tbuckley/cabot-search huggingface dataset:
Importance of the great vessels in the genesis of the electrocardiogram.
Authors: DKilpatrick, S JWalker, A JBell
Journal: Circulation Research (1990)

The electrocardiogram is the graphic representation against time of the difference in potential between points of the body caused by the current field of the heart. To examine the origin of this current field, a method of transforming body surface electrocardiographic data to the epicardial surface has been developed. The computed epicardial current density distributions in 219 patients with acute inferior myocardial infarction showed that, in 89% of patients, the current flow out of the heart during the ST segment came from two regions, not only from the infarction region but also from a region over the great vessels. This findings suggests that current flows from the ischemic region, through the low-resistance pathway provided by the intracavity blood, out the great vessels, and back to the epicardium. A similar pathway has been hypothesized when ischemia caused endocardial ST elevation, such as during a stress test or with unstable angina. To test this hypothesis, a group of patients with ST depression...
Endoscopic Resection of Lesions Invading Colonic Diverticulas is Feasible Using Clip and Rubber Band Traction
Authors: M Pioche, T Wallenhorst, J Jacques, J Rivory
Journal: Endoscopy (2021)

We present the case of a non granular LST involving a sigmoid diverticula deeply. Thanks to the clip and rubber band traction it was possible to remove all the diverticulum mucosa with a R0 en bloc resection of the lesion without adverse events.
Autonomic mechanisms in ventricular fibrillation induced by myocardial ischemia during exercise in dogs with healed myocardial infarction. An experimental preparation for sudden cardiac death.
Authors: P JSchwartz, G EBillman, H LStone
Journal: Circulation (1984)

The relationship between activity of the autonomic nervous system, myocardial ischemia, and malignant arrhythmias has been investigated in a new experimental preparation for sudden death. Fifty-seven dogs were chronically instrumented and studied under control conditions (n = 15) and 1 month after production of an anterior myocardial infarction (n = 42). The protocol consisted in occluding the left circumflex coronary artery for 2 min, commencing at the last minute of an exercise stress test and extending through the first minute after cessation of exercise. With this protocol, ventricular fibrillation was observed in 40% of normal dogs and 66% of dogs with infarction. In 14 dogs with infarction, left stellectomy reduced the incidence of ventricular fibrillation to zero (p less than .001). The reflex changes in heart rate elicited within the first minute of ischemia during exercise in the animals that survived (from 204 +/- 14 to 198 +/- 31 beats/min, -6) were opposite those in animals that had ventricula...
"Reverse coronary steal" induced by coronary vasoconstriction following coronary artery occlusion in dogs.
Authors: MChiariello, L GRibeiro, M ADavis, P RMaroko
Journal: Circulation (1977)

The phenomenon of  steal, i.e., the shunting of blood from ischemic to normally perfused areas of myocardium, has been described as an effect of the administration of several vasodilating agents. This study was performed to ascertain whether the reverse situation can be induced, i.e., whether vasoconstriction of the vessels supplying the nonischemic zone could increase the collateral flow to the ischemic area. In 16 open chest dogs, 15 and 30 min after occlusion of the left anterior descending coronary artery, epicardial electrograms were recorded and regional myocardial blood flow (RMBF) was measured with radiolabeled microspheres. Methoxamine was infused intravenously between 17 and 30 min, the mean arterial pressure being kept constant. The results indicate that while the coronary arterial flow to the normal myocardium fell from 90.6 +/- 4.3 to 77.7 +/- 3.2 ml/min/100 g (P less than 0.01), the collateral blood flow to the ischemic area increased from 21.4 +/- 3.5 to 41.0 +/- 4.2 ml/min/100 g ...
Myogenic vasoregulation overrides local metabolic control in resting rat skeletal muscle.
Authors: G AMeininger, C AMack, K LFehr, H GBohlen
Journal: Circulation Research (1987)

Microvascular reactions to increases in intravascular pressure were studied in the cremaster muscle of the anesthetized rat by enclosing the animal in an airtight box with the muscle exteriorized for observation of the microcirculation. Since the cremaster was exposed to atmospheric pressure, increasing pressure within the box produced equal increases in arterial and venous pressures. Thus, intravascular pressure was altered without affecting the pressure gradient for blood flow. Raising box pressure had no effect on respiration or heart rate and did not change the systemic activity of the sympathetic system, angiotensin II, or vasopressin. Diameters and flows were measured for first (107 +/- 3 micron, mean +/- SEM), second (87 +/- 5), third (29 +/- 2), and fourth (15 +/- 2) order arterioles during increases in intravascular pressure of +10, +20, and +30 mm Hg. No significant changes in the diameters of first or second order arterioles were elicited when pressure was increased. However, when box pressure ...
Etiology, warning signs and therapy of torsade de pointes. A study of 10 patients.
Authors: AKeren, DTzivoni, DGavish, JLevi, SGottlieb, JBenhorin, SStern
Journal: Circulation (1981)

