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Biomedical subjects

Jochanan E Naschitz

Publications and source records attributed to Jochanan E Naschitz.

At least 19 recordsLinked to original sources
PubMed2006

Patterns of hypocapnia on tilt in patients with fibromyalgia, chronic fatigue syndrome, nonspecific dizziness, and neurally mediated syncope.

OBJECTIVES: To assess whether head-up tilt-induced hyperventilation is seen more often in patients with chronic fatigue syndrome (CFS), fibromyalgia, dizziness, or neurally mediated syncope (NMS) as compared to healthy subjects or those with familial Mediterranean fever (FMF). PATIENTS AND METHODS: A total of 585 patients were assessed with a 10-minute supine, 30-minute head-up tilt test combined with capnography. Experimental groups included CFS (n = 90), non-CFS fatigue (n = 50), fibromyalgia (n = 70), nonspecific dizziness (n = 75), and NMS (n =160); control groups were FMF (n = 90) and healthy (n = 50). Hypocapnia, the objective measure of hyperventilation, was diagnosed when end-tidal pressure of CO2 (PETCO2) less than 30 mm Hg was recorded consecutively for 10 minutes or longer. When tilting was discontinued because of syncope, one PETCO2 measurement of 25 or less was accepted as hyperventilation. RESULTS: Hypocapnia was diagnosed on tilt test in 9% to 27% of patients with fibromyalgia, CFS, dizziness, and NMS versus 0% to 2% of control subjects. Three patterns of hypocapnia were recognized: supine hypocapnia (n = 14), sustained hypocapnia on tilt (n = 76), and mixed hypotensive-hypocapnic events (n = 80). Hypocapnia associated with postural tachycardia syndrome (POTS) occurred in 8 of 41 patients. CONCLUSIONS: Hyperventilation appears to be the major abnormal response to postural challenge in sustained hypocapnia but possibly merely an epiphenomenon in hypotensive-hypocapnic events. Our study does not support an essential role for hypocapnia in NMS or in postural symptoms associated with POTS. Because unrecognized hypocapnia is common in CFS, fibromyalgia, and nonspecific dizziness, capnography should be a part of the evaluation of patients with such conditions.

Adult↗
PubMed2006

Predicting outcomes on head-up tilt based on orthostatic hypotension patterns.

OBJECTIVE: To assess the frequency of different orthostatic hypotension (OH) patterns in patients having supine hypertension with OH ('SHOH') versus patients with OH and normal supine blood pressure ('OH alone'); and to relate OH patterns with outcomes on head-up tilt. METHODS: Consecutive patients with nonspecific dizziness were studied with a 10-min supine, 30-min head-up tilt test. Supine hypertension was diagnosed when supine systolic blood pressure (SBP) was at least 140 mmHg and/or supine diastolic blood pressure was at least 90 mmHg. OH was defined as SBP reduction of at least 20 mmHg within 3 min of tilt. OH patterns were identified corresponding to SBP time-curves during the initial 5 min of tilt: progressive, sustained and transient patterns. RESULTS: Among 400 patients tested, 31 had 'SHOH' and 39 had 'OH alone'. Frequencies of OH patterns were similar in both groups. The progressive OH pattern predicted symptomatic hypotension, leading to early tilt termination in all 'SHOH' and 88% of 'OH alone' patients. In comparison, tilt was early terminated in 33-48% of patients with sustained OH, transient OH and without OH. Early tilt termination was unrelated to age, gender, magnitude of supine SBP, pulse pressure and nadir SBP within 5 min tilt. CONCLUSIONS: Five minutes of postural challenge permitted assessing OH patterns. Outcome on protracted tilt was related to OH patterns, the worse outcome being likened to progressive OH, both in patients with 'SHOH' and in patients with 'OH alone'. Future studies will show whether OH patterns may serve as guidance for blood pressure therapy in selected patients.

Adult↗
PubMed2005

Search for disease-specific cardiovascular reactivity patterns: developing the methodology.

