Nocebo vs Placebo Effects: Their Clinical Relevance.

The placebo effect can be defined as any improvement of illnesses or reduction of subjective symptoms that result from interventions possessing no known physical effects. By contrast, the nocebo effect refers to undesirable symptoms or illnesses that follow interventions also lacking known physical effects. It may also play a role in chronic illnesses that lack objective confirmation. Both placebo and nocebo effects can be potent and must be understood by both practitioners and researchers for proper application in clinical medicine. Individual caregivers can apply these principles to modify results in the daily care of patients.

Somatic symptom disorders without known physical causes: one disease with many names?

Patients complaining of pain or fatigue in the absence of known physical diseases constitute a high percentage of those seeking general medical care. Depending upon the type of physician/specialist consulted, those individuals may receive disease labels that range from an implied psychological origin such as somatoform or psychosomatic disease, or to a presumed physical disease such as fibromyalgia. Although all these conditions are regularly associated with fatigue, we have provided a new label suggesting another disease category, "systemic exertion intolerance disease," which replaces the previous "chronic fatigue syndrome." All these conditions have common, overlapping features that usually consist of both fatigue and pain, and, in the absence of definitive objective confirmation, might be best classified under one heading such as somatic symptom disorder. Management of these disorders is challenging, but suggestions for proper identification and treatment are presented.

The placebo effect: the good, the bad, and the ugly.

The placebo effect is defined as any improvement of symptoms or signs following a physically inert intervention. Its effects are especially profound in relieving subjective symptoms such as pain, fatigue, and depression. Present to a variable extent in all therapeutic encounters, this effect is intensified by hands-on contact with close verbal communication between caregiver and recipient. Thus, it may be used to benefit patients but provides a ready avenue for unscrupulous "healers" of all types. Conventional medical practitioners often intervene in some way and, without knowing what caused the improvement, may claim credit for the apparent benefit. Physicians must be skeptical about apparent "responses" to treatments, using the information described herein to better understand what we are-or are not-accomplishing to provide the best possible outcomes for our patients. Less well studied, the "nocebo effect" defines negative responses to placebo interventions. This latter effect may be quite profound and likely is causative in many maladies believed to have psychic origins.

The cervical bruit: sound spectral analysis related to severity of carotid arterial disease.

Cervical bruits may signal the presence of high-grade narrowing of arterial supply to the brain. Previous small studies have suggested that severe arterial stenosis may produce bruits that persist longer and contain a greater proportion of higher-frequency sound spectral components. This study included 96 patients referred for duplex/Doppler testing after cervical bruits had been detected. With the use of a stethoscope equipped with wireless communication to an ordinary hand-held computer, we recorded these bruits, analyzed peak sound frequencies and the durations of sound persistence > or = 200 Hz, and correlated them with Doppler velocities. Overall, the durations and peak frequencies within the bruits correlated significantly with the peak Doppler derived velocities, that is, severity of arterial obstruction. In the presence of high-grade arterial stenosis (peak Doppler velocity > or = 200 cm/s), bruits regularly possessed either high peak frequencies or prolonged signal durations with a sensitivity approaching 90%. Bruits containing lower and nonsustained peak frequencies were uncommonly associated with severe arterial obstruction. Only well-transmitted bruits with frequencies reaching 200 Hz could be analyzed satisfactorily. In conclusion, we confirm earlier observations that peak frequencies and duration of arterial bruits correlate significantly with severity of underlying arterial obstruction. Equipment used is inexpensive, convenient, and portable. This method provides an objective means for confirming and quantifying subjective auditory impressions of bruits gained at the bedside. It can provide assistance in selecting patients for further testing and as a means for serial follow-up of individuals with known disease.

Cardiac auscultation: a glorious past--and it does have a future!

Cardiac auscultation remains an important part of clinical medicine. The standard acoustic stethoscope, which has been useful for more than a century, cannot process, store, and play back sounds or provide visual display, and teaching is hindered because there is no means to distribute the same sounds simultaneously to more than one listener. Modern portable and inexpensive tools are now available to provide, through digital electronic means, better sound quality with visual display and the ability to replay sounds of interest at either full or half speed with no loss of frequency representation or sound quality. Visual display is possible in both standard waveform and spectral formats. The latter format is readily available and provides certain advantages over the time-honored waveform (phonocardiographic) method. Both methods, however, can and should be used simultaneously. Sound signals obtained electronically may then be subjected to objective visual and numerical analysis, transmitted to distant sites, and stored in medical records. Signal analysis shows early promise for clinical application, such as in the assessment of severity of aortic stenosis and in the separation of innocent from organic murmurs. In addition to their clinical value, these methods provide a critical vehicle for the teaching of cardiac auscultation, a method that can and should be preserved for future generations.

Usefulness of a new sound spectral averaging technique to distinguish an innocent systolic murmur from that of aortic stenosis.

We present a new method to record and display heart sounds that uses a hand-held computer and stethoscopic recording device. It allows for rapid spectral and waveform displays of murmurs and provides a means for signal averaging of spectral frequency content. Compared with aortic stenosis, innocent murmurs primarily contain frequencies of <300 Hz and persist for a shorter duration at the upper-frequency levels. This method provides for rapid characterization of innocent murmurs, a means for comparison with other murmurs, and transmission of acoustic data to distant sites.

Assessment of severity of aortic stenosis through time-frequency analysis of murmur.

STUDY OBJECTIVE: The accurate and inexpensive noninvasive assessment of the presence and severity of aortic stenosis remains a challenge. In this study, we performed spectral analysis on the murmurs of a group of patients with this disease in order to assess its severity. DESIGN: An electronic stethoscope was used to generate a spectral analysis of murmurs in patients with aortic stenosis. The durations of the spectra at different frequencies (ie, 200, 250, and 300 Hz) were correlated to the Doppler echocardiogram-derived mean and peak pressure gradients. Heart murmurs from the patients were recorded, and the spectra of the recordings were produced via fast-Fourier transformation. The duration of the spectra above the three given frequencies was then measured. PATIENTS: Forty-one patients (age range, 45 to 94 years; mean age, 68 years) met the inclusion criteria, which included a minimum ejection fraction of 40% and no other significant systolic murmur or coexistent valve disease. RESULTS: The peak pressure gradient measured via Doppler echocardiogram ranged from 15.3 to 185 mm Hg with the mean of 63 mm Hg. The duration of the spectra of > 300 Hz correlated best with the peak pressure gradient measured using the Doppler echocardiogram. An exponential regression model was created showing a significant correlation coefficient of r = 0.86 (p < 0.0001). CONCLUSIONS: This study demonstrated a good correlation between the duration of spectra at 300 Hz and the Doppler derived peak pressure gradient. This simple and inexpensive technique may prove to be valuable in the evaluation and monitoring of patients with suspected and proven aortic stenosis.