Management of the sensitized cardiac recipient: the use of plasmapheresis and intravenous immunoglobulin.

Previously, we reported that the combination of plasmapheresis (PP) and intravenous immunoglobulin (IVIg) allow sensitized patients to undergo orthotopic heart transplantation (OHT), even across a positive crossmatch. In the current study, the effect of that combination, PP+IVIg, on survival of a larger group of such recipients is investigated. The latter group (I) consisted of 35 sensitized patients who received PP+IVIG together with standard immunosuppressive drugs. Rejection was seen in 11 patients, findings strongly suggestive of a vascular (humoral) being identified in five of those cases. Four deaths occurred, two of them in the immediate post-operative period, one after almost six months, and one after almost two yr post-OHT. Follow-up range 4.5 months to 7.8 yr post-OHT (average=1.1 yr). Patient survival was analyzed after generation of a Kaplan-Meier plot. Comparison with a control OHT group (II) given standard immunosuppressive drugs only (N=276) showed enhanced survival of group I (p=0.0414 by log-rank test). We conclude that the combination of PP and IVIG (i) is associated with declines in T- and B-percent-reactive antibody and in crossmatch positivity, and (ii) is very useful in the management of the sensitized cardiac patient undergoing OHT, often allowing a successful outcome to transplantation in the face of a positive crossmatch.

Improving heart failure care by using a telemedicine system.

Heart failure constitutes the most frequent and expensive hospital discharge diagnosis in the United States, costing annually over $10 billion. Optimal care requires an understanding of their illness, participating in clinical decisions, and frequent communication. Current surveillance is labor intensive and expensive. Follow-up is often inadequate, incomplete, and inconsistent. To address these problems, we developed an Internet-based telemedicine system, consisting of a secure server and database. Patients send or receive data to or from their care provider via the Internet. The system optimizes function and minimizes cost (all hardware is off the shelf and FDA approved). This paper describes our initial experience with this system. We are currently using this telemedicine system in a prospective, randomized clinical trial, comparing Class III or IV heart failure patients with standard care versus standard care plus telemedicine.

Pulmonary edema associated with scuba diving : case reports and review.

Acute pulmonary edema has been associated with cold-water immersion in swimmers and divers. We report on eight divers using a self-contained underwater breathing apparatus (scuba) who developed acute pulmonary edema manifested by dyspnea, hypoxemia, and characteristic chest radiographic findings. All cases occurred in cold water. All scuba divers were treated with complete resolution, and three have returned to diving without further episodes. Mechanisms that would contribute to a raised capillary transmural pressure or to a reduced blood-gas barrier function or integrity are discussed. Pulmonary edema in scuba divers is multifactorial, and constitutional factors may play a role. Physicians should be aware of this potential, likely underreported, problem in scuba divers.

Technological advances and the next 50 years of cardiology.

The fiftieth anniversary of the ACC and the end of the twentieth century are arbitrary points in time, yet they seem to coincide with a true watershed. The last 50 years have brought a rush of new techniques and understandings that have, for the first time, given cardiovascular specialists real tools to prevent and fight cardiovascular disease. Only now, for the first time, has science begun to understand exactly what happens when plaque forms in an artery, when heart muscle fibers cross-link and weaken, when an atrial chamber fibrillates, and when heart muscle cells die en masse after a heart attack. We are beginning to track down the actual chemical, mechanical, and electrical pathways by which the heart is damaged or dies. When we can interfere with those pathways and stop the chain of events, we will have defeated heart disease. Imagination is rapid, but progress is often both uncertain and slow because of the many constraints of cost, regulation, and time needed to test and evaluate new developments. Yet we can now foresee a future in which medical science might actually defeat cardiovascular disease the way it has defeated polio, smallpox, and other serious scourges of the past.

Infraorbital hypesthesia after maxillary sinus barotrauma.

