Magnetocardiographic Intra-QRS Fragmentation Analysis in the Identification of Patients with Sustained Ventricular Tachycardia after Myocardial Infarction

KORHONEN, P., et al. : Magnetocardiographic Intra-QRS Fragmentation Analysis in the Identification of Patients with Sustained Ventricular Tachycardia after Myocardial Infarction. The aim of this study was to investigate if magnetocardiographic (MCG) analysis of cardiac micropotentials within the QRS complex can identity patients prone to ventricular arrhythmias, and to compare it to MCG time-domain, late-field analysis. The study population consisted of 136 patients with remote MI, 53 with and 83 without a history of VT. After averaging and high pass filtering of multichannel MCG signals, time-domain parameters describing the end-QRS activity and fragmentation index M and score S describing the whole QRS complex were computed. Fragmentation and time-domain parameters differed between the VT and control groups: fragmentation index M was  12 ± 3  versus  9 ± 2  (  P < 0.001  ), fragmentation score S was  83 ± 42  versus  56 ± 21  (  P < 0.001  ), and filtered QRS duration was  144 ± 32  versus  114 ± 19 ms  (  P < 0.001  ) in VT and control groups, respectively. A combination of fragmentation parameters yielded 87% sensitivity and 61% specificity in VT identification. Corresponding figures for a time-domain parameter combination were 81% and 72%. Sensitivity of time-domain analysis was 88% and specificity was 75% in a subgroup with anterior MI. In multivariate analysis, fragmentation and time-domain analyses discriminated VT patients from controls independently of the extent of coronary artery disease or left ventricular dysfunction. MCG in postinfarction patients reveals pathology associated with propensity to ventricular arrhythmias inside and not only at the end of the QRS complex. MCG seems most accurate in the anterior infarct location.     

Novel galanin receptor ligands

Galanin is a neuroendocrine peptide which is 29/30 amino acids in length and is recognised by G-protein-coupled central nervous system receptors via its N-terminus. We synthesised several galanin receptor ligands and fragments around C-terminal extensions of galanin(l-13) to yield chimeric peptides with C-terminals corresponding to bioactive peptides like bradykinin(2-9), mastoparan, neuropeptide Y(25-36) or substance P(5-11), respectively. We also synthesised short galanin analogs in which galanin(l-13) was C-terminally elongated with Lys¹⁴; different pharmacologically active small molecules were then attached to the ε-amino group of Lys¹⁴. Several cysteine-substituted linear and ring closed analogs of galanin(l-9) and galanin(l-16) were also synthesised. The equilibrium binding constants for these peptides at hypothalamic galanin receptors were determined and found in the subnanomolar to micromolar range. The large number of peptides and their binding affinities presented here permit structure-activity relationship analysis of peptide-type ligands to galanin receptors.     

USE OF SIMPLE TESTS TO DETERMINE THE RESIDUAL EFFECTS OF THE ANALGESIC COMPONENT OF BALANCED ANAESTHESIA

In order to evaluate simple means of determining the rate ofrecovery after general anaesthesia, the usefulness of the criticalflicker fusion threshold test, the Maddox wing apparatus andthe visual analogue scale were compared. The postanaestheticrecovery score was used as a reference. Two patient groups (n= 15 in each) received, in a randomized double-blind study,a similar balanced anaesthesia for Caesarean section, exceptthat the analgesic component was either fentanyl 2.5µgkg^–1 i.v. or buprenorphine 7.5 µg kg^–1 i.v.Maddox wing apparatus and visual analogue scale were sensitiveenough to differentiate between the postanaesthetic residualeffects of the two opioids, but critical flicker fusion thresholdand, especially, postanaesthetic recovery score were insensitivein this respect. There was no difference between the two patientgroups in mean arterial pressure and heart rate. Our resultsshow that the residual effects of different kinds of opioidsas an analgesic component of balanced anaesthesia can be differentiatedusing simple means like Maddox wing apparatus and visual analoguescales.     