Torsade de pointes, also called atypical ventricular tachycardia (AVT), was diagnosed in 10 patients, nine on antiarrhythmic therapy and one with acute central nervous system damage. Four patients received quinidine and five disopyramide, either alone or in combination with amiodarone. AVT was dose-dependent in some, but in others, it started shortly after initiation of drug therapy (idiosyncrasy). All patients had QT prolongation longer than 0.60 second immediately before the onset of AVT. This measurement appeared to be a more sensitive predictor of the development of AVT than QTc prolongation or QRS widening. All patients also showed bradycardia before AVT onset. After therapy, the QT immediately decreased, while QTc and QRS remained prolonged for longer periods. Isoproterenol was effective in five of seven patients, but was contraindicated in two others. Ventricular pacing was used in four patients, including the two who did not respond to isoproterenol, and this abolished AVT promptly. Isoproterenol ...
Key Performance Measures For Lower Gastrointestinal Endoscopy In A Tertiary Center
Authors: C Konstantakis, T Lourida, G Diamantopoulou, M Kalafateli, G Theoxaris, C Triantos, K Thomopoulos
Journal: Endoscopy (2021)

Aims Key performance measures for lower gastrointestinal endoscopy have been recommended by ESGE and other endoscopic societies, as a means of improving the quality of the services provided. The aim of this study is to assess the degree of implementation of performance measures into the daily endoscopic practice of our center during the past decade.
Hemodynamic effects of octreotide in patients with autonomic neuropathy.
Authors: R DHoeldtke, K MDavis, JJoseph, RGonzales, I PPanidis, A CFriedman
Journal: Circulation (1991)

BACKGROUNDThe somatostatin analogue, ectrootide, is being used to treat postprandial hypotension in patients with autonomic neuropathy. Although the therapeutic effect of the drug is presumably secondary to a splanchnic vasoconstrictor action, its effect on splanchnic hemodynamics has never been characterized in patients with autonomic neuropathy. Moreover, it is unknown whether octreotide acts on other vascular beds in this group of patients or whether it affects cardiac output. We, therefore, measured splanchnic, forearm, and systemic vascular resistance and cardiac output before and after administering octreotide (0.4 microgram/kg s.c.) to patients with idiopathic autonomic neuropathy and diabetic autonomic neuropathy.METHODS AND RESULTSSplanchnic blood flow was determined from the clearance of indocyanine green in seven patients. We observed that octreotide decreased splanchnic blood flow (from 850 +/- 77 to 664 +/- 48 ml/min, p less than 0.005), increased mean blood pressure (from 97 +/- 6 to 115 +/-...
Inhibition of platelet function in thrombosis.
Authors: A JMarcus, L BSafier, H LUllman, M JBroekman, NIslam, T DOglesby, R RGorman, J WWard
Journal: Circulation (1985)

Accumulating experimental and clinical evidence indicates that a time for reappraisal of therapeutic modalities designed to inhibit the eicosanoid pathway as it may affect vascular disease may be approaching. Pharmacologic agents originally used were chosen because they were capable of suppressing platelet functions such as aggregation, release, and adhesion. The goals of clinical trials were to evaluate medications that would prevent or reduce platelet accumulation in critically located blood vessels of the heart, brain, and extremities and on vascular prostheses. Evaluation of results of therapeutic trials has been difficult and this is superimposed on less-than-complete knowledge of the basic pharmacology of the drugs that have been used. Participation of neutrophils and possibly macrophages in the thrombotic process is now well recognized on morphologic grounds. Because different cell types such as platelets, neutrophils, and endothelial cells have been shown to interact biochemically by sharing precu...
Nonuniform loss of regional flow reserve during myocardial ischemia in dogs.
Authors: D LCoggins, A EFlynn, R EAustin, G SAldea, DMuehrcke, MGoto, J IHoffman
Journal: Circulation Research (1990)

