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Jonathan Myers

Publications and source records attributed to Jonathan Myers.

At least 55 records · Page 3Linked to original sources
PubMed2003

Prevalence and prognostic value of exercise-induced ventricular arrhythmias.

OBJECTIVE: The purpose of this study was to determine the prevalence and prognostic significance of exercise-induced ventricular arrhythmias (EIVAs) in patients referred for exercise testing, considering the arrhythmic substrate and exercise-induced ischemia. BACKGROUND: EIVAs are frequently observed during exercise testing, but their prognostic significance is uncertain. The design of this study was a retrospective analysis of prospectively collected data, and it took place in 2 university-affiliated Veterans Affairs Medical Centers. Patients comprised 6213 consecutive males referred for exercise tests. We measured clinical exercise test responses and all-cause mortality after a mean follow-up of 6 +/- 4 years. EIVAs were defined as frequent premature ventricular contractions (PVCs) constituting >10% of all ventricular depolarizations during any 30 second electrocardiogram recording, or a run of > or =3 consecutive PVCs during exercise or recovery. RESULTS: A total of 1256 patients (20%) died during follow-up. EIVAs occurred in 503 patients (8%); the prevalence of EIVAs increased in older patients and in those with cardiopulmonary disease, resting PVCs, and ischemia during exercise. EIVAs were associated with mortality irrespective of the presence of cardiopulmonary disease or exercise-induced ischemia. In those without cardiopulmonary disease, mortality differed more so later in follow up than earlier. In those without resting PVCs, EIVAs were also predictive of mortality, but in those with resting PVCs, poorer prognosis was not worsened by the presence of EIVAs. CONCLUSIONS: Exercise induced ischemia does not affect the prognostic value of EIVAs, whereas the arrhythmic substrate does. EIVAs and resting PVCs are both independent predictors of mortality after consideration of other clinical and exercise-test variables. These findings are of limited clinical significance because of the modest change in risk and the lack of any established intervention. However, they explain some of the previous controversy and highlight the need to consider resting PVCs and follow-up duration in assessing the clinical implications of EIVAs.

Electrocardiography↗
PubMed2003

Technical considerations related to the minute ventilation/carbon dioxide output slope in patients with heart failure.

BACKGROUND: The minute ventilation (VE)-carbon dioxide output (VCO(2)) relationship has recently been demonstrated to have prognostic significance in the heart failure (HF) population. However, the method by which the VE/VCO(2) slope is expressed has been inconsistent. METHODS: One hundred eighty-eight subjects, who had received diagnoses of HF, underwent exercise testing. Two VE/VCO(2) slope calculations were made, one using exercise data prior to the ventilatory threshold (VT), and one using all data points from rest to peak exercise. Four separate peak exercise VE/VCO(2) slope calculations also were derived with unaveraged, 10-s, 30-s, and 60-s ventilatory expired gas sampling intervals. RESULTS: Although univariate Cox regression analysis demonstrated pre-VT and peak VE/VCO(2) slope calculations to both be significant predictors of cardiac-related mortality and hospitalization (p < 0.001), the peak classification scheme was significantly better (p < 0.01). The ventilatory expired gas-sampling interval that was used did not impact the predictive ability of the peak VE/VCO(2) slope. CONCLUSION: Although both the pre-VT and peak VE/VCO(2) slope calculations were prognostically significant, the peak expression was superior. The sampling interval did not appear to have a significant impact on prognostic utility. We hope that the results of the present study will contribute to the standardization of the VE/VCO(2) slope and will enhance its clinical application.

Adolescent↗
PubMed2003

Clinical and exercise test determinants of survival after cardiac transplantation.

