Interrelation of ST-segment depression during bicycle ergometry and extent of myocardial ischaemia by myocardial perfusion SPECT

Purpose: The aim of this study was to compare ST-segment depression (STD) during bicycle ergometry and extent of myocardial ischaemia assessed by myocardial perfusion SPECT (MPS) in a large patient cohort. Methods: Consecutive patients (n = 955) referred for MPS with bicycle ergometry and interpretable stress ECG were evaluated with respect to ECG and MPS findings of ischaemia. The maximal STD was recorded and exercise ECG was considered ischaemic if STD was horizontal or downsloping (≥1mm). MPS was interpreted using a 20-segment model with a scale of 0 to 4. A summed stress (SSS), summed rest (SRS) and summed difference score (SDS = SSS−SRS, e.g. extent of ischaemia) were derived. Ischaemia was defined as an SDS ≥ 2. Results: An exercise-induced STD was present in 215 patients (22%) and myocardial ischaemia on MPS was present in 366 patients (38%). The extent of ST-segment depression and the number of ECG leads with significant STD were each strongly and significantly associated with increasing severity of ischaemia and the number of coronary territories involved (p < 0.01 for all correlations). Conclusion: These data demonstrate a strong correlation between the extent of STD, number of ischaemic leads and severity of myocardial ischaemia as assessed by MPS during bicycle ergometr

Gate-keeper to coronary angiography: comparison of exercise testing, myocardial perfusion SPECT and individually tailored approach for risk stratification

We aimed to evaluate the differences between exercise testing (ET), myocardial perfusion SPECT (MPS) and a combination of ET and MPS based risk assessment as outlined by the guidelines with respect to their "gate-keeper” role to coronary angiography (cath) and the associated diagnostic procedural costs if prognostic considerations, as those proposed by the current guidelines and the recent literature, were taken into account. The Duke-score and the summed difference score (SDS; extent of ischemia) were assessed in 955 consecutive patients referred for MPS combined with ET. According to the guidelines and the available literature, three different algorithms for risk stratification were retrospectively applied: (1) ET based risk stratification and cath if intermediate or high risk Duke-score; (2) MPS based risk stratification and cath if SDS≥8; (3) combined approach with ET as first step and MPS in case of intermediate risk Duke-score. A cath would have been suggested in every patient with either high risk Duke-score or SDS≥8 in patients with intermediate risk Duke-score. The referral rate to cath was 27% according to the ET alone, 13% using MPS, and finally 12% applying the combined risk stratification. The cost of the diagnostic work-up including cath were: 615€, 1'299€, and 598€ per patient, respectively. The coronary angiography referral rate widely depends on the diagnostic modality used for risk stratification and according to the referral criteria provided by the guidelines. In the present study, the use of a stress imaging modality (MPS) and published prognostic data was associated with a lower referral rate to cath as compared to exercise testing alone and thus underlines the advantage of a risk based approach applying stress imaging in patients with intermediate risk Duke-scor

influence of teeth anatomical characteristics on the efficacy of manual toothbrushing manoeuvres

Abstract Purpose The aim of the study was to investigate the efficacy of two toothbrushing techniques on the amount of plaque accumulation and to evaluate how the changes were correlated to the anatomical characteristics of the anterior maxillary arch. Methods Thirty subjects of both genders were included, they were asked not to brush for 12 hours. Afterwards, they were asked to manually brush the left side of their maxillary arch with the modified Bass technique and the right side adopting the roll technique. The comparison of photographs taken before and after the manoeuvres, using a plaque disclosing agent, allowed the researchers to measure the changes in plaque accumulation measured using the Quigley and Hein plaque scoring classification. Linear regression analysis was used to evaluate the correlation between such changes and the teeth and arch anatomical characteristics. Results A mean reduction of 9.6 +- 5.2% considering both arches after brushing was observed. The changes in plaque accumulation were not different between the two techniques. The length of the line obtained joining the contact point between the central incisors and the contact point between the second premolar and the first molar on the left side and the distance between that line and the lateral incisor on the same side positively correlated to the decrease in the plaque scores (P = 0.046 and P = 0.044, respectively). Conclusion Both tested techniques were effective in plaque removal in the anterior maxillary arches. However, the research for the anatomical factors influencing the amount of efficacy of the toothbrushing manoeuvres was inconclusive. We can hypothesise that the adoption of one adequate technique could be more important than the teeth characteristics

