Clinical Physiology and Functional Imaging (Clin Physiol Funct Imag)

Publications in this journal

• Article: Lower limb vascular conductance and resting popliteal blood flow during head-up and head-down postural challenges.

  Rodrigo Villar, Richard L Hughson
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  ABSTRACT: This study hypothesized that central and local reflex mechanisms affecting vascular conductance (VC) through the popliteal artery compensated for the reduction in muscle perfusion pressure (MPP) to maintain popliteal blood flow (PBF) during head-down tilt (35˚ HDT), but not in head-up tilt (45˚ HUT). Resting measurements were made on 15 healthy men in prone position to facilitate the access to the popliteal artery, on two separate days in random order during horizontal (HOR), HDT or HUT. In each body position, the body was supported, and the ankles were maintained in relaxed state so that there was no muscle tension, as with normal standing. Popliteal blood flow velocity and popliteal arterial diameter were measured by ultrasound, and PBF was calculated. MPP was corrected to mid-calf from measured finger cuff pressure, and VC was estimated by dividing PBF by MPP. The MPP in HDT (48 ± 2 mmHg) was ~100mmHg less than in HUT (145 ± 2 mmHg). PBF was similar between HOR (51 ± 18 ml( ) min(-1) ) and HDT (47 ± 13 ml min(-1) ), but was lower in HUT (30 ± 9 ml min(-1) ). VC was different between HDT (1·0 ± 0·3 ml min(-1) mmHg(-1) ), HOR (0·6 ± 0·2 ml min(-1) mmHg(-1) ) and HUT (0·2 ± 0·1 ml min(-1) mmHg(-1) ). In conclusion, the interactions of central and local regulatory mechanisms resulted in a disproportionate reduction of VC during HUT lowering PBF even though MPP was higher, while in HDT, increased VC contributed to maintain PBF at the same level as the HOR control condition.
  Clinical Physiology and Functional Imaging 05/2013; 33(3):186-91.
• Article: Plasma oxidative stress is induced by single-sprint anaerobic exercise in young cigarette smokers.

  Shunsuke Taito, Kiyokazu Sekikawa, Keisuke Oura, Norimichi Kamikawa, Ryosuke Matsuki, Tatsushi Kimura, Makoto Takahashi, Tsutomu Inamizu, Hironobu Hamada
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  ABSTRACT: Cigarette smoking increases oxidative stress, which is a risk factor for several diseases. Smoking has also been reported to enhance plasma oxidative stress during strenuous exercise. However, no prior study has examined the changes in plasma oxidative stress after single-sprint anaerobic exercise in cigarette smokers. The purpose of this study was to investigate these changes in young cigarette smokers by measuring reactive oxygen species generation and total antioxidant content. Participants were 15 male smokers (mean age: 25·9 ± 2·9 years) and 18 male non-smokers (mean age: 24·2 ± 4·3 years). Hydroperoxide concentration and biological antioxidant potential (BAP) in plasma were measured at baseline and after the Wingate anaerobic test. A significant interaction between group and time was observed for plasma hydroperoxide concentration (P = 0·037). Plasma hydroperoxide concentration was significantly increased after exercise in both smokers and non-smokers (P = 0·001 and <0·001, respectively). However, no significant interaction was observed between groups by time on plasma BAP (P = 0·574), and a main effect of time was observed (P<0·001). Plasma BAP was significantly increased after exercise in both groups (both, P<0·001). These findings indicate that plasma oxidative stress is higher in cigarette smokers than in non-smokers after single-sprint anaerobic exercise, which may increase the risk of oxidative damage.
  Clinical Physiology and Functional Imaging 05/2013; 33(3):241-4.
• Article: (99m) Tc-labelled human serum albumin cannot replace (125) I-labelled human serum albumin to determine plasma volume in patients with liver disease.

