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Dive into the research topics where Michael Karpf is active.

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Featured researches published by Michael Karpf.


The New England Journal of Medicine | 1983

A Prospective Evaluation and Follow-up of Patients with Syncope

Wishwa N. Kapoor; Michael Karpf; Sam Wieand; Jacqueline Peterson; Gerald S. Levey

We prospectively evaluated and followed 204 patients with syncope to determine how often a cause of syncope could be established and to define the prognosis of such patients. A cardiovascular cause was established in 53 patients and a noncardiovascular cause in 54. The cause remained unknown in 97 patients. At 12 months, the overall mortality was 14 +/- 2.5 per cent. The mortality rate (30 +/- 6.7 per cent) in patients with a cardiovascular cause of syncope was significantly higher than the rate (12 +/- 4.4 per cent) in patients with a noncardiovascular cause (P = 0.02) and the rate (6.4 +/- 2.8 per cent) in patients with syncope of unknown origin (P less than 0.0001). The incidence of sudden death was 24 +/- 6.6 per cent in patients with a cardiovascular cause, as compared with 4 +/- 2.7 per cent in patients with a noncardiovascular cause (P = 0.005) and 3 +/- 1.8 per cent in patients with syncope of unknown origin (P = 0.0002). Patients with syncope can be separated into diagnostic categories that have prognostic importance. Patients with a cardiovascular cause have a strikingly higher incidence of sudden death than patients with a noncardiovascular or unknown cause.


The American Journal of Medicine | 1986

Syncope in the Elderly

Wishwa N. Kapoor; Diane Snustad; Jacqueline Peterson; Harry S. Wieand; Ruth Cha; Michael Karpf

This report describes the evaluation of syncope in 210 elderly patients as compared with 190 younger patients. The elderly group had a mean age of 71 years (range 60 to 90) and the younger group had a mean age of 39 years (range 15 to 59). A cardiovascular cause was found in 33.8 percent of the elderly and in 16.8 percent of the young (p = 0.0001), a noncardiovascular cause in 26.7 percent of the elderly and 37.9 percent of the young (p = 0.02), and unknown cause in 38.5 percent of the elderly and 45.3 percent of the young (NS). Prolonged electrocardiographic monitoring established the diagnosis in 17 percent of the elderly but in only 8 percent of the young (p = 0.008). Syncope resulted in trauma in 39 percent of the elderly and in 32 percent of the young, but the elderly more often had major trauma. The two-year overall mortality was 26.9 +/- 3.4 percent in the elderly and 8.3 +/- 2.1 percent in the young (p less than 0.0001). The overall mortality and incidence of sudden death in the elderly with a cardiovascular diagnosis were similar to those in the young; however, in the elderly with a noncardiovascular diagnosis and syncope of unknown cause, the mortality and incidence of sudden death were higher. Multivariate analyses using mortality and sudden death as endpoints revealed that a cardiovascular cause of syncope was a very strong risk factor. In patients with a noncardiovascular cause or unknown cause of syncope, a history of congestive heart failure, older age, and male sex are important prognostic factors.


JAMA Internal Medicine | 1990

The Duration of Holter Monitoring in Patients With Syncope: Is 24 Hours Enough?

Eric B Bass; Edward I. Curtiss; Vincent C. Arena; Barbara H. Hanusa; Alfred Cecchetti; Michael Karpf; Wishwa N. Kapoor

To determine the incremental yield of ambulatory monitoring in the evaluation of syncope, three serial 24-hour Holter recordings were obtained in a consecutive series of 95 patients with syncope, the cause of which was not explained by history, physical examination, or 12-lead electrocardiogram. The mean age of patients was 61 years and 41% were men. Major electrocardiographic abnormalities were found in 26 patients (27%), including unsustained ventricular tachycardia (19 patients), pauses of at least 2 seconds (8 patients), profound bradycardia (1 patient), and complete heart block (1 patient). The first 24-hour Holter recording had at least one major abnormality in 14 patients (15%) (95% confidence interval, 8.3% to 23.4%). Of the 81 patients without a major abnormality on the first Holter recording, the second Holter recording had major abnormalities in 9 (11%) (95% confidence interval, 5.1% to 20.0%). Of the 72 patients without a major abnormality on the first two Holter recordings, only 3 patients (4.2%) had a major abnormality on the third Holter recording (95% confidence interval, 0.8% to 11.7%). Four factors were significantly associated with an increased likelihood of a major abnormality on 72 hours of monitoring: age above 65 years (relative risk, 2.2), male gender (relative risk, 2.0), history of heart disease (relative risk, 2.2), and an initial nonsinus rhythm (relative risk, 3.5). These results suggest that 24 hours of Holter monitoring is not enough to identify all potentially important arrhythmias in patients with syncope. Monitoring may need to be extended to 48 hours if the first 24-hour Holter recording is normal.


