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Biomedical subjects

George E Tzelepis

Publications and source records attributed to George E Tzelepis.

14 recordsLinked to original sources
PubMed2007

Determinants of pulmonary arterial hypertension in scleroderma.

OBJECTIVE: To define risk factors associated with pulmonary arterial hypertension (PAH) in a large cohort of patients with systemic sclerosis (SSc). METHODS: SSc patients undergoing screening for PAH by means of Doppler echocardiography were identified and their charts were retrospectively reviewed. In all patients, we recorded systolic pulmonary artery pressure along with pulmonary function testing, clinical, and laboratory data. PAH was defined as right ventricular systolic pressure equal or greater than 40 mm Hg. RESULTS: Of 114 SSc patients with echocardiographic measurements, PAH was found in 33 (29%) patients. In a multiple logistic regression analysis, the presence of pulmonary fibrosis on thoracic computed tomography (OR 6.78, CI 1.54 to 29.9), forced vital capacity less than 80% predicted (OR 3.03, CI 1.1 to 8.35), and duration of Raynaud's phenomenon preceding the onset of skin changes for at least 3 years (OR 5.75, CI 1.9 to 17.41) were found to be independent predictors of PAH. Age, disease duration, disease subtype, or autoantibodies were not associated with PAH in our patients. CONCLUSIONS: The present analysis identified pulmonary fibrosis and Raynaud's phenomenon preceding SSc skin manifestations by at least 3 years as risk factors for PAH in our scleroderma cohort. Screening for PAH in these high-risk patients may detect PAH at an earlier stage and guide decisions on therapeutic interventions.

Adolescent↗
PubMed2006

Inter-session reproducibility of peak expiratory flow with standardized expiratory maneuvers.

BACKGROUND: In adults performing forceful expiratory maneuvers, the length of post-inspiratory pause prior to forced expiration may influence the subsequently measured peak expiratory flow (PEF) and increase its variability. We investigated the effects of two different lengths of breath-hold at total lung capacity (TLC) on the short-term reproducibility of PEF in healthy volunteers. METHODS: Forty-six healthy volunteers (age 34.6+/-8.5; 23 men) performed a series of maximal forceful expirations in two different test sessions, separated by approximately 2 weeks. In each test-session, PEF was measured with two different types of maneuvers. One maneuver (P) included a brief (<2s) post-inspiratory pause at TLC prior to forced expiration, whereas the second maneuver (NP) included no pause at TLC. The speed of inspiration to TLC was fast and similar for both maneuvers. In a given test session, all volunteers performed four efforts for each type of maneuver. The highest PEF for each maneuver was used for analysis. The Bland-Altman statistical analysis was used to determine inter-session reproducibility of PEF. RESULTS: Within-maneuver analysis of the between-test session reproducibility of PEF showed that neither maneuver systematically biased the measured PEF (mean difference 0.02L/s for the P and 0.17L/s for the NP maneuver). Inter-maneuver between-test session analysis similarly showed that neither maneuver introduced a systematic bias in the maximal PEF (mean difference ranged from -0.15 to -0.01L/s). The limits of agreement were comparable in all maneuver-pair analyses. CONCLUSIONS: Forceful expiratory maneuvers with or without a brief (<2s) pause at TLC produce comparable PEF values in test-retest sessions.

Adult↗
PubMed2006

Scleroderma lung: initial forced vital capacity as predictor of pulmonary function decline.

OBJECTIVE: To determine the ability of initial forced vital capacity (FVC) of patients with scleroderma to predict subsequent pulmonary function deterioration. METHODS: Data on 78 patients with scleroderma were retrospectively collected and analyzed. FVC (percent predicted), diffusing capacity for carbon monoxide (percent predicted), and various clinical and laboratory parameters were recorded. Pulmonary function decline (outcome) was defined as at least a 15-point sustained decrease in FVC (percent predicted). Kaplan-Meier analyses were performed separately for 60 patients initially assessed within the first 3 years from disease onset (group A) and 16 patients whose FVC values in the fourth or fifth year from disease onset were ascribed as baseline measurements (group B). RESULTS: Based on baseline FVC, patients in each group were categorized into those with normal FVC (> or =80% predicted) and those with decreased FVC (<80% predicted). In group A, the percent-predicted FVC of 89% of patients with normal initial FVC and of 75% of patients with reduced baseline FVC did not decrease by > or =15 points at 5 years (log rank P = 0.04). Four patients with decreased baseline FVC developed respiratory failure (FVC <50% predicted) versus none with normal initial FVC. Analysis of group B showed no difference between patients with normal baseline FVC and those with decreased FVC in the ability to further predict pulmonary function decline (log rank P = 0.13). Clinical and laboratory parameters (age, male sex, baseline diffusion capacity, anti-topoisomerase I, or duration of Raynaud's phenomenon preceding skin manifestations) were not associated with pulmonary function decline. CONCLUSION: Measured within the first 3 years from disease onset, baseline FVC (percent predicted) may predict deterioration of pulmonary function in patients with scleroderma. Patients with normal pulmonary function at initial assessment are at low risk to develop considerable impairment of pulmonary function.

