333 research outputs found
Identification of false positive exercise tests with use of electrocardiographic criteria: A possible role for atrial repolarization waves
Atrial repolarization waves are opposite in direction to P waves, may have a magnitude of 100 to 200 mu V and may extend into the ST segment and T wave. It was postulated that exaggerated atrial repolarization waves during exercise could produce ST segment depression mimicking myocardial ischemia. The P waves, PR segments and ST segments were studied in leads II, III, aVF and V4 to V6 in 69 patients whose exercise electrocardiogram (ECG) suggested ischemia (100 mu V horizontal or 150 mu V upsloping ST depression 80 ms after the J point). All had a normal ECG at rest. The exercise test in 25 patients (52% male, mean age 53 years) was deemed false positive because of normal coronary arteriograms and left ventricular function (5 patients) or normal stress single photon emission computed tomographic thallium or gated blood pool scans (16 patients), or both (4 patients). Forty-four patients with a similar age and gender distribution, anginal chest pain and at least one coronary stenosis greater than or equal to 80% served as a true positive control group. The false positive group was characterized by (1) markedly downsloping PR segments at peak exercise, (2) longer exercise time and more rapidmore » peak exercise heart rate than those of the true positive group, and (3) absence of exercise-induced chest pain. The false positive group also displayed significantly greater absolute P wave amplitudes at peak exercise and greater augmentation of P wave amplitude by exercise in all six ECG leads than were observed in the true positive group.« les
Influence of calcium administration on the short-term hemodynamic and anti-ischemic effects of nifedipine
This prospective study investigated whether pretreatment with intravenously administered calcium would influence the effect of nifedipine on rest hemodynamics and treadmill performance in patients with ischemic heart disease. Seventeen patients were studied after undergoing a qualifying treadmill exercise test that revealed ST segment depression indicative of ischemic heart disease. Study subjects performed three additional treadmill tests as part of the protocol. One treadmill test was obtained from each patient to provide baseline measurements without a preceding intravenous infusion and in the absence of all antianginal drugs including nifedipine two additional exercise tests were preceded by an infusion and 10 mg of bite-and-swallow nifedipine. The infusions, administered in a randomized, double-blind, crossover fashion, consisted of either 10 ml of 10% calcium chloride (13.6 mEq) in 50 ml of 5% dextrose in water or 5% dextrose in water alone. Rest systolic blood pressure (134 +/- 4.6 mm Hg) was unchanged after placebo infusion (135 +/- 4.6 mm Hg) but decreased to 124 +/- 4.1 mm Hg (p less than 0.01) 25 min after nifedipine administration. Rest systolic blood pressure increased after calcium infusion (from 139 +/- 4.3 to 148 +/- 4.8 mm Hg, p less than 0.01) and then decreased significantly 25 min after nifedipine administration to 135 +/- 4.2 mm Hg (p less than 0.01). Despite a decrease at the time of peak nifedipine effect after either infusion, systolic blood pressure was significantly lower after administration of nifedipine alone than after administration of calcium and nifedipine (124 +/- 4.1 vs. 135 +/- 4.2 mm Hg, p less than 0.01)
The effect of mirabegron on patient-related outcomes in patients with overactive bladder: the results of post hoc correlation and responder analyses using pooled data from three randomized Phase III trials
Purpose To understand how improvements in the symptoms
of overactive bladder (OAB) seen with the b3-adrenoceptor
agonist mirabegron 50 mg, correlate with patient experience
as measured by validated and standard patient-reported
outcomes (PROs), and to identify whether there is overall
directional consistency in the responsiveness of PROs to
treatment effect.
Methods In a post hoc analysis of pooled data from three
randomized, double-blind, placebo-controlled, 12-week
Phase III trials of mirabegron 50 mg once daily, responder
rates for incontinence frequency (C50 % reduction in
incontinence episodes/24 h from baseline to final visit),
micturition frequency (B8 micturitions/24 h at final visit),
and PROs [minimally important differences in patient
perception of bladder condition (PPBC) and subsets of the
overactive bladder questionnaire (OAB-q) measuring total
health-related quality of life (HRQoL), and symptom
bother] were evaluated individually and in combination.
Results Mirabegron 50 mg demonstrated greater
improvement from baseline to final visit than placebo for
each of the responder analyses, whether for individual
objective and subjective outcomes or combinations thereof.
These improvements versus placebo were statistically significant
for all double and triple responder analyses and for
all single responder analyses except PPBC. PRO measurements
showed directional consistency and significant
correlations, and there were also significant correlations
between objective and subjective measures of efficacy.