Aberrations of CVR (cardiovascular reactivity), an expression of autonomic function, lack specificity for a particular disorder. Recently, a CVR pattern particular to chronic fatigue syndrome has been observed. In the present study, we aimed to develop methodologies for assessing disease-specific CVR patterns. As a prototype, a population of 50 consecutive patients with FMF (familial Mediterranean fever) was studied and compared with control populations. A 10 min supine/30 min head-up tilt test with recording of the heart rate and blood pressure or the pulse transit time was performed. Five studies were conducted applying different methods. In each study, statistical analysis identified independent predictors of CVR in FMF. Based on regression coefficients of these predictors, a linear DS (discriminant score) was computed for every subject. Each study established an equation to assess CVR, calculate DS for FMF and determine the sensitivity and specificity of the DS cut-off. In each of the five studies, abnormal CVR was observed in FMF patients. The best accuracy (88% sensitivity and 90.1% specificity for FMF) was obtained by a method based on beat-to-beat heart rate and pulse transit time recordings. Data was processed by fractal and recurrence quantitative analysis with recordings in FMF patients compared with a mixed control population. Identification of disease-specific CVR patterns was possible with the methodologies described in the present study. In FMF, disease-specific CVR may be explained by the interplay between neuroendocrine loops specific to FMF with cardiovascular homoeostatic mechanisms. Recognition of disease-specific CVR patterns may advance the understanding of homoeostatic mechanisms and have implications in clinical practice.

Adult↗
PubMed2005

Cardiovascular reactivity in fibromyalgia: evidence for pathogenic heterogeneity.

OBJECTIVE: To evaluate disease-specific cardiovascular reactivity patterns in patients with fibromyalgia (FM) using a recently described method called fractal and recurrence analysis score (FRAS). METHODS: The study group included 30 women with FM, average age 46.7 years (SD 7.03). An age matched group of 30 women with other rheumatic disorders or having a dysautonomic background [chronic fatigue syndrome (CFS), non-CFS fatigue, neurally mediated syncope, and psoriatic arthritis (PsA)] served as controls. Subjects were evaluated with a head-up tilt test with beat-to-beat recording of the heart rate (HR) and pulse transit time. A 10-minute supine phase was followed by 600 cardiac cycles recorded on tilt. Data were processed by recurrence plot and fractal analysis. Variables acting as independent predictors of the cardiovascular reactivity were identified in FM patients versus controls. RESULTS: No statistically significant differences were found between the groups by univariate analysis comparing 92 variables of cardiovascular reactivity in FM patients compared to controls. CONCLUSION: Study of cardiovascular reactivity utilizing a head-up tilt test and processing the data using the FRAS method did not reveal a specific FM-associated abnormality. Our data confirm studies that utilized other methodologies and reached similar conclusions. Patients with FM represent a heterogenous group with respect to their pattern of cardiovascular reactivity.

Arthritis, Psoriatic↗
PubMed2004

Pulse transit time by R-wave-gated infrared photoplethysmography: review of the literature and personal experience.

OBJECTIVE: Pulse transit time (PTT) is the time it takes a pulse wave to travel between two arterial sites. A rela tively short PTT is observed with high blood pressure (BP), aging, arteriosclerosis and diabetes mellitus. Most methods used for measuring the PTT are cumbersome and expensive. In contrast, the interval between the peak of the R-wave on the electrocardiogram and the onset of the corresponding pulse in the finger pad measured by photoplethysmography can be easily measured. We review herein the literature and impart the experience at our institution on clinical applications of R-wave-gated photo-plethysmography (RWPP) as measurement of PTT. METHODS: The MEDLINE data base on clinical applications of RWPP was reviewed. In addition, studies performed in the author's institution are presented. RESULTS: When used as a surrogate for beat-to-beat BP monitoring, RWPP did not meet the level of accuracy required for medical practice (two studies). RWPP produced accurate and reproducible signals when utilized as a surrogate for intra-thoracic pressure changes in obstructive sleep apnea, as well as BP arousals which accompany central sleep apnea (five studies). In estimation of arterial stiffness, RWPP was unsatisfactory (one study). In assessment of cardiovascular reactivity, abnormal values of RWPP were noted in autonomic failure (one study), while disease-specific reactivity patterns were identified utilizing a method involving RWPP (two studies). CONCLUSIONS: In clinical practice, sleep-apnea may be accurately monitored by RWPP. RWPP seems to reflect autonomic influences and may be particularly well-suited for the study of vascular reactivity. Thus, further descriptions of disease-specific cardiovascular reactivity patterns may be possible with techniques based on RWPP. Other clinical uses of RWPP are investigational.