Adult↗
PubMed2006

Effects of theophylline on pulmonary function in patients with traumatic tetraplegia.

BACKGROUND/OBJECTIVES: To assess the effects of theophylline on pulmonary function in patients with chronic traumatic tetraplegia, we conducted a double-blind placebo-controlled crossover study in 10 patients. METHODS: The patients (age: 41 +/- 3 years; time from injury: 16 +/- 3 years; neurological levels: C3 to C7-T1) were randomized to receive oral theophylline or placebo for 6 weeks. After 2 months of washout, the patients received the medication not taken in the first trial for an additional 6 weeks. We measured lung volumes, expiratory flow rates, maximal inspiratory pressure (MIP), and maximal expiratory pressure (MEP) at both baseline and at the end of each treatment arm. Theophylline blood serum assays were measured during the first week of the treatment and on the day of respiratory measurements. RESULTS: Mean theophylline level on the day of treatment completion was 12.6 +/- 1.4 microg/mL. In analyzing the data from the group of 10 patients, the percent changes from baseline in total lung capacity, forced vital capacity, forced expiratory volume at 1 second, MIP, and MEP did not differ significantly between the two treatment arms (P > 0.05 in all). CONCLUSION: These data show that in this small group of 10 subjects with chronic tetraplegia, administration of oral theophylline did not improve pulmonary function.

Adult↗
PubMed2005

Interstitial lung disease in a patient with antisynthetase syndrome and no myositis.

Interstitial lung disease in patients with antisynthetase syndrome and no evidence of myositis is rare and may precede other disease manifestations. We report a patient who initially presented with symptoms primarily related to lung involvement. The diagnosis of the antisynthetase syndrome without myositis was made many months later when he developed a characteristic hand rash (mechanic's hands), which was confirmed by positive antibodies to Jo-1. With treatment, both the hand rash and the interstitial lung disease improved. Antisynthetase syndrome should be considered in patients presenting with interstitial lung disease with no evidence of myositis. Appropriate laboratory testing with measurement of specific autoantibodies may help in the early diagnosis and treatment of the syndrome.

Adult↗
PubMed2005

Myelofibrosis-associated massive splenomegaly: a cause of increased intra-abdominal pressure, pulmonary hypertension, and positional dyspnea.

We describe a patient with myelofibrosis, giant splenomegaly, and pulmonary hypertension related to increased intra-abdominal pressure. Focusing on alterations in hemodynamic studies, we conclude that in patients with myelofibrosis, dyspnea, and hypoxemia, the measurement of intra-abdominal pressure should be included in the initial evaluation. It is an inexpensive, non-invasive diagnostic tool that can provide crucial information about the cause of dyspnea and disclose the pathogenetic link between massive splenomegaly and pulmonary compromise in myelofibrosis.

Abdomen↗
PubMed2005

Cardiac and sternocleidomastoid muscle involvement in Duchenne muscular dystrophy: an MRI study.

OBJECTIVE: To examine the extent of cardiac muscle and sternocleidomastoid muscle (SCM) involvement detected by MRI measurement of T2 relaxation time in patients with Duchenne muscular dystrophy (DMD) and no cardiorespiratory symptoms. DESIGN: Prospective controlled study. SETTING: Teaching referral hospital and university hospital. SUBJECTS: Seventeen patients with DMD (age range, 7 to 25 years) and 17 age-matched control subjects. All patients were free of cardiac or respiratory complaints and had normal ECG, echocardiograph, and Holter monitor examination findings. METHODS: We assessed respiratory function by means of standard pulmonary function testing. MRI measurements included the T2 relaxation time of the myocardium and the SCM in patients and control subjects. RESULTS: The FVC and FEV1 values were lower in patients with DMD than in age-matched control subjects, whereas the FEV1/FVC ratio was normal in all subjects. Patients with DMD had lower T2 relaxation time of the heart (37.8 +/- 6.1 ms vs 58.1 +/- 7.1 ms, p < 0.001) and lower T2 relaxation time of the right SCM (24.5 +/- 2.6 ms vs 42.2 +/- 1.3 ms, p < 0.001) and left SCM (23.2 +/- 3.2 ms vs 42.2 +/- 1.6 ms, p < 0.001), compared to control subjects (+/- SD). In children (< 12 years of age), the T2 of the SCM was lower than that of the control subjects, but T2 of the heart did not differ between the two groups. In the patient group, T2 relaxation time of the heart decreased with age (r = - 0.80, p < 0.001). In patients with FVC < 80% of predicted, the T2 values of the heart were lower than the T2 values of patients with FVC > or = 80% of predicted (35.6 +/- 5.8 ms vs 41.8 +/- 4.6 ms, p < 0.05). CONCLUSIONS: MRI measurements of the T2 relaxation time in the myocardium and SCM of patients with DMD and no cardiorespiratory symptoms are abnormal, indicating altered tissue composition. These measurements may prove a clinically useful test for monitoring cardiac and respiratory muscle involvement in these patients.

