Lower leg electrical impedance after distal bypass surgery

Electrical impedance was determined in 13 patients following distal bypass surgery to evaluate lower leg oedema as reflected by its circumference. Tissue injury was assessed by the plasma concentration of muscle enzymes. After surgery, the volume of the control lower leg increased from 1250 (816–2373) to 1384 (874–2345) ml (median and range; P<0·05), where the impedance did not change significantly from 140 (92–181) ohms. The volume of the operated leg increased more [from 1129 (824–2373) to 1600 (1090–2837) ml], and the decrease in electrical impedance was also pronounced [137 (125–169) to 83 (69–104) ohms (P<0·001)]. Tissue injury after surgery was indicated by an increase in total creatine kinase (n = 17) and MB isoenzyme of creatine kinase (n = 8) (P<0·05). Myoglobin (n = 8) had increased already during surgery (P<0·05), whereas there was no significant change in the plasma concentration of troponin I (n = 8). In conclusion, tissue injury was reflected by increases in muscle enzymes in plasma. We found an inverse correlation between lower leg electrical impedance and volume, but the deviation in electrical impedance was approximately twice that of the leg volume. Electrical impedance appears to be a useful method for the evaluation of lower leg oedema after distal bypass surgery.     

Venous circulation after fasciotomy of the lower leg in man

Summary. The study was performed in order to evaluate the effect of fasciotomy of the lower leg on venous circulation and venous muscle pump function. Twenty patients with unilateral fasciotomy were investigated with photoplethysmography (PPG), strain-gauge plethysmography, foot volumetry and Doppler ultrasound. In the operated legs shorter venous refilling times were registered both with PPG (P<0·1) and foot volumetry (P<0·05). PPG recordings from different parts of the leg showed regional changes in venous circulation with shorter refilling times only with the transducer placed over the affected muscular compartment. With foot volumetry a reduced expelled volume was found in patients earlier treated with extensive fasciotomies. The results of the study indicate that an intact muscle fascia is of importance for venous return and venous pump function.     

Vasoactive neuroendocrine responses associated with tolerance to lower body negative pressure in humans

The purpose of this investigation was to test the hypothesis that peripheral vasoconstriction and orthostatic tolerance are associated with increased circulating plasma concentrations of noradrenaline, vasopressin and renin–angiotensin. Sixteen men were categorized as having high (HT, n=9) or low (LT, n=7) tolerance to lower body negative pressure (LBNP) based on whether the endpoint of their pre‐syncopal‐limited LBNP (peak LBNP) exposure exceeded ?60 mmHg. The two groups were matched for age, height, weight, leg volume, blood volume and maximal oxygen uptake, as well as baseline blood volume and plasma concentrations of vasoactive hormones. Peak LBNP induced similar reductions in mean arterial pressure in both groups. The reduction in legarterial pulse volume (measured by impedance rheography), an index of peripheral vascular constriction, from baseline to peak LBNP was greater (P<0·05) in the HT group (?0·041 ± 0·005 ml 100 ml^?1) compared to the reduction in the LT group (?0·025 ± 0·003 ml 100 ml^?1). Greater peak LBNP in the HT group was associated with higher (P<0·05) average elevations in plasma concentrations of vasopressin (pVP, Δ=+7·2 ± 2·0 pg ml^?1) and plasma renin–angiotensin (PRA, Δ=+2·9 ± 1·3 ng Ang II ml^?1 h^?1) compared to average elevations of pVP (+2·2 ± 1·0 pg ml^?1) and PRA (+0·1 ± 0·1 ng Ang II ml^?1 h^?1) in the LT group. Plasma noradrenaline concentrations were increased (P<0·05) from baseline to peak LBNP in both HT and LT groups, with no statistically distinguishable difference between groups. These data suggest that the renin–angiotensin and vasopressin systems may contribute to sustaining arterial pressure and orthostatic tolerance by their vasoconstrictive actions.     

