tbuckley/cabot-search huggingface dataset:
Effectiveness of a prehospital medical control system: an analysis of the interaction between emergency room physician and paramedic.
Authors: M WPozen, R BD'Agostino, P ASytkowski, R JSchneider, M MBerezin, L HBremer, R JRiggen
Journal: Circulation (1981)

Medical control for paramedics by means of radio and ECG telemetry is costly, time consuming, and of unproved value. We assessed the interaction between emergency room physicians and paramedics during ambulance transport of seriously ill cardiac patients (cardiac arrest, acute myocardial infarction, or new onset of crescendo angina pectoris) with paramedics in service. Thirty-five percent of all arrhythmias and 35% of potentially life-threatening arrhythmias were misclassified. Correct treatment was rendered in 74% of the cases, although only 65% were correctly diagnosed (p < 0.01). The principal predictive variable for misdiagnosing or incorrectly treating a patient was the presence of a potentially life-threatening arrhythmia, precisely the condition for which medical control and the paramedic system has the most to offer. Only 39% of patients with life-threatening arrhythmias were correctly diagnosed and correctly treated, whereas 64% of patients without life-threatening arrhythmias were correctly di...
High-Intensity Strength Training in Nonagenarians
Authors: Maria A. Fiatarone
Journal: JAMA (1990)

Muscle dysfunction and associated mobility impairment, common among the frail elderly, increase the risk of falls, fractures, and functional dependency. We sought to characterize the muscle weakness of the very old and its reversibility through strength training. Ten frail, institutionalized volunteers aged 90 ± 1 years undertook 8 weeks of high-intensity resistance training. Initially, quadriceps strength was correlated negatively with walking time (<i>r</i>= -.745). Fat-free mass (<i>r</i>=.732) and regional muscle mass (<i>r</i>=.752) were correlated positively with muscle strength. Strength gains averaged 174% ±31% (mean ± SEM) in the 9 subjects who completed training. Midthigh muscle area increased 9.0%± 4.5%. Mean tandem gait speed improved 48% after training. We conclude that high-resistance weight training leads to significant gains in muscle strength, size, and functional mobility among frail residents of nursing homes up to 96 years of age. (<i>JAMA</i>. 1990;263:3029-3034)
Improvement of postischemic myocardial function and metabolism induced by administration of deferoxamine at the time of reflow: the role of iron in the pathogenesis of reperfusion injury.
Authors: GAmbrosio, J LZweier, W EJacