True Incidence of Pacemaker Syndrome

HELDMAN, D., ET AL.: True Incidence of Pacemaker Syndrome. 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 WI 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 < 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 WI 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.     

Validity of sputum eosinophilia in diagnosing coexistent asthma in children with cystic fibrosis

Sputum eosinophilia was quantitated in 50 children with cystic fibrosis in order to determine the value of this investigation in diagnosing coexistent asthma. On microscopic examination 23 children (46%) had no eosinophils in their sputum, 20 (40%) had occasional eosinophils and 7 (14%) had one or more eosinophils per high power field. There was no correlation between the presence of sputum eosinophilia and the following parameters: a clinical diagnosis of asthma, severity of pulmonary disease, response to inhaled sympathomimetics, use of gentamicin inhalations, microorganisms cultured from the sputum or family history of atopy. Sputum eosinophilia is not a helpful investigation in supporting the diagnosis of coexistent asthma in a child with cystic fibrosis.     

Physical Determinants of the Endocardial P Wave

SHANDLING, A.H., ET AL.: Physical Determinants of the Endocardial P Wave. Reliable atrial sensing of intrinsic P wave activity is important to ensure optimal atrial or dual chamber pacemaker function. Various physical factors (e.g., posture, respiration, exercise) may influence P wave characteristics and impair adequate sensing. To investigate this phenomenon, we measured the average of three P wave amplitudes (PWA) and calculated slew rates from telemetered printouts acquired from Pacesetter pacemakers in 32 patients. These measurements were performed in various body positions, with upright exercise and in varying stages of respiration. Results: the mean supine PWA increased on full inspiration (3.56 ± 1.3 mV versus 3.25 ± 1.2 mV during quiet respiration, p < 0.001), and also increased significantly with full expiration. The mean PWA increased on assuming the erect position (3.25 ± 1.2 mV increasing to 3.49 ± 2.3 mV, p < 0.001); in the upright position, the mean erect PWA during quiet respiration was not significantly influenced by the stage of respiration. The mean upright exercise PWA did not differ significantly from the preexercise erect PWA (3.50 f 1.2 with exercise, and 3.47 ± 1.5 before exercise; P = NS). Calculated slew rates were not different lying versus standing. Conclusions: the mean supine PWA increases significantly at the extremes of respiration and on assuming the erect body position; upright exercise results in no appreciable change in the erect PWA. Atrial sensitivity adjustments based on standard supine testing should be adequate for all body positions. (PACE, Vol. 13, December, Part I 1990)     

EFFECTIVENESS OF A DAPSONE COMPLIANCE PROGRAM IN LEPROSY

Background. Long-term effectiveness of a dapsone compliance program was assessed in patients with leprosy. Methods. The monitoring program consists of urine dap-sone/creatinine ratio determination at each visit with subsequent patient feedback and education. Eighty-eight patients receiving dapsone and seen in a leprosy clinic from 1985–1990 were included. Results. The proportion of patients compliant with dapsone during a given year ranged from 70.0% (1987) to 94.4% (1989). Overall compliance for the 6-year period was 81.6%. This level of compliance was significantly different (P < 0.05) than the baseline compliance in the leprosy clinic of 46.7%. Conclusions. Compliance monitoring, combined with active patient involvement, was effective in sustaining high compliance over a 6-year period.     

Effectiveness of Medical Nutrition Therapy Provided by Dietitians in the Management of Non–Insulin-Dependent Diabetes Mellitus: A Randomized, Controlled Clinical Trial

Objective To assess the the effect of medical nutrition therapy (MNT) provided by dietitians on medical and clinical outcomes for adults with non–insulin-dependent diabetes mellitus (NIDDM), and to compare MNT administered according to practice guidelines nutrition care (PGC) to MNT administered with basic nutrition care (BC).Design A prospective, randomized, controlled clinical trial of two levels of MNT on metabolic control in persons newly diagnosed with or currently under treatment for NIDDM was conducted at diabetes centers in three states (Minnesota, Florida, and Colorado). BC consisted of a single visit with a dietitian; PGC involved an initial visit with a dietitian followed by two visits during the first 6 weeks of the study period. Data were collected at entry to the study and at 3 and 6 months.Subjects Results are reported for 179 men and women aged 38 to 76 years: 85 assigned randomly to BC and 94 to PGC. This represents 72% of the 247 subjects enrolled. An additional 62 adults with NIDDM at one site who had no contact with a dietitian were identified as a nonrandom comparison group.Outcomes Medical outcome measures included fasting plasma glucose (FPG), glycated hemoglobin (HbA_1c), and serum lipid levels. Clinical outcomes included weight, body mass index, waist-to-hip ratio, and changes in medical therapy.Statistical analyses Initial analysis of the discrete variables was done using the χ² statistic with Yates' correction. Initial analysis of continuous variables was done by analysis of variance. The changes in variables between time periods were analyzed by paired t test, and comparisons between groups were analyzed using a t test for independent groups.Results At 6 months, PGC resulted in significant improvements in blood glucose control as indicated by FPG and HbA_1c levels and BC resulted in significant improvements in HbA_1c level. Participants assigned to the PGC group had a mean FPG level at 6 months that was 10.5% lower than the level at entry, and those in the BC group had a 5.3% lower value. Among subjects who had diabetes for longer than 6 months, those who received PGC had a significantly better HbA_1c level at 3 months compared with those receiving BC. The comparison group showed no improvement in glycemic control over a comparable 6 months. PGC subjects had significant improvements in cholesterol values at 6 months, and subjects in both the PGC and the BC groups had significant weight loss.Conclusions MNT provided by dietitians resulted in significant improvements in medical and clinical outcomes in both the BC and PGC groups and is beneficial to persons with NIDDM. Persons with a duration of diabetes longer than 6 months tended to do better with PGC than with BC. Because of the upward trend in glucose levels after 3 months, ongoing MNT by dietitians is important for long-term metabolic control. J Am Diet Assoc. 1995; 95:1009-1017.     

A randomized trial of weekly cardiotocography in highrisk obstetric patients

Summary. A randomized clinical trial of once-weekly antenatal fetal heart rate monitoring in 539 high-risk patients could find no benefit of monitoring in terms of perinatal mortality, morbidity or Apgar score. The previously well-documented association between abnormal antenatal fetal heart rate traces and low Apgar score was confirmed. A detailed case review showed that in this population monitoring was irrelevant to almost all of the 13 perinatal deaths.