psudo: Exploring Multi-Channel Biomedical Image Data with Spatially and Perceptually Optimized Pseudocoloring

Over the past century, multichannel fluorescence imaging has been pivotal in myriad scientific breakthroughs by enabling the spatial visualization of proteins within a biological sample. With the shift to digital methods and visualization software, experts can now flexibly pseudocolor and combine image channels, each corresponding to a different protein, to explore their spatial relationships. We thus propose psudo, an interactive system that allows users to create optimal color palettes for multichannel spatial data. In psudo, a novel optimization method generates palettes that maximize the perceptual differences between channels while mitigating confusing color blending in overlapping channels. We integrate this method into a system that allows users to explore multi-channel image data and compare and evaluate color palettes for their data. An interactive lensing approach provides on-demand feedback on channel overlap and a color confusion metric while giving context to the underlying channel values. Color palettes can be applied globally or, using the lens, to local regions of interest. We evaluate our palette optimization approach using three graphical perception tasks in a crowdsourced user study with 150 participants, showing that users are more accurate at discerning and comparing the underlying data using our approach. Additionally, we showcase psudo in a case study exploring the complex immune responses in cancer tissue data with a biologist.

Percutaneous left atrial to femoral arterial bypass pumping for circulatory support in high-risk coronary angioplasty

Left atrial to femoral arterial bypass was evaluated as a means of supporting patients who were considered to be at high risk for the performance of percutaneous transluminal coronary angioplasty. A 20 French drainage catheter was inserted percutaneously into the left atrium via a modified transseptal technique. Blood was withdrawn from the left atrium and returned through a femoral arterial cannula using a roller pump. Thirteen patients were treated in this fashion with excellent circulatory support. Pump flows varied from 1.5 to 3 liters per minute and bypass time ranged from 27 to 106 min (mean = 43 +/- 17). Aortic mean pressure was well supported during balloon inflation. No significant complications were encountered. Neither an oxygenator nor a perfusionist is required. The ability to obtain direct left ventricular decompression offers a major potential advantage. Further evaluation of this technique for the support of such patients is indicated.

Oral iron therapy with ferrous fumarate and polysaccharide iron complex

Oral iron replacement therapy with Chromagen, containing ferrous fumarate, and Niferex, containing polysaccharide iron complex, can successfully maintain hematologic and iron indices in dialysis clients and demonstrated fewer adverse effects in selected clients. Their multiple ingredient dose forms, which further support erythropoiesis, and their possible decrease in distressing side effects should enhance client compliance, making these two drugs excellent alternatives to traditional iron therapies.

Comparison of cardiac catheterization and Doppler echocardiography in the decision to operate in aortic and mitral valve disease

Clinical decisions utilizing either Doppler echocardiographic or cardiac catheterization data were compared in adult patients with isolated or combined aortic and mitral valve disease. A clinical decision to operate, not operate or remain uncertain was made by experienced cardiologists given either Doppler echocardiographic or cardiac catheterization data. A prospective evaluation was performed on 189 consecutive patients (mean age 67 years) with valvular heart disease who were being considered for surgical treatment on the basis of clinical information. All patients underwent cardiac catheterization and detailed Doppler echocardiographic examination. Three sets of two cardiologist decision makers who did not know patient identity were given clinical information in combination with either Doppler echocardiographic or cardiac catheterization data. The combination of Doppler echocardiographic and clinical data was considered inadequate for clinical decision making in 21% of patients with aortic and 5% of patients with mitral valve disease. The combination of cardiac catheterization and clinical data was considered inadequate in 2% of patients with aortic and 2% of patients with mitral valve disease. Among the remaining patients, the cardiologists using echocardiographic or angiographic data were in agreement on the decision to operate or not operate in 113 (76% overall). When the data were analyzed by specific valve lesion, decisions based on Doppler echocardiography or catheterization were in agreement in 92%, 90%, 83% and 69%, respectively, of patients with aortic regurgitation, mitral stenosis, aortic stenosis and mitral regurgitation. Differences in cardiac output determination, estimation of valvular regurgitation and information concerning coronary anatomy were the main reasons for different clinical management decisions. These results suggest that for most adult patients with aortic or mitral valve disease, alone or in combination, Doppler echocardiographic data enable the clinician to make the same decision reached with catheterization data.

