Is interventional technique better than the traditional over-the-wire method for left ventricular lead implantation in cardiac resynchronization therapy?

Background: Interventional cardiac resynchronization therapy (I-CRT) for left ventricular lead (LVL) placement works as a supplement to traditional (over-the-wire) cardiac resynchronization therapy (T-CRT). It has been argued that I-CRT is a time-consuming and complicated procedure.

Objective: The purpose of this study was to investigate differences in procedure-related, perioperative, postoperative, and clinical endpoints between I-CRT and T-CRT.

[Radiofrequency ablation of ventricular tachycardia after acute myocardial infarction].

A 66 year-old man presented drug-refractory, repetitive ventricular tachyarrhythmias after acute myocardial infarction. Despite successful revascularization, the patient suffered recurrent episodes of rapid ventricular tachycardia which could only be managed by radiofrequency ablation.

Effect of glucose/insulin infusion and magnesium supplementation on serum and muscle sodium and potassium and muscle [3H]ouabain binding capacity in Type 1 diabetes mellitus.

Glucose has recently been found to decrease muscle potassium content. The aim of this study was to evaluate the effect of the infusion of glucose and insulin and the effect of magnesium supplementation on serum and muscle sodium and potassium and muscle [3H]ouabain binding capacity in patients with Type 1 diabetes mellitus and in controls. Muscle potassium and sodium content, muscle [3H]ouabain binding capacity and serum potassium and sodium concentrations were determined in 10 patients with Type 1 diabetes mellitus and in 5 controls before and after an euglycaemic, hyperinsulinaemic clamp, and after an intravenous magnesium load test.

Magnesium, sodium, and potassium content and [3H]ouabain binding capacity of skeletal muscle in relatives of patients with type 2 diabetes: effect of dexamethasone.

Theoretically, disturbancies in sodium (Na) and potassium (K) homeostasis and a magnesium (Mg) deficit could be possible factors in the development of obesity, type 2 diabetes, and hypertension. Therefore, we measured electrolyte content and [3H]ouabain binding capacity of skeletal muscle in 20 relatives of type 2 diabetic patients and in 20 controls before and after glucose infusion and before and after treatment with dexamethasone, which decreases insulin sensitivity. Muscle electrolyte content and [3H]ouabain binding capacity did not differ between groups.

Skeletal muscle magnesium content in identical twins, discordant for type 2 diabetes.

Background: Low magnesium (Mg) status has been implied as a factor in the development of type 2 diabetes mellitus (DM) and its complications. We therefore studied Mg-status in identical twins, discordant for type 2 DM and in matched controls. Through correlation analysis, possible associations between Mg-status and glucose uptake were evaluated.

Measured muscle sodium content in biopsy specimens is a reflection of true intracellular content.

Determined on the basis of small skeletal muscle biopsies, muscle sodium content has a very high coefficient of variation. Furthermore, at least some of the measured sodium must originate from the extracellular space. In order to assess the applicability of the measurement of intracellular sodium on small muscle biopsy specimens, the measured sodium content was related to the content of dry solids in 25 muscle biopsy samples, and compared with the theoretical content of sodium with varying extra- and intracellular water content in biopsy samples.

Magnesium reduces insulin-stimulated glucose uptake and serum lipid concentrations in type 1 diabetes.

A magnesium (Mg) deficit has been described in patients with type 1 diabetes, and it has been related to the development of cardiovascular disease. We tested the hypothesis that type 1 diabetic patients have deficits in dietary Mg intake and that proper long-term (24 weeks) oral Mg supplementation would reduce cardiovascular risk factors. Therefore, the Mg status, dietary Mg intake, and the effect of Mg supplementation were evaluated in 10 type 1 diabetic patients and 5 control subjects.

New data on the mechanisms of hypermagnesuria in type I diabetes mellitus.

It has been known for long that renal Mg excretion is increased in patients with type I diabetes mellitus, and that these patients have a Mg deficit. It can be hypothesized, that this deficit might be related to the development of late complications in the diabetic. In recent years it has been shown that the increased renal Mg excretion in patients with type I diabetes is due primarily to an elevated plasma glucose concentration.

Muscle sodium, potassium, and [(3)H]ouabain binding in identical twins, discordant for type 2 diabetes.

A reduced functional capacity of the sodium (Na), potassium (K) pump might reduce energy expenditure, inducing obesity and type 2 diabetes. Consequently, the Na and K content and [(3)H]ouabain binding capacity of skeletal muscle were measured in 10 monozygotic twin pairs discordant for type 2 diabetes and in 10 obese controls. Muscle [(3)H]ouabain binding capacity was reduced by approximately 20% in type 2 diabetes.

Hyperglycaemia enhances renal magnesium excretion in type 1 diabetic patients.

Magnesium depletion is a common feature of diabetes mellitus, apparently related to glycaemic control. The aim of the study was to investigate the isolated effect of hyperglycaemia upon renal magnesium excretion. Urinary magnesium excretion rates were measured in 10 patients with Type 1 diabetes mellitus on two different days with different levels of blood glucose concentration but equal plasma insulin concentration.

Effect of moderate improvement in metabolic control on magnesium and lipid concentrations in patients with type 1 diabetes.

Objective: To evaluate the effect of clinically obtainable improvements in metabolic control in patients with type 1 diabetes on biochemical cardiovascular risk factors.