Reproducibility of orthostatic changes in cerebral oxygenation in healthy subjects aged 70 years or older

In the elderly, standing can frequently be accompanied by blood pressure (BP) changes and cerebral symptoms such as dizziness, fall, or even syncope, but this may vary from day‐to‐day. Therefore, we aimed to investigate the reproducibility of orthostatic responses of cerebral cortical oxygenation and systemic haemodynamics in elderly subjects. In 27 healthy elderly subjects (age 70–84 years), changes in systolic BP (SBP), diastolic BP (DBP), heart rate (HR) and stroke volume (SV) were continuously monitored by Finapres (Finger Arterial Pressure), and changes in oxyhaemoglobin ([O₂Hb]) and deoxyhaemoglobin ([HHb]) concentrations were continuously measured over the right frontal cortex by near infrared spectroscopy (NIRS) during supine rest and 10 min of active standing on two separate occasions. SBP and DBP increased by 6·7 ± 15·4 mmHg (P<0·05, mean ± SD) and 8·2 ± 6·4 mmHg (P<0·01), respectively, whereas HR increased by 9·5 ± 5·0 bpm (P<0·01) and SV decreased by –8·3 ± 7·4 ml (P<0·01) during standing on the first occasion. [O₂Hb] decreased by –3·9 ± 2·9 μmol l^–1 (P<0·01), while [HHb] increased by 1·8 ± 2·2 μmol l^–1 (P<0·01). Group‐averaged orthostatic changes in cortical oxygenation and systemic haemodynamics were very similar on the two occasions, although an intraindividual variation was found. Cortical oxygenation changes were not accompanied by severe cerebral symptoms. Active standing induced reproducible group‐averaged frontal cortical oxygenation declines in healthy elderly subjects, although an intraindividual day‐to‐day variability was present, possibly related to the variability of orthostatic BP responses. These findings indicate that cerebral autoregulation fails to compensate completely for postural changes in elderly subjects, which might predispose elderly subjects to ischaemic cerebral symptoms.     

Insulin treatment increases skeletal muscle fibre area in patients with diabetes mellitus type 2

The effects of insulin treatment on skeletal muscle characteristics were studied in 18 patients (62 ± 11 years) with poorly controlled diabetes mellitus type 2 (mean duration 7·5 ± 6 years). Skeletal muscle biopsy samples were taken from the lateral portion of the quadriceps muscle before and after a period of insulin treatment of 40 ± 14 days. Enzyme activities (phosphofructokinase, 3‐hydroxyacyl‐CoA dehydrogenase, citrate synthase, lactate dehydrogenase and creatine kinase) and myoglobin content were assessed. In a subgroup of 11 patients (60 ± 11 years), skeletal muscle fibre type composition (type I, IIA, IIB and IIC) and fibre type cross‐sectional area were also analysed. Following insulin treatment there were 32 and 38% increases, respectively, in the cross‐sectional areas of type IIA and IIB fast‐twitch fibres (P<0·02). The fibre type distribution did not change. The myoglobin content in muscle decreased by 20% (P<0·01). Of the enzymes tested, the 3‐hydroxyacyl‐CoA dehydrogenase activity decreased by 10% (P<0·04). Serum glucose, HbA1_C and serum triglyceride levels decreased (P<0·001) and body weight and arm muscle circumference increased (P<0·02). In conclusion, insulin treatment of patients with poorly controlled non‐insulin‐dependent diabetes mellitus increased the fast‐twitch fibre area, reduced myoglobin levels and decreased muscle enzyme activity related to fatty acid oxidation.     