To determine whether coronary vasodilator reserve that persists during myocardial ischemia is present in all left ventricular regions, we measured regional blood flow in 192 left ventricular pieces (mean weight, 201 mg) in each of eight dogs by using radioactive microspheres while perfusing the left main coronary artery at 70, 50, 40, and 30 mm Hg. Flows were measured before and during adenosine infusion to determine flow reserve. Perfusion at 40 and 30 mm Hg produced ischemia in all dogs. At 70 mm Hg, 100% of left ventricular regions had significant flow reserve, compared with 92%, 55%, and 8% during perfusion at 50, 40, and 30 mm Hg, respectively. A greater amount of flow reserve and a greater number of regions responded to adenosine in the subepicardium than in the subendocardium at 50, 40, and 30 mm Hg. We conclude that coronary flow reserve persists in only a subset of left ventricular regions during ischemia and that the number of regions with persistent flow reserve decreases with perfusion pressur...
Safety of transesophageal echocardiography. A multicenter survey of 10,419 examinations.
Authors: W GDaniel, RErbel, WKasper, C AVisser, REngberding, G RSutherland, EGrube, PHanrath, BMaisch, KDennig
Journal: Circulation (1991)

BACKGROUNDDuring the past few years, transesophageal echocardiography (TEE) has been increasingly used in clinical cardiology; data concerning the practicability and safety of the technique, however, are rare.METHODS AND RESULTSThis report analyzes the experience of 15 European centers performing TEE studies for at least 1 year. At the time of this survey, 10,419 TEE examinations had been attempted or performed in these institutions. These TEE examinations were carried out by 54 physicians, 53.7% of whom had been trained in endoscopic techniques. Within the same time period, 160,431 precordial echocardiographic examinations were performed in the 15 institutions; the ratio between TEE and transthoracic studies averaged 9.03 +/- 6.4% (range of the 15 centers, 1.4-23.6%). Of the 10,419 patients, 9,240 (88.7%) were conscious inpatients or outpatients at the time of the TEE examination; the vast majority of the conscious patients did not receive intravenous sedation before TEE. In 201 cases (1.9%), insertion o...
Behavior of genes directly injected into the rat heart in vivo.
Authors: P MButtrick, AKass, R NKitsis, M LKaplan, L ALeinwand
Journal: Circulation Research (1992)

Gene transfer can be achieved in the adult rat heart in vivo by direct injection of plasmid DNA. In this report we define the spatial and temporal limits of reporter gene expression after a single intracardiac injection. pRSVCAT (100 micrograms), in which the Rous sarcoma virus long terminal repeat is fused to the chloramphenicol acetyltransferase reporter gene, and p alpha MHCluc (100 micrograms), in which the alpha-cardiac myosin heavy chain promoter is fused to the firefly luciferase gene, were injected into hearts, and reporter gene activities were assayed at various times. Both chloramphenicol acetyltransferase and luciferase were detectable in 100% of the rats from 1 to 7 days, in 60% of the rats from 17 to 23 days, and in 30% of the rats from 38 to 60 days after injection. Reporter gene activity was largely limited to a 1-2-mm region of the ventricle surrounding the injection site. Closed circular DNA was far more effective than linear DNA in transfecting cells in vivo. The relative strengths of th...
Megakaryocytic TGFβ1 Partitions Hematopoiesis into Amplifying Stem and Progenitor Cells and Maturing Effector Cells
Authors: Silvana Di Giandomenico, Pouneh Kermani, Nicole Molle, Mia Yabut, Fabienne Brenet, Shahin Rafii, Joseph Scandura
Journal: Blood (2017)
Assessment of preoperative left ventricular function in patients with mitral regurgitation: value of the end-systolic wall stress-end-systolic volume ratio.
Authors: B ACarabello, S PNolan, L BMcGuire
Journal: Circulation (1981)

Twenty-one patients with symptomatic, chronic, severe mitral regurgitation (MR) but without other valvular heart disease or coronary disease were evaluated to determine which hemodynamic and angiographic factors might be prognostic of surgical outcome. Sixteen patients were in New York Heart Association functional classes I or II postoperatively and formed group A. One patient remained in class III postoperatively and four patients died perioperatively; they constitute group B. End-diastolic volume index (EDVI) was less for group A than for group B, 119 +/- 25 ml/m2 vs 170 +/- 28 ml/m2 (p less than 0.001). End-systolic volume index (ESVI) was also lower in group A, 39 +/- 19 ml/m2 vs 72 +/- 32 ml/m2 for group B (p less than 0.01). The ratio of end-systolic wall stress to end-systolic volume index (ESWS/ESVI) was examined in normal persons and in groups A and B. This ratio was significantly lower in both groups than in normal persons, indicating relatively greater end-systolic volume at a given wall stress...
Beta-adrenergic agonists stimulate the synthesis of noncontractile but not contractile proteins in cultured myocytes isolated from adult rat heart.
Authors: IDubus, J LSamuel, FMarotte, CDelcayre, LRappaport
Journal: Circulation Research (1990)