  Ulrik Lütken Henriksen, Jens H Henriksen, Flemming Bendtsen, Søren Møller
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  ABSTRACT: Determination of plasma volume (PV) is important in several clinical situations. Thus, patients with liver disease often have augmented PV as part of their sodium-water retention. This study was undertaken to compare PV determination by two indicators: technetium-labelled human serum albumin ((99m) Tc-HSA) and iodine-labelled human serum albumin ((125) I-HSA), as the former may have advantages at repeated measurements and the latter is the classical gold standard. In 88 patients, (64 with liver disease, mainly cirrhosis, and 24 patients without liver disease), simultaneous measurements of PV were taken with (99m) Tc-HSA and (125) I-HSA after 1 h in the supine position. Blood samples were obtained before and 10 min after quantitative injection of the two indicators. In a subset of patients (n = 32), the measurements were repeated within 1 h. In all patients, a close correlation was present between PV determined by the two indicators (r = 0·89, P<0·0001). In all, but twelve patients, a higher PV was obtained with (99m) Tc-HSA compared with (125) I-HSA (P<0·0001). PV determined with (99m) Tc-HSA exceeded PV determined with (125) I-HSA by 367 ml (5·2 ml kg(-1) ) in liver patients as compared to 260 ml (3·5 ml kg(-1) ) in patients without liver disease (P<0·05). The precision of repeated PV determination was 1·75% (coefficient of variation) with (99m) Tc-HSA and 1·71% with (125) I-HSA (ns), and similar values were found in patients with and without liver disease. The study demonstrates that (99m) Tc-HSA has the same precision as that of (125) I-HSA. However, especially in patients with liver disease, (99m) Tc-HSA consistently overestimates the PV, most likely owing to indicator heterogeneity with subsequent fast removal from the circulating medium with a higher volume of distribution as the outcome.
  Clinical Physiology and Functional Imaging 05/2013; 33(3):211-7.
• Article: A combined test of acetylcholine-mediated vasodilation of both the forearm resistance vessels and the radial artery.

  Lars Lind
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  ABSTRACT: To evaluate a new combined test of endothelium-dependent vasodilation (EDV) in the forearm resistance vessel and the radial artery. Acetylcholine (ACh) and sodium nitroprusside (SNP) infusion in the brachial artery were used to simultaneous evaluate EDV and endothelium-independent vasodilation (EIDV) in forearm resistance vessels (plethysmography) and in the radial artery (ultrasound) in 76 healthy subjects. Brachial artery ultrasound was used to assess flow-mediated vasodilation (FMD). Acetylcholine induced a 4·5% (median value, P = 0·0010) increase in the radial artery diameter, while SNP induced a 31·2% increase in diameter (P<0·0001). While no increase in radial artery blood flow was induced by ACh (P = 0·69), an increase by 181% in radial blood flow was induced by SNP (P<0·0001). When relating the radial artery diameter data to FMD, the change in radial artery diameter induced by ACh was significantly correlated with FMD (r = 0·35, P = 0·013). No such relationship was seen for the diameter change induced by SNP (r = -0·03, P = 0·81). When relating the radial artery blood flow data to EDV and EIDV, the change in radial artery blood flow induced by ACh was significantly correlated with EDV in an inverse fashion (r = -0·42, P = 0·0032). No such relationship was seen for the blood flow change induced by SNP when related to EIDV (r = -0·07, P = 0·63). Simultaneous measurements of blood flow in forearm vessels by plethysmography and in the radial artery by ultrasound during ACh infusion is a new way to assess EDV in both resistance and conduit arteries during one investigation.
  Clinical Physiology and Functional Imaging 05/2013; 33(3):206-10.
• Article: Long-term prognostic value of inducible and resting perfusion defects detected by single-photon emission computed tomography in the era of wide availability of coronary revascularization.