Changes in cardiac autonomic regulation after prolonged maximal exercise

Harmful cardiac events occurs frequently after exercise. However, the cardiac autonomic regulation after vigorous exercise is not well known. This study was designed to assess heart rate (HR) variability before and after a 75 km cross‐country skiing race. HR variability was assessed by using standard statistical measures along with spectral and quantitative Poincarè plot analysis of HR variability in 10 healthy male subjects (age 36 ± 11 years). The average HR was at the same level 1 day after the race as before the race, but on the second day, HR was significantly lower (P<0·001) compared with the prerace and 1 day after values. The normalized high‐frequency (HF) spectral component of HR variability (nuHF) was lower (P<0·01) on the first day after the maximal exercise compared with the pre‐exercise values but returned to or even exceeded the prerace level on the second day (P<0·01). The changes in short‐term R‐R interval variability analysed from the Poincaré plot were similar to those observed in the HF spectral component. The normalized low‐frequency (LF) spectral component of HR variability (nuLF) was higher (P<0·01) on the first day after the exercise compared with the prerace levels and it also returned to the pre‐exercise level or even dropped below it on the second day after the race. The mean time it took the HF spectral component to return to the pre‐exercise level was 4·2 ± 4·2 h (ranging from 0 to 12 h). This recovery time correlated inversely with the maximal oxygen consumption (VO_2max) measured during the bicycle exercise test before the skiing race (r=?0·712, P<0·016). The cardiac vagal outflow is blunted for several hours after prolonged vigorous exercise. The recovery time of reduced vagal outflow depends on individual cardiorespiratory fitness and there is an accentuated rebound of altered autonomic regulation on the second day after prolonged exercise.     

Comparison of bioimpedance and radioisotope methods in the estimation of extracellular water volume before and after coronary artery bypass grafting operation

To estimate extracellular water volume (ECW) changes in connection with coronary artery bypass grafting operation, simultaneous ECW estimations by ⁵¹Cr‐EDTA dilution and whole‐body bioimpedance techniques were performed in 15 patients. The assessments of ECW were compared with patients’ weighing results. Whole‐body bioimpedance‐derived ECW correlated significantly with ⁵¹Cr‐EDTA dilution‐based ECW in the pre‐operative period (r=0·74; P<0·005); the bias was 0·2 ± 1·1 l (±SD). In the post‐operative period, the agreement between these methods was poor, the bias being 0·5 ± 2·5 l, and no significant correlation between the methods was found (r=0·38; P>0·05). Whole‐body bioimpedance‐derived ECW changes correlated significantly with weight changes of the patient induced by the operation (r=0·52; P<0·05). ⁵¹Cr‐EDTA dilution‐based ECW changes correlated neither with weight changes (r=0·33; P>0·05) nor with bioimpedance‐derived ECW changes (r=0·03; P>0·05). Alterations in radioisotope tracer distribution and loss of it due to blood leakage in the post‐operative period were presumed to explain the discrepancy between dilution technique and weighing results. The results suggest that bioimpedance is a useful non‐invasive method for assessment of extracellular volume changes induced by coronary artery bypass grafting operations. ⁵¹Cr‐EDTA dilution‐based ECW determination is not suitable in related conditions.     

Microcirculation of skeletal muscle adapts differently to a resistive exercise intervention with and without superimposed whole‐body vibrations

Whole‐body vibration (WBV) training is commonly practiced and may enhance peripheral blood flow. Here, we investigated muscle morphology and acute microcirculatory responses before and after a 6‐week resistive exercise training intervention without (RE) or with (RVE) simultaneous whole‐body vibrations (20 Hz, 6 mm peak‐to‐peak amplitude) in 26 healthy men in a randomized, controlled parallel‐design study. Total haemoglobin (tHb) and tissue oxygenation index (TOI) were measured in gastrocnemius muscle (GM) with near‐infrared spectroscopy (NIRS). Whole‐body oxygen consumption (VO₂) was measured via spirometry, and skeletal muscle morphology was determined in soleus (SOL) muscle biopsies. Our data reveal that exercise‐induced muscle deoxygenation both before and after 6 weeks training was similar in RE and RVE (P = 0·76), although VO₂ was 20% higher in the RVE group (P<0·001). The RVE group showed a 14%‐point increase in reactive hyperaemia (P = 0·007) and a 27% increase in blood volume (P<0·01) in GM after 6 weeks of training. The number of capillaries around fibres was increased by 15% after 6 weeks training in both groups (P<0·001) with no specific effect of superimposed WBV (P = 0·61). Neither of the training regimens induced fibre hypertrophy in SOL. The present findings suggest an increased blood volume and vasodilator response in GM as an adaptation to long‐term RVE, which was not observed after RE alone. We conclude that RVE training enhances vasodilation of small arterioles and possibly capillaries. This effect might be advantageous for muscle thermoregulation and the delivery of oxygen and nutrients to exercising muscle and removal of carbon dioxide and metabolites.     