BACKGROUND: Cardiac transplantation (CTX) is now a viable option for patients with end-stage heart failure, but there remains a paucity of available donor hearts relative to the demand for them. Establishing prognosis after CTX can help direct this resource to patients most likely to benefit, as well as to help guide therapy for CTX recipients. Clinical, exercise, and hemodynamic factors associated with survival after CTX have not been well established. METHODS: One hundred seventy-four randomly selected patients who underwent heart transplantation between 1983 and 1999 at Rikshospitalet University Hospital were included in the study. Data were collected as a part of routine posttransplantation management a mean of 3.5 +/- 2.1 years (+/- SD) after CTX. Clinical, cardiopulmonary exercise testing, and hemodynamic measures were performed, including measures of peak oxygen uptake (O(2)), ejection fraction, cardiac index, pulmonary capillary wedge pressure (PCWP), pulmonary artery pressure, creatinine, and the presence of coronary artery disease. Patients were followed up for a mean of 7.1 +/- 2.1 years; all-cause mortality was used as the end point for survival analysis. RESULTS: During the follow-up period, 39 patients died; the average annual mortality was 3.6%. Peak O(2) was 19.6 +/- 5.6 mL/kg/min, representing 70.5 +/- 6.7% of the age-predicted value. Only right atrial pressure and PCWP differed between those who survived and those who died; both were slightly higher among those who died. By Cox proportional hazard analysis, there were no age-adjusted univariate or multivariate predictors of survival among continuous variables. Exploring various cut points revealed that serum creatinine > 118 micromol/L, PCWP > 12 mm Hg, and mean pulmonary artery pressure > 25 mm Hg were significant univariate predictors of mortality. These cut points for PCWP and pulmonary artery pressure generated hazard ratios of 2.3 and 2.9, respectively. CONCLUSION: Long-term survival after CTX was comparatively high in our cohort, with 5-year survival > 80%. Standard clinical, hemodynamic, and cardiopulmonary exercise test variables were not strong predictors of mortality in CTX patients a mean of 7 years after CTX. The association between elevated hemodynamic pressures and mortality, although weak, suggests that ventricular compliance, pulmonary vascular resistance, or both, may predict long-term survival after CTX.

Blood Pressure↗
PubMed2003

Adaptation of pulmonary oxygen consumption slow component following 6 weeks of exercise training above and below the lactate threshold in untrained men.

STUDY OBJECTIVES: To examine the effects of 6 weeks of exercise training above or below the lactate threshold (LT) on the slow component (SC) of pulmonary oxygen consumption (.VO(2)). DESIGN: Randomized controlled trial. SETTING: University human performance laboratory. PARTICIPANTS: Apparently healthy, untrained men (n = 18). INTERVENTIONS: Subjects were randomized to one of three groups: high-intensity exercise training (HI) [above the LT], moderate-intensity exercise training (MOD) [below the LT], or no exercise training (CON). Exercise groups performed cycle ergometry 4 d/wk for 6 weeks. Total work throughout training was constant between groups. MEASUREMENTS AND RESULTS: Maximal cycle ergometry was performed at baseline and after training to assess power output at the LT (WLT), .VO(2) at the LT (.VO(2)LT), and peak .VO(2) (.VO(2)PK). High-intensity, constant-load cycling was performed at baseline and weeks 1, 2, 4, and 6 to assess SC adaptations. WLT, .VO(2)LT, and .VO(2)PK increased after 6 weeks in both exercise groups compared to the CON group (p < 0.05), although there were no differences between the training groups. SC of .VO(2) decreased 44% in the HI group following 1 week of exercise training vs MOD (20%, p < 0.05) and CON (12%, p < 0.01) groups. The SC attenuation was more prominent at all time points in the HI group compared to the MOD group. Total SC attenuation over the 6-week training period did not differ between the HI (71%) and MOD (57%) groups. CONCLUSIONS: Training at HI or MOD produced similar improvements in the LT, .VO(2), and power output at peak exertion when total work output was held constant. Attenuation of the SC with training above and below the LT were similar, although above-LT training promoted faster SC adaptations.

Adult↗
PubMed2002

The prognostic value of exercise testing in elderly men.