  Dominika Filipiak-Strzecka, Ewelina Kowalczyk, Piotr Hamala, Nina Kot, Jarosław D Kasprzak, Jacek Kuśmierek, Anna Płachcińska, Piotr Lipiec
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  ABSTRACT: To assess the long-term prognostic value of various types of perfusion defects detected by single-photon emission computed tomography (SPECT) in patients with stable angina. Seven hundred and thirty two patients (299 men, mean age 57 ± 9 years) with suspected or known stable coronary artery disease underwent rest/exercise SPECT protocol using 99mTc-methoxyisobutylisonitrile (MIBI). All patients completed clinical follow-up regarding cardiac events (cardiac death, sudden cardiac death, acute coronary syndrome, revascularization, cardiac hospitalization) for a mean period of 58 ± 8 months. Event rates were analysed in subgroups defined according to the presence of fixed or inducible myocardial perfusion defects. During the follow-up, 15 cardiac deaths were recorded, 13 of which were qualified as a sudden cardiac death, 59 acute coronary syndromes, 65 revascularizations and 209 cardiac hospitalizations. The presence of inducible perfusion defects on SPECT was associated with a high risk for occurrence of all analysed end points: sudden cardiac death (HR = 3·96, P = 0·01), cardiac hospitalization (HR = 1·5, P = 0·004), coronary syndrome (HR = 2·33, P = 0·001) and coronary revascularization (HR = 2·76, P = 0·0002), except for the cardiac death (P = 0·27). Resting perfusion defects were highly predictive for cardiac death (HR = 7·45; P = 0·001), but not for other cardiac events (P = NS). The presence of any (inducible or resting) perfusion defects was associated with a high risk of all cardiovascular complications. In long-term follow-up, SPECT proved highly predictive of cardiac events in patients with suspected or known CAD. In the revascularization era, cardiac death is most accurately related to the presence of resting perfusion defects, but all other cardiac events were better predicted by inducible perfusion defects.
  Clinical Physiology and Functional Imaging 05/2013; 33(3):218-23.
• Article: Reliability of endogenous markers for estimation of residual renal function in haemodialysis patients.

  Krista D Kjaergaard, Michael Rehling, Jens D Jensen, Bente Jespersen
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  ABSTRACT: Residual renal function in haemodialysis patients is of increasing interest. However, reproducibility and agreement between methods to measure and estimate glomerular filtration rate (GFR) require further elucidation. The aim of this study was to evaluate the accuracy and reproducibility of GFR estimates based on endogenous markers in haemodialysis patients. Twelve patients were examined twice. GFR was estimated by (i) urine clearances of creatinine, urea and the average of creatinine and urea clearance [U-Cl(crea-urea)]; (ii) an equation based on serum concentration of cystatin C [eGFR(CysC)]. These were compared to (51) Cr-EDTA clearance in plasma [P-Cl(EDTA)] and urine [U-Cl(EDTA)]. U-Cl(crea-urea) produced results similar to U-Cl(EDTA). eGFR(CysC) had a low week-to-week variability. Visually, eGFR(CysC) differed from y = x when compared to the other methods indicating bias, probably due to extrarenal elimination of cystatin C. Coefficients of variation were significantly different, P<0·001: P-Cl(EDTA), 10%; U-Cl(EDTA), 13%; and U-Cl(crea-urea), 13%. P-Cl(EDTA) was 2·1 ml min(-1) 1·73 m(-2) higher than U-Cl(EDTA) (mean). Glomerular filtration rate in haemodialysis patients can be estimated from U-Cl(crea-urea) when complete urine collection is performed. The available eGFR(CysC) in haemodialysis patients seemed to be biased, and further development and validation is desirable. P-Cl(EDTA) was the most reproducible method and might be useful in special situations.
  Clinical Physiology and Functional Imaging 05/2013; 33(3):224-32.
• Article: Update of exocrine functional diagnostics in chronic pancreatitis.

  Camilla Nøjgaard, Søren Schou Olesen, Jens Brøndum Frøkjaer, Asbjørn Mohr Drewes
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  ABSTRACT: Diagnostics of pancreatic insufficiency rely mainly on tests of pancreatic exocrine function based on either measurement of pancreatic secretion or the secondary effects resulting from lack of digestive enzymes or imaging modalities. These methods have been developing rapidly over the last decades, and the aims of this review were to describe exocrine functional testing and imaging of the pancreas in chronic pancreatitis..
  Clinical Physiology and Functional Imaging 05/2013; 33(3):167-72.
• Article: Ultrasound imaging of the serratus anterior muscle at rest and during contraction.