Reduction of ST-elevation myocardial infarction in Canton Ticino (Switzerland) after smoking bans in enclosed public places—No Smoke Pub Study

Background: Second-hand smoke increases the risk of acute myocardial infarction. Canton Ticino (CT) first introduced a smoking ban in public places in 2007. This offered the opportunity to assess the long-term impact of a smoking ban on the incidence of ST-elevation myocardial infarctions (STEMI) compared with a population where the law was not yet implemented. Methods: We assessed the incidence of STEMI hospitalizations per 100 000 inhabitants both during 3 years before and after the ban application in CT and in Canton Basel City (CBC), where this law was not yet applied. Data were obtained from the codified hospital registry (ICD-10 codes). Results: In CT, the mean incidence of STEMI admissions during the 3 pre-ban years (123.7) was significantly higher than the incidence of admissions in each of the 3 post-ban years (92.9, 101.6 and 89.6 respectively; P <.024). Analysing population subsets, a post-ban reduction was observed among ≥65-year-old people of both sexes in each of the 3 post-ban years and in the <65-year age group during the first post-ban year (P = 0.02). Conversely, the mean incidence of STEMI hospitalizations in CBC (92.4) didn't change significantly in each of the 3 post-ban years (83.9, 83.3 and 79.5, P = NS) during the same period. However, a significant long-term reduction in STEMI admissions was observed in CBC among the male group with ≥65 years (P < 0.01). Conclusion: Our work suggests a significant impact of the smoke-free policy on the number of annual STEMI. Specific population subsets (i.e. ≥65-year-old females) were particularly affected by the smoking ban, showing a significant reduction in STEMI hospitalization

End-of-life preferences of elderly patients with chronic heart failure

Aims Elderly heart failure (HF) patients are assumed to prefer improved quality of life over longevity, but sufficient data are lacking. Therefore, we assessed the willingness to trade survival time for quality-of-life (QoL) and the preferences for resuscitation. Methods and results At baseline and after 12 and 18 months, 622 HF patients aged ≥60 years (77 ± 8 years, 74% NYHA-class ≥III) participating in the Trial of Intensified vs. standard Medical therapy in Elderly patients with Congestive Heart Failure had prospective evaluation of end-of-life preferences by answering trade-off questions (willingness to accept a shorter life span in return for living without symptoms) and preferences for resuscitation if necessary. The time trade-off question was answered by 555 patients (89%), 74% of whom were not willing to trade survival time for improved QoL. This proportion increased over time (Month 12: 85%, Month 18: 87%, P < 0.001). In multivariable analysis, willingness to trade survival time increased with age, female sex, a reduced Duke Activity Status Index, Geriatric Depression Score, and history of gout, exercise intolerance, constipation and oedema, but even combining these variables did not result in reliable prediction. Of 603 (97%) patients expressing their resuscitation preference, 51% wished resuscitation, 39% did not, and 10% were undecided, with little changes over time. In 430 patients resuscitation orders were known; they differed from patients' preferences 32% of the time. End-of-life preferences were not correlated to 18-month outcome. Conclusion Elderly HF patients are willing to address their end-of-life preferences. The majority prefers longevity over QoL and half wished resuscitation if necessary. Prediction of individual preferences was inaccurate. Trial Registration: isrctn.org Identifier: ISRCTN4359647

High-efficiency linear power amplifier for active magnetic bearings

A modified class-G linear amplifier has been developed to improve the overall efficiency of a transconductance amplifier loaded with the high inductance and low resistance typical of the magnetic bearing coils. A simple theoretical characterization has been used to provide some diagrams to optimize the power efficiency as a function of a nonconstant load such as that due to a rotor unbalance. Experimental results are reported that show a more than satisfactory agreement with the expected results and the developed theory