PURPOSE: Our purposes were to compare the responses to exercise testing in elderly (> or =65 years of age) and younger men, and to investigate whether exercise testing has similar prognostic value in the two age groups. METHODS: We included all elderly (n = 1185) and younger (n = 2789) male veterans without established coronary heart disease who underwent routine clinical exercise testing between 1987 and 2000 at two academically affiliated Veteran's Affairs medical center laboratories. Measurements included a standardized medical history, exercise testing, and all-cause mortality. RESULTS: Compared with younger patients, elderly patients achieved a lower workload (a mean [+/- SD] of 7 +/- 3 vs. 10 +/- 4 metabolic equivalents [METs], P <0.001) and were more likely to have abnormal ST depression (27% [n = 324] vs. 16% [n = 436], P <0.001). During the mean follow-up of 6 years, annual mortality was twice as high among elderly patients as among younger patients (4% vs. 2%, P <0.001). The only exercise test variable that was associated significantly with time to death in both age groups was maximal METs achieved: each 1 MET increase in exercise capacity was associated with an 11% reduction in annual mortality. Exercise-induced ST depression was more common in those who subsequently died, but was not an independent predictor of mortality. CONCLUSION: In elderly men, exercise testing provided prognostic information incremental to clinical data. Achieved workload (in METs) was the major exercise testing variable associated with all-cause mortality. Its prognostic importance was the same in elderly as in younger men.

Age Factors↗
PubMed2002

Exercise capacity and mortality among men referred for exercise testing.

BACKGROUND: Exercise capacity is known to be an important prognostic factor in patients with cardiovascular disease, but it is uncertain whether it predicts mortality equally well among healthy persons. There is also uncertainty regarding the predictive power of exercise capacity relative to other clinical and exercise-test variables. METHODS: We studied a total of 6213 consecutive men referred for treadmill exercise testing for clinical reasons during a mean (+/-SD) of 6.2+/-3.7 years of follow-up. Subjects were classified into two groups: 3679 had an abnormal exercise-test result or a history of cardiovascular disease, or both, and 2534 had a normal exercise-test result and no history of cardiovascular disease. Overall mortality was the end point. RESULTS: There were a total of 1256 deaths during the follow-up period, resulting in an average annual mortality of 2.6 percent. Men who died were older than those who survived and had a lower maximal heart rate, lower maximal systolic and diastolic blood pressure, and lower exercise capacity. After adjustment for age, the peak exercise capacity measured in metabolic equivalents (MET) was the strongest predictor of the risk of death among both normal subjects and those with cardiovascular disease. Absolute peak exercise capacity was a stronger predictor of the risk of death than the percentage of the age-predicted value achieved, and there was no interaction between the use or nonuse of beta-blockade and the predictive power of exercise capacity. Each 1-MET increase in exercise capacity conferred a 12 percent improvement in survival. CONCLUSIONS: Exercise capacity is a more powerful predictor of mortality among men than other established risk factors for cardiovascular disease.

Adrenergic beta-Antagonists↗
PubMed2002

A comparison of treadmill scores to diagnose coronary artery disease.

BACKGROUND: Recently, several treadmill scores have been proposed as means for improving the diagnostic accuracy of the exercise treadmill test (ETT). Questions remain regarding the diagnostic accuracy of treadmill scores when applied to a different patient population than that from which they were derived; furthermore, many treadmill scores have not been compared with one another in the same population. HYPOTHESIS: The diagnostic accuracy of treadmill scores may not be the same. METHODS: A retrospective analysis of data collected prospectively was performed on consecutive patients referred for evaluation of chest pain. All patients underwent a standard ETT followed by coronary angiography. Using angiographic evidence of coronary artery disease (CAD) as a reference, the area under the curve (AUC) of receiver operator characteristic (ROC) plots of the ST response alone, the Duke Treadmill Score (DTS), the Morise score, the Detrano score, the VA score, and a Consensus score consisting of the Morise, Detrano, and VA scores together were calculated and compared. The predictive accuracies of the DTS and the Consensus score to stratify patients for the likelihood of CAD were calculated and compared. RESULTS: In all, 1,282 patients without a prior myocardial infarction had an ETT and coronary angiography. The AUC (+/- standard error) was 0.67+/-0.01 for the ST response, 0.73+/-0.01 for DTS, 0.76+/-0.01 for Detrano score, 0.77+/-0.01 for Morise score, 0.78+/-0.01 for VA score, and 0.78+/-0.01 for Consensus score. The AUC for each treadmill score was significantly higher (z-score > 1.96) than for the ST response alone. The AUC of DTS was significantly lower than all other treadmill scores (z-score > 1.96). The predictive accuracy (+/-95% confidence interval) of the DTS to risk stratify patients into high and low likelihood for CAD was 71 (65-77)%, versus 80 (74-86)% for the Consensus score (p < 0.0001). CONCLUSION: In this population, the DTS remains useful for diagnosing CAD and stratifying for the likelihood of CAD, although it is less accurate than other treadmill scores.