Research Design And Methods: Blood and 24-h urinary samples were obtained from 49 patients with type 1 diabetes before and after a run-in period and after 3 months of intervention, with frequent adjustment of insulin dosage according to measured blood glucose concentrations.

Results: The intervention caused a mean insulin dosage increment of 10%, a 20% decrease in fasting plasma glucose concentration, a 10% decrease in albumin corrected serum fructosamine, and a somewhat lesser decrease in HbAlc.

Improved running economy following intensified training correlates with reduced ventilatory demands.

Purpose: To compare the effects of three types of intensive run training on running economy (RE) during exhaustive running and to establish possible relationships with changes in ventilatory function and/or muscle fiber type distribution.

Methods: Thirty-six male recreational runners were divided into three groups and assigned to either exhaustive distance training (DT), long-interval training (LIT), or short-interval training (SIT) three times 20-30 minxwk(-1) for 6 wk. VO(2 max) and RE were measured during treadmill running before and after training.

Methodological aspects of measuring human skeletal muscle electrolyte content and ouabain binding capacity.

The aim of the study was to evaluate the use of freeze-dried and dissected small muscle biopsy specimens ("dry") for the determination of human muscle electrolyte content and ouabain binding capacity, compared with an easier method, without this freeze-drying step ("wet"). Freeze-drying and dissection of muscle biopsy specimens reduced the variation in the determination of muscle potassium and magnesium content. The total coefficient of variation was 8.

Multiple anomalies, hypokalaemic paralysis and partial symptomatic relief by terbutaline.

In this paper a follow-up is presented of a case report initially described by Andersen in 1971. The patient presented with a syndrome including elements of familial periodic paralysis with hypokalaemia, long QT syndrome, ventricular ectopy, myopathy with fibre-type disproportion and dysmorphic features resembling Treacher Collins' syndrome. The main symptom was hypokalaemic paralysis.

Antioxidant status and lipid peroxidation after short-term maximal exercise in trained and untrained humans.

The purpose of this study was to measure resting muscle and blood antioxidant status in untrained (n = 8) and jump-trained (n = 8) humans and to evaluate free radical-mediated muscle damage after a strenuous jump test consisting of six bouts of 30-s continuous jumping separated by 2 min of rest. Resting muscle antioxidant activities [superoxide dismutase (SOD), glutathione peroxidase (GPX), glutathione reductase (GR), and manganese SOD] were significantly higher in jump-trained compared with untrained subjects. Blood antioxidant enzyme activities and muscle catalase, however, were not different between the two groups.

Calcium content and respiratory control index of skeletal muscle mitochondria during exercise and recovery.

The purpose of this study was to evaluate the relationship between mitochondrial Ca2+ concentration and the respiratory control index (RCI; state III/state IV) in isolated mitochondria before and after exhaustive exercise at 75% of maximal O2 consumption. Muscle biopsies of 100-150 mg from 12 moderately trained men were sampled at rest, immediately after exercise, and 30 or 60 min after exercise. The mitochondrial Ca2+ content after exhaustive exercise was significantly higher than the preexercise level [15.

[Bartter's syndrome. A condition with chronic hypokalemia].

Bartter's syndrome (BS) is a disease with severe hypokalaemia due to renal potassium wasting. The potassium loss is due to lesions at different sites within the renale tubule. Additional features include metabolic alkalosis, excess renal production of prostaglandins, hyperreninaemia, hyperaldosteronism and impaired pressor responses to exogenous angiotensin II.

Biological variation of serum and urinary magnesium in apparently healthy males.

The biological variations of serum (S-) magnesium and urinary (U-) magnesium concentrations and excretions have been investigated. Serum samples, 24-h and fasting urinary samples were collected from each of 60 supposedly healthy male volunteers. In addition, 12 volunteers collected additional samples 7 and 112 days after the initial sample.

Insulin increases renal magnesium excretion: a possible cause of magnesium depletion in hyperinsulinaemic states.

The effects of insulin upon renal magnesium excretion were examined. Urinary magnesium excretion rates were measured in seven healthy volunteers (three men, four women) before and during a euglycaemic, hyperinsulinaemic clamp. Insulin was infused at 120 pmol m-2 min-1 and at 240 pmol m-2 min-1.

Potassium and magnesium distribution, ECG changes, and ventricular ectopic beats during beta 2-adrenergic stimulation with terbutaline in healthy subjects.

Objective: To study the effect of intravenous (i.v.) terbutaline on potassium (K) and magnesium (Mg) distribution, ECG changes, and prevalence of ventricular ectopic beats in healthy subjects.

[Injection site for quick-acting insulin. Significance for glycemic control in basal bolus insulin regimen].

The impact on glycaemic control of soluble insulin injected either intramuscularly into the thigh (IMT), subcutaneously into the abdominal wall (SCA) or subcutaneously into the thigh (SCT) was evaluated in 49 Type 1 diabetic outpatients following a randomised three-month intervention study. Insulin doses were adjusted based on patients' self-monitored blood glucose values and reported hypoglycaemic episodes. More patients in the SCA and IMT groups than in the SCT group had serum fructosamine values within normal limits following intervention.

Effects of detraining on endurance capacity and metabolic changes during prolonged exhaustive exercise.

The effects of 4 wk of detraining on maximal O2 uptake (VO2max) and on endurance capacity defined as the maximal time to exhaustion at 75% of VO2max were studied in nine well-trained endurance athletes. Detraining consisted of one short 35-min high-intensity bout per week as opposed to the normal 6-10 h/wk. Detraining had no effect on VO2max (4.