Noninvasive evaluation of the athletic heart: sprinters versus endurance runners.

To evaluate possible differences in the cardiac effects of different types of running training, 22 competing male runners--10 sprinters and 12 endurance runners--were studied with a physical examination, electrocardiography, chest X-ray film and echocardiography. Thirteen sedentary men served as control subjects. There were no differences between the athletic groups in physical findings. However, left ventricular hypertrophy in the electrocardiogram was more apparent in the endurance runners (P less than 0.05), whose relative heart size on chest X-ray examination was also greater than in the sprinters (P less than 0.02). On echocardiography the left ventricular end-diastolic volume was equally greater than normal in both groups of athletes (P less than 0.005), but in the endurance runners the percent chance of the minor axis diameter in systole was greater than in the sprinters or control subjects (P less than 0.02). Values for left ventricular wall thickness and mass were greater than normal in both groups of athletes but were higher in the endurance runners than in the sprinters (P less than 0.001). The left atrial diameter was apparently greater in the endurance runners than in the sprinters or control subjects (P less than 0.001), whereas that of the sprinters did not differ from normal. Thus, intensive sprinter training seems to dilate the left ventricle but causes less increase in wall thickness and mass than training for endurance running and no change in left ventricular function or left atrial size. Endurance running causes left ventricular dilatation equal to that of sprinter training, greater wall hypertrophy and improved systolic emptying of the left ventricle, and it also dilates the left atrium perhaps because of decreased left ventricular compliance.     

Pharmacokinetics of digoxin in patients with acute myocardial infarction.

The effects of acute myocardial infarction on the pharmacokinetics of digoxin were studied. Digoxin, 0.75 mg, was given orally to 12 patients with left-sided cardiac failure due to acute myocardial infarction and to 9 healthy control subjects. Serum concentration of digoxin in the first 4 hours and the area under the serum concentration-time curve in the first 12 hours after administration of the drug were lower in patients with infarction than in control subjects (P less than 0.01). The 24 hour area under the concentration curve, the amount excreted in urine and the renal clearance did not differ between the groups. The 24 hour area under the concentration curve correlated with the predigoxin pulmonary capillary wedge pressure and with heart rate (P less than 0.01). The decrease of renal clearance of digoxin was related to the serum activity of MB isoenzyme of creatine kinase (P less than 0.001). Morphine reduced and delayed the peak serum concentrations of digoxin (P less than 0.001). Thus, the absorption of oral digoxin was slower and the peak concentrations remained lower in patients with acute myocardial infarction than in healthy control subjects. However, the total amount of digoxin absorbed was unchanged.     

The prevalence of REM-related obstructive sleep apnoea is reduced by the AASM 2012 hypopnoea criteria

Purpose

The variations in reported prevalence of rapid eye movement-related obstructive sleep apnoea (REM-OSA) have been attributed to different definitions, although the effect of hypopnoea criteria has not been previously investigated.

Methods

Within this retrospective study, 134 of 382 consecutive patients undertaking polysomnography (PSG) for the suspicion of OSA met the inclusion criteria. PSGs were scored using both the 2007 AASM recommended hypopnoea criteria (AASM_2007Rec) and the 2012 AASM recommended hypopnoea criteria (AASM_2012Rec). For each hypopnoea criteria, REM-OSA patients were grouped as REM-related [either as REM-predominant OSA (rpOSA) or REM-isolated OSA (riOSA)] or non-stage-specific OSA (nssOSA). Outcome measures (SF-36, FOSQ and DASS-21) were also compared between groups.

Results

Incorporation of the AASM_2012Rec criteria compared to the AASM_2007Rec criteria increased the apnoea-hypopnoea index (AHI) for NREM and REM sleep but decreased the AHI_REM/AHI_NREM ratio from 1.9 to 1.3 (p < 0.001). It also decreased the prevalence of riOSA [15.7 vs 2.2% (p < 0.001) for AASM_2007Rec and AASM_2012Rec, respectively]. The prevalence of rpOSA remained the same for each hypopnoea criteria although the prevalence of nssOSA increased with the AASM_2012Rec hypopnoea criteria [53.0 vs 66.4% (p < 0.006) for AASM_2007Rec and AASM_2012Rec, respectively]. There were no differences in clinical symptoms between the groups, irrespective of hypopnoea criteria used.

Conclusions

This study demonstrates that in comparison with AASM_2007Rec, the AASM_2012Rec hypopnoea criteria reduce the prevalence of riOSA but not rpOSA by reducing the ratio of REM respiratory events and NREM respiratory events.

     

Impact of chemotherapy on collagen metabolism: a study of serum PIIINP (aminoterminal propeptide of type III procollagen) in advanced sarcomas

We have previously shown that the serum aminoterminal propeptide of type III procollagen (PIIINP) is a prognostic factor for survival in localised soft-tissue sarcomas, and that elevated values are frequent in metastatic discase. In the present study PIIINP is analysed during chemotherapy in 26 patients with advanced sarcomas. Non-responders had a significantly higher pretreatment level of PIIINP than responders (P=0.05), when only patients with no recent therapeutic interventions were studied. However, during chemotherapy PIIINP followed the clinical course of the malignant disease in only a minority of patients. Patients with recent surgery or recently completed chemotherapy had an increased pretreatment PIIINP value (P=0.03). In these patients PIIINP declined during chemotherapy irrespective of tumour response. A pretreatment PIIINP level within the reference range tended to increase with time irrespective of response. Moreover, the values taken during a chemotherapy infusion were significantly higher than those immediately preceding the corresponding cycle (P=0.001). Our results suggest that pretreatment PIIINP is of value as a prognostic factor for chemotherapy response in patients with advanced sarcomas. During chemotherapy PIINP is of minor importance in monitoring response because of the influence of chemotherapy and other therapeutic interventions on the level of PIIINP.This study was supported in part by grants from the Finnish Cancer Foundations, the Medical Research Council of the Academy of Finland and Finska Läkaresällskapet (Finnish Medical Society)     