The effect of catecholamines on adult myocardial protein synthetic activity was studied by use of an experimental model of isolated adult rat cardiac myocytes maintained in culture for 1-6 days. During this period, the majority of myocytes retained their rod-shaped morphology, but the cell number decreased progressively (50% of the initial density after 2 days in culture). Between day 1 and day 3 in culture, the specific synthetic activities of total proteins and of electrophoretically purified myosin heavy chain and actin ([14C] phenylalanine incorporation into protein, in disintegrations per minute per microgram protein) decreased (-19%,-32%, and -73%, respectively). Addition of isoproterenol or norepinephrine (10 nM) from the onset of the culture for 3 days increased the specific activity of both total and noncontractile proteins (greater than 20%) but had no effect on the specific activity of myosin heavy chain and actin when compared with 3-day cultured control cells. beta-Adrenergic receptors are sp...
Management of Women With Congenital or Inherited Cardiovascular Disease From Pre-Conception Through Pregnancy and Postpartum
Authors: Kathryn J Lindley, C Noel Bairey Merz, Anita W Asgar, Natalie A Bello, Sonal Chandra, Melinda B Davis, Mardi Gomberg-Maitland, Martha Gulati, Lisa M Hollier, Eric V Krieger, Ki Park, Candice Silversides, Natasha K Wolfe, Carl J Pepine
Journal: Journal of the American College of Cardiology (2021)
Changes in mitochondrial DNA in cardiac hypertrophy in the rat.
Authors: CRajamanickam, SMerten, BKwiatkowska-Patzer, C HChuang, RZak, MRabinowitz
Journal: Circulation Research (1979)

We studied DNA (mtDNA) replication in adult female rat hearts undergoing hypertrophy secondary to constriction of the ascending aorta. MtDNA was measured in isolated mitochondria by a fluorometric method adapted for that purpose. The conditions for removal of contaminating nuclear DNA were developed, and the purity of the mtDNA was assessed from its molecular conformation (open and closed circles) and by renaturation-kinetic analysis. The mtDNA concentration in mitochondria, expressed as micrograms of DNA per milligram of mitochondrial protein, increased 2, 4, and 7 days postoperatively by 21, 73, and 98%, respectively. Similar results were obtained when mtDNA was expressed per nonomole of cytochrome a. The population of replicative intermediates of mtDNA was analyzed by electron microscopy. In normal hearts, we observed molecular forms characteristic of animal mtDNA, such as circular monomers and dimers, catenated molecules, D-loops, expanded D-loops, and gapped molecules. D-loop frequency, which was nea...
Enhanced detection of the evolution of tissue changes after acute myocardial infarction using color-encoded two-dimensional echocardiography.
Authors: A FParisi, MNieminen, J EO'Boyle, P FMoynihan, S FKhuri, R AKloner, E DFolland, F JSchoen
Journal: Circulation (1982)

Acute myocardial infarction was produced in 26 dogs by ligation of the left anterior descending coronary artery. Two-dimensional echocardiograms (2-D echoes) were performed through the chest wall before and serially after coronary ligation. The dogs were then killed in four groups at the following intervals: 24-48 hours, 1-2 weeks, 3 weeks and 6-8 weeks. Each 2-D echo was processed through a video quantizer, which encoded echo amplitudes progressively into eight regions of color. The myocardium was graded with respect to color composition in regions that showed any abnormally contracting segment (ACS). The ACS exhibited a progressive increase in echo intensity that became maximal 6-8 weeks after coronary ligation. Histopathologic and histochemical studies verified that these increases in echo amplitude correlated with the evolution of healing and myocardial scar formation. At 6-8 weeks, the mean collagen content of infarcted myocardium had increased by a factor of 4; concurrently, ACS echo amplitude had i...
Evidence for a splanchnic sodium input monitor regulating renal sodium excretion in man. Lack of dependence upon aldosterone.
Authors: R MCarey
Journal: Circulation Research (1978)