Blood Pressure↗
PubMed2004

The case for hepatitis C arthritis.

OBJECTIVE: To present the data available supporting the existence of an arthropathy associated with hepatitis C infection. METHODS: The MEDLINE database was searched for "arthritis" intersecting with "hepatitis C" in addition to the authors' investigations and experience on this subject. RESULTS: Arthritis, not otherwise explained, has been noted in 2% to 20% of hepatitis C virus (HCV) patients. This arthritis is rheumatoid-like in two thirds of the cases and a waxing/waning oligoarthritis in the rest. Cryoglobulinemia alone does not explain the arthritis, and there is difficulty in differentiating it from rheumatoid arthritis. The arthropathy is nonerosive/nondeforming. Whereas nonsteroidal anti-inflammatory drugs, low-dose corticosteroids, and hydroxychloroquine may be helpful, conventional treatment of arthritis may be problematic in the context of viral hepatitic arthropathy. Antiviral therapy is most effective, even without viral clearance, but rheumatic complications may ensue. CONCLUSIONS: HCV arthropathy should be considered in the differential diagnosis of new-onset arthritis.

Algorithms↗
PubMed2004

Dysautonomia in chronic fatigue syndrome: facts, hypotheses, implications.

The diagnosis of chronic fatigue syndrome (CFS) is based on patient history and treatment on cognitive behavior therapy and graded exercise. There is increasing evidence that dysautonomia occurs in CFS manifest primarily as disordered regulation of cardiovascular responses to stress. We impart our experience relating to diagnosis, monitoring, and treatment of CFS based on identification and management of dysautonomia. Recently proposed methods for assessment of the cardiovascular reactivity, the 'hemodynamic instability score' (HIS) and the 'Fractal and Recurrence Analysis-based Score' (FRAS), served for this purpose. On HUTT, a particular dysautonomia is revealed in CFS patients that differ from dysautonomia in several other disorders. This distinct abnormality in CFS can be identified by HIS >-0.98 (sensitivity 84.5% and specificity 85.1%) and FRAS > +0.22 (sensitivity 70% and specificity 88%). Therefore, the HIS and FRAS may be used, in the appropriate clinical context, to support the diagnosis of CFS, which until now, could only be subjectively inferred. A pilot study suggested that midodrine treatment, directed at the autonomic nervous system in CFS, results first in correction of dysautonomia followed by improvement of fatigue. This finding implies that dysautonomia is pivotal in the pathophysiology CFS, at least in a large part of the patients, and that manipulating the autonomic nervous system may be effective in the treatment of CFS.

Arrhythmias, Cardiac↗
PubMed2004

The feeling of fatigue--fatigue severity by unidimensional versus composite questionnaires.

The authors' purpose in this study was to compare the perception of fatigue severity as measured by different fatigue questionnaires. The authors evaluated 3 groups of patients in a cross-sectional study: chronic fatigue syndrome (CFS, n = 20), non-CFS fatigue (n = 20), and familial Mediterranean fever (FMF n = 25). In addition, the authors tracked 7 patients with CFS longitudinally for severity of fatigue. The severity of fatigue-related symptoms was assessed with 2 questionnaires: the unidimensional Chalder's Fatigue Severity Scale (CH) and the composite Fatigue Impact Scale (FI) which has 3 subscales--cognitive, physical, and social--and a total score. In the cross-sectional study, correlations between CH and FI cognitive scores were r = .78 (p < .0001), CH versus FI physical scores r = .603 (p < .0001), CH versus FI social scores r = .66 (p < .0001), and CH versus FI total scores r = .74 (p < .0001). In the longitudinal survey of CFS patients, the authors compared 30 questionnaires revealing correlations of CH versus FI cognitive scores r = .64 (p = .0004), CH versus FI physical r = .68 (p = .0001), CH versus FI social r = .87 (p < .0001), and CH versus FI total r = .90 (p < .0001). Fatigue severity as assessed by the unidimensional CH scale and the composite FI scale is comparable. The simple CH scale may be adequate for the assessment of the feeling of fatigue, in general, and for monitoring the severity of fatigue in CFS, in particular.

Cross-Sectional Studies↗
PubMed2003

Cardiovascular reactivity score for the assessment of dysautonomia in familial Mediterranean fever.

OBJECTIVE: The aim of this study was to assess the presence of dysautonomia, as manifested in abnormal cardiovascular reactivity, in patients with familial Mediterranean fever (FMF). METHODS: Fifty-five consecutive patients with FMF and 23 age- and sex-matched healthy controls were evaluated. Cardiovascular reactivity was studied: (1) using recordings of blood pressure (BP) and heart rate (HR) during 10 min of recumbence and 30 min of head-up tilt test to identify clinical endpoints and (2) during tilt-test, identifying parameters acting as independent predictors of FMF reactivity and enabling computation of a cardiovascular reactivity score (CVRS). RESULTS: Clinically, vasovagal reaction, postural tachycardia syndrome, and/or orthostatic hypotension were observed in ten patients (18.1%). Utilizing a derived equation, the group average CVRS in FMF was 5.83+/-1.78 (healthy group -7.60+/-5.41) ( P=<0.0001). A CVRS of >3.25 was associated with FMF, with 98% sensitivity and 100% specificity. CONCLUSION: A very high percentage of FMF patients exhibit abnormal cardiovascular reactivity which is clinically occult but can be detected on autonomic challenge and application of the CVRS.

Adult↗
PubMed2003

Quantitative liver-spleen scan using single photon emission computerized tomography (SPECT) for assessment of hepatic function in cirrhotic patients.

BACKGROUND/AIMS: Accurate quantitative determination of liver function is critical in cirrhotic patients in order to predict outcome, particularly in patients who undergo hepatic resection or non-hepatic surgery. As colloid uptake by perfused Kupffer cells is proportional to perfused hepatocyte mass, quantitative liver spleen scan may be used as an index of perfused hepatocyte mass. Thus, this study was conducted to evaluate quantitative single photon emission computerized tomography (SPECT) of Tc-99mm-phytate colloid uptake by the liver as a test for hepatic function in cirrhotic patients. METHODS: Quantitative SPECT was used to measure liver volume, quantitative colloid uptake by the liver and percentage of injected dose/ml of liver tissue in cirrhotic patients (n=75), non-cirrhotic patients with chronic liver disease (n=52) and patients without liver disease (n=36). RESULTS: Although liver volume was similar among the three groups, the cirrhotic patients had significantly lower total quantitative uptake and quantitative uptake/ml compared to groups 2 and 3 (P<0.001). Quantitative liver uptake in the cirrhotic patients was highly correlated with Child-Pugh score (r=-0.64, P<0.0001) and with indocyanine green retention at 15 min (r=-0.84, P<0.0001). CONCLUSIONS: Quantitative SPECT of the liver may be an additional, useful, non-invasive quantitative test for assessment of hepatic function and severity of liver disease in cirrhotic patients.