Whole‐body vibration dosage alters leg blood flow

The effect of whole‐body vibration dosage on leg blood flow was investigated. Nine healthy young adult males completed a set of 14 random vibration and non‐vibration exercise bouts whilst squatting on a Galileo 900 plate. Six vibration frequencies ranging from 5 to 30 Hz (5 Hz increments) were used in combination with a 2·5 mm and 4·5 mm amplitude to produce twelve 1‐min vibration bouts. Subjects also completed two 1‐min bouts where no vibration was applied. Systolic and diastolic diameters of the common femoral artery and blood cell velocity were measured by an echo Doppler ultrasound in a standing or rest condition prior to the bouts and during and after each bout. Repeated measures MANOVAs were used in the statistical analysis. Compared with the standing condition, the exercise bouts produced a four‐fold increase in mean blood cell velocity (P<0·001) and a two‐fold increase in peak blood cell velocity (P<0·001). Compared to the non‐vibration bouts, frequencies of 10–30 Hz increased mean blood cell velocity by approximately 33% (P<0·01) whereas 20–30 Hz increased peak blood cell velocity by approximately 27% (P<0·01). Amplitude was additive to frequency but only achieved significance at 30 Hz (P<0·05). Compared with the standing condition, squatting alone produced significant increases in mean and peak blood cell velocity (P<0·001). The results show leg blood flow increased during the squat or non‐vibration bouts and systematically increased with frequency in the vibration bouts.     

Both leg blood flow and the femoral blood flow pattern are related to left ventricular mass in elderly men

Left ventricular mass (LVM) was significantly related to both the leg blood flow (r = –0·31, P<0·05) and a Doppler-derived index of femoral arterial stiffness (r = 0·35, P<0·05) in a sample of elderly men. Together with blood pressure, these two characteristics of peripheral blood flow explained 42% of the variation in LVM.     

Comparison of two methods of assessing total body water at sea level and increasing high altitude

Fluid retention is a recognized feature of acute mountain sickness. However, accurate assessment of hydration, including the quantification of body water, has traditionally relied on expensive and non‐portable equipment limiting its utility in the field setting. We compared the assessment of total body water (TBW) and their relationship to total body weight using two non‐invasive methods using the NICas single‐frequency bioimpedance analysis (SF‐BIA) system and the BodyStat QuadScan 4000 multifrequency BIA system (MF‐BIA). TBW measurements were performed at rest at sea level and at high altitude (HA) at 3833 m postexercise and at rest and thereafter at rest at 4450 m and 5129 m on 47 subjects. The average age was 34·5 ± 9·3 years with an age range of 21–54 years (70·2% male). There were strong correlations between TBW assessment with both methods at sea level (r = 0·90; 95% CI 0·78–0·95: P<0·0001) and at HA (r = 0·92; 0·89–0·94: P<0·0001), however, TBW readings were 0·2 l and 1·91 l lower, respectively, with the NICaS. There was a stronger correlation between TBW and body weight with the QuadScan (r = 0·91; P<0·0001) than with the NICaS (r = 0·83; P<0·0001). The overall agreement between the two TBW methods was good, but the 95% confidence intervals around these agreements were relatively wide. We conclude that there was reasonable agreement between the two methods of BIA for TBW, but this agreement was lower at HA.     