  Nancy R Talbott, Dexter W Witt
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  ABSTRACT: The purpose of this study is to describe a clinically feasible method for measuring the thickness of the serratus anterior (SA) muscle using rehabilitative ultrasound imaging (RUSI) and to determine the reliability of repeated measures of that method. An exploratory clinical measurement study using a test-retest methodology was utilized to determine the reliability of the measurements in a sample of 20 healthy subjects. While sitting with the arm flexed 120°, the SA of each subject was imaged at rest, during an active hold and while holding a three pound weight. On Day 1, images were repeated three times for each condition by the same examiner. On Day 2, Examiner 1 and Examiner 2 repeated the scans. Images were examined offline by Examiner 1 with SA thickness measured superior to the most distal rib in the image. Reliability was evaluated using intraclass correlation coefficients (ICCs) and Bland-Altman plots. The intra-examiner reliability (same day) during rest, active hold and active hold with resistance was ICC3,3 = 0·892; ICC3,3 = 0·951; and ICC3,3 = 0·869-0·971, respectively. Intra-examiner reliability between days ranged from ICC3,2 = 0·613 at rest to ICC3,2 = 0·736 during active hold with resistance. Interexaminer reliability was moderate during active hold (ICC2,2 = 0·526) and active hold with resistance (ICC2,2 = 0·535) and poor during rest (ICC2,2 = 0·425). This study demonstrates that SA thickness can be measured reliably using RUSI by the same examiner and suggests that active movements may increase that reliability.
  Clinical Physiology and Functional Imaging 05/2013; 33(3):192-200.
• Article: Small animal positron emission tomography imaging and in vivo studies of atherosclerosis.

  Anne Mette Fisker Hag, Rasmus Sejersten Ripa, Sune Folke Pedersen, Rasmus Poul Bodholdt, Andreas Kjaer
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  ABSTRACT: Atherosclerosis is a growing health challenge globally, and despite our knowledge of the disease has increased over the last couple of decades, many unanswered questions remain. As molecular imaging can be used to visualize, characterize and measure biological processes at the molecular and cellular levels in living systems, this technology represents an opportunity to investigate some of these questions in vivo. In addition, molecular imaging may be translated into clinical use and eventually pave the way for more personalized treatment regimes in patients. Here, we review the current knowledge obtained from in vivo positron emission tomography studies of atherosclerosis performed in small animals.
  Clinical Physiology and Functional Imaging 05/2013; 33(3):173-85.
• Article: Cardiac power output and its response to exercise in athletes and non-athletes.

  Aleksandar V Klasnja, Djordje G Jakovljevic, Otto F Barak, Jelena Z Popadic Gacesa, Damir D Lukac, Nikola G Grujic
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  ABSTRACT: Cardiac power output (CPO) is an integrative measure of overall cardiac function as it accounts for both, flow- and pressure-generating capacities of the heart. The purpose of the present study was twofold: (i) to assess cardiac power output and its response to exercise in athletes and non-athletes and (ii) to determine the relationship between cardiac power output and reserve and selected measures of cardiac function and structure. Twenty male athletes and 32 age- and gender-matched healthy sedentary controls participated in this study. CPO was calculated as the product of cardiac output and mean arterial pressure, expressed in watts. Measures of hemodynamic status, cardiac structure and pumping capability were assessed by echocardiography. CPO was assessed at rest and after peak bicycle exercise. At rest, the two groups had similar values of cardiac power output (1·08 ± 0·2 W versus 1·1 ± 0·24 W, P>0·05), but the athletes demonstrated lower systolic blood pressure (109·5 ± 6·2 mmHg versus 117·2 ± 8·2 mmHg, P<0·05) and thicker posterior wall of the left ventricle (9·8 ± 1 mm versus 9 ± 1·1 mm, P<0·05). Peak CPO was higher in athletes (5·87 ± 0·75 W versus 5·4 ± 0·69 W, P<0·05) as was cardiac reserve (4·92 ± 0·66 W versus 4·26 ± 0·61 W, P<0·05), respectively. Peak exercise CPO and reserve were only moderately correlated with end-diastolic volume (r = 0·54; r = 0·46, P<0·05) and end-diastolic left ventricular internal diameter (r = 0·48; r = 0·42, P<0·05), respectively. Athletes demonstrated greater maximal cardiac pumping capability and reserve than non-athletes. The study provides new evidence that resting measures of cardiac structure and function need to be considered with caution in interpretation of maximal cardiac performance.
  Clinical Physiology and Functional Imaging 05/2013; 33(3):201-5.
• Article: Vascular adaptations induced by 6 weeks WBV resistance exercise training.