Conclusions The improvements in objective measures
seen with mirabegron 50 mg translate into a meaningful
clinical benefit as evident by the directional consistency
seen in HRQoL measures of benefit
Onset of action of the beta 3-adrenoceptor agonist, mirabegron, in Phase II and III clinical trials in patients with overactive bladder
Purpose Long-term persistence with pharmacotherapy for
overactive bladder (OAB) requires a drug with an early onset
of action and good efficacy and tolerability profile. Although
antimuscarinics improve OAB symptoms within 1–2 weeks
of initiating treatment, adherence after 3 months is relatively
poor due to bothersome side effects (e.g., dry mouth and
constipation). Mirabegron, a b3-adrenoceptor agonist, has
demonstrated significant improvements in key symptoms of
OAB and good tolerability after 12 weeks in Phase III studies.
Methods This was a prespecified pooled analysis of three
randomized, double-blind, placebo-controlled, 12-week
studies, and a Phase II study, to evaluate efficacy and tolerability
of mirabegron 25 and 50 mg versus placebo. The
main efficacy endpoints were change from baseline to
week 1 (Phase II only), week 4, and final visit in mean
number of incontinence episodes/24 h, micturitions/24 h,
and mean volume voided/micturition (MVV).
Results A significant benefit for mirabegron 25 and 50 mg
versus placebo was evident at the first assessment point,
4 weeks after initiation of therapy, in Phase III studies for
incontinence, micturitions, and MVV. The earliest measured
benefit was after 1 week, in the Phase II study. Quality-of-life
parameters also significantly improved with mirabegron 25
and 50 mg as early as week 4. Significant benefits continued
throughout the studies. Mirabegron was well tolerated.
Conclusions The early onset of action and good overall
efficacy and tolerability balance that mirabegron offers
may lead to high rates of persistence with mirabegron in
the long-term treatment of OAB
Prehospital management of exertional heat stroke at sports competitions for Paralympic athletes
Objectives: To adapt key components of exertional heat stroke (EHS) prehospital management proposed by the International Olympic Committee (IOC) Adverse Weather Impact Expert Working Group for the Olympic Games Tokyo 2020 so that it is applicable for the Paralympic athletes.Methods: An expert working group representing members with research, clinical and lived sports experience from a Para sports perspective reviewed and revised the IOC consensus document of current best practice regarding the prehospital management of EHS.Results: Similar to Olympic competitions, Paralympic competitions are also scheduled under high environmental heat stress; thus, policies and procedures for EHS prehospital management should also be established and followed. For Olympic athletes, the basic principles of EHS prehospital care are: early recognition, early diagnosis, rapid, on-site cooling, and advanced clinical care. Although these principles also apply for Paralympic athletes, slight differences related to athlete physiology (e.g., autonomic dysfunction) and mechanisms for hands-on management (e.g., transferring the collapsed athlete or techniques for whole-body cooling) may require adaptation for care of the Paralympic athlete.Conclusions: Prehospital management of EHS in the Paralympic setting employs the same procedures as for Olympic athletes with some important alterations.</div
Risk of injuries in Paralympic track and field differs by impairment and event discipline A prospective cohort study at the London 2012 Paralympic Games
Background: The incidence rates (IRs) and factors associated with injuries in the sport of Paralympic athletics (track and field) have not been comprehensively and prospectively studied. Purpose: To determine injury IRs, characteristics of injuries, and associated factors in the sport of athletics at the London 2012 Paralympic Games. Study Design: Cohort study; Level of evidence, 2. Methods: A total of 977 athletes competing in the sport of athletics were followed over a total 10-day competition period of the Paralympic Games. Daily injury data were obtained via 2 databases: (1) a custom-built, web-based injury and illness surveillance system (WEB-IISS), maintained by team medical personnel; and (2) the organizing committee database, maintained by medical providers in the medical stations operated by the London Organising Committee of the Olympic and Paralympic Games. Athlete impairment and event discipline were obtained via the International Paralympic Committee athlete database. IRs (injuries per 1000 athlete-days) by impairment, event discipline, sex, and age were examined. Results: The overall IR was 22.1 injuries per 1000 athlete-days (95% CI, 19.5-24.7). In track disciplines, ambulant athletes with cerebral palsy experienced a lower incidence of injuries (IR, 10.2; 95% CI, 4.2-16.2) when compared with ambulant athletes from other impairment categories. Athletes in seated throwing experienced a higher incidence of injuries (IR, 23.7; 95% CI, 17.5-30.0) when compared with athletes in wheelchair racing (IR, 10.6; 95% CI, 5.5-15.6). In both track and field disciplines, the majority of injuries did not result in time loss from competition or training. Ambulant athletes experienced the greatest proportion of injuries to the thigh (16.4% of all injuries; IR, 4.0), observed predominantly in track athletes. Wheelchair or seated athletes experienced the greatest proportion of injuries to the shoulder/clavicle (19.3% of all injuries; IR, 3.4), observed predominantly in field athletes. Conclusion: This is the first prospective cohort study examining injury IRs and associated factors in the sport of athletics at the Paralympic Games. Injury patterns were specific to the event discipline and athlete impairment. The majority of injuries occurred to the thigh (ambulant athletes) or shoulder/clavicle (wheelchair or seated athletes) and did not result in time loss. </jats:sec
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