Upright body position and weight loss improve respiratory mechanics and daytime oxygenation in obese patients with obstructive sleep apnoea

To determine whether upright body position and weight loss would improve daytime gas exchange in moderately obese patients with obstructive sleep apnoea (OSAS), 13 patients with mild or moderate OSAS were studied before and after weight loss. Pulmonary function tests, arterial blood gases and respiratory gas analysis were measured prior to and after a very low calorie diet (VLCD) period of six weeks. Arterial blood gases were measured in supine and standing positions and closing volume in supine and sitting positions before and after weight loss. In the upright position, there was a significant increase in PaO₂ (P<0·005) accompanied by a significant decrease in alveolar–arterial PO₂ difference (P<0·005) and closing volume (P<0·05). The median weight loss was 11 kg (range 5–18). The number of desaturation episodes (four percentage units or more per hour during sleep) (ODI₄) decreased (P<0·01) after weight loss. The change in PaO₂ with weight loss correlated with the decrease in ODI₄ (r=0·73, P<0·01). The increase in expiratory reserve volume (ERV) was closely related to the amount of weight lost (r=0·895, P<0·01). The results indicate that weight loss and upright body position improved daytime respiratory mechanics and gas exchange in obese patients with OSAS. The findings suggest that obesity plays an important role in the pathogenesis of daytime gas exchange disturbances in obese OSAS patients. The adoption of a more upright sleep posture might improve nocturnal oxygenation in obese patients with OSAS.     

Effect of bicycle exercise on insulin absorption and subcutaneous blood flow in the normal subject

Summary. Elimination of 8 units ¹²⁵I-insulin and ^99mTc-pertechnetate from a subcutaneous depot on the thigh or the abdomen was studied at rest and during intense bicycle exercise in healthy postabsorptive volunteers. Disappearance rates of the tracers as well as plasma insulin and glucose concentrations were determined before, during and after the 20 min exercise period, and compared to corresponding values obtained during a non-exercise, control study on another day. Leg exercise caused a two-fold increase in the rate of ¹²⁵I-insulin disappearance from a leg depot (first-order rate constants rose from 0·68 ± 0·15 to 1·12 ± 0·12%·min^-1, P <0·05), but had no significant effect on the rate of disappearance from an abdominal depot (rate constants were 0·75 ±0·17 and 0·87±0·18%·min^-1 at rest and during exercise, respectively). ^99mTc-pertechnetate clearance from leg or abdomen showed no significant change during exercise, indicating that subcutaneous blood flow was unaltered. Leg, but not abdominal, injection of insulin was associated with a greater rise in plasma insulin during exercise than at rest. The average difference between exercise and control insulin area-under-curve in the leg group (1426 ± 594%·min) was significantly greater (P <0·05) than that from the abdominal group (298 ±251%· min). When the data from the two study groups were pooled, a direct relationship was found to exist between the change in ¹²⁵I-insulin disappearance rate and the change in plasma insulin concentration (r=0·61, P <0·02). Plasma glucose levels fell throughout the observation period both during the exercise and the control study, following leg as well as abdominal injection. The glucose decremental area was greater during exercise than at rest both following leg (P <0·05) and abdominal injection (P <0·01). The exercise-induced mean reduction in plasma glucose was 60% lower following abdominal injection, but this difference was not significant.     

Measurement of maximal isometric torque and muscle quality of the knee extensors and flexors in healthy 50‐ to 70‐year‐old women

Muscle quality is defined as strength per unit muscle mass. The aim of this study was to measure the maximal voluntary isometric torque of the knee extensor and flexor muscle groups in healthy older women and to develop an index of muscle quality based on the combined knee extensor and flexor torque per unit lean tissue mass (LTM) of the upper leg. One hundred and thirty‐six healthy 50‐ to 70‐year‐old women completed an initial measurement of isometric peak torque of the knee extensors and flexors (Con‐Trex MJ; CMV AG, Dubendorf, Switzerland) that was repeated 7 days later. Subsequently, 131 women returned for whole‐ and regional‐body composition analysis (iDXA^?; GE Healthcare, Chalfont St Giles, Buckinghamshire, UK). Isometric peak torque demonstrated excellent within‐assessment reliability for both the knee extensors and flexors (ICC range: 0·991–1·000). Test–retest reliability was lower (ICC range: 0·777–0·828) with an observed mean increase of 5% in peak torque [6·2 (17·2) N m] on the second day of assessment (P<0·001). The relative mean decrease in combined isometric peak torque (?12·2%; P = 0·001) was double that of the relative, non‐significant, median difference in upper leg LTM (?5·3%; P = 0·102) between those in the 5th and 6th decade. The majority of difference in peak isometric torque came from the knee extensors (15·1 N m, P<0·001 versus 2·4 N m, P = 0·234). Isometric peak torque normalized for upper leg LTM (muscle quality) was 8% lower between decades (P = 0·029). These findings suggest strength per unit tissue may provide a better indication of age‐related differences in muscle quality prior to change in LTM.     