  Tobias Weber, Asa Beijer, André Rosenberger, Edwin Mulder, Pengfei Yang, Eckhard Schönau, Wilhelm Bloch, Jörn Rittweger
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  ABSTRACT: The impact of whole-body vibration (WBV) upon the cardiovascular system is receiving increasing attention. Despite numerous studies addressing the acute cardiovascular effects of WBV training, very little is known regarding long-term adaptations in healthy humans. A 6-week training study, with a 70 days follow-up was designed to compare resistive exercise with or without super-imposed whole-body vibrations. Arterial diameter, intima media thickness and flow-mediated dilation (FMD) were assessed by ultrasonography in the superficial femoral artery (SFA), the brachial (BA) and the carotid arteries (CA). SFA resting diameter was increased from 6·22 mm (SD = 0·69 mm) at baseline to 6·52 mm (SD = 0·74 mm) at the end of the training period (P = 0·03) with no difference between groups (P = 0·48). Arterial wall thickness was significantly reduced by 4·3% (SD = 11%) in the CA only (P = 0·04). FMD was not affected by any of the interventions and in any of the investigated arteries. To the best of our knowledge, this has been the first study to show that the superposition of vibration upon conventional resistance exercise does not have a specific effect upon long-term vascular adaptation in asymptomatic humans. Our findings seem to be at variance with the findings observed in a bed-rest setting. One possible explanation could be that the independently saturable effects of flow-mediated versus acceleration-related endothelial shear stresses on arterial structure and function differ between ambulatory and bed-rest conditions.
  Clinical Physiology and Functional Imaging 03/2013; 33(2):92-100.
• Article: Absence of parasympathetic reactivation after maximal exercise.

  Tiago Peçanha de Oliveira, Raphael de Alvarenga Mattos, Rhenan Bartels Ferreira da Silva, Rafael Andrade Rezende, Jorge Roberto Perrout de Lima
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  ABSTRACT: The ability of the human organism to recover its autonomic balance soon after physical exercise cessation has an important impact on the individual's health status. Although the dynamics of heart rate recovery after maximal exercise has been studied, little is known about heart rate variability after this type of exercise. The aim of this study is to analyse the dynamics of heart rate and heart rate variability recovery after maximal exercise in healthy young men. Fifteen healthy male subjects (21·7 ± 3·4 years; 24·0 ± 2·1 kg m(-2) ) participated in the study. The experimental protocol consisted of an incremental maximal exercise test on a cycle ergometer, until maximal voluntary exhaustion. After the test, recovery R-R intervals were recorded for 5 min. From the absolute differences between peak heart rate values and the heart rate values at 1 and 5 min of the recovery, the heart rate recovery was calculated. Postexercise heart rate variability was analysed from calculations of the SDNN and RMSSD indexes, in 30-s windows (SDNN(30s) and RMSSD(30s) ) throughout recovery. One and 5 min after maximal exercise cessation, the heart rate recovered 34·7 (±6·6) and 75·5 (±6·1) bpm, respectively. With regard to HRV recovery, while the SDNN(30s) index had a slight increase, RMSSD(30s) index remained totally suppressed throughout the recovery, suggesting an absence of vagal modulation reactivation and, possibly, a discrete sympathetic withdrawal. Therefore, it is possible that the main mechanism associated with the fall of HR after maximal exercise is sympathetic withdrawal or a vagal tone restoration without vagal modulation recovery.
  Clinical Physiology and Functional Imaging 03/2013; 33(2):143-9.
• Article: Head-to-head comparison between Actigraph 7164 and GT1M accelerometers in adolescents.

  Tina Tanha, Asa B Tornberg, Per Wollmer, Magnus Dencker
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  ABSTRACT: We compared, head-to-head, the old generation Actigraph model 7164 with the new generation Actigraph GT1M accelerometer. A total of 15 randomly selected teenagers (eight girls and seven boys) were investigated. They performed a treadmill test wearing the two kinds of accelerometers around the waist simultaneously. The treadmill test consisted of three different levels of speed 4, 6 and 8 km h(-1) for four consecutive minutes. Accelerometer counts per 1 sec epoch for the Actigraph GT1M versus the Actigraph 7164 were at 4 km h(-1) 21·6 ± 12·9 versus 26·5 ± 11·5 counts, at 6 km h(-1) 56·0 ± 23·2 versus 62·9 ± 25·6 counts and at 8 km h(-1) 142·6 ± 37·2 versus 156·4 ± 34·9 counts (P<0·01 for all levels of speed). Data from the old generation Actigraph 7164 and the new generation Actigraph GT1M accelerometers differ, where the Actigraph GT1M generates 10-23% lower values. Correction equation for Actigraph GT1M was Actigraph 7164 = 5·2484 + Actigraph GT1M counts × 1·0448. These results need to be taken into consideration when using these devices.
  Clinical Physiology and Functional Imaging 03/2013; 33(2):162-5.
• Article: Effect of 2 days of intensive resistance training on appetite-related hormone and anabolic hormone responses.

  Kazushige Goto, Kohei Shioda, Sunao Uchida
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  ABSTRACT: This study was designed to determine endocrine responses during 2 days of strenuous resistance training. Ten healthy men performed resistance training twice a day for two successive days to induce acute fatigue (excessive physical stress). The resistance training consisted of four exercises for the lower body in the morning and seven exercises for the upper body in the afternoon. Maximal isometric and isokinetic strengths were measured from day 1 (before the training period) to day 3 (after the training period). Fasting blood samples were taken on days 1-3. Maximal isometric and isokinetic strengths significantly decreased with two successive days of training (P<0·05), with significant increases in serum creatine phosphokinase and myoglobin concentrations (P<0·05). Significant reductions in the fasting concentrations of serum insulin-like growth factor-1, free testosterone, insulin and high-molecular-weight adiponectin were observed on day 3 (P<0·05), whereas there were no changes in the serum cortisol concentration or the free testosterone/cortisol ratio. Plasma active ghrelin and serum leptin concentrations decreased by -20·7 ± 2·8% and -29·6 ± 4·1%, respectively (P<0·05). Two days strenuous resistance training significantly affects the profiles of anabolic hormone and endocrine regulators of appetite and energy balance, such as ghrelin and leptin. The present findings suggest that decreased ghrelin and leptin concentrations might reflect excessive physical stress and may be early signs of accumulated fatigue.
  Clinical Physiology and Functional Imaging 03/2013; 33(2):131-6.
• Article: The echogenicity of the intima-media complex in the common carotid artery is related to insulin resistance measured by the hyperinsulinemic clamp in elderly men.