Area Under Curve↗
PubMed2002

The prognostic value of body mass index and standard exercise testing in male veterans with congestive heart failure.

OBJECTIVE: To evaluate the prognostic characteristics of body mass index (BMI) and standard exercise test variables in a consecutive series of patients with mild to moderate congestive heart failure (CHF) referred for standard exercise tests. BACKGROUND: Controversy exists regarding the prognostic importance of BMI, etiology, and exercise test variables in patients with CHF. METHODS: All patients referred for evaluation at two university-affiliated Veterans Affairs Medical Centers who underwent treadmill tests for clinical indications between 1987 and 2000 were determined to be dead or alive using the Social Security Death Index after a mean 6 years follow-up. Clinical and exercise test variables were collected prospectively according to standard definitions; testing and data management were performed in a standardized fashion using a computer-assisted protocol. Survival analysis was performed using all-cause mortality as the endpoint for follow-up. RESULTS: A total of 522 patients with a history and clinical findings of CHF underwent exercise testing. Forty-two percent died during the follow-up period, for an average annual mortality of 6.7%. Cox proportional hazards model chose peak metabolic equivalents (METs), BMI, age, and ischemic etiology in rank order as independently and significantly associated with time to death. A score based on these variables classified patients into low (2% annual mortality), medium (5.2%), and high-risk groups (7% annual mortality). CONCLUSION: Standard exercise testing and BMI can be used to estimate prognosis in outpatients with heart failure. A score incorporating METs, BMI, age, and etiology efficiently stratified these patients. BMI was chosen by the survival analysis, confirming its surprising inverse relationship to prognosis in CHF patients (i.e., heavier patients do better).

Aerospace Medicine↗
PubMed2002

Comparison of treadmill scores with physician estimates of diagnosis and prognosis in patients with coronary artery disease.

OBJECTIVE: Our purpose was to compare exercise test scores and ST measurements with a physician's estimation of the probability of the presence and severity of angiographic disease and the risk of death. The American College of Cardiology/American Heart Association exercise testing guidelines provide equations to calculate treadmill scores and recommend their use to improve the predictive accuracy of the standard exercise test. However, if physicians can estimate the probability of coronary artery disease and prognosis as well as the scores, there is no reason to add this complexity to test interpretation. METHODS: A clinical exercise test was performed and an angiographic database was used to print patient summaries and treadmill reports. The clinical/treadmill test reports were sent to expert cardiologists and to 2 other groups, including randomly selected cardiologists and internists. They classified the patients summarized in the reports as having a high, low, or intermediate probability for the presence of any severe angiographic disease and estimated a numerical probability from 0% to 100%. The Social Security Death Index was used to determine survival status of the patients. RESULTS: Twenty-six percent of the patients had severe angiographic disease, and the annual mortality rate for the population was 2%. Forty-five expert cardiologists returned estimates on 473 patients, 37 randomly chosen practicing cardiologists returned estimates on 202 patients, 29 randomly chosen practicing internists returned estimates on 162 patients, 13 academic cardiologists returned estimates on 145 patients, and 27 academic internists returned estimates on 272 patients. When probability estimates for presence and severity of angiographic disease were compared, in general, the treadmill scores were superior to physicians' and ST analysis at predicting severe angiographic disease. When prognosis was estimated, treadmill prognostic scores did as well as expert cardiologists and better than most other physician groups. CONCLUSION: Estimates of the presence of clinically significant and severe angiographic coronary artery disease provided by scores were superior to physician estimates and ST analysis alone. Estimates of prognosis provided by scores were similar to the estimates made by expert cardiologists and more accurate than the estimates made by most other physician groups.

Clinical Competence↗
PubMed2002

Effects of bisoprolol fumarate on left ventricular size, function, and exercise capacity in patients with heart failure: analysis with magnetic resonance myocardial tagging.

