To evaluate the variability in the reported diagnostic accuracy of the exercise electrocardiogram, we applied meta-analysis to 147 consecutively published reports comparing exerciseinduced ST depression with coronary angiography. These reports involved 24,074 patients who underwent both tests. Population characteristics and technical and methodologic factors, including publication year, number of electrocardiographic leads, exercise protocol, use of hyperventilation, definition of an abnormal ST response, exclusion of certain subgroups, and blinding of test interpretation were analyzed. Wide variability in sensitivity and specificity was found (mean sensitivity, 68%; range, 23-100%; SD, 16%; and mean specificity, 77%; range, 17-100%; SD, 17%). The four study characteristics found to be significantly and independently related to sensitivity were the treatment of equivocal test results, comparison with a "better" test such as thallium scintigraphy, exclusion of patients on digitalis, and publication year. The four variables found to be significantly and independently related to specificity were the treatment of upsloping ST depressions, the exclusion of subjects with prior infarction or left bundle branch block, and the use of preexercise hyperventilation. Stepwise linear regression explained less than 35% of the variance in sensitivities and specificities reported in the 147 publications. There is wide variability in the reported accuracy of the exercise electrocardiogram. This variability is not explained by information reported in the medical literature. (Circulation 1989;80:87-98) T he diagnosis of coronary artery disease in patients with chest pain syndromes is a major application of the exercise electrocardiogram (ECG) sion to determine the expected value and variability in this test's accuracy and determine which technical and methodologic factors independently affect the reported accuracy and its variability. Methods Literature ReviewThe Bibliography Retrieval Service and Medlars were used to search the National Library of Medicine data base for reports published after 1967 on the diagnostic accuracy of the exercise ECG when compared with coronary angiography. Though both exercise testing and angiography were used before 1967, few reports of their use in the same patients had appeared before that date. The search terms used were "exercise electrocardiogram" and "coronary artery disease." The bibliographies of three major textbooks on the subject were also searched.1-3 The bibliographies of review articles published between 1984 and 1987 and retrieved from the computer search were also scanned to complete the meta-analytic data base.The 325 publications resulting from these searches were screened for studies involving groups of 50 patients or more undergoing exercise electrocardiography with ST segment measurement and coronary angiography; for the latest report when more than one report from the same institution and same time period (within 3 years) was found, unless it could be verified that duplicatio...

To evaluate the variability in the reported accuracy of the exercise electrocardiogram (ECG) for predicting severe coronary disease, meta analysis was applied to 60 consecutively published reports comparing exercise-induced ST depression with coronary angiographic findings. The 60 reports included 62 distinct study groups comprising 12,030 patients who underwent both tests. Both technical and methodologic factors were analyzed. Wide variability in sensitivity and specificity was found (mean sensitivity 81% [range 40% to 100%, SD 12%]; mean specificity 66% [range 17% to 100%, SD 16%]). All three variables found to be significantly and independently related to sensitivity were methodologic (the exclusion of patients with right bundle branch block, the comparison with another exercise test thought to be superior in accuracy and the exclusion of patients taking digitalis). Exclusion of patients with right bundle branch block and comparison with a "better" exercise test were both significantly associated with sensitivity for the prediction of triple vessel or left main coronary artery disease. Adjustment of exercise-induced ECG changes for changes in heart rate was strongly associated with the specificity for critical disease (partial R2 = 0.436, p = 0.0001).

Although the purported incidence of pacemaker syndrome according to the literature is only 5%-15%, this is based on a series of patients with VVI pacing. Increasing numbers of studies are being reported in which patients prefer the dual chamber mode despite little benefit being demonstrated on objective testing, suggesting that pacemaker syndrome may be more common than is generally reported. This study was designed to evaluate the reported symptoms in a series of patients programmed to both the VVI and one or more dual chamber modes. Forty unselected patients with dual chamber pacemakers were entered into a blind, randomized trial comparing the symptoms associated with VVI pacing to those associated with dual chamber pacing. Patients were randomized to either VVI or dual chamber pacing. At the end of 1 week, questionnaires rating 16 different symptoms were completed. Blood pressure, LV function, presence of ventriculoatrial conduction, and ability to override the pacemaker were evaluated. The pacemaker was then programmed to the other mode. Overall, 12 of 16 symptoms were significantly worse in the VVI as compared to dual chamber mode. The most highly significant (P less than 0.005) were shortness of breath, dizziness, fatigue, pulsations in the neck or abdomen, cough, and apprehension. Pacemaker syndrome was clinically recognized in 83% of patients paced in the VVI mode with 65% of patients experiencing moderate to severe symptoms. There were no readily identified clinical, hemodynamic, or electrophysiological parameters that predicted which patients would develop pacemaker syndrome. Thus, when patients have an opportunity to experience both pacing modes in close proximity to one another, there is a high incidence of pacemaker syndrome in the VVI mode.

Background: Bone anchored hearing implants (BAHI) are widely used and highly successful, accompanied with a high level of patient satisfaction across most techniques. A large UK teaching hospital switched from the previously used wide diameter titanium fixture and drilling system to the novel minimally invasive technique and laser ablated titanium implant. Before this change the rates of fixture failure and skin problems necessitating abutment change were 1% each. Methods: Retrospective case note review of consecutive BAHI patients drawn from an electronic database between January 2015 and October 2016. Results: Data from a total of 118 procedures were reviewed, with different combinations of surgical techniques and implant types. Sixty procedures were performed via the novel minimally invasive technique with 21 failures (35%). Fourty-eight modified minimally invasive technique procedures were performed with seven failures. In 64 of the procedures, laser ablated titanium fixtures were placed with 21 failures (32.8%). In 54 procedures wide diameter titanium fixtures were placed with eight failures (5%). Conclusion: Initial experience with the novel minimally invasive technique and laser ablated titanium fixture showed significantly higher failure rates than expected. This prompted a change to an open technique and subsequent abandonment of the laser ablated titanium fixture and custom drilling solution in our institution.