Transesophageal echocardiography to detect atrial clots in candidates for percutaneous transseptal mitral balloon valvuloplasty

Left atrial thrombi are common in patients with mitral stenosis. When percutaneous balloon mitral valvuloplasty is performed on such patients, there is a potential risk of thrombus dislodgment and embolization. In this study conventional transthoracic echocardiography and transesophageal echocardiography were performed for percutaneous balloon mitral valvuloplasty on 19 consecutive candidates (6 men, 13 women, 23 to 81 years old). In five patients (26%), transesophageal echocardiography revealed a left atrial thrombus; in only one of these was there a suspicion of left atrial thrombus on transthoracic echocardiography. Balloon mitral valvuloplasty was canceled in four of the five patients. Three underwent mitral valve surgery that confirmed the echocardiographic findings. Transesophageal echocardiography is better than conventional transthoracic echocardiography in detecting left atrial clots in candidates for balloon mitral valvuloplasty. Because of the potential risk of embolization, transesophageal echocardiography is recommended in all candidates for balloon mitral valvuloplasty.

Diagnosis of unexpected atrial septal defect by inspired hydrogen appearance time in adult patients referred for cardiac catheterization

Atrial septal defects may have clinical consequences regardless of their size. We evaluated the incidence of clinically unsuspected atrial septal defects in 4,411 consecutive adult patients referred for cardiac catheterization by the previously validated method of inspired hydrogen appearance time. Oximetry was performed only when an abnormally short inspired hydrogen appearance time was measured. Seventy-five patients (1.7%) were discovered to have a left-to-right shunt by this method. The shunting was at the atrial level in 65 patients. Thirty-five of these patients (0.8% of all catheterizations) were not suspected of having any form of congenital heart disease by history, physical examination, chest X-ray, EKG, or echocardiogram. In 19 cases there was no significant oxygen step-up and the diagnosis would have been missed by oximetry. The atrial septum was explored during open heart surgery in 7 patients. Atrial septal defects were detected and closed in all. Four patients had the finding confirmed by echocardiography after the catheterization. Small atrial septal defects are frequently not detected by clinical evaluation, noninvasive testing, or oximetry and are easily detected by the rapid, safe, and accurate method of inspired hydrogen appearance time.

Metastatic cardiac liposarcoma: diagnosis by transesophageal echocardiography and magnetic resonance imaging

The most superior portion of the right atrium is not well visualized by transthoracic echocardiography. This limits the ability of the technique to detect intracardiac disease in this area. We describe a 41-year-old man with a history of liposarcoma in whom transthoracic echocardiography was unable to elucidate a right atrial metastasis. Transesophageal echocardiography demonstrated the morphology and extent of the large right atrial mass. These findings were well correlated with both magnetic resonance imaging and surgery.

Discrete atherosclerotic coronary artery aneurysms: a study of 20 patients

The incidence, angiographic features and natural history of discrete atherosclerotic coronary aneurysms were evaluated in 20 patients with 22 aneurysms (0.2% of 8,422 patients referred for coronary angiography). Fifteen aneurysms (68%) were in the left anterior descending, four (18%) in the circumflex, two (9%) in the right and one (5%) in the left main coronary artery. Aneurysm diameter ranged from 4 to 35 mm (mean 8); 95% of aneurysms were adjacent to a severe obstruction. Seventy-five percent of patients had severe triple vessel disease that included severe left main disease in 15%. Total obstruction of one or two arteries was present in 75%. In patients with wall motion abnormalities, 78% of the abnormalities were in the distribution of the aneurysm. Follow-up (range 1 to 90 months [mean 30]) was obtained in all 20 patients. There were two cardiac and two noncardiac deaths; 12 patients had coronary bypass surgery and of 16 survivors, 13 were angina-free. In conclusion, discrete coronary aneurysms are much less common than diffuse ectasia. Unlike ectasia, they are never found in arteries without severe stenosis, and are most common in the left anterior descending coronary artery. Associated coronary artery disease is more severe in patients with discrete aneurysms than in those with diffuse ectasia. Discrete coronary aneurysms do not appear to rupture, and their resection is not warranted.

Ten-year experience with aortic valve replacement in 482 patients 70 years of age or older: operative risk and long-term results

A retrospective analysis of an institutional experience with aortic valve replacement (AVR) in patients 70 years of age or older during 1976 to 1987 was performed. The study was prompted in part by the current interest in palliative aortic valvoplasty, an interest based to a certain extent on the impression that AVR in the elderly has a high mortality. The mean age of the patients was 75.0 +/- 4.0 years (+/- the standard deviation) (range, 70 to 89 years). Eighty-three percent of patients received porcine valves and 17%, mechanical valves. Preoperatively 32% were in New York Heart Association class III, and 59% were in class IV. Operative mortality was 5.6% for elective isolated AVR for aortic stenosis (19% of all patients), 8.2% for all isolated AVR (38%), and 12.4% overall. Concomitant operative procedures were done in 62.0%; AVR with coronary artery bypass grafting (42%) had an operative mortality of 14.3%. Multivariate analysis showed significant predictors of operative mortality to be emergency operation (p less than 0.01), isolated aortic regurgitation (p = 0.01), and previous cardiac operation (p = 0.02). Follow-up (34 +/- 27 months) was 94% complete. Five-year survival from late cardiac-related death was 81.0%. The constant yearly hazard rate for late death for patients 70 years of age or older who underwent AVR was 5.42% per year, which is similar to the 5.77% per year rate calculated for age-matched and sex-matched controls. Five-year freedom from reoperation was 99%; from late thromboembolic complications, 91%; and from late anticoagulant-related complications, 94%. Freedom from all valve-related morbidity and mortality was 61% at 5 years.(ABSTRACT TRUNCATED AT 250 WORDS)

Echocardiographic and hemodynamic characteristics of atrial septal defects created by percutaneous valvuloplasty

Twenty-nine patients were studied by pulsed, continuous wave, and color Doppler before and after percutaneous transseptal valvuloplasty. New atrial septal defects were detected in 14 patients, and the patients were monitored for up to 320 days after the procedure. The diameter of the defect, best evaluated by the transesophageal approach, was 3 to 15 mm. A narrow, high velocity (1.4 to 3.1 meters per second) left-to-right shunt jet was detected in 13 of 14 patients. The shunt jet was continuous in nine of 14 patients, late systolic-holodiastolic in four patients, and bidirectional in one patient. Cardiac catheterization in nine patients confirmed the Doppler findings and demonstrated a peak pressure gradient of 10 to 32 mm Hg between the left and right atria. Oximetry revealed a calculated pulmonary to systemic flow ratio ranging from 2.3:1 in the patient with the largest atrial septal defect by echocardiography to 1:1 (no oxygen saturation step-up) in the patient with the smallest atrial septal defect. In the three patients who underwent cardiac surgery, the operative findings confirmed those of echocardiography. We concluded that atrial septal defects are common after transseptal valvuloplasty. Usually, their relatively small size and the underlying valvular disease that produces high left atrial pressure are responsible for the high pressure gradient between the left and right atria. This results in the high velocity and continuous shunt jet detected by Doppler echocardiography.

Transesophageal echocardiography during percutaneous mitral valvuloplasty

Transesophageal echocardiography was performed during mitral balloon valvuloplasty. It provided valuable information about the position of the transseptal needle, wires, and balloon catheter throughout the procedure, and it helped in the immediate evaluation of its results. Transesophageal echocardiography was well tolerated and there were no complications.

Swift increase in alcohol metabolism in humans

One hundred and fifteen human male subjects, 19-30 years of age, received ethanol orally as vodka (0.55, 0.7, or 0.85 g/kg) followed by a second drink (0.3-0.4 g/kg) given 3-4 hr later. After both doses, blood ethanol levels reached approximately 100 mg/dl. Breath samples were taken every 20-30 min and rates of ethanol elimination were determined. In addition to the design described above, 100 subjects received 0.7 g/kg ethanol in two separate visits to the laboratory. In a third experimental design, ethanol was given i.v. to 12 subjects. With the single-day experimental design, the frequency distribution of changes in rates of ethanol elimination between the first compared with the second administration of ethanol was not unimodal. Up to 20% of the subjects demonstrated rates more than 40% greater than basal values in response to ethanol. Based on these findings in humans, a Swift Increase in Alcohol Metabolism (SIAM) was defined as an increase in the rate of ethanol elimination of at least 40% over the basal rate. Under these conditions, the frequency of SIAM was dose dependent (studied with 0.55, 0.7, and 0.85 g/kg); nearly 20% of the subjects demonstrated SIAM with a dose of ethanol of 0.85 g/kg. In the two-day experimental design, a SIAM response was also observed in about 10% of 49 well-fed subjects; however, none of 51 subjects tested exhibited a SIAM response following an overnight fast. In addition, a rapid and transient SIAM reflecting a 60% increase in the rate of ethanol elimination above basal values was observed when ethanol was given continuously for 5 hr i.v.(ABSTRACT TRUNCATED AT 250 WORDS)

A comparison of methods for limiting myocardial infarct expansion during acute reperfusion--primary role of unloading

