investigator evaluated the response of oxygen pulse to incremental exercise testing without knowledge of electrocardiographic response or scintigraphic findings.

Results: Exercise myocardial perfusion scintigraphy detected transient perfusion defects in 36% of the patients. Compared with patients with normal perfusion studies, patients with exercise-induced ischemia presented similar peak double product, peak oxygen uptake, and anaerobic threshold. Oxygen pulse at 25% of peak (ischemia: 9.7 +/- 2 mL per beat; no ischemia: 9.3 +/- 2 mL per beat), 50% of peak (11.2 +/- 3 vs 10.8 +/- 3 mL per beat), 75% of peak (12.5 +/- 3 vs 11.9 +/- 3 mL per beat), and at peak exercise (13 +/- 4 vs 13 +/- 4 mL per beat) were not different in exercise-induced ischemia and normal groups, respectively. However, patients who presented extensive transient perfusion defects during exercise had a lower peak oxygen pulse (12.8 +/- 3.8 vs 16.4 +/- 4.6 mL per beat; P < 0.05).

Conclusion: The analysis of the oxygen pulse response to incremental exercise test does not identify mild myocardial ischemia. Flattening of oxygen pulse response during incremental exercise might be present only with extensive myocardial ischemia.

Download full-text PDF

Source
http://dx.doi.org/10.1249/mss.0b013e3180601136DOI Listing

Publication Analysis

Top Keywords

oxygen pulse
32
+/- beat
24
myocardial ischemia
16
flattening oxygen
12
exercise testing
12
pulse response
12
response incremental
12
myocardial perfusion
12
perfusion defects
12
incremental exercise
12

Similar Publications

The long-lasting impact of high-intensity training via collaborative care in patients with schizophrenia: A 5-year follow-up study.

Schizophr Res

December 2024

Faculty of Health Sciences and Social Care, Molde University College, Molde, Norway; Department of Psychosis and Rehabilitation, Psychiatry Clinic, St. Olavs Hospital, Trondheim University Hospital, Trondheim, Norway. Electronic address:

Unlabelled: Although exercise is medicine for outpatients with schizophrenia, it is unclear if one-year adherence-supported exercise leads to a "tipping point", at which the exercise becomes a routine manifested as life-long training in the patient group.

Methods: Forty-eight outpatients (28 men/20 women: 35 ± 11 (mean ± SD) years) with schizophrenia (ICD-10: F20-29) were randomised to: 1) collaborative care group (TG), performing aerobic interval (AIT; 4 × 4-min treadmill walking/running at ∼90 % peak heart rate) and leg press maximal strength training (MST; 4 × 4 repetitions at ∼90 % maximal strength [1RM]) 2d·wk. for 1-year, supported by transportation and training supervision; or 2) control group (CG).

View Article and Find Full Text PDF

Objective: To analyze the results of nocturnal breathing parameters during sleep based on nocturnal pulse oximetry and to study of characteristics of external respiration in genetically confirmed patients with dystrophic myotonia (DM).

Material And Methods: The subjects of the study were patients with genetically confirmed DM types 1 and 2 who were hospitalized in the neurological departments of the Republican Scientific and Practical Center for Neurology and Neurosurgery. The clinical picture of the disease, comorbidities, sleep questionnaires, laboratory tests, overnight pulse oximetry and spirometry were performed and analyzed.

View Article and Find Full Text PDF

Individual FiO guided by SO prevents hyperoxia and reduces postoperative atelectasis in colorectal surgery: A randomized controlled trial.

J Clin Anesth

December 2024

Department of Anesthesiology, Second Affiliated Hospital of Harbin Medical University, China; The Key Laboratory of Anesthesiology and Intensive Care Research of Heilongjiang Province, China. Electronic address:

Study Objective: To determine whether individualized fraction of inspired oxygen (iFiO) improves pulmonary atelectasis after elective laparoscopic colorectal surgery relative to 60 % FiO.

Design: This was a single-center, prospective, randomized study.

Setting: This study was conducted in a single tertiary care hospital in China.

View Article and Find Full Text PDF

The aim of this retrospective clinical study was to compare the combinations of ketamine/diazepam (KD group) and tiletamine/zolazepam (TZ group) for the induction of general anaesthesia in horses undergoing elective surgery. The data from the clinical and the anaesthetic records of 138 horses from 2021 to 2023 were evaluated, and the horses were divided in two groups: KD ( = 60) and TZ ( = 72). The horses were premedicated with romifidine and methadone IV; anaesthesia was induced with ketamine/diazepam for the KD group and tiletamine/zolazepam for the TZ group and was maintained with isoflurane and a constant rate infusion of romifidine.

View Article and Find Full Text PDF

Frequent changes in altitude and oxygen levels limit the practical application of traditionally derived exercise thresholds or training zones based on heart rate (HR) or blood lactate concentration (bLa). We investigated the transferability of a muscle oxygenation (SmO)-based intensity prescription between different hypoxic conditions to assess the suitability of real-time SmO measurements for ski-mountaineering (SKIMO) athletes during submaximal endurance exercise. A group of 15 well-trained male SKIMO athletes performed a graded-intensity run test in normoxia (87 m ASL, FiO = 20.

View Article and Find Full Text PDF

Want AI Summaries of new PubMed Abstracts delivered to your In-box?

Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!