Aortic root dissection complicating coronary bypass surgery.

Four cases are presented of aortic root dissection after aortocoronary bypass surgery in which the origin of the intimal tear was at or very near the aortic site of saphenous vein anastomosis. Two cases were documented at autopsy. In one of two cases diagnosed with aortography, the patient underwent surgical correction and survived. All patients had long-standing severe hypertensive cardiovascular disease or severe generalized atherosclerotic disease, or both. Clinical awareness of aortic dissection after coronary bypass surgery in this group of patients should make early diagnosis with successful surgical correction feasible.     

On denial

Evaluation of 612 episodes of gram-negative bacteremia over a 10-year period demonstrated its progressively increasing frequency. This increase was associated with an increasing proportion of patients with more severe underlying disease, increasing patient age, increasing frequency of cardiac surgery and manipulative procedures, and increasing frequency of treatment with antibiotics, corticosteroids and antimetabolites in patients with bacteremia. Fatality rates paralleled the severity of the host's underlying disease as noted in previous reports. The urinary tract was the most frequent source of bacteremia, but in 30 per cent of the patients, predominantly those with more severe underlying disease, the original source could not be identified. Of all blood cultures obtained in these patients, 72 per cent were positive. Bacteremia was of low magnitude with 77 per cent of the patients having quantitative blood cultures with less than 10 gram-negative bacilli per milliliter of blood. Escherichia coli was the most frequent etiologic agent followed in frequency by Klebsiella-Enterobacter-Serratia species, Pseudomonas aeruginosa, Proteus and Providencia species, and species of Bacteroides. Sixteen per cent of the bacteremias were polymicrobic. K and O-antigen typing of Escherichia coli and capsular typing of K. pneumonias demonstrated that a large number of serologic types of these strains were responsible for bacteremia. Over-all, bacteremia caused by multiple species of bacteria was associated with higher fatality rates, but no significant differences in fatality rates could be demonstrated for bacteremias caused by individual species of gram-negative bacilli when comparisons were made between patients with underlying diseases of similar severity. The presence or type of K-antigen did not influence the lethality of Esch. coli infections. Although some O-antigen types, 0:4, 0:6 and 0:8, were associated with higher fatality rates than other O-antigen types, “rough” or autoagglutinable Esch. coli were as lethal as smooth strains. These findings indicate that bacterial factors, other than antibiotic resistance, have little influence on the outcome of gram-negative bacteremia and that gram-negative bacilli function primarily as “opportunistic” pathogens.     

Carotid sinus hypersensitivity and syncope.

Hyperactivity of the carotid sinus reflex is common in older men. However, an unequivocal diagnosis of carotid sinus syncope is difficult to establish because the symptoms are nonspecific, and both hyperactivity of the carotid sinus reflex and syncope are common. Twenty-one men were evaluated for episodes of lightheadedness or syncope, or both, associated with a hypersensitive carotid sinus reflex. Seventeen patients had the cardioinhibitory type, two the vasodepressor type and two both the cardioinhibitory and vasodepressor types. Patients with the cardioinhibitory type benefited from the insertion of a permanent pacemaker if they had multiple episodes of syncope. A history of syncope associated with some event capable of stimulating the carotid sinus was also helpful in selecting patients for pacemaker treatment. The combination of the cardioinhibitory and vasodepressor types may be missed unless carotid sinus stimulation is repeated after the administration of atropine. The results of electrophysiologic studies in 17 patients with the cardioinhibitory type suggest that intrinsic sinus nodal dysfunction is not the major cause for asystole after carotid sinus stimulation.     

Learning curve for percutaneous transluminal coronary angioplasty: Skill, technology or patient selection

As with all sophisticated techniques, operators who perform PTCA show a learning curve. It can best be visualized by observing changes in success rate with growing numbers of patients. Thus, the current success rate and complication rate of a particular operator may permit an estimate of the accumulated number of patients treated by that operator. Most likely, the learning curve is also reflected in the rate of long-term success, although it may be obscured by other factors in the variable natural course of CAD. The initial steep upslope of the learning curve is mainly caused by the growing skill of the particular operator. The later, flatter part appears to be secondary to improvements in technical equipment, which take more time. Patient selection has 2 effects on the learning curve that may be self-compensating. If lessons from the past are used for selection and conservatism is preserved, the learning curve will become more pronounced.     