Current use of angioplasty, thrombolysis, and surgical techniques for prompt reperfusion of an acute myocardial infarction raises questions concerning the optimum reperfusion technique for maximum myocardial salvage. Alterations in the conditions of reperfusion and/or the composition of the initial reperfusate can exert a significant effect on the extent of myocardial salvage. In an effort to define an optimum reperfusion technique, we used 40 dogs in a series of experiments in which the left anterior descending coronary artery (LAD) was snared for 2 hr followed by reperfusion by one of five methods for 4 hr. In addition, in a control group(group I, n = 6) the LAD was occluded for 6 hr without any reperfusion. In group 2 (n = 12), simulating medical reperfusion, reperfusion was achieved by simply releasing the snare for 4 hr. Group 3 dogs (n = 6) were placed on pulsatile left atrial-femoral bypass throughout 4 hr of reperfusion. Group 4 dogs (n = 9) were placed on percutaneous, synchronized pulsatile cardiopulmonary bypass during reperfusion. The procedure in group 5 (n = 7) dogs simulated coronary artery bypass grafting with cardiopulmonary bypass and cold blood, low-Ca++ cardioplegia during reperfusion. Group 6 (n = 6) was treated similarly except that during reperfusion amino acid-enriched cardioplegia was administered by warm induction techniques. At the end of 4 hr of reperfusion, the left ventricular area of infarction was determined by triphenyltetrazolium chloride staining and expressed as a percentage of the left ventricular area at risk for infarction (area of infarction [AI]/area at risk [AR]).(ABSTRACT TRUNCATED AT 250 WORDS)

Percutaneous cardiopulmonary bypass with a synchronous pulsatile pump combines effective unloading with ease of application

Percutaneous total cardiopulmonary bypass offers the advantage of rapid, simple implementation without the need for thoracic incision and provides the ability to support both left and right ventricular failure as well as pulmonary insufficiency. Previous studies using roller pump percutaneous bypass were only partially successful because of the inability to effectively unload the left ventricle. In the present experiment we attempted to determine in a normal canine model whether use of synchronous pulsatile pumping for percutaneous bypass could overcome this problem. Fourteen dogs were placed on percutaneous bypass for 1 hour. A roller pump was used in seven and a synchronous pulsatile pump with an electrocardiogram triggering mechanism in the other seven. All animals were maintained on percutaneous bypass for 1 hour. In the pulsatile pump group there was a significantly greater percent decrease from baseline in tension-time index (-56.3% versus -19.1%, p less than 0.01) and in myocardial oxygen consumption (-45.8% versus +2.1%, p less than 0.05) and a significantly greater percent increase in the endocardial/epicardial blood flow ratio (27.6% versus -6.5%, p less than 0.01) than in the roller pump group. These results show that superior unloading can be achieved by percutaneous pulsatile bypass compared with percutaneous roller pump bypass. The findings suggest that percutaneous total cardiopulmonary bypass with a synchronous pulsatile pump offers a relatively simple but effective method for providing appropriate patients with temporary hemodynamic stability before cardiac catheterization or medical or surgical revascularization.

Catalase-dependent ethanol metabolism in vivo in deermice lacking alcohol dehydrogenase

Pathways of ethanol elimination in alcohol dehydrogenase (ADH)-positive and -negative deermice were studied using the catalase inhibitor, 3-amino-1,2,4-triazole. To verify that aminotriazole inhibited catalase effectively, the characteristic decrease in catalase-H2O2 which occurs in saline-treated controls when ethanol is peroxidized was monitored at 660-640 nm in perfused deermouse livers. Following 1.5 hr of pretreatment with aminotriazole (1.5 g/kg), the peroxidatic activity of catalase measured in vitro was inhibited by greater than 99%. Under these conditions, ethanol did not decrease catalase-H2O2 in perfused livers, indicating that catalase was inhibited. Ethanol and aniline oxidation by microsomes were also inhibited by about 67-90% after 1.5 hr of pretreatment with aminotriazole. In ADH-positive deermice, pretreatment with aminotriazole for 1.5 hr prior to injection of ethanol (2.0 g/kg) decreased rates of ethanol elimination in vivo from 13.2 +/- 0.8 to 10.2 +/- 0.4 mmoles/kg/hr. In ADH-negative deermice, similar treatment decreased rates of ethanol elimination in vivo from 4.5 +/- 0.4 to 1.1 +/- 0.6 mmoles/kg/hr. Following pretreatment with aminotriazole (1.0 g/kg) for 6 hr, rates of ethanol elimination in ADH-negative deermice returned to near basal values. Under these conditions, the peroxidatic activity of catalase measured in vitro and the ethanol-dependent decrease in catalase-H2O2 in perfused livers also returned to near basal levels; however, the oxidation of ethanol by cytochrome P-450 was inhibited completely. It is concluded, therefore, that time of pretreatment with aminotriazole is an important variable which must be controlled carefully to inhibit catalase completely. Since catalase was active while cytochrome P-450 was not following 6 hr of pretreatment with aminotriazole, it is concluded that ethanol elimination occurs predominantly via catalase-H2O2 in ADH-negative deermice under these conditions.