Eight normal male subjects were placed on a constant 10 mEq sodium, 60 mEq potassium diet for 5 days. At 8:00 a.m. on the 5th day, the subjects were given a standard dose of 100 mEq of sodium orally or intravenously. Subjects receiving oral sodium also received 200ml of 5% dextrose in water intravenously, and those receiving intravenous sodium also received placebo capsules orally. Water intake and posture were controlled. The subjects then returned to a free diet for 1 month and subsequently were restudied by using the opposite route of sodium administration. The subjects given the oral sodium load excreted greater quantities of sodium in their urine than those repleted intravenously. The differential natriuresis was significant as early as 2 hours after sodium loading. Plasma aldosterone concentration was similar irrespective of the route of sodium administration. Six patients with primary adrenocortical insufficiency and documented hypoaldosteronism were studied with the same protocol after 5 days of 5...
Echocardiographic assessment of mitral valve size in obstructive hypertrophic cardiomyopathy. Anatomic validation from mitral valve specimen.
Authors: H GKlues, M AProschan, A LDollar, PSpirito, W CRoberts, B JMaron
Journal: Circulation (1993)

BACKGROUNDIn patients with hypertrophic cardiomyopathy, obstruction to left ventricular outflow is produced by systolic anterior motion of the mitral valve. In many of these patients, the mitral leaflets are elongated and increased in overall size. Mitral valve size may be responsible, in part, for the presence and magnitude of the outflow gradient and the pattern of systolic anterior motion of the leaflets. It may also influence the effectiveness of ventricular septal myotomy-myectomy in relieving subaortic obstruction. Therefore, the present study was undertaken to determine whether mitral valve dimensions could be assessed in quantitative terms from the echocardiogram in patients with hypertrophic cardiomyopathy.METHODS AND RESULTSA group of 37 patients with hypertrophic cardiomyopathy was selected for this study by virtue of having a high-quality transthoracic or intraoperative echocardiogram suitable for certain quantitative measurements from stop-frame images as well as a morphologically intact mitr...
Electrophysiologic effects of disopyramide in patients with atrioventricular nodal dysfunction.
Authors: P RWilkinson, JDesai, JHollister, RGonzalez, J AAbbott, M MScheinman
Journal: Circulation (1982)

Seventeen patients with first-degree or Mobitz I atrioventricular (AV) block and narrow QRS complexes underwent electrophysiologic drug testing before and after i.v. administration of disopyramide. Disopyramide did not significantly change the mean sinus cycle length (895 +/- 131 vs 877 +/- 119 msec), mean maximal sinus node recovery time (1134 +/- 160 vs 1133 +/- 13 msec), mean atrial effective refractory period (314 +/- 72 vs 307 +/- 54 msec), mean AV nodal conduction time (187 +/- 79 vs 180 +/- 73 msec) or the mean paced cycle length at which AV nodal Wenckebach conduction occurred (545 +/- 144 vs 497 +/- 130 msec) after disopyramide. The mean AV nodal effective refractory period decreased significantly (from 535 +/- 137 to 521 +/- 122 msec), and both infranodal conduction time and the paced ventricular cycle length producing ventriculoatrial block increased significantly (from 56 +/- 12 to 63 +/- 13 msec and from 625 +/- 158 to 655 +/- 157 msec, respectively). We conclude that i.v. disopyramide admini...
Effects of sublingual nitroglycerin on resting pulmonary gas exchange and hemodynamics in man.
Authors: SMookherjee, DFuleihan, R AWarner, SVardan, A IObeid
Journal: Circulation (1978)

Simultaneous hemodynamic, ventilation and blood gas measurements were performed in 19 males during cardiac catheterization for evaluation of chest pain syndrome before and 3 to 5 min after 0.4 mg sublingual nitroglycerin. Pulmonary arterial pressures and total pulmonary vascular resistance fell (P less than 0.001 for both), and mean systemic arterial pressure decreased (P less than 0.05). However, peripheral vascular resistance, cardiac output, and mixed venous PO2 did not change. Total and tidal ventilation, PCO2, pH, and base excess remained unchanged. However, the arterial PO2 decreased from a mean of 80 +/- 3 (SEM) to 72 +/- 2 mm Hg (P less than 0.001) and mean venous admixture increased from 8.8 +/- 1% to 12.6 +/- 1.5% (P less than 0.001). The alveolar arterial PO2 difference increased (P less than 0.001) and the dead space tidal volume ratio rose (P less than 0.05). We conclude that the decrease in arterial PO2 following sublingual nitroglycerin is caused by redistribution of pulmonary blood flow wi...