The American Journal of Medicine | 1987

Diagnostic and prognostic implicatioins of recurrences in patients with syncope

Wishwa N. Kapoor; Jacqueline Peterson; Harry S. Wieand; Michael Karpf

The incidence and the diagnostic and prognostic implications of recurrences in 433 patients enrolled in a prospective syncope study are reported. Over a mean follow-up of 30 months, 146 patients had recurrent syncope. Patients with an initial diagnosis of a cardiovascular cause of syncope had a recurrence rate of 31 percent, patients with a noncardiovascular cause had a recurrence rate of 36 percent, and patients with syncope of unknown origin had a recurrence rate of 43 percent at three years (these differences were not significant; the minimum for any two-way comparison was p greater than or equal to 0.11). In eight of the 191 patients in whom a cause of syncope could not be found on initial evaluation, a diagnosis was assigned in follow-up after recurrent syncope. Recurrences led to major morbidity in eight of 146 patients (5 percent) and minor trauma in 10 patients (7 percent). Using recurrence as a time-dependent variable in the Cox models, it was found that this variable was not a significant predictor of overall mortality or sudden death. It is concluded that recurrences are common in patients with syncope, but new diagnosis are rarely established on the basis of evaluation of recurrences. Recurrences are not predictors of mortality or sudden death.


Journal of General Internal Medicine | 1992

The inter-rater reliability and internal consistency of a clinical evaluation exercise

Frank J. Kroboth; Barbara H. Hanusa; Susan C. Parker; John L. Coulehan; Wishwa N. Kapoor; Frank H. Brown; Michael Karpf; Gerald S. Levey

Objective:To assess the internal consistency and interrater reliability of a clinical evaluation exercise (CEX) format that was designed to be easily utilized, but sufficiently detailed, to achieve uniform recording of the observed examination.Design:A comparison of 128 CEXs conducted for 32 internal medicine interns by full-time faculty. This paper reports alpha coefficients as measures of internal consistency and several measures of inter-rater reliability.Setting:A university internal medicine program. Observations were conducted at the end of the internship year.Participants:Participants were 32 interns and observers were 12 full-time faculty in the department of medicine. The entire intern group was chosen in order to optimize the spectrum of abilities represented. Patients used for the study were recruited by the chief resident from the inpatient medical service based on their ability and willingness to participate.Intervention:Each intern was observed twice and there were two examiners during each CEX. The examiners were given a standardized preparation and used a format developed over five years of previous pilot studies.Measurements and main results:The format appeared to have excellent internal consistency; alpha coefficients ranged from 0.79 to 0.99. However, multiple methods of determining inter-rater reliability yielded similar results; intraclass correlations ranged from 0.23 to 0.50 and generalizability coefficients from a low of 0.00 for the overall rating of the CEX to a high of 0.61 for the physical examination section. Transforming scores to eliminate rater effects and dichotomizing results into pass-fail did not appear to enhance the reliability results.Conclusions:Although the CEX is a valuable didactic tool, its psychometric properties preclude reliable assessment of clinical skills as a one-time observation.


The American Journal of Medicine | 1987

Prolonged electrocardiographic monitoring in patients with syncope: Importance of frequent or repetitive ventricular ectopy

Wishwa N. Kapoor; Ruth Cha; Jacqueline Peterson; Harry S. Wieand; Michael Karpf

The purposes of this study were to document the findings on prolonged electrocardiographic monitoring in patients with syncope, correlate these findings with symptoms during monitoring, and define the prognostic importance of these findings. A total of 235 patients with syncope in whom a cause was not assigned or suggested by the initial history, physical examination, and electrocardiography were studied. Although a variety of arrhythmias were documented during monitoring, the vast majority of arrhythmias were of short duration and did not produce symptoms. At two years, the patients with frequent or paired premature ventricular contractions (PVCs) when compared with patients with rare PVCs, had a higher incidence of sudden death (18.2 percent versus 4.0 percent; p less than 0.001) and higher overall mortality (28.3 percent versus 10.8 percent; p less than 0.003). Similarly, patients with ventricular tachycardia, when compared with patients with rare PVCs, had a higher incidence of sudden death (18.7 percent versus 4.0 percent; p less than 0.0001) and higher overall mortality (36.5 percent versus 10.8 percent; p less than 0.00001). Cox regression analyses revealed that frequent or repetitive PVCs and sinus pauses were independent electrocardiographic predictors of sudden death and mortality in patients presenting with syncope. Therefore, patients with syncope and frequent or repetitive ventricular ectopy or sinus pauses constitute a high-risk subgroup and may be candidates for more extensive diagnostic evaluation.