Strategy for treatment of acute evolving myocardial infarction with pulsatile left heart assist device. Can this modality increase survival and enhance myocardial salvage?

This article describes the technique of left heart bypass in the treatment of both experimental and clinical acute myocardial infarction. A new technique of closed-chest percutaneous left heart bypass that can be used in patients with acute evolving myocardial infarction and cardiogenic shock is also described.

Activation of ethanol metabolism in humans by fructose: importance of experimental design

Fed human male subjects 18 to 30 years of age received 0.85 g/kg of ethanol p.o. as vodka followed by a second drink (0.3-0.4 g/kg) given 3 to 4 hr later. Blood ethanol levels reached approximately 100 mg% after both doses. Breath samples were taken every 20 to 30 min, and the rate of ethanol elimination was determined. Subjects returned 1 to 2 weeks later and the study was repeated with fructose (1.0 g/kg). When ethanol and fructose were given simultaneously, the peak blood ethanol values reached were reduced significantly. This resulted in calculated increases in the apparent volume of distribution of ethanol; however, the slope (beta) of the ethanol elimination curve was not increased. Thus, under these conditions, fructose appeared to have minimal effects on rates of ethanol elimination (ca. 10%). In another experimental design, subjects received 1 g/kg of fructose 1 hr after ethanol. Under these conditions, fructose did not affect the peak blood ethanol concentration or the apparent volume of distribution; however, the slopes of the ethanol elimination curves (beta) were increased significantly by fructose. Further, the time estimated to eliminate the ethanol completely was reduced by 90 min with fructose. Under these conditions, the stimulation of ethanol elimination by fructose was 20 to 30%. This increase in the rate of ethanol elimination was observed in every subject studied. Similar results were obtained with rats. To understand why blood ethanol values were lower when ethanol and fructose were given simultaneously, female Sprague-Dawley rats were given ethanol alone (1.5 g/kg) or ethanol and fructose (1 g/kg) simultaneously.(ABSTRACT TRUNCATED AT 250 WORDS)

Methionine intolerance: a possible risk factor for coronary artery disease

Homocystinuria, an inherited disorder associated with premature atherosclerosis, represents a severe form of methionine intolerance. To analyze the importance of milder forms of methionine intolerance in the genesis of vascular disease, the relation between provokable methionine intolerance and coronary artery disease was investigated. In a group of 138 men, aged 31 to 65 years (mean 53), referred for cardiac catheterization, plasma homocystine was measured before and 6 hours after an oral l-methionine load (0.1 g/kg). Thirty-nine subjects found to have normal coronary arteries had a mean post-load plasma homocystine level of 0.59 +/- 0.37 mumol/liter. A criterion at the 95th percentile (1.64 SD above the mean) was selected and applied to the remaining 99 subjects with coronary artery disease (0.70 +/- 0.68 mumol/liter). Sixteen (16%) of 99 subjects with coronary artery disease exceeded this level as compared with 1 (2%) of 39 subjects without coronary artery disease (p less than 0.04). The risk of coronary artery disease in men with provokable methionine intolerance was increased sevenfold as estimated by the odds ratio. By correlation matrix and multivariate regression analyses, provokable homocystinemia was predictive of coronary artery disease and was independent of tobacco smoking, hypertension, diabetes mellitus, serum cholesterol and age. It is proposed that men with mild methionine intolerance exposed to the high methionine content of the Western diet may develop intermittent homocystinemia and thus may be at greater risk for the development of coronary artery disease.

Use of two-dimensional echocardiography during transseptal cardiac catheterization

Inadvertent puncture of the intrapericardial aorta is a serious complication of transseptal catheterization. Two-dimensional echocardiography allows delineation and spatial resolution of the aorta and interatrial septum. Thirteen patients underwent transseptal catheterization with simultaneous monitoring of needle and catheter position using fluoroscopy and two-dimensional echocardiography. The interatrial septum was demonstrated in the short-axis and four chamber views, and clearly separated from the ascending aorta. The transseptal needle and catheter were visualized by echocardiography while the needle tip was manipulated into the fossa ovalis avoiding puncture of the aortic root. In some cases, under pressure from the needle tip just before puncture, the interatrial septum appears to bulge toward the left atrium. Saline solution contrast echocardiography helped to confirm the needle position in the right atrium, and in the left atrium after puncture. These data suggest that two-dimensional echocardiography is a useful adjunct to fluoroscopy during transseptal catheterization that may improve its safety and prevent complications.

