Intravenous xenon-133 for the determination of radionuclide first pass right ventricular ejection fraction

The use of intravenous xenon-133 for determination of radionuclide first pass right ventricular ejection fraction is described. First pass determinations of right ventricular ejection fraction were made with both xenon-133 and technetium-99m in 13 subjects (15 right ventricular ejection fraction determinations); results obtained with xenon-133 show an excellent correlation (r = 0.98, p < 0.002) with results obtained using technetium-99m. Because of rapid pulmonary elimination of xenon-133 from the body, the use of this radioisotope allows multiple first pass right ventricular ejection fraction determinations within a short period of time, without significant radiation exposure for the patient.     

Electromechanical suppression of a demand pacemaker associated with electrode perforation

Electromechanical inhibition of a demand pacemaker is reported due to the contact of two perforated right ventricular endocardial pacemaker electrodes. Electrode contact occurring during ventricular systole was verified at surgery. In vitro suppression of the demand function of a powerpack was accomplished by intermittently tapping two electrodes and generating an effective electrical signal.     

The mechanism of dysrhythmies in variant angina pectoris: Occlusive versus reperfusion

Thirty-six patients with variant angins pectoris (VAP) were analyzed to investigate whether the mechanism underlying dysrhythmia is related to coronary occlusion or reperfusion. Fifteen of the 36 patients demonstrated dysrhythmias (42%). Twelve of 15 patients (80%) experienced dysrhythmia prior to the acme of ST-segment elevation (occlusive dysrhythmia), and those of tachyarrhythmia type were characterized by the presence of ventricular premature beats initially isolated, increasing in frequency, and preceding the more malignant forms of dysrhythmias, such as ventricular tachycardia or ventricular fibrillation. The occlusive dysrhythmias included ventricular dysrhythmia (ventricular premature beats, ventricular tachycardia, slow ventricular tachycardia, ventricular fibrillation) in eight patients and conduction abnormalities (second- and third-degree AV block, left posterior fascicular block) in four patients. Thirteen episodes of VAP were fully recorded electrocardiographically. The average time to onset of dysrhythmia, after the beginning of ST-segment elevation, was 4.94 minutes ± 1.52. The duration of the episodes without dysrhythmia was 0.86 minute ± 0.53. The “reperfusion dysrhythmia” occurred in three patients (20%) and was characterized by the appearance of isolated couplets of ventricular premature beats, ventricular tachycardia, or ventricular fibrillation without prodromal ectopic activity. The dysrhythmia occurred in one patient during the resolution of ST-segment elevation and in two patients within seconds of ST-segment normalization. We conclude that the occlusive related dysrhythmias are the most important mechanism in VAP. They are dependent on the duration of the ischemic episode.     

Evaluation of phentolamine as a provocative test for idiopathic hypertrophic subaortic stenosis

Intravenous injection of phentolamine potentially offers a better provocative test for aortic left ventricular outflow tract obstruction than do Valsalva's maneuver, inhalation of isoproterenol, or of amyl nitrite. In hemodynamic studies, phentolamine enhanced myocardial contractility, and decreased afterload with only induction of slight tachycardia. Phentolamine (5 mg.) was administered intravenously to five patients who had idiopathic hypertrophic subaortic stenosis, and 35 patients who had valvular dysfunctions, after which echocardiographic and phonocardiographic recordings were performed. Recordings were of high quality despite changing hemodynamics. Systolic pressures fell an average of 20 mm. Hg; no pressure fell below 90 mm. Hg; there was no notable increase in heart rate. In the five patients with typical idiopathic hypertrophic subaortic stenosis, the amyl nitrite increased the obstructive index from 39.6 +/- 12 to 51 +/- 18.9 (P less than 0.05); whereas, phentolamine increased the obstructive index to 69.8 +/- 25.6 (P less than 0.015). After a 2 week course of oral administration of 80 mg. of propranolol daily, and then either inhalation of amyl nitrite or injection of phentolamine, there was no change from the mean resting obstructive index. Phentolamine appears to be a safe, simple and specific diagnostic agent, and more potent than amyl nitrite in eliciting dynamic obstruction in IHSS; phentolamine and amyl nitrite do not affect the obstructive index in patients with beta blockade.     

Interactions among the critical factors affecting sinus node function: The quantitative effects of the duration and frequency of atrial pacing and of vagal and sympathetic stimulation upon overdrive suppression of the sinus node

A multifactorial analysis was used in anesthesized dogs in order to characterize the effects of the duration of overdrive, the atrial pacing interval, and the frequencies of vagal and sympathetic stimulation on overdrive suppression of the sinus node. The sinus node recovery time (SNRT) and the summated effect (SE) over the first 20 cardiac cycles were measured with various combinations of the independent variables. We conclude that (1) both the rate and the duration of overdrive have significant effects on SNRT and SE; (2) vagal stimulation has greater effects on SNRT and SE than does the rate or duration of overdrive; (3) sympathetic stimulation had only a small effect on overdrive suppression; and (4) there were significant interactions between vagal stimulation and the duration of overdrive and between the duration and rate of overdrive, but not between sympathetic and vagal stimulation.     

Procainamide-induced lupus lung disease characterized by neutrophil alveolitis

Bronchoalveolar lavage demonstrated a flux of neutrophils into the lung of a patient with procainamide-induced lupus pulmonary disease. Serial lavage studies have shown persistent low-grade alveolitis despite the absence of clinical, serologic, and radiographic evidence of disease activity.     

Estimating prognosis in systemic lupus erythematosus

Knowledge of prognosis is critical for rational choice of therapy. Systemic lupus erythematosus, with its broad clinical spectrum, presents an example of the problem of prognostication for the individual patient. The life table method can provide prognostic information. It need not be limited to estimation of survivorship, and its utility can be multiplied by a computer databank. Analysis of prognosis for different groups of patients, from different events in their course, over different time periods, and to different end points can then be performed. Using this technic, specific clinical variables in systemic lupus erythematosus were assessed for their effect upon particular outcomes. Clinical variables representing functional organ impairment were found to carry a worse prognosis than the popular serologic indicators. New abnormalities were found to occur less frequently in later years of the disease. Different subpopulations of patients have strikingly different expectations, and these differences carry important therapeutic implications.     

Autoimmune hemolytic anemia and periodic pure red cell aplasia in systemic lupus erythematosus

A patient with systemic lupus erythematosus and autoimmune hemolytic anemia complicated by periodic episodes of red cell hypoplasia is described. Using a plasma clot culture system a serum inhibitor of erythropoiesis was detected. In addition, heat eluates of the red cells of this patient were capable of impairing erythroid colony formation. The possibility that the autoantibodies of acquired autoimmune hemolytic anemia might influence the proliferation and/or maturation of erythroid progenitor cells is raised by these findings.     

ANA-negative systemic lupus erythematosus.

The presence of antinuclear antibodies (ANA) in serum is generally considered a decisive diagnostic sign of systemic lupus erythematosus (SLE). Ten patients with clinical signs of disease but persistent negative tests for ANA are examined in this study. Hair fall, Raynaud's phenomenon and recurrent oral ulcers were common in the ANA-negative group. ANA-negative SLE seems to be a subgroup of SLE that has not previously been given adequate attention.     

Sickle cell anemia and epidural extramedullary hematopoiesis

Acute flaccid paralysis due to epidural extramedullary hematopoiesis developed in a 43-year-old man with sickle cell anemia. The patient showed no response to emergency decompressive laminectomy, radiotherapy, or exchange transfusion, and his neurologic deficit persisted unimproved. This is the first reported case of acute or irreversible spinal cord compression due to epidural extramedullary hematopoiesis in a patient with sickle cell anemia.     

Massive spontaneous unilateral hemothorax in systemic lupus erythematosus

Described here is an unusual pulmonary complication of systemic lupus erythematosus in a 37 year old man with an 8 year history of the disease. His management and further central nervous system complications are discussed.     

Genetic factors predisposing to autoimmune diseases. Autoimmune hemolytic anemia, chronic thrombocytopenic purpura, and systemic lupus erythematosus

Genetic factors predisposing to autoimmune diseases were investigated in 10 families having more than one affected member. Seventy relatives and 23 spouses from two large kindreds (one in whom the proband had autoimmune hemolytic anemia and the other immune thrombocytopenic purpura) were examined for immunologically mediated disorders, autoantibodies, immunoglobulin abnormalities, and HLA genotypes. Significant differences between relatives and spouses were found for immune diseases (21 percent versus 0 percent; p = 0.02), antinuclear antibody titer of 1:80 or more (18 percent versus 0 percent; p = 0.04), single-strand DNA antibodies (18 percent versus 0 percent; p = 0.04), high-titer antinuclear antibody or antibodies to single-strand DNA or both (33 percent versus 0 percent; p = 0.001), and the combined frequencies of immune diseases and serologic abnormalities (44 percent versus 4 percent; p = 0.0004). Similar frequencies were found in 41 relatives from eight families in whom the proband had SLE. Segregation analyses using these abnormalities as genetic traits were most compatible with a Mendelian dominant model. Impressive odds (100:1) against linkage to HLA were calculated.     

