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B Boal

Publications and source records attributed to B Boal.

3 recordsLinked to original sources
PubMed1996

Serum prolactin concentrations are elevated after syncope.

The distinction between syncope and epileptic seizures is a common clinical diagnostic problem. Elevated serum prolactin (PRL) concentrations are used to help differentiate epileptic from nonepileptic attacks such as pseudoseizures. Reports of PRL concentrations following syncope have been variable. To determine whether PRL rises after syncope, we measured serum PRL concentrations during a 45-minute passive 60-degree head-up tilt in 21 patients with a history of near-fainting or syncope. Head-up tilt triggered hypotension (mean arterial pressure 51 mm Hg, 95% CI = 45-57) with syncope in 11 patients. PRL concentrations were elevated ( > 19 ng/mL) and reached a maximum within the first 30 minutes after tilt-induced syncope in nine patients (PRL supine: 11 ng/mL, 95% CI = 7-15, vs. PRL after syncope: 52 ng/mL, 95% CI = 36-67; a greater than fourfold rise), while they remained unchanged in 10 patients who had a normal response to head-up tilt (PRL supine: 6 ng/mL, 95% CI = 5-8, vs. maximum PRL while upright: 8 ng/mL, 95% CI = 6-10). The findings indicate that elevated PRL concentrations are present after hypotensive syncope and are of little use in differentiating such syncope from epileptic seizures.

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PubMed1989

Evaluation of the temperature response to exercise testing in patients with single chamber, rate adaptive pacemakers: a multicenter study.

UNLABELLED: Temperature responsive pacemakers were implanted in 45 patients (ages 44 to 90); 31 patients were evaluated by randomized, paired treadmill exercise tests 1 month postimplant. Of 28 males and 17 females, 19 had coronary artery disease; 8 had congestive heart failure. Pacing indications included sinus node disease (26), atrial fibrillation (15), AV block (10), and brady/tachy syndrome (10); some had multiple indications. Blood temperature (every 10 seconds, resolution = 0.004 degrees C) and pacing rate (every minute) were telemetered from the pacemaker. Average heart rate, exercise duration (5.7 min VVI; 6.7 min VVIR), VVIR response time (22 sec), initial temperature drop (0.23 degrees C) and maximum rate of drop (0.65 degrees C/min), temperature rise (0.31 degrees C VVI; 0.38 degrees C VVIR) and rate of rise (0.27 degrees C/min) were studied in a subset of patients. In pacer-dependent patients, average paired increases in exercise duration and heart rate was 56% and 34%, respectively. Including all (31) patients, some with intermittent sinus rhythm, increases were 28% and 9%, respectively. Because exercise duration increased, temperature rise was higher with rate adaptation. Rate adaptation was obtainable in all patients and patients averaged 99 +/- 48 increases above basic pacing rate per day at nominal temperature sensitivity. CONCLUSION: Beneficial rate adaptation is achievable using blood temperature to modify rate in a sensor based system.

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