The incidence and natural history of pericardial effusion after cardiac surgery--an echocardiographic study

One hundred twenty-two consecutive patients (104 men; 18 women) were studied to determine the incidence and natural history of pericardial effusion occurring 2, 5, 10, and 20 to 50 days after cardiac surgery. Three patients had pericardial effusions before and 103 patients (91 men; three women) had effusions after surgery. Effusions were first recorded on the second postoperative day in 72 patients, on the fifth postoperative day in 29 patients, and on the tenth postoperative day in two patients. In 96 of these patients, effusions reached their maximum size by postoperative day 10. Of the 103 patients with effusions, 66 (64%) were followed to complete resolution. A specific pattern was observed in most resolving effusions. The echo-free space diagnostic of pericardial effusion became progressively more echo-dense as the effusion diminished in size. As the effusion became echo-dense, the posterior pericardium, which had been motionless, resumed its normal systolic anterior motion. One patient developed cardiac tamponade on postoperative day 3. We conclude that pericardial effusion occurs frequently after cardiac surgery, but that associated complications are rare.

Left atrium-to-femoral artery bypass: effectiveness in reduction of acute experimental myocardial infarction

The effects of prompt institution of left atrium-to-femoral artery (LA-FA) bypass on myocardial infarct area (AI) as a percentage of myocardial area at risk for infarction (AR) during a 4 hour period following ligation of the left anterior descending coronary artery (LAD) were studied in 26 dogs. Following LAD ligation, baseline measurements of myocardial tension-time index (TTI) and regional myocardial blood flow (RMBF) were obtained. Group I (controls, n = 16) received no further support. Group II (LA-FA bypass, n = 10) underwent left ventricular unloading via LA-FA bypass beginning 15 minutes after coronary occlusion. Four hours after LAD occlusion, measurements of TTI and RMBF were repeated in both groups. Just before sacrifice, gentian violet was injected into the aortic root to delineate the AR. The hearts were then removed and sectioned transversely through the left ventricle (LV) and septum. The AR (that ventricular area not perfused by gentian violet) was measured by planimetry and compared to the AI as identified by incubation of heart slices in triphenyltetrazolium chloride dye. In comparisons of control versus LA-FA bypass groups, both AI/LV (21.6% versus 10.4%) and AI/AR ratios (73.7% versus 21.8%) were significantly reduced in the bypass group (p less than 0.005). Mortality in the control group (5/16, 31.2%) was significantly greater (p less than 0.005) than in the bypass group (0/10, 0%). Mean TTI over the 4 hour ischemic period was essentially unchanged in the control group as compared to a reduction of 62.8% in the bypass group (p less than 0.005). Furthermore, RMBF at 4 hours was significantly improved in all regions of the LV in hearts undergoing LA-FA bypass when compared with control hearts (p = 0.025). These results demonstrate by a consistent method that prompt institution of LA-FA bypass significantly reduces the mortality associated with acute coronary artery occlusion, as well as the total AI and AI/AR. The protective mechanisms provided by LA-FA bypass probably include the highly significant reduction of LV work and the opening of new bridge collateral blood vessels with redistribution of blood flow to the ischemic region.

Late functional and hemodynamic status of surviving patients following insertion of the left heart assist device

Since July, 1978, we have inserted a roller pump type of left heart assist device between the left atrium and ascending aorta in 35 patients. There were no significant complications related to use of the device. Seventeen patients recovered sufficiently to have the device removed. There were four early deaths, 60 to 120 days following removal of the device. Three of these patients died of septic complications and one patient died as a result of a cardiac arrest. Of the 13 long-term survivors, seven are working and six are retired. Five patients have mild to moderate cardiac symptoms, whereas eight others are completely asymptomatic. In three patients the ejection fraction was significantly lower than preoperatively; however, in all other patients the ejection fraction either stayed the same or improved postoperatively. We conclude that this type of left heart assist device can provide adequate cardiac support in patients with profound left ventricular dysfunction following cardiac operations. Furthermore, surviving patients generally have satisfactory long-term cardiac function and are leading productive lives.