  Lars Lind, Martin Wohlin, Bertil Andren, Johan Sundström
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  ABSTRACT: The echogenicity of the intima-media complex (IM-GSM) has recently been shown to be related to the echogenicity in carotid artery plaque and to predict cardiovascular (CV) mortality. The present study aims to evaluate the relationship between metabolic CV risk factors, with special emphasis on insulin resistance, and IM-GSM in the carotid artery. Carotid artery ultrasound with grey-scale median analysis of the intima-media complex, IM-GSM, was performed in a population sample of 480 men aged 75 years. In these subjects, a euglycemic hyperinsulinemic clamp to investigate insulin resistance was performed together with measurements of conventional CV risk factors at the age of 70. The metabolic syndrome (MetS) was defined by the NCEP/ATPIII-criteria. In univariate analysis, IM-GSM in the common carotid artery was inversely correlated with the intima-media thickness (IMT), body mass index (BMI), waist/hip ratio, fasting glucose, serum triglycerides, low HDL cholesterol and insulin resistance at the clamp (r = -0·24, P<0·001). In multiple regression analysis, only insulin resistance at the clamp and BMI were independently related to IM-GSM. Subjects with the MetS (22%) showed a reduced IM-GSM when compared to those without (64 ± 20 SD versus 68 ± 19, P<0·05). Because the echogenicity of the intima-media complex in the carotid artery is related to obesity and insulin resistance at clamp independently of IMT, this new vascular characteristic would serve as a marker of vascular alterations induced by insulin resistance and the MetS and has the advantage to be obtainable in almost all subjects.
  Clinical Physiology and Functional Imaging 03/2013; 33(2):137-42.
• Article: Validation of the BCIS-1 Myocardial Jeopardy score using cardiac magnetic resonance perfusion imaging.

  Geraint D J Morton, Kalpa De Silva, Masaki Ishida, Amedeo Chiribiri, Andreas Indermuehle, Andreas Schuster, Simon Redwood, Eike Nagel, Divaka Perera
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  ABSTRACT: The recently described angiographic BCIS-1 Myocardial Jeopardy Score (BCIS-JS) provides a semi-quantitative estimate of the extent of coronary artery disease (CAD). It is simple to use and applicable to all patients including those with bypass grafts. Our objective was to validate the BCIS-JS by evaluating its correlation with myocardial ischaemic burden and its accuracy at predicting a prognostic ischaemic threshold. Seventy-five patients with angina and known or suspected CAD referred for coronary angiography prospectively underwent high-resolution CMR perfusion imaging. There was good correlation between the BCIS-JS and myocardial ischaemic burden: r = 0·75, P<0·0001. Area under the ROC curve for BCIS-JS to detect ≥12% myocardial ischaemic burden was 0·87 (95% CI 0·78-0·96). BCIS-JS ≥6 predicted ≥12% myocardial ischaemic burden with a sensitivity of 68% and a specificity of 91%. The BCIS-JS correlates well with myocardial ischaemic burden. A BCIS-JS ≥6 predicts the prognostically important ischaemic threshold of 12% with high specificity. These findings demonstrate that the BCIS-JS has functional relevance and support its utility for classification of CAD burden in clinical trials and in clinical practice.
  Clinical Physiology and Functional Imaging 03/2013; 33(2):101-8.
• Article: Autonomic nervous system profile in fibromyalgia patients and its modulation by exercise: a mini review.

  Poorvi Kulshreshtha, Kishore K Deepak
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  ABSTRACT: This review imparts an impressionistic tone to our current understanding of autonomic nervous system abnormalities in fibromyalgia. In the wake of symptoms present in patients with fibromyalgia (FM), autonomic dysfunction seems plausible in fibromyalgia. A popular notion is that of a relentless sympathetic hyperactivity and hyporeactivity based on heart rate variability (HRV) analyses and responses to various physiological stimuli. However, some exactly opposite findings suggesting normal/hypersympathetic reactivity in patients with fibromyalgia do exist. This heterogeneous picture along with multiple comorbidities accounts for the quantitative and qualitative differences in the degree of dysautonomia present in patients with FM. We contend that HRV changes in fibromyalgia may not actually represent increased cardiac sympathetic tone. Normal muscle sympathetic nerve activity (MSNA) and normal autonomic reactivity tests in patients with fibromyalgia suggest defective vascular end organ in fibromyalgia. Previously, we proposed a model linking deconditioning with physical inactivity resulting from widespread pain in patients with fibromyalgia. Deconditioning also modulates the autonomic nervous system (high sympathetic tone and a low parasympathetic tone). A high peripheral sympathetic tone causes regional ischaemia, which in turn results in widespread pain. Thus, vascular dysregulation and hypoperfusion in patients with FM give rise to ischaemic pain leading to physical inactivity. Microvascular abnormalities are also found in patients with FM. Therapeutic interventions (e.g. exercise) that result in vasodilatation and favourable autonomic alterations have proven to be effective. In this review, we focus on the vascular end organ in patients with fibromyalgia in particular and its modulation by exercise in general.
  Clinical Physiology and Functional Imaging 03/2013; 33(2):83-91.
• Article: Cerebral oxygen saturation evaluated by near-infrared time-resolved spectroscopy (TRS) in pregnant women during caesarean section - a promising new method of maternal monitoring.