Adolescent↗
PubMed2005

Peak expiratory flow with or without a brief postinspiratory pause.

BACKGROUND: The duration of postinspiratory pause prior to forced expiration may significantly influence the peak expiratory flow (PEF) measured during maximal forceful expirations. In comparison with maneuvers without a postinspiratory pause, maneuvers with 4 to 6-s pause at total lung capacity (TLC) result in decreased PEF values. The extent to which brief pauses (< 2 s) similarly affect PEF values is unknown. METHODS: Thirty-six healthy volunteers (mean [+/-SD] age, 35 +/- 8 years; 18 men) performed a series of maximal forceful expirations with two different types of maneuvers. One maneuver (NP) included no inspiratory pause at TLC prior to forceful expiration, whereas the second (P) included a brief pause (< or = 2 s). The speed of inhalation to TLC was rapid and similar for both maneuvers. The highest PEF for each maneuver was used for analysis. RESULTS: The maximal PEF did not differ (p > 0.05) between the P and NP maneuvers (7.78 +/- 1.45 vs 7.83 +/- 1.45 L/s, respectively). Comparison of the intermaneuver differences showed a bias of 0.05 L/s and 95% confidence interval in the range of -0.9 to 1.0 L/s. CONCLUSIONS: Forceful expiratory maneuvers with or without postinspiratory pauses of < or = 2 s produce identical maximal PEF values and, therefore, can be used interchangeably for the spirometric measurement of PEF in healthy subjects.

Adult↗
PubMed2004

Expiratory effort enhancement and peak expiratory flow in humans.

Peak expiratory flow (PEF) has previously been considered an effort-dependent, non flow-limited parameter that is constrained by the force-velocity relationship of the respiratory muscles. It has also been assumed that, if the muscles were able to augment the expiratory pressure, the PEF would increase. We tested the validity of this notion in normal volunteers who were able to enhance their expiratory pressure with maneuvers utilizing the stretch-shortening cycle (greater force when contractions were immediately preceded by eccentric contractions). Five healthy volunteers [35 (2) years] performed two successive maximal expiratory flow-volume maneuvers (MEFV) in rapid sequence. MEFV1 was a standard maneuver, whereas MEFV2 included a forceful inspiration to total lung capacity; a strategy designed to augment expiratory pressure via the stretch-shortening cycle. Neither maneuver included a post-inspiratory pause. We measured PEF, esophageal pressure (P(es)), and the electromyographic activity of the abdominal muscles. Compared to MEFV1, MEFV2 produced greater activation of the abdominal muscles during inspiration (eccentric contraction), greater peak expiratory P(es), greater rate of rise of P(es), shorter time to PEF, but similar PEF. Our findings directly demonstrate the inability of the augmented expiratory effort to increase PEF and thus support the notion that PEF is determined by a flow-limiting mechanism and not by the velocity of muscle shortening.

Adult↗
PubMed2003

Maximal dynamic expiratory pressures with fast and slow inspirations.

Maximal dynamic expiratory pressures are higher when forced expiration is preceded by a fast inspiration to total lung capacity (TLC) than when preceded by a slow inspiration and a few seconds pause at TLC. We hypothesized that these pressure differences are due to the stretch-shorten cycle (SSC), which refers to enhancement of muscle force when a concentric muscle contraction is immediately preceded by an eccentric contraction. Seven volunteers [36 (2) years; mean (SEM)] performed maximal forced expirations against minimal resistance with fast (F) or slow (S) maneuvers. F maneuvers consisted of a fast inspiration to TLC followed immediately by a fast expiration, whereas S consisted of a slow inspiration to TLC and a 4- to 5-s pause at TLC prior to forced expiration. We measured esophageal pressure ( P(es)), peak expiratory flow rate (PEFR), and the EMG activity of the transversus abdominis (Tr) by means of intramuscular fine-wire electrodes. The subjects performed several runs of each maneuver in a random order, and runs with the greatest expiratory P(es) were analyzed. In comparison with S, F yielded greater P(es) [182 (15) versus 167 (15) cm H(2)O; P=0.003)] but similar PEFR [9.8 (0.7) versus 9.6 (0.7) l/s, P>0.05] and EMG activity of the Tr during forced expiration [221 (31) versus 208 (34) a.u., P>0.05]. Further analysis revealed significant EMG activity of Tr during end-inspiration (eccentric contraction) with F maneuvers only [73 (22) versus 32 (17) a.u., P<0.05]. We conclude that the ability of expiratory muscles to generate greater P(es) with F maneuvers is related to the sequence of an eccentric contraction, which is followed immediately by concentric contraction in a manner analogous to SSC described in skeletal muscles.

Adult↗