We report a case of a diver who suffered an episode of maxillary sinus barotrauma that presented with decreased sensation over the cutaneous distribution of the infraorbital nerve after an ascent which produced facial pain and crepitus. This case illustrates a potential confusion between a decompression sickness etiology and a barotraumatic etiology for the observed sensory deficit. The clinical features of this case were most consistent with a barotraumatic etiology for the findings noted. The anatomy of the trigeminal nerve and previous reports of cranial nerve deficits following barotrauma are reviewed.

Risk of decompression sickness with patent foramen ovale.

Several reports have described populations of divers with decompression sickness (DCS) who have a patent foramen ovale (PFO). The presence of a PFO is known to occur in about 30% of the normal population, hence 30% of divers are likely to have a PFO. Although observations have been made on the presence of a PFO in divers with and without DCS, the risk of developing DCS when a diver has a PFO has not been determined. In this study, Logistic Regression and Bayes' theorem were used to calculate the risk of DCS from data of three studies that reported on echocardiographic analysis of PFO in a diving population, some of whom developed DCS. Overall incidence of DCS was obtained from the sport diving population, from the U.S. Navy diving population, and from a commercial population. The analysis indicates that the presence of a PFO produces a 2.5 time increase in the odds ratio for developing serious (type II) DCS in all three types of divers. Since the incidence of type II DCS in these three populations averages 2.28/10,000 dives, the risk of developing DCS in the presence of a PFO remains small, and does not warrant routine screening by echocardiography of sport, military, or commercial divers.

Fatal pulmonary barotrauma due to obstruction of the central circulation with air.

Cardiac arrest in cases of barotraumatic arterial gas embolism (AGE) is usually ascribed to reflex dysrhythmias secondary to brainstem embolization or secondary to coronary artery embolization. Several case reports suggest that obstruction of the central circulation (i.e., the heart, pulmonary arteries, aorta, and arteries to the head and neck) may play a role in the pathogenesis of sudden death in victims of pulmonary barotrauma. We report three consecutive cases of fatal AGE in patients in whom chest roentgenograms demonstrated confluent air lucencies filling the central vascular bed, the heart, and great vessels. In none of the victims was there evidence by history or at autopsy that the intravascular gas was iatrogenically introduced. Total occlusion of the central vascular bed with air is a mechanism of death in some victims of AGE, and resuscitation efforts for such patients should take this possibility into consideration.

Current knowledge and significance of coronary artery ectasia: a chronologic review of the literature, recommendations for treatment, possible etiologies, and future considerations.

Coronary artery ectasia is the abnormal enlargement of the coronary artery. The prognosis, treatment, and etiology of this disease remain an enigma. There is some evidence to suggest that the incidence of ectasia is increasing, and therefore understanding of this entity needs to improve. This article reviews the current literature on coronary artery ectasia and summarizes the findings. A treatment plan that targets each of the suggested clinical complications is provided. Using multiple indirect observations and current understanding of endothelium-derived relaxation factor, a possible etiology that implicates overstimulation of endogenous nitric oxide is provided. Current literature suggests that ectatic coronary arteries, even without the presence of coronary stenosis, are subject to thrombus formation, vasospasm, and spontaneous dissection. Newer subgroups of ectasia are arising with the use of multiple interventional devices to dilate coronary artery stenosis. By design, these destroy the media of the coronary artery, and it is not clear whether these "iatrogenic" ectatic arteries are subject to the same complications as "idiopathic" coronary artery ectasia. Further investigation is necessary to help define the benefit of the proposed treatment regimen, to clarify the prognosis of these newer groups of "iatrogenic" ectasia, and to confirm or disprove the hypothesis targeting nitric oxide as an etiologic factor.

Active control of hypertension.

Hypertension is common, and even slight elevations in blood pressure can be associated with health risks. Regular aerobic exercise helps prevent hypertension. In patients who already have hypertension, such exercise has been shown to lower systolic and diastolic blood pressure by a mean of 10 mm Hg. For mild or labile hypertension, lifestyle modification that includes at least a half hour of moderate aerobic exercise at least 3 days a week should be tried before using drug therapy. If medication is needed, one that is not likely to impede the patient's ability to exercise should be considered.