  Kaori Yamazaki, Kazunao Suzuki, Hiroaki Itoh, Keiko Muramatsu, Kotomi Nagahashi, Naoaki Tamura, Toshiyuki Uchida, Kazuhiro Sugihara, Hideki Maeda, Naohiro Kanayama
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  ABSTRACT: Time-resolved spectroscopy (TRS-20) measures tissue oxygen saturation (%) by evaluating the absolute concentrations of oxygenated, deoxygenated and total haemoglobin based on measurement of the transit time of individual photons through a tissue of interest. We measured tissue oxygen saturation in the prefrontal lobes of the brain by TRS-20 in eighteen pregnant women during caesarean section. In a case of placenta previa, massive bleeding immediately decreased cerebral oxygen saturation from 67·2% to 54·2%, but did not alter peripheral tissue oxygenation as measured by pulse oximetry. Four cases of pre-eclampsia revealed chronic changes in elevated base levels of cerebral oxygen saturation, though peripheral oxygen saturation was similar to that in normotensive pregnant women. Average cerebral oxygen saturation in the cases of pre-eclampsia before the introduction of anaesthesia was 73·6 ± 4·4 (SD)% (n = 4), significantly higher than in normotensive pregnant women, 67·2 ± 4·3% (n = 13, P<0·05). Z-scores of cerebral oxygen saturation prior to anaesthesia positively correlated with those of systolic or diastolic blood pressure. TRS-20 could detect acute as well as chronic changes in brain oxygen saturation in response to pregnancy-associated complications.
  Clinical Physiology and Functional Imaging 03/2013; 33(2):109-16.
• Article: Speckle-tracking analysis based on 2D echocardiography does not reliably measure left ventricular torsion.

  Valentina Parisi, Maria Angela Losi, Carla Contaldi, Elena Chiacchio, Fabio Pastore, Alessandra Scatteia, Alessandra Giamundo, Carlo di Nardo, Raffaella Lombardi, Sandro Betocchi
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  ABSTRACT: Worldwide left ventricular (LV) twist is measured by 2D speckle tracking acquiring apical short axis at a LV level where papillary muscles are no longer visible; however, we hypothesized that this methodological recommendation is not enough accurate to obtain a reliable measurement of apical rotation. We measured twist and untwist rate in 30 healthy subjects by following the earlier method. By 3D echocardiography, we identified two LV apex levels: (i) 3D Apex, defined as the last apical slice at which LV cavity was visible; (ii) 2D Apex, defined as the level where diameters are equal to those of apical LV short axis used for twist analysis in the same subject. The ratio between the distance of 2D Apex and 3D Apex from LV base was calculated and expressed as percentage (2D Apex/3D Apex). 2D Apex/3D Apex was strongly related to the magnitude of twist and untwisting rate (r = 0·82, P<0·001; r = -0·46, P = 0·015, respectively). The only determinant of twist was 2D Apex/3D Apex (r(2) = 0·68; r = 0·82; F ratio: 52·6, P<0·001); whereas untwisting rate was influenced by 2D Apex/3D Apex and age (r(2) = 0·42; r = 0·65; F ratio: 7·7; P = 0·003 for 2D Apex/3D Apex; and P = 0·011 for age). Left ventricular apical level acquisition, even when recorded in a standard manner, determines variability of twist mechanics measurements. Thus, current anatomical markers used to identify LV apex for twist analysis are not reliable and need different standardization. 3D echocardiography may help in such standardization.
  Clinical Physiology and Functional Imaging 03/2013; 33(2):117-21.