BACKGROUND: Recent data suggest that beta-blockers can be beneficial in subgroups of patients with chronic heart failure (CHF). For metoprolol and carvedilol, an increase in ejection fraction has been shown and favorable effects on the myocardial remodeling process have been reported in some studies. We examined the effects of bisoprolol fumarate on exercise capacity and left ventricular volume with magnetic resonance imaging (MRI) and applied a novel high-resolution MRI tagging technique to determine myocardial rotation and relaxation velocity. METHODS: Twenty-eight patients (mean age, 57 +/- 11 years; mean ejection fraction, 26 +/- 6%) were randomized to bisoprolol fumarate (n = 13) or to placebo therapy (n = 15). The dosage of the drugs was titrated to match that of the the Cardiac Insufficiency Bisoprolol Study protocol. Hemodynamic and gas exchange responses to exercise, MRI measurements of left ventricular end-systolic and end-diastolic volumes and ejection fraction, and left ventricular rotation and relaxation velocities were measured before the administration of the drug and 6 and 12 months later. RESULTS: After 1 year, heart rate was reduced in the bisoprolol fumarate group both at rest (81 +/- 12 before therapy versus 61 +/- 11 after therapy; P <.01) and peak exercise (144 +/- 20 before therapy versus 127 +/- 17 after therapy; P <.01), which indicated a reduction in sympathetic drive. No differences were observed in heart rate responses in the placebo group. No differences were observed within or between groups in peak oxygen uptake, although work rate achieved was higher (117.9 +/- 36 watts versus 146.1 +/- 33 watts; P <.05) and exercise time tended to be higher (9.1 +/- 1.7 minutes versus 11.4 +/- 2.8 minutes; P =.06) in the bisoprolol fumarate group. A trend for a reduction in left ventricular end-diastolic volume (-54 mL) and left ventricular end-systolic volume (-62 mL) in the bisoprolol fumarate group occurred after 1 year. Ejection fraction was higher in the bisoprolol fumarate group (25.0 +/- 7 versus 36.2 +/- 9%; P <.05), and the placebo group remained unchanged. Most changes in volume and ejection fraction occurred during the latter 6 months of treatment. With myocardial tagging, insignificant reductions in left ventricular rotation velocity were observed in both groups, whereas relaxation velocity was reduced only after bisoprolol fumarate therapy (by 39%; P <.05). CONCLUSION: One year of bisoprolol fumarate therapy resulted in an improvement in exercise capacity, showed trends for reductions in end-diastolic and end-systolic volumes, increased ejection fraction, and significantly reduced relaxation velocity. Although these results generally confirm the beneficial effects of beta-blockade in patients with chronic heart failure, they show differential effects on systolic and diastolic function.

Adrenergic beta-Antagonists↗
PubMed2002

Do transmyocardial and percutaneous laser revascularization induce silent ischemia? An assessment by exercise testing.

BACKGROUND: Transmyocardial and percutaneous laser revascularization (TMR, PTMR) may reduce angina and increase exercise tolerance in otherwise untreatable angina patients, although the mechanism is unknown and the placebo effect may be significant. One other proposed mechanism is cardiac denervation leading to silent ischemia. METHODS: Electrocardiograms obtained during symptom-limited exercise (ETT, modified Bruce protocol) at baseline and 12 months were analyzed (blinded core laboratory) from 182 patients randomized to TMR (n = 92) or medical therapy alone (MED(TMR), n = 90) and 219 patients randomized to PTMR (n = 109) or medical therapy alone (MED(PTMR), n = 110). RESULTS: Exercise duration increased 1 year after TMR or PTMR relative to medically treated patients (6.8 +/- 3.4 min vs 8.6 +/- 3.5 min for TMR; 7.3 +/- 3.1 min vs 9.1 +/- 3.6 min for PTMR, P <.05). At baseline, 20% of TMR and MED(TMR) subjects had ST depression >1.0 mm, >80% had angina during exercise, but only 3% had ST changes without chest pain (silent ischemia). This did not change after TMR. In the PTMR group, more subjects exercised to >1.0 mm ST depression (from 17% to 34%, P <.05), with no change in MED(PTMR), but the proportion with silent ischemia did not change in either group. CONCLUSION: Exercise tolerance improved after TMR and after PTMR. Relative to PTMR, TMR more effectively suppressed pain during exercise and ischemic ST depression. However, neither TMR nor PTMR induced significant silent ischemia. These results suggest that denervation may not be a significant factor contributing to angina relief after these procedures. The contribution of the placebo effect was not determined by these results.