Comparative cost of myocardial revascularization: percutaneous transluminal angioplasty and coronary artery bypass surgery

A consecutive series of 78 patients having percutaneous transluminal coronary angioplasty for single vessel coronary artery disease and 85 patients having single vessel coronary artery bypass graft surgery were followed up prospectively for 1 year. Days in hospital and angiographic and revascularization procedures were counted in the two groups of patients and total cost of care for 12 months was calculated using current billing levels. Angioplasty was initially successful in 74% of patients; because of initial failure in 26% and late restenosis in 18%, bypass surgery was ultimately needed in 23 of 78 patients having coronary angioplasty. Nevertheless, total cost of care per patient was 43% lower for those having angioplasty as an initial procedure for single vessel coronary artery disease.     

Serum opsonization of salmonella in sickle cell anemia.

Systemic salmonellosis occurs with increased frequency in sickle cell anemia. This predisposition to Salmonella infections is poorly understood. Since serum opsonizing activity is an important host defense mechanism, we studied the ability of serum from patients with sickle cell anemia and control subjects to promote phagocytosis and killing of Salmonella typhimurium by normal leukocytes. Heat-labile factors were required for opsonization of S. typhimurium by serum from control subjects, and this opsonizing capacity was deficient in 12 of 28 serums from patients with sickle cell anemia. In an effort to account for this decreased phagocytosis-promoting activity, we evaluated those serum factors known to serve as specific opsonins. Serum immunoglobulin and specific antibody levels were similar in the patients with sickle cell anemia and in the control subjects. In contrast, several complement system abnormalities were documented in patients with sickle cell disease. These abnormal findings included (1) defective alternative complement pathway function, (2) low levels of the third component of complement (C3) and (3) slightly reduced concentrations of the fourth component of complement (C4). Of these complement system abnormalities, only decreased function of the alternative pathway was significantly associated with deficient serum opsonizing activity (P < 0.01). The complement defects and associated opsonic deficiency may be manifestations of profound macrophage (reticuloendothelial system) dysfunction in sickle cell anemia. This reduction in complement-mediated serum opsonizing activity for Salmonella, in association with other consequences of abnormal reticuloendothelial system function, may predispose to salmonellosis in sickle cell anemia.     

Improvement of left ventricular function after percutaneous transluminal coronary angioplasty

Cardiac function and left ventricular dynamics were measured in seven consecutive patients 1 day before and 6 months after percutaneous transluminal balloon angioplasty of subtotal proximal stenosis of the left anterior descending coronary artery. Before angioplasty all patients had obvious left ventricular dysfunction during exercise and to a smaller degree during isoproterenol infusion; the condition of all patients was greatly improved 6 months after angioplasty. After angioplasty, left ventricular end-diastolic pressure was normal at rest and decreased from a mean (± standard error of the mean) of 33.8 ± 1.6 to 19.2 ± 0.5 mm Hg on exercise. Left ventricular ejection fraction, measured by a gated blood pooling technique with technetium-99m, improved on exercise from 46 ± 5.0 percent to 69 ± 1.0 percent. Cardiac output and stroke volume index increased significantly with exercise after angioplasty. The peak negative rate of pressure reduction in the left ventricle (dP/dt/min), an index of left ventricular relaxation, was highly abnormal on exercise before (2,307 ± 260 mm Hg/s) and increased to the normal range (3,154 ± 200 mm Hg/s) after angioplasty. The improvement in left ventricular function after transluminal angioplasty in these cases of proximal left anterior descending coronary arterial stenosis is extremely encouraging.     

Natural history of patients with single-vessel disease suitable for percutaneous transluminal coronary angioplasty

To permit comparison of percutaneous transluminal coronary angioplasty (PTCA) with conventional therapy, the clinical outcome was established in patients who would have been suitable candidates for PTCA but who presented before the technique was available. Coronary angiograms were reviewed of patients who met the following criteria: single-vessel disease with proximal subtotal coronary stenosis, chest pain of at least class II, and cardiac catheterization before 1981. Angiograms were evaluated according to established criteria for PTCA by an experienced angiographer. One hundred ten patients (2.1% of the patient population) were judged suitable for PTCA. Clinical and catheterization findings closely resembled those of patients in the national PTCA registry. Five years after catheterization, 97% of PTCA candidates treated medically were alive and 85% had not had myocardial infarction. Forty-six patients had coronary artery bypass surgery within 6 months of catheterization and 10 other patients had subsequent surgery. Five years after surgery, 91% were alive and 87% had not had myocardial infarction. At 6 months of follow-up, 78% of all patients had improved at least 1 functional class, and 86% of all patients working before catheterization were still employed. Functional capacity was well maintained during long-term follow-up (median 6.5 years, range 1.4 to 12.2). These data indicate that PTCA candidates have an excellent prognosis for survival, a low risk of infarction, and well-maintained functional capacity when revascularization is reserved for those with inadequate control of symptoms by medical therapy.