Low-pressure workouts for hypertension.

Regular exercise is a central part of your program for controlling hypertension (high blood pressure). For most people who have hypertension, a few sessions of moderate physical activity each week will reduce blood pressure significantly and lower the risk of stroke and heart attack. If your blood pressure is just mildly elevated, exercise (along with a healthy diet and lifestyle) may be enough to bring it down to normal. If you need medication, exercise probably will make it more effective, and possibly allow you to take a lower dose.

Hyperbaric oxygen therapy for acute ankle sprains.

We conducted a randomized double-blind study of 32 subject with acute ankle sprains to compare treatment with hyperbaric oxygen at 2 atmospheres absolute pressure (N = 16) (treatment group) with treatment with air at 1.1 atmosphere absolute pressure (N = 16) (control group) in a hyperbaric chamber. Each group received three treatments at their respective pressures: one for 90 minutes and two for 60 minutes each. Mean age, severity grade, and time to treatment (treatment group, 34.3 +/- 6.3 hours; control group, 32.6 +/- 4.6 hours) were similar in both groups. Joint function measured by a functional index improved from 0.40 +/- 0.2 to 6.3 +/- 0.4 with hyperbaric oxygen and from 0.8 +/- 0.3 to 5.3 +/- 0.6 with air. The change from initial to final evaluation was significantly greater in the treatment group. Foot and ankle volume by water displacement decreased from 1451 +/- 57 ml to 1425 +/- 63 ml with hyperbaric oxygen and from 1403 +/- 50 ml of 1371 +/- 45 ml with air (no difference was noted between hyperbaric oxygen treatment and air treatment using a two-day analysis of variance). Subjective pain index fell from 3.3 +/- 0.5 to 0.8 +/- 0.3 with hyperbaric oxygen and from 2.6 +/- 0.3 to 0.3 +/- 0.2 with air. No differences were noted in passive or active range of motion when comparing hyperbaric oxygen treatment with air treatment. Time to recovery was the same in both groups (treatment, 16.0 +/- 6.3 days; control, 15.4 +/- 2.8 days). Regression analysis to determine the influence of time to treatment, initial severity of injury, hyperbaric oxygen, and age showed no effect of hyperbaric oxygen treatment on time to recovery.

Donor-specific HLA antibodies after transplantation are associated with deterioration in cardiac function.

Although there is increasing evidence that mismatched donor HLA antigens are associated with a lowering of survival of human cardiac allografts, the effect of antibodies that bind those antigens is less clear. The existence of lymphocytotoxic antibodies prior to cardiac transplantation has been associated with a poor outcome in the majority of reports of relevant studies, as has their appearance post-transplantation. But how such antibodies, especially those with HLA specificity, cause poor outcomes has been poorly understood. The purpose of this study was to investigate the effect of anti-HLA antibodies appearing in the circulation after human orthotopic heart transplantation. Such antibodies were identified by a standard microlymphocytotoxicity technique using panels of frozen lymphocytes from normal donors who had been tissue typed. Of 74 patients transplanted over a 12-month period, 4 (5.4%) developed alloantibodies specific for mismatched donor HLA antigens. The first patient developed antibodies to HLA-A23 and B44 together with poor ventricular function and vascular rejection requiring retransplantation within 4 months. The other patients (3) developed antibodies specific for HLA-DQ antigens and experienced variable numbers of episodes of cellular rejection with no evidence of vascular rejection on endomyocardial biopsy. Two of these three patients died (8 and 11 months post-transplant) after three and six rejection episodes, respectively. The one surviving patient had seven rejection episodes and continues to have poor ventricular function 18 months post-transplant. We conclude that alloantibodies specific for mismatched donor HLA antigens may have a deleterious effect on the outcome of the human cardiac allograft and should be monitored closely post-transplant. Furthermore, such antibodies may mediate effects on the transplanted heart which are not detectable in specimens obtained by endomyocardial biopsy.