Leisure-time physical activity is inversely related to risk factors for coronary heart disease in middle-aged Finnish men

Coronary risk factors and levels of physical activity at leisurewere measured in a random sample of 3975 men 25–64 yearsof age residing in four areas of Finland. An index of leisure-timephysical activity (LTPA) as the product of weekly exercise sessionstimes their usual intensity (expressed as metabolic equivalents)was computed. It showed a graded, inverse association with meanarterial blood pressure, smoking and serum thiocyanate, coronaryheart disease risk estimate (combining blood pressure, totalcholesterol and smoking), and a nonlinear favorable associationwith serum lipoproteins. In multiple regression analysis, LTPAcontributed significantly and independently to the variationin mean arterial pressure; the standardized regression coefficientswere –0.06 for LTPA, 0.09 for weekly alcohol consumption,0.25 for body mass index, 0.25 age. In the regression of coronaryrisk estimate, the standardized regression coefficients were–0.19 for LTPA, 0.22 for weekly alcohol consumption, 0.09for body mass index, 0.15 for age. There was no evidence thatLTPA above 2000 kcal of weekly energy expenditure was associatedwith further reduced coronary risk factor levels. These findingsthus support the inverse direction of the association betweenexercise and coronary risk factors but they also point towardsan independent, but modest, role of leisure-time physical activityas determinant of coronary risk estimate and blood pressure     

One Turn More: Threshold Superiority of 3-turn versus 2-turn Screw-in Myocardial Electrodes

Epicardial electrodes are an alternative for patients in whom the transvenous approach presents technical difficulties. We have had clinical experience with two types of myocardial sutureless electrodes inserted in the anterior left ventricular wall: the 3-turn screw-in electrode (Medtronic 6917) was used in 209 patients from 1974 to 1977 and the 2-turn screw-in lead (Medtronic 6917 A) was used in 61 patients from 1978 to 1981. The initial threshold was equal and acceptable with both types of electrodes. During a follow-up period (up to 48 months), critical elevation of the pacing threshold resulting in exit block was found in 12% (25) of the patients with the 3-turn screw-in electrode and in 20% (12) of the patients with the 2-turn electrode (p less than 0.05). Elevation of the pacing threshold developed fairly early, usually within 6 months, with the 2-turn screw-in electrode, but much later, within 2-4 years, with the 3-turn electrode. During a longer follow-up time of up to 96 months the frequency of exit block increased up to 16% with the 3-turn electrode. Our results indicate that late critical elevation of the pacing threshold is surprisingly frequent with screw-in electrodes inserted into the left ventricular myocardium, and it is especially common with the 2-turn screw-in electrode.     

Smoking, blood pressure and serum cholesterol as risk factors of acute myocardial infaction and death among men in Eastern Finland

The impact of smoking, serum cholesterol and blood pressureon the risk of acute myocardial infarction and death due toall causes and cardiovascular diseases was studied in a randomsample of men aged 35 to 59 years from the North Karelia andKuopio counties of Eastern Finland. This is an area with anexceptionally high incidence of coronary heart disease. Altogether,4034 men were studied with a participation rate of 92%. Thesemen were followed-up with a myocardial infarction register anddeath certificate data. During the first five years 256 deathsoccurred among all subjects. There were 66 acute myocardialinfarctions in the North Karelian men reporting no recent coronaryheart disease. Smoking, elevated serum cholesterol and bloodpressure were independently and jointly related to an increasedrisk of acute myocardial infarction and death due to all causesand to cardiovascular disease. Smokers had a 2–3-foldage-adjusted risk of acute myocardial infarction, a 2-2-foldrisk of any death and a 2.1-fold risk of cardiovascular deathcompared with non-smokers. The age-adjusted risk ratios forsystolic blood pressure of 160 mm Hg or more were 1.3, 1.4 and1.9 and those for serum cholesterol at least 8 mmol/l (309 mg/100ml) 2.6, 1.5 and 2.6 concerning myocardial infarction, all deathsand cardiovascular deaths, respectively. All risk ratios exceptthat of systolic blood pressure for acute myocardial infarctionwere significant at levels of at least P < 0.05     

