J wave patterns—morphology,prevalence and nomenclature

The recent resurgence of interest in early repolarization has demonstrated a variation in the definition of the term and a consequent variation in the prevalence of the pattern in different studies. This can vary from 35% in males and 21.5% in females if ST elevation is not considered part of the definition, to 3.3% and 0.5% in females with the inclusion of ST elevation. In contrast, the prevalence of the Brugada Syndrome is in the order of 0.1%–0.2% in Japan for example and has been found to be significantly lower in Denmark. Standardisation of measurement definitions, particularly for early repolarisation, is required.     

Normal limits of the electrocardiogram in Nigerians

Background

There has been no large study of ECG measures derived by automated methods in an apparently healthy indigenous West African population.

Methods

ECGs were recorded from apparently healthy Nigerians and analysed using automated methods. Age and sex based normal ranges were then established.

Results

A total of 782 males and 479 females aged between 20 and 87 years were studied. Mean QRS duration in males was 87.9 ± 9.4 ms and 83.4 ± 7.6 ms in females (P < .0001). Mean QTc (Hodges) was 393 ± 16 ms in males and 406 ± 16 ms in females (P < .0001). The Cornell index (SV3 + RaVL) was higher in males and decreased with increasing age in males though the reverse was true in females (P < .0001). STj amplitude was lower in older compared to younger males and higher in males.

Conclusion

This is the first large study of automated ECG measurements from healthy blacks living in West Africa which allows the determination of ECG normal limits in such a population.     

In vivo bracket retention comparison of a resin-modified glass ionomer cement and a resin-based bracket adhesive system after a year.

Glass ionomer orthodontic adhesives cause less enamel demineralization during fixed orthodontic appliance treatment than do traditional resin-based products. An in vivo randomized clinical trial was performed comparing the clinical performance of a resin-modified glass ionomer (RMGI) adhesive with a no-mix, resin-based (the control) adhesive over a 12-month period. The split-mouth technique was used to analyze bracket retention, bracket failure causes, and mode of failure for both adhesives in 61 patients. Bracket-failure rates were 10% for the RMGI and 4% for the resin-based adhesive. Both adhesives had 4 times more bracket failures when opposing occlusion was present. The resin-based product demonstrated a higher proportion of resin-to-enamel adhesive failures than did the RMGI. Compared with the resin-based adhesive, the RMGI-bracketed teeth showed improved clinical performance, no enamel surface loss, less enamel demineralization, and faster adhesive removal. However, the RMGI had a 2.6 times greater bracket-failure rate than did the resin-based product.     

Implanted cardiac pacemaker pulses as recorded from the body surface

This study investigates the characteristics of contemporary pacemaker pulses as recorded from the body surface. Twelve-lead paced ECGs from 140 patients (68 ± 12 years, 71% males) were collected at 32,000 samples per second. Pacer pulses were manually annotated based on the high-sampling rate data stream. The results show that durations of the various pulses are stable, while amplitudes exhibit large variations. Also, more than 50% of pulses have either durations < 0.5 ms or amplitudes < 2 mV, which are the AAMI/IEC thresholds for detection and marking of pacemaker pulses on an ECG report. Therefore the current standards for pacemaker pulse detection are not fit for purpose and require to be updated. Further, this study suggests that a high-sampling rate database should be used as a standard test for pacemaker annotation and detection from body surface ECGs.     

Dietary nucleotides and fecal microbiota in formula-fed infants: a randomized controlled trial

BACKGROUND: Dietary nucleotides are nonprotein nitrogenous compounds that are thought to be important for growth, repair, and differentiation of the gastrointestinal tract. A higher nucleotide intake may also have favorable effects on the fecal microbial composition and incidence of diarrhea in infancy. However, few studies have tested this hypothesis with an experimental study design. OBJECTIVE: We tested the hypothesis that nucleotide supplementation of infant formula has beneficial effects on fecal bacteriology. DESIGN: Oligonucleotide probes were used to measure bacterial genus-specific 16S ribosomal RNA in stools of a subset of infants (mean age: 20.4 wk) who were randomly assigned to nucleotide-supplemented (31 mg/L; n = 35) or control formula (n = 37) from birth until age 20 wk or were breastfed (reference group; n = 44). The microbial pattern was assessed as the ratio of Bacteroides-Porphyromonas-Prevotella group (BPP) to Bifidobacterium species. RESULTS: The ratio of BPP to Bifidobacterium spp. rRNA in infants randomly assigned to the nucleotide-supplemented formula was lower than in infants receiving the control formula (mean difference: -118%; 95% CI: -203%, -34%; P = 0.007), but it did not differ in infants who were breastfed. The difference between randomized formula-fed groups was independent of potential confounding factors (P = 0.003). CONCLUSIONS: Our data support the hypothesis that nucleotide supplementation improves the composition of the gut microbiota in formula-fed infants. Because this effect could contribute to previously described benefits of nucleotide supplementation for gastrointestinal tract and immune function, these findings have important implications for optimizing the diet of formula-fed infants.