Clinical and immunologic studies in identical twins discordant for systemic lupus erythematosus

Middle-aged female identical twins, one of whom had systemic lupus erythematosus (SLE), were evaluated for immunologic reactivity to previous antigenic challenges, including primary immunization with a foreign antigen, keyhole limpet hemocyanin (KLH). These two women had lived together for all of their 58 years and neither was receiving anti-inflammatory or immunosuppressive drugs at the time of these studies. Both twins demonstrated comparable 7S and 198 humoral antibody response to KLH, as well as similar viral antibody titers. However, the twin with SLE was anergic to common antigens, streptokinase-streptodornase, Trichophyton and Candida; furthermore delayed hypersensitivity to KLH did not develop after immunization. This observed discrepancy between humoral and cellular immunity in genetically similar subjects may be significant in the pathogenesis of SLE.     

Erythroid aplasia in systemic lupus erythematosus

A patient with systemic lupus erythematosus presented with red cell aplasia. Her anemia responded to prednisone therapy. The occurrence of red cell aplasia in association with a variety of immune phenomena lends support to the concept that in systemic lupus erythematosus also, erythroid aplasia may be of immune etiology.     

Effect of cyclic nucleotides on mitogen. Responsiveness of lymphocytes from patients undergoing dialysis.

Lymphocytes from 10 asymptomatic patients undergoing hemodialysis and from eight control subjects were repeatedly cultured with exposure to various concentrations of cyclic nucleotides and theophylline in addition to mitogen. The blastogenic response of the patients' lymphocytes was inhibited by molar concentrations of dibutyryl cyclic AMP which had much less or no inhibitory effected on the response of the control subjects' lymphocytes. This suppressive effect was not potentiated by theophylline. Cyclic GMP enhanced the proliferative response of the patients' lymphocytes as well as that of the controls. In contrast to absolute counts per minute per culture, the suppression by dibutyryl cyclic AMP of mitogen-induced blastogenesis noted in this study clearly separated the in vitro behavior of the patients' lymphocytes from that of the controls' lymphocytes and may serve as a useful marker of cellular dysfunction in such patients.     

Immune complex deposition and coronary vasculitis in systemic lupus erythematosus. Report of two cases

Extramural coronary arteries were examined in two patients with systemic lupus erythematosus (SLE). Coronary vasculitis was found in both patients. One patient with clinically and serologically inactive SLE had died suddenly and was found to have a myocardial infarction secondary to the coronary vasculitis. Immunopathologic studies demonstrated immune reactants in the walls of inflamed and noninflamed arterial segments in a pattern consistent with immune complex aggregates. Immunologic injury secondary to immune complex deposition may be responsible for the development of coronary disease in patients with SLE. This has been demonstrated in experimental animals but not in humans. Although this is an uncommon complication of SLE, it represents a cause of sudden death and a potentially treatable lesion in this patient population. Its occurrence may be related to the deposition of immune aggregates in the walls of coronary vessels.     

"Ischemia at a distance" during intermittent coronary artery occlusion: a coronary anatomic explanation

The mechanism of electrocardiographic ST segment changes during acute coronary occlusion was evaluated in 28 consecutive patients with single vessel coronary artery disease undergoing coronary angioplasty. Patients were continuously monitored with a six lead electrocardiogram. Twenty-three patients showed ST changes in the primary zone of occlusion, and 13 of these had additional ST changes in a remote zone. Ten of these 13 had unusually extensive arteries supplying the remote zone. The balloon occluded two adjacent normal arteries in two patients, and no coronary anatomic explanation was evident in one patient. Ten patients with striking primary zone ST changes showed no remote change. Seven had nonextensive primary zone arteries, and three others had abundant collateral vessels. Five patients showed no electrocardiographic changes in primary or remote zones. Four had collateral vessels, and one had left ventricular hypertrophy on the baseline electrocardiogram. It was concluded that remote electrocardiographic changes are probably due to occlusion of unusually extensive coronary arteries and are not simply reciprocal.