Chest injury. Factors influencing management and outcome.
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Abdominal Injuries↗
Biomedical subjects
R M Mills
Publications and source records attributed to R M Mills.
Subcortical visual function in the newborn.
Early behavioral visual function in infants may not depend upon the geniculocalcarine pathway but may be mediated through more primitive subcortical pathways. This subcortical visual system may exist in early life and be responsible for visual pursuit and perhaps fixation. In some infants with damage to the visual cortex, the subcortical pathway may persist beyond the neonatal period. Three infants with major defects in the visual cortex are reported. These infants displayed persistent preservation of visual pursuit movements without evidence of visual recognition. Limited behavioral expressions of vision in the infant with damage to the visual cortex may not always be an indicator of preserved function of the visual cortex.
Brain↗
Rate-responsive pacing improves exercise tolerance in heart transplant recipients: a pilot study.
BACKGROUND: Chronotropic incompetence is one cause of diminished exercise capacity in heart transplant recipients. If reinnervation occurs, it often is late after transplantation and is not always accompanied by functional improvements in peak heart rate and appropriate tachycardia during exercise. To determine the efficacy of rate-responsive pacing on peak heart rate and exercise capacity, the authors studied eight male heart transplant recipients (age 57 +/- 12 years; 23 +/- 9 months after transplantation) that had either atrial or dual-chambered pacemakers. METHODS: All subjects completed two maximal graded exercise tests (GXT) using the Naughton treadmill protocol. During the first GXT, pacemakers were programmed for bradycardia support only and without rate responsiveness (unpaced). After a 14-day regimen of beta blockade with metoprolol to nullify the influence of circulating catecholamines on heart rate, subjects performed the second GXT with pacemakers programmed to respond optimally in the rate-responsive mode (paced). RESULTS: Peak heart rate (149 versus 129 bpm), peak oxygen uptake (18.9 versus 15.4 mL/kg/min), treadmill time to exhaustion (14.6 versus 12.4 min), and minute ventilation (76.7 versus 66.2 L/min) were significantly increased (P < or = 0.05) during the paced versus unpaced GXT. CONCLUSIONS: The results of this study demonstrate that chronotropic support of the transplanted heart using a rate-responsive pacemaker, with activity-based sensors programmed for maximal sensitivity, improves both peak heart rate and exercise capacity in heart transplant recipients significantly more than circulating catecholamines alone.
Adrenergic beta-Antagonists↗
Heart failure and sleep-related breathing disorders.
Despite advances in medical and surgical therapy, heart failure (HF) remains a common and serious problem. An association between HF and sleep-related breathing disorders has been recognized since Cheyne's observations in 1818, but only recently have treatment options targeting sleep-related breathing disorders become available. This overview will consider the clinical features, pathophysiology, and treatment options of sleep-related breathing disorders in patients with HF.
Cheyne-Stokes Respiration↗
Cardiac transplantation: problems and opportunities.
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Heart Transplantation↗
Quantitative analysis of nitroglycerin-induced coronary artery vasodilation in transplanted hearts.
Quantitative serial coronary angiograms performed annually over a 3-year period after transplantation in 26 orthotopic heart transplant recipients showed persistently normal nitroglycerin-induced vasodilation. The vasodilator response to nitroglycerin did not predict development of graft arteriopathy; the presence of graft arteriopathy did not prevent a substantial vasodilator response to nitroglycerin.
Adult↗
Serial quantitative coronary angiography in the assessment of coronary disease in the transplanted heart.
Quantitative angiographic studies with use of cine-videodensitometry after maximal coronary vasodilation with nitroglycerin in 18 "angiographically normal" heart transplant recipients demonstrated significant loss of lumen diameter between years 1 and 3. When sensitive angiographic techniques are used, graft arteriopathy appears to be ubiquitous in heart transplant recipients.
Coronary Angiography↗
Risk factors for late recurrent rejection after heart transplantation: a multiinstitutional, multivariable analysis. Cardiac Transplant Research Database Group.
BACKGROUND: Previous studies of allograft rejection have focused on early episodes and risk factors from pretransplant variables. METHODS: This multiinstitutional study compared early (< 1 year) and late (> 1 year) rejection episodes and risk factors for recurrent rejection from variables both before and after transplantation among 1251 patients who underwent primary heart transplantation and available follow-up of greater than 1 year. RESULTS: There were a total of 1882 rejection episodes over a mean follow-up of 26 +/- 0.3 months. The hazard function (instantaneous risk per patient per month) peaked at 1 month followed by a low constant risk of rejection after 12 months. By multivariable analysis, the most dominant risk factors for recurrent rejection during the first posttransplantation year were a shorter time interval since transplantation and a shorter time since a previous rejection episode. Other factors included young age, female gender, female donor, positive cytomegalovirus serology, prior infections, and OKT3 induction. In contrast, after the first year, the dominant risk factors for rejection were a greater number of rejections during the first year and the presence of prior cytomegalovirus infections. CONCLUSIONS: These data show a striking time dependency for rejection episodes among heart transplant recipients. Factors that increase risk for rejection in the first year differ from risk factors for rejection in subsequent years. These data suggest that it may be possible to tailor rejection surveillance protocols and immunosuppression intensity, according to specific patient and time-related risk factors.
Adolescent↗
Infection after heart transplantation: a multiinstitutional study. Cardiac Transplant Research Database Group.
The incidence, causes, and impact of acute infection were analyzed among 814 consecutive patients from 24 institutions undergoing primary heart transplantation between January 1, 1990, and June 30, 1991, with mean follow-up of 8.2 months (range 0 to 18 months). Sixty-nine percent of the patients had no infections during the follow-up, whereas 31% of patients had one or more infection episodes. The cumulative incidence of infections per patient was 0.41 at 3 months, 0.55 at 6 months, and 0.62 at 12 months after transplantation. Bacterial and viral infections were most common (47% and 41% of infections), with fungi and protozoa accounting for 12%. Overall mortality per infection was 13%, but mortality with fungal infections was higher (36%, p < 0.0001). The most common organ infected was the lung, with a mortality of 23%. The probability of infection by 12 months was higher when OKT3 or antithymocyte globulin induction therapy was used (41% versus 35%, p = 0.01). The single most frequent infecting organism was cytomegalovirus, accounting for 26% of all infections. The probability of cytomegalovirus infection by 12 months was increased with a cytomegalovirus-positive donor and cytomegalovirus-negative recipient (27% versus 15% in all others, p < 0.0001) and with the use of OKT3 or antithymocyte globulin induction therapy (19% versus 12% without induction therapy, p = 0.07). Infection remains the leading cause of death after heart transplantation. The hazard function of likelihood of developing each type of infection at various times after transplantation, as well as response to therapy, are discussed.
Adolescent↗