Cardiac performance during exercise in patients with Fabry's disease

Background Fatigability and dyspnoea on effort are present in many patients with Fabry's disease. We assessed the determinants of cardiac performance during exercise in patients with Fabry's disease and preserved left ventricular ejection fraction at rest. Materials and methods Sixteen patients with Fabry's disease and 16 control subjects underwent radionuclide angiography at rest and during exercise, tissue Doppler echocardiography and magnetic resonance imaging at rest. Results The exercise‐induced change in stroke volume was +25 ± 14% in controls and +5·8 ± 19% in patients with Fabry's disease (P < 0·001). In 10 patients (group 1), the stroke volume increased (+19 ± 10%), and in 6 patients (group 2) it decreased (–16 ± 9%) with exercise. Patients of group 2 were older, had worse renal function, higher left ventricular mass and impaired diastolic function compared to group 1. The abnormal stroke volume response to exercise in group 2 was associated with a decrease in end‐diastolic volume (P < 0·001) and a lack of reduction of end‐systolic volume (P < 0·01) compared with both controls and group 1. The ratio of peak early‐diastolic velocity from mitral filling to peak early‐diastolic mitral annulus velocity was the only independent predictor of exercise‐induced change in stroke volume (B –0·44; SE 0·119; β–0·70; P < 0·005). Conclusions The majority of patients with Fabry's disease were able to augment stroke volume during exercise by increasing end‐diastolic volume, whereas patients with more advanced cardiac involvement may experience the inability to increase cardiac output by the Frank Starling mechanism.     

Acute effect of wearing compression stockings on lower leg swelling and muscle stiffness in healthy young women

Compression stockings are known to be effective in reducing peripheral oedema or leg swelling by increasing tissue pressure and venous blood flow. While previous studies on compression stockings have focused on its prolonged, preventive effect on leg swelling, the aim of this study was to investigate an acute effect of wearing compression stockings on lower leg swelling and muscle stiffness. Twenty healthy women aged 18–23 years participated in the experiment conducted in the evening, in which they wore below‐knee graduated compression stockings and rested in a seated position for 30 min. Before and after the application of stockings, maximum calf circumference, volume, extracellular water resistance (R_ECW) and muscle stiffness of the right lower leg were determined by tape measure, water displacement volumetry, segmental bioelectrical impedance spectroscopy and ultrasound shear‐wave elastography, respectively. The maximum calf circumference and the reciprocal of R_ECW (an index of extracellular fluid volume) significantly decreased after the application of stockings, whereas the total lower leg volume and the stiffness (shear modulus) of the medial gastrocnemius muscle tended to decrease. These changes, except for that in the medial gastrocnemius muscle stiffness, were opposite to those from morning to evening studied in the subgroup of participants (n = 8). However, partial correlation analysis failed to detect significant associations among these changes. These results suggest that even for a short period of application, compression stockings have some positive effects against lower leg swelling.     

Comparison of amplitude‐mode ultrasound versus air displacement plethysmography for assessing body composition changes following participation in a structured weight‐loss programme in women