'Pulsatile' left atrial-femoral artery bypass. A new method of preventing extension of myocardial infarction

A left atrial-femoral artery (LA-FA) bypass system was designed to deliver synchronous pulsatile blood flow. We compared it with nonpulsatile LA-FA bypass in its effectiveness to limit infarct extension after ligation of the left anterior descending coronary artery at its origin in 35 dogs. Nonpulsatile LA-FA bypass resulted in a 70% reduction in the size of infarct. The addition of synchronous diastolic counterpulsation (P-LA-FA) further reduced the size of infarct, when compared with that in controls (95%) or animals that underwent LA-FA bypass (83%). Both LA-FA and P-LA-FA bypasses limited infarct extension and reduced mortality after acute coronary occlusion through effective unloading of the left ventricle. The addition of diastolic counterpulsation to LA-FA bypass led to further significant infarct reduction, when compared with LA-FA bypass alone. These effects were most likely secondary to improvements in myocardial blood flow distribution.

The swift increase in alcohol metabolism (SIAM) in four inbred strains of mice

Ethanol metabolism increases two to three hours after the administration of ethanol. This phenomenon, called the Swift Increase in Alcohol Metabolism (SIAM), has been compared in four inbred strains of mice (DBA/2J; C3H/HeJ; AKR/J; C57BL/6J). Basal rates of ethanol elimination were determined in individual mice after intraperitoneal injections of ethanol. Little variability in this basal rate of ethanol elimination was observed within each strain. Mice were then exposed to ethanol vapor for 4 hours. In both injected and treated mice the dose of ethanol was varied to produce blood ethanol levels ranging from 50 to 250 mg%. Ethanol elimination increased maximally 1.5 to 4-fold in all four strains following 4 hours of vapor treatment at the same blood ethanol level; however, the dose at which the maximal increase occurred differed among the strains. DBA/2J mice exhibited a maximal increase in the rate of ethanol elimination when ethanol concentrations were in the range of 30 to 50 mg%; the increase was smaller as the dose was increased. In contrast, AKR/J and C57BL/6J mice required 100 to 150 mg% ethanol to activate SIAM. These data indicate clearly that the SIAM effect is a common phenomenon, and that dose-response relations differ in various inbred strains of mice.

Swift increase in alcohol metabolism (SIAM) in the mouse: comparison of the effect of short-term ethanol treatment on ethanol elimination in four inbred strains

Ethanol metabolism increases 2 to 3 hr after the administration of ethanol. This phenomenon, called the swift increase in alcohol metabolism, has been compared in four inbred strains of mice (DBA/2J, C3H/HeJ, AKR/J and C57BL/6J). Basal rates of ethanol elimination were determined in individual mice after an i.p. injection of ethanol (2 g/kg). Little variability in this basal rate of ethanol elimination was observed within each strain. Mice were then exposed to ethanol vapor (20--22 mg/l) and rates of ethanol elimination were determined every 2 hr for 8 hr. By 2 to 3 hr, the rates of ethanol elimination initially increased 2- to 3-fold and then declined toward basal rates over the 8-hr interval in all strains studied. In another experiment, the dose of ethanol was varied to produce blood ethanol levels ranging from 50 to 250 mg/100 ml in both basal- and ethanol vapor-treated mice. Ethanol elimination increased greater than 1.5-fold in all four strains studied when basal rates were compared to rates observed after 4 hr of vapor treatment at the same blood ethanol level; however, the dose at which the maximal increase occurred differed among the strains. DBA/2J mice exhibited a maximal increase in the rate of ethanol elimination when ethanol concentrations were in the range of 30 to 50 mg/100 ml; the increase was smaller as the dose was increased. In contrast, AKR/J and C57BL/6J mice required 100 to 150 mg/100 ml of ethanol to activate the swift increase in alcohol metabolism effect. These data indicate clearly that the swift increase in alcohol metabolism effect is a common phenomenon and that dose and time relations differ in various inbred strains of mice.

Long-term survival with partial left heart bypass following perioperative myocardial infarction and shock

During the period from July 1, 1978 to Dec. 31, 1980, we employed a partial left heart bypass (left atrium to ascending aorta) in 16 patients who could not be weaned from cardiopulmonary bypass with inotropic agents and the intra-aortic balloon pump. Flow rates up to 3,500 ml/min could be obtained with this device. Eight of the 16 patients survived and left the hospital. One patient died of a cardiac arrest 4 months postoperatively and one has recurrent angina and moderate congestive heart failure 24 months postoperatively. Six patients are well 5 to 17 months after discharge. Seven of the eight deaths were characterized by progressive myocardial failure. One patient died of ventricular fibrillation 18 hours after discontinuation of the left heart bypass. All survivors had significant improvement in ventricular function 12 to 24 hours afer institution of the left heart bypass, which was continued for 16 to 68 hours. These results indicate that early institution of left heart bypass in seriously ill patients can provide satisfactory long-term results.