Adult↗
PubMed2002

Effects of exercise training on left ventricular volumes and function in patients with nonischemic cardiomyopathy: application of magnetic resonance myocardial tagging.

BACKGROUND: Exercise training is now an accepted component of the therapeutic regimen in patients with heart failure and underlying ischemia, but few data are available on the effects of training in patients with nonischemic dilated cardiomyopathy. METHODS: Twenty-four patients (mean age 55 +/- 9 years, mean ejection fraction 26.6% +/- 10%) were randomized to an exercise (n = 12) or a control (n = 12) group. Patients in the exercise group underwent 5 45-minute sessions of supervised training per week. Before and after the 2-month study period, exercise testing with respiratory gas exchange and lactate analysis was performed, left ventricular volumes and ejection fraction were measured with magnetic resonance imaging, and left ventricular rotation and relaxation velocities were measured with a novel magnetic resonance imaging tagging technique. RESULTS: Training resulted in increases in peak oxygen uptake (VO2) (21.7 +/- 4 mL/kg/min to 25.3 +/- 5 mL/kg/min, P <.05) and VO2 at the lactate threshold (12.8 +/- 4 mL/kg/min to 19.0 +/- 5 mL/kg/min, P <.01). No differences were observed within or between groups in left ventricular end-diastolic volume, end-systolic volume, or ejection fraction. Velocity of left ventricular rotation during systole was unchanged in both groups, and relaxation velocity was higher after training in the exercise group (21.2 +/- 5 degrees/s versus 29.7 +/- 12 degrees/s, P <.05). CONCLUSION: Training resulted in increases in peak VO2 and VO2 at the lactate threshold. Left ventricular volumes and systolic function (ie, ejection fraction and rotation velocity) were unchanged with training, suggesting that training in patients with dilated cardiomyopathy does not lead to further myocardial damage. However, the increase in relaxation velocity after exercise training indicates an improvement in diastolic function. The latter finding suggests an additional potential benefit of exercise training in patients with dilated cardiomyopathy.

Cardiac Output, Low↗
PubMed2002

Early repolarization in patients with spinal cord injury: prevalence and clinical significance.

OBJECTIVES: The objective was to examine the prevalence of early repolarization in a spinal cord injury (SCI) clinic and the relationship of level of injury to this electrocardiogram (ECG) finding. BACKGROUND: ST elevation on the resting ECG can be either a normal variant or a sign of acute ischemia, evolving myocardial infarction, or pericarditis. It is frequently seen as a normal variant (early repolarization) in healthy individuals, but has also been reported in individuals with SCI. While the etiology of benign ST elevation (early repolarization) has not been clearly defined, current opinion is that this finding is seen in individuals with high vagal tone. METHODS: Retrospective analysis was made of 31 5 individuals with SCI at T5 or above (140 with complete injuries), and 1 98 with SCI at T6 or below, and who had ECGs in the computerized database at the Palo Alto VA Medical Center. A comparison cohort of 32,841 able-bodied male controls also was identified in the same ECG database. Patient demographics and computerized ST measurements were analyzed. RESULTS: The prevalence of ST elevation was significantly higher in both the total high-level injury group (19%) and the complete high-injury group (24.5%) than in either the low-injury (6.5%) or control groups (13%), with P < 0.001 for comparisons between both high- and low-injury groups and high injury vs control. The magnitude of ST elevation was also higher in the high-injury groups vs the low-injury and control groups. CONCLUSION: There is a higher prevalence of early repolarization in individuals with SCI at levels of injury that can disrupt central sympathetic command of the heart. It appears that either enhanced vagal tone or loss of sympathetic tone is responsible for ST elevation.

Adolescent↗
PubMed2002

Electrocardiographic findings in patients with chronic spinal cord injury.