A PET Study on the Acute Effect of Ethanol on Striatal D2 Dopamine Receptors with [11C]Raclopride in Healthy Males

The effect of acute oral ethanol intake (1·0 g/kg) on cerebral D2-receptors ([¹¹C]raclopride binding) was studied in seven healthy volunteers, using water and alcohol in two separate 59-min PET sessions. In the alcohol experiments, the blood ethanol concentration at the beginning of the imaging was 26·4±3·8 mmol/l and remained stable during the PET session. Ethanol was not found to influence binding of [¹¹C]raclopride to the dopamine D2 receptors in the human striatum, as indicated by the unchanged ratio B_max/K_d of the whole (left and right) striatum. The T_max values of the control and ethanol experiments did not differ in the whole striatum, but the right to left difference of striatal T_max was turned from negative to positive by ethanol (P=0·02). However, the difference between hemispheres in B_max/K_d was not significantly altered by ethanol intake. There was considerable interindividual variation in the response of all the above parameters to acute ethanol exposure. According to the present results, the acute effects of peroral ethanol exposure on striatal D2 receptor binding potential are of relatively small magnitude in man. However, the changes in T_max suggest that ethanol may influence the right–left difference of [¹¹C]raclopride binding. © 1997 by John Wiley & Sons, Ltd.     

Intrathecal Immune Responses in Mumps Meningitis Patients

The in vitro 3H-thymidine incorporation of peripheral blood (PB) and cerebrospinal fluid (CSF) lymphocytes from 11 mumps meningitis patients was studied after stimulation with non-specific mitogens and microbial antigens. Although corresponding viral antibodies were always found in the CSF of seropositive patients by a sensitive radioimmunoassay, their intrathecal synthesis was directed mainly against mumps virus. Most of the patients had PB lymphocytes that reacted on stimulation with phytohaemagglutinin (PHA) or pokeweed mitogen (PWM), but a smaller number of them had reactive CSF cells. Only four patients showed stronger responses to PHA in the CSF than in PB. Most patients had mumps-reactive lymphocytes in PB but only two of them in the CSF. In contrast, these patients more often had increased CSF cell reactivity when tested with purified protein derivative, measles, and herpes simplex virus antigens. The results could not be explained by a damaged blood-brain barrier alone but may reflect the immunological status of the brain compartment in these patients.     

Influence of complete denture renewal on craniomandibular disorders: a 1-year follow-up study

summary Great individual variation in the signs and symptoms of craniomandibular disorders (CMD) and in the adaptability of the masticatory system is evident among complete denture wearers. The masticatory system of 64 edentulous patients (41 women, 23 men; mean age 59 years, range 41-80 years), who came to the Institute of Dentistry for renewal of their complete dentures, was examined before prosthetic treatment and after a 1-year follow-up period. The degree of CMD was assessed using the anamnestic and clinical dysfunction indices of Helkimo. The results show that few complete denture wearers had severe signs and symptoms of CMD. No statistically significant correlation was noted between CMD and either the duration of edentulousness or the number of sets of dentures.     

Gingival crevicular fluid fibronectin degradation in periodontal health and disease

Abstract— The molecular forms of fibronectin (FN) in gingival crevicular fluid of five subjects with at least two sites exhibiting clinical signs of inflammation and pockets of at least 4 mm (test group) and five subjects with clinically healthy periodontium (control group) were investigated. Samples were collected with standard filter paper strips. In the test group samples from both diseased and healthy sites were collected. After collection the test group received one episode of periodontal treatment (scaling and root planing). The sampling and clinical recordings were repeated for the diseased sites after about 2 wk. The crevicular fluid FN was analyzed using sodium dodecyl sulphate gel electrophoresis followed by western blotting with polyclonal antibodies against FN. Both intact FN and FN fragments were found in all samples. A larger proportion of FN was in degraded form in the diseased sites than in the healthy or the treated sites. FN was also degraded into smaller peptide fragments in the diseased than in the treated sites. These results suggest that crevicular fluid FN is partially degraded both in periodontal health and disease and that the degree of degradation of FN increases with periodontal inflammation and decreases with periodontal treatment.