Angiology | 1984

Deep Venous Thrombosis of the Upper Extremity Five Years Experience at a University Hospital

Thomas D. Painter; Michael Karpf

All patients with deep vein thrombosis of the arm seen at one University Hospital over a 5 year period were reviewed. The 17 cases could be divided into distinct patient groups. The first group (primary thrombosis) consisted of 7 patients primarily healthy young males (mean age 23) who had vocations or avocations which involved vigorous physical activity of the arms. The 10 pa tients with secondary thrombosis tended to be older (mean age 47.3) and to be ill or hospitalized at the time of onset of their illness. Followup information could be obtained in 9 of the cases and 7 of these patients had persistence in their symptoms consisting of residual discomfort and edema of the involved arm es pecially after exercise. None of the patients treated with anticoagulation were asymptomatic. The only patients who were symptomatic were one patient who received streptokinase and another who underwent thrombectomy. Three illus trative case studies are included.


JAMA Internal Medicine | 1986

Defecation Syncope: A Symptom With Multiple Etiologies

Wishwa N. Kapoor; Jacqueline Peterson; Michael Karpf

To our knowledge, there is no previous clinical description in the literature of patients with defecation syncope. We evaluated 20 patients with this disorder who were a subgroup of a larger, prospective study of syncope, 13 women and seven men, with a mean age of 59 years. Eleven patients had had one episode and nine had experienced multiple episodes. Fourteen patients were recumbent before the urge to defecate, nine of these asleep. The diagnostic evaluation disclosed that two patients had gastrointestinal tract problems, three had cardiac diseases, and one had transient ischemic attacks. Three additional patients had marked orthostatic hypotension. No identifiable cause for defecation syncope was found in 11 patients, but new medical problems were noted in four of those patients. In follow-up at two years, syncope had recurred in ten patients, but the majority of recurrences were unassociated with defecation. Seven patients died during the follow-up period of underlying chronic diseases. We conclude that defecation syncope is not a single distinct clinical entity. Multiple pathologic abnormalities in association with physiologic changes during sleep and defecation may contribute to syncope. Patients with defecation syncope should undergo a careful evaluation for diagnosis of underlying illness causing syncope.


Academic Medicine | 2006

The U.S. health care system is in crisis: implications for academic medical centers and their missions.

Richard Lofgren; Michael Karpf; Jay Perman; Courtney M. Higdon

The medical care system in the United States is in crisis. Health care costs are escalating and threatening coverage for millions of people. Concerns about the quality of care and patient safety are heightening; patients and payers now publicly share these concerns and want to make providers more accountable. Traditionally, the response to rising health care costs has been to modify reimbursement models and incentives. Currently there is a movement to shift the responsibility of cost containment to the patients. The authors express doubts about the overall effectiveness of this strategy and propose reengineering the health care system to improve quality and efficiency. Leaders of academic medical centers must understand the forces and dynamics of change, and the potential institutional response to improve the quality and efficiency of their delivery systems and to preserve their missions: clinical care, education, research, and community service. As they suggest the operational changes needed to respond to this evolving health care environment, the authors discuss the implications for the various missions. The graduates of training programs must be prepared to function within multidisciplinary teams and constantly seek ways to improve quality and efficiency to ensure that care is accessible, affordable, and safe. Academic medical centers need to expand their research agenda to develop more expertise in quality and process improvement research. Additionally, they must provide the leadership to foster the transition from an era of “managed care” to an era of “organized systems of care.”


Annals of Internal Medicine | 1984

Issues in evaluating patients with syncope.

Wishwa N. Kapoor; Michael Karpf; Gerald S. Levey

Excerpt Recent studies have focused on the diagnosis of syncope and the prognosis for patients with this symptom (1-4). The usefulness of many diagnostic tests has been questioned, and subgroups of...

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Frank H. Brown

University of Pittsburgh

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