Transvenous intracardiac echocardiography

A specially designed ultrasonic transducer, 0.2 mm in length and 0.75 mm in diameter, operating at 7.5 megahertz and mounted on a thin flexible coaxial cable was advanced to the distal tip of a right heart or transseptal catheter in 20 patients during cardiac catheterization. Left atrial, aortic root and right atrial cavity size, pulmonary arterial diameter at various sites, right ventricular wall thickness and the width of a pericardial effusion were demonstrated. Tricuspid, pulmonary, and aortic valves were seen and their motion displayed. With the transducer positioned at the tip of a transseptal needle it could be recognized when it made contact with the interatrial septum. Puncture into the left atrium, avoiding such structures as the aorta, was facilitated in this fashion. No complications were encountered in any patient. Intracardiac echocardiography appears to be a safe, valuable adjunct to both conventional echocardiography and cardiac catheterization. Furthermore, recordings of structures that may be difficult or impossible to obtain with routine external echocardiography may be made possible.

Mechanism of relief of angina after coronary bypass surgery: an angiographic study

Coronary angiography was performed before and after coronary revascularization in 67 patients. The interval between studies ranged from 1 to 38 months (average 9.9). The patients were separated into four clinical groups on the basis of their symptoms at the time of restudy; Group I, 13 asymptomatic patients; Group II, 19 patients with nonanginal chest pain (18 cases) or dyspnea (1 case); Group III, 12 patients whose angina was relieved but not eliminated; and Group IV, 23 patients whose angina was not alleviated. The graft patency rate was 72 percent in Group I, 78 percent in Group II, 61 percent in Group IIII and 34 percent in Group IV. The sum of diseased, but not bypassed and unsuccessfully bypassed arteries per patient was 1.6 in Groups I and II. 2.9 in Group III and 4.0 in Group IV. The incidence of perioperative myocardial infarction, defined using enzymatic and electrocardiographic criteria, was 8 percent for Group I, 26 percent for Group II, 25 percent for Group III and 52 percent for Group IV. Anginal relief after coronary bypass surgery is achieved by successful and complete revascularization rather than by perioperative myocardial infarction.

Digital range-gated echocardiographic tracking

Many applications of standard echocardiography require velocity computation which is usually determined by manually measuring slopes on an echocardiogram. However, manual techniques are limited by the inaccuracy with which slopes may be drawn and measured, the large amount of time required for detailed analysis, and the lack of real time information. A system is described which automatically provides real time and continuous and essentially instantaneous position and velocity measurements on selected heart structures. The system is designed with digital electronics wherever possible to facilitate data processing and the transfer of information to a computer. The system has advantages over continuous wave ultrasonic Doppler techniques and a range-gated ultrasonic Doppler system because dynamic, range-gated digital tracking allows target isolation and identification. Also, because range gate size may be kept small, noise susceptibility is minimized.

Isolated diagonal artery disease

The clinical, electrocardiographic, angiographic, and hemodynamic features of seven patients with isolated, severe (greater than 75% of diameter) narrowing of a diagonal branch of the left anterior descending artery are presented. The incidence of this entity was 0.5% among patients with arteriosclerotic heart disease undergoing coronary angiography. Angina was severe in two patients, moderate in four, and mild in one. One patient had unstable angina. Stress tests were abnormal in two of three patients. Six patients had normal left ventricular angiograms, and one had a mildly decreased ejection fraction. All patients survived a mean follow-up of 18 months (range 6 to 32). No patient suffered a myocardial infarction. Five became asymptomatic on medical therapy; one patient with mild and another with moderate angina were unimproved. This rare anatomic subset of patients with coronary artery disease has a favorable short-term prognosis.

Echocardiographic findings in severe paradoxical pulse due to pulmonary embolization

A 47 year old man with acute pulmonary embolism had severe pulsus paradoxicus in the absence of pericardial disease. Echocardiography demonstrated inspiratory failure of the aortic valve to open, a decreases in left ventricular cavity size and a decrease in mitral valve diastolic excursion.

Pseudocoarctation and mid-arch aortic coarctation

A 21-year-old woman was found to have a mid-arch aortic coarctation in combination with pseudocoarctation. The angiographic disgnosis was established by left atrial injection after transseptal puncture.

Left internal mammary--left ventricular fistula after Vineberg operation

This communication presents an unusual complication in a patient who underwent the Vineberg procedure with the formation of an internal mammary to left-ventricular fistula, which caused a new apical diastolic murmur. This represents a previously unreported etiology for the appearance of an apical blowing diastolic murmur.