The purpose of this study was to compare body composition changes as measured by A‐mode ultrasound (US) versus a criterion densitometry‐based measure, air displacement plethysmography (ADP), over a 4‐week weight‐loss protocol in healthy, non‐obese young women. Twenty healthy, young female volunteers were provided with customized dietary plans for the length of the study intended to facilitate a 500 calorie‐a‐day deficit. Subjects also performed 3 h a week of supervised aerobic exercise. Per cent fat mass and lean body mass were obtained via ADP and US both pre‐ and postintervention. Pretesting, post‐testing and delta data for %fat resulted in no significant differences in mean values along with a slope of the regression line no different than one and a y‐intercept no different than zero (P<0·05). Similar to %fat values, pretesting, post‐testing and delta data for fat‐free mass resulted in no significant differences in mean values along with a slope of the regression line no different than one and a y‐intercept no different than zero (P<0·05) with the exception of the delta for slope (0·39, P = 0·04). The current findings indicate that US can provide a similar degree of accuracy for tracking group‐based fat loss in women compared to ADP. Given the low‐cost relative to DXA and ADP, researchers and practitioners therefore can consider US as a viable option for monitoring group‐based changes in body fat over time.     

Atrioventricular plane displacement correlates closely to circulatory dimensions but not to ejection fraction in normal young subjects

Aims Mitral atrioventricular plane displacement (AVPD) provides information about left ventricular systolic function. M‐mode of systolic annulus amplitude or tissue Doppler imaging of systolic annulus velocity are the current methods of evaluating AVPD. A correlation to ejection fraction (EF) has been demonstrated in patients with coronary artery disease and left ventricular dysfunction. Our aim was (i) to investigate the mitral AVPD of normal subjects with different physical work capacities and (ii) to further evaluate AVPD as an index of left ventricular systolic function. Methods and results Twenty‐eight healthy men mean age 28 years (20–39) were included: endurance trained (ET) (n=10), strength trained (ST) (n=9) and untrained (UT) (n=9). The systolic AVPD was recorded at four sites, septal, lateral, anterior and posterior, using M‐mode. Left ventricular volumes were calculated according to Simpson’s rule. Systolic AVPD was higher in endurance trained, 16·9 ± 1·5 mm, as compared with both strength trained, 13 ± 1·6 (P<0·001) and untrained, 14 ± 1·6 (P<0·001). Left ventricular systolic AVPD correlated strongly with end‐diastolic volume (r=0·82), stroke volume (r=0·80) and maximal oxygen consumption per body weight (r=0·72). The correlation between AVPD and EF was poor (r=0·22). Conclusion In the subjects studied, with a range of normal cardiac dimensions, AVPD correlated to stroke volume, end‐diastolic volume and maximal oxygen consumption per body weight, but not to EF. On theoretical grounds, it also seems reasonable that a dimension like AVPD is related to other cardiac dimensions and volumes, rather than to a fraction, like EF. AVPD is one parameter that is useful for evaluation of left ventricular systolic function but is not interchangeable with other measurements such as EF.     

Disturbances in airflow dynamics and tracheal sounds during forced and quiet breathing in subjects with unilateral vocal fold paralysis

Variable extra thoracic obstruction has been found in spirometric studies in subjects with unilateral vocal fold paralysis. The aim of the study was to further evaluate airflow dynamics in these subjects with body plethysmography and tracheal sound analysis. Ten patients with unilateral vocal fold paralysis without a history of chronic pulmonary diseases and 10 healthy control subjects were studied. Flow‐volume spirometry, body plethysmography and tracheal sound analysis were performed within 1 day. The study shows that peak inspiratory flow (PIF) and specific airway conductance (SG_aw) expressed as percentage of Finnish reference values were significantly lower and airway resistance (R_aw) was higher among the patients than among the controls (P=0·004, P=0·026 and P=0·004, respectively). The patients had higher sound amplitude of both inspiratory and expiratory tracheal sounds than the controls [root mean square (RMS) values of the power spectra were 31·5 and 25 dB, P=0·006 in inspiration and 31·5 and 26 dB, P=0·013 in expiration, respectively]. Quartile frequencies (F25 and F50) and RMS of expiratory tracheal sounds had significant negative correlation with PIF (P=0·02, P<0·001, P=0·02, respectively) and forced inspiratory volume in 1 s (FIV₁) (P=0·01, P<0·001, P=0·01, respectively). There was also an association between F50 and peak expiratory flow (PEF) (P=0·02). According to the present study, both quiet breathing and forced inspiration are disturbed in subjects with unilateral vocal fold paralysis. A close relationship between tracheal sounds and respiratory function tests exists.