Adult↗
PubMed2003

Vascular disorders preceding diagnosis of cancer: distinguishing the causal relationship based on Bradford-Hill guidelines.

The literature investigating the association between vascular disorders and malignant neoplasms does not comprehensively review the full spectrum of vascular disorders associated with cancer, or provide proof that cancer is an etiologic factor in the development of these disorders. This paper investigates the causal role of cancer in the pathogenesis of vascular disorders, based on the Bradford-Hill criteria of causation. The Medline database was searched for articles on vascular disorders preceding the diagnosis of cancer (VDPCD). Included in the analysis were vascular disorders caused either by direct tumoral involvement of vessels or by paraneoplastic mechanisms. Vascular disorders caused by adverse reactions to anticancer therapy were excluded from analysis. Seven categories of VDPCDs were recognized: venous thromboembolism, arterial thrombosis and embolism, nonbacterial thrombotic endocarditis, migratory superficial thrombophlebitis, vasculitis, thrombotic microangiopathy, and leukothrombosis. To establish causality of the association between VDPCDs and malignancy, the degree of fulfillment of the Bradford-Hill criteria was assessed. A strong association was found in the literature between venous thromboembolism and cancer (OR 2.3-14.9 and SIR 1.3-4.4). Consistency and temporality of the association were confirmed in all VDPCD variants. Seven Bradford-Hill criteria were fulfilled for cancer associated with venous thromboembolism, six criteria for superficial phlebitis and cancer, and five criteria for each of the other VDPCDs. In conclusion, these data support the causal role of cancer in the pathogenesis of all seven categories of VDPCDs. Recognition of such a causal link between cancer and various vascular disorders may promote an earlier cancer diagnosis.

Causality↗
PubMed2002

Systemic sclerosis sine scleroderma: is it always the same disease? Report of three patients and discussion.

The recent description of a large cohort of patients with the diagnosis of systemic sclerosis sine scleroderma (ssSSc) provided significant progress in our understanding of this entity. The prognosis of patients with ssSSc is, however, very variable, from benign in most cases to rapidly disabling in others. By reporting three new cases and analyzing previously published data, we discuss possible subsets and variants of the disease form.

Adolescent↗
PubMed2002

Fractal analysis and recurrence quantification analysis of heart rate and pulse transit time for diagnosing chronic fatigue syndrome.

This study aimed to develop a method to distinguish between the cardiovascular reactivity in chronic fatigue syndrome (CFS) and other patient populations. Patients with CFS (n = 23), familial Mediterranean fever (n = 15), psoriatic arthritis (n = 10), generalized anxiety disorder (n = 12), neurally mediated syncope (n = 20), and healthy subjects (n = 20) were evaluated with a shortened head-up tilt test (HUTT). A 10-minute supine phase of the HUTT was followed by recording 600 cardiac cycles on tilt, i. e., 5 to 10 minutes. Beat-to-beat heart rate (HR) and pulse transit time (PTT) were acquisitioned. Data were processed by recurrence plot and fractal analysis. Fifty-two variables were calculated in each subject. On multivariate analysis, the best predictors of CFS were HR-tilt-R/L, PTT-tilt-R/L, HR-supine-DET, PTT-tilt-WAVE, and HR-tilt-SD. Based on these predictors, the 'Fractal & Recurrence Analysis-based Score' (FRAS) was calculated: FRAS = 76.2 + 0.04*HR-supine-DET - 12.9*HR-tilt-R/L - 0.31*HR-tilt-SD - 19.27*PTT-tilt-R/L - 9.42* PTT-tilt-WAVE. The best cut-off differentiating CFS from the control population was FRAS = + 0.22. FRAS > + 0.22 was associated with CFS (sensitivity 70 % and specificity 88 %). The cardiovascular reactivity received mathematical expression with the aid of the FRAS. The shortened HUTT was well tolerated. The FRAS provides objective criteria which could become valuable in the assessment of CFS.

Anxiety Disorders↗