OBJECTIVE: To demonstrate the prevalence and prognostic value of electrocardiographic abnormalities in patients with chronic spinal cord injury. METHODS: All electrocardiographs obtained in the Palo Alto Veterans Affairs Medical Center since 1987 have been digitally recorded and stored in a computerized database. For this study, only the first electrocardiograph was considered for analysis. The subjects were divided according to age and level of spinal cord injury. The Social Security Death Index was used to ascertain vital status as of December 1999. RESULTS: Annual mortality was similar in those with chronic spinal cord injury and the able-bodied. However, individuals with a higher level of injury had a significantly higher death rate than those with a lower level of injury. The prognostic characteristics of electrocardiographic abnormalities were similar in both the able-bodied and those with spinal cord injury. CONCLUSION: In general, electrocardiographic abnormalities had the same prevalence in the spinal cord injury subjects as in the able-bodied ones. The prognostic value of electrocardiographic abnormalities in subjects with spinal cord injury is similar to that observed in able-bodied subjects.

Adult↗
PubMed2002

Exercise testing scores as an example of better decisions through science.

INTRODUCTION: The application of common statistical techniques to clinical and exercise test data has the potential to become a useful tool for assisting in the diagnosis of coronary artery disease, assessing prognosis, and reducing the cost of evaluating patients with suspected coronary disease. Since general practitioners function as gatekeepers and decide which patients must be referred to the cardiologist, they need to optimally use the basic tools they have available (i.e., history, physical exam, and the exercise test). METHODS: Review of the literature with a focus on the scientific techniques for aiding the decision-making process. RESULTS: Scores derived from multivariable statistical techniques considering clinical and exercise data have demonstrated superior discriminating power when compared using receiver-operating-characteristic curves with the ST segment response. In addition, by stratifying patients as to probability of disease and prognosis, they provide a management strategy. While computers as part of information management systems can calculate complicated equations to provide scores, physicians are reluctant to trust them. Thus, these scores have been represented as nomograms or simple additive tables so physicians are comfortable with their application. Scores have also been compared with physician judgment and been found to estimate the presence of coronary disease and prognosis as well as expert cardiologists, and often better than nonspecialists. CONCLUSION: Multivariate scores can empower the clinician to assure the cardiac patient with access to appropriate and cost-effective cardiological care.

Adult↗
PubMed2002

The disc damage likelihood scale: reproducibility of a new method of estimating the amount of optic nerve damage caused by glaucoma.

PURPOSE: The major objective of this study was to test the reproducibility of a new method of estimating the amount of optic disc damage in patients with glaucoma. METHODS: The Disc Damage Likelihood Scale (DDLS) is based on the appearance of the neuroretinal rim of the optic disc corrected for disc diameter. The eight stages, extending from no damage to far advanced damage, are based on the width of the neuroretinal rim or the circumferential extent of absence of neuroretinal rim. Reproducibility was measured by two masked observers staging 48 optic nerve stereoscopic photographs by two different methods, the cup/disc ratio (c/d) and the DDLS. Also, reproducibility was assessed by three observers examining 34 eyes of 24 patients. RESULTS: With regard to the photographs, the intraobserver and interobserver reproducibility was better using the DDLS than the c/d ratio (98% versus 85% for intraobserver of reproducibility, and 85% versus 74% for interobserver reproducibility). The DDLS correlated better with the Humphrey Visual Field than did any Heidelberg Retina Tomograph parameter. CONCLUSION: In a clinical setting, the DDLS is as reproducible as, or more reproducible than, the c/d ratio system of estimating the amount of disc damage in patients with glaucoma.

Diagnostic Techniques, Ophthalmological↗
PubMedDate not supplied

Autonomic nervous system interaction with the cardiovascular system during exercise.

There is considerable recent evidence that parameters thought to reflect the complex interaction between the autonomic nervous system and the cardiovascular system during exercise testing can provide significant prognostic information. Specific variables of great importance include heart rate (HR) response to exercise (reserve), HR recovery after exercise, and multiple components of HR variability both at rest and with exercise. Poor HR response to exercise has been strongly associated with sudden cardiac death and HR recovery from a standard exercise test has been shown to be predictive of mortality. In addition, there are limited studies evaluating the components of HR variability at rest and during exercise and their prognostic significance. Research continues seeking to refine these exercise measurements and further define their prognostic value. Future findings should augment the power of the exercise test in risk-stratifying cardiovascular patients.

Autonomic Nervous System↗