Effect of coronary arterial occlusion on vagal control of heart rate

Diminished variation in heart rate as a sign of impaired vagal control is common in coronary arterial disease. To evaluate the effect of short-term myocardial ischaemia induced by coronary arterial occlusion during therapeutic percutaneous transluminal coronary angioplasty we measured the variation in heart rate during controlled deep breathing in 50 patients before and during arterial occlusion. Variation in heart rate diminished from 11.1 ± 4.5 to 9.5 ± 5.1 beats/min (P < 0.01) during occlusion. No change occurred in heart rate, blood pressure or levels of noradrenaline and adrenaline. The attenuation of variation in the heart rate was not significantly associated with the site or duration of arterial occlusion nor concomitant chest pain. Thus, brief coronary arterial occlusion seems to be associated with impairment of the vagal control of heart rate in patients with coronary arterial disease.     

Two-point tactile discrimination ability is influenced by temporal features of stimulation

Two-point discrimination threshold is commonly used for assessing tactile spatial resolution. Since the effect of temporal features of cutaneous test stimulation on spatial discrimination ability is not yet well known, we determined whether the ability to discriminate between two stimulus locations varies with the interstimulus interval (ISI) of sequentially presented tactile stimuli or the length of the stimulus train. Electrotactile stimuli were applied to one or two locations on the skin of the thenar eminence of the hand in healthy human subjects. Tactile discrimination ability was determined using methods based on the signal detection theory allowing the assessment of sensory performance, independent of the subject’s response criterion. With stimulus pairs, the ability to discriminate spatial features of stimulation (one location vs. two stimulus locations 4 cm apart) was improved when the ISI was equal to or longer than that required for tactile temporal discrimination. With stimulus trains, the ability to discriminate spatial features of stimulation was significantly improved with an increase in the stimulus train (from 3 to 11 pulses corresponding to train lengths from 40 to 200 ms). These results indicate that temporal features of tactile stimulation significantly influence sensory performance in a tactile spatial discrimination task. Precise control of temporal stimulus parameters should help to reduce variations in results on the two-point discrimination threshold.     

QTL Analysis of Behavior in Nine-Spined Sticklebacks (Pungitius pungitius)

The genetic architecture of behavioral traits is yet relatively poorly understood in most non-model organisms. Using an F₂-intercross (n = 283 offspring) between behaviorally divergent nine-spined stickleback (Pungitius pungitius) populations, we tested for and explored the genetic basis of different behavioral traits with the aid of quantitative trait locus (QTL) analyses based on 226 microsatellite markers. The behaviors were analyzed both separately (viz. feeding activity, risk-taking and exploration) and combined in order to map composite behavioral type. Two significant QTL—explaining on average 6 % of the phenotypic variance—were detected for composite behavioral type on the experiment-wide level, located on linkage groups 3 and 8. In addition, several suggestive QTL located on six other linkage groups were detected on the chromosome-wide level. Apart from providing evidence for the genetic basis of behavioral variation, the results provide a good starting point for finer-scale analyses of genetic factors influencing behavioral variation in the nine-spined stickleback.     

Withdrawal from long‐term use of zopiclone,zolpidem and temazepam may improve perceived sleep and quality of life in older adults with primary insomnia

Long‐term use of benzodiazepines or benzodiazepine receptor agonists is widespread, although guidelines recommend short‐term use. Only few controlled studies have characterized the effect of discontinuation of their chronic use on sleep and quality of life. We studied perceived sleep and quality of life in 92 older (age 55‐91 years) outpatients with primary insomnia before and after withdrawal from long‐term use of zopiclone, zolpidem or temazepam (BZDA). BZDA was withdrawn during 1 month, during which the participants received psychosocial support and blindly melatonin or placebo. A questionnaire was used to study perceived sleep and quality of life before withdrawal, and 1 month and 6 months later. 89 participants completed the 6‐month follow‐up. As melatonin did not improve withdrawal, all participants were pooled and then separated based solely on the withdrawal results at 6 months (34 Withdrawers. 55 Nonwithdrawers) for this secondary analysis. At 6 months, the Withdrawers had significantly (P < 0.05) shorter sleep‐onset latency and less difficulty in initiating sleep than at baseline and when compared to Nonwithdrawers. Compared to baseline, both Withdrawers and Nonwithdrawers had at 6 months significantly (P < 0.05) less fatigue during the morning and daytime. Stress was alleviated more in Withdrawers than in Nonwithdrawers (P < 0.05). Satisfaction with life and expected health 1 year later improved (P < 0.05) in Withdrawers. In conclusion, sleep disturbances, daytime fatigue and impaired quality of life may resolve within 6 months of BZDA withdrawal. These results encourage withdrawal from chronic use of benzodiazepine‐type hypnotics, particularly in older subjects.