Comparison of passive leg raising and hyperemia on macrovascular and microvascular responses.

Passive leg raising is a simple diagnostic maneuver that has been proposed as a measure of arterial vasodilator reserve and possibly endothelial function. While passive leg raising has previously been shown to lower blood pressure, increase flow velocity and cause brachial artery dilation, its effects on microvascular flow has not been well studied. Also, passive leg raising has been directly compared previously to upper arm but never to lower arm occlusion of blood flow induced hyperemia responses. We compared changes in macrovascular indices measured by brachial artery ultrasound and microvascular perfusion measured by Laser Doppler Flowmetry induced by passive leg raising to those provoked by upper arm and lower arm induced hyperemia in healthy subjects. Upper arm induced hyperemia increased mean flow velocity by 398%, induced brachial artery dilatation by 16.3%, and increased microvascular perfusion by 246% (p<.05 for all). Lower arm induced hyperemia increased flow velocity by 227%, induced brachial artery dilatation by 10.8%, and increased microvascular perfusion by 281%. Passive leg raising increased flow velocity by 29% and brachial artery dilatation by 5.6% (p<.05 for all), but did not change microvascular perfusion (-5%, p=ns). In conclusion, passive leg raising increases flow velocity orders of magnitude less than does upper arm or lower arm induced hyperemia. Passive leg raising-induced brachial artery dilatation is less robust than either of these hyperemic techniques. Finally, although upper arm and lower arm hyperemia elicits macrovascular and microvascular responses, passive leg raising elicits only macrovascular responses.

Determination of heart rate variability with an electronic stethoscope.

INTRODUCTION: Heart rate variability (HRV) is widely used to characterize cardiac autonomic function by measuring beat-to-beat alterations in heart rate. Decreased HRV has been found predictive of worse cardiovascular (CV) outcomes. HRV is determined from time intervals between QRS complexes recorded by electrocardiography (ECG) for several minutes to 24 h. Although cardiac auscultation with a stethoscope is performed routinely on patients, the human ear cannot detect heart sound time intervals. The electronic stethoscope digitally processes heart sounds, from which cardiac time intervals can be obtained. METHODS: Accordingly, the objective of this study was to determine the feasibility of obtaining HRV from electronically recorded heart sounds. We prospectively studied 50 subjects with and without CV risk factors/disease and simultaneously recorded single lead ECG and heart sounds for 2 min. RESULTS: Time and frequency measures of HRV were calculated from R-R and S1-S1 intervals and were compared using intra-class correlation coefficients (ICC). CONCLUSION: The majority of the indices were strongly correlated (ICC 0.73-1.0), while the remaining indices were moderately correlated (ICC 0.56-0.63). In conclusion, we found HRV measures determined from S1-S1 are in agreement with those determined by single lead ECG, and we demonstrate and discuss differences in the measures in detail. In addition to characterizing cardiac murmurs and time intervals, the electronic stethoscope holds promise as a convenient low-cost tool to determine HRV in the hospital and outpatient settings as a practical extension of the physical examination.

Lupus Never Fails to Deceive US: A Case of Rowell's Syndrome.

BACKGROUND: Rowell's syndrome is comprised of the presentation of erythema multiforme- (EM-) like lesions in association with lupus erythematosus (LE), along with serologies of speckled antinuclear antibodies (ANAs), positive rheumatoid factor (RF), positive anti-La/anti-Ro, and the clinical finding of chilblains. As per the redefined criteria by Zeitouni et al., three major criteria in addition to at least 1 minor criterion are necessary for diagnosis. Case Presentation. A 20-year-old male presented with a one-week history of worsening nonpruritic erythematous maculopapular skin rash (resembling EM) which appeared on the face and subsequently spread to the trunk, arms, legs, palms, and soles. There was no mucosal involvement. At the onset of rash, the patient reported headaches, associated with photosensitivity and intermittent fevers. Workup for viral meningitis yielded negative results. Laboratory investigation revealed mild anemia, elevated inflammatory markers, a positive ANA with speckled pattern, a positive anti-Ro/SSA, anti-La/SSB antibodies, and a positive rheumatoid factor (RF). Lupus anticoagulant antibody was positive along with a low-positive anticardiolipin IgM antibody and a negative beta-2 glycoprotein antibody. Anti-dsDNA, anti-Smith, anti-Jo-1, anti-centromere, and anti-Scl-70 antibodies were negative. Hepatitis serologies, herpes simplex virus 1 and 2, mycoplasma, Epstein-Barr virus, HIV, and parvovirus B19 were negative. Left arm skin biopsy demonstrated vacuolar interface dermatitis and positive colloidal iron stain suggestive of dermal mucin deposition, favoring the diagnosis of cutaneous collagen vascular disease. Cutaneous lesions improved with administration of oral prednisolone. CONCLUSION: Rowell's syndrome should be considered in patients who present with cutaneous LE and lesions resembling EM. Further serological markers should be pursued in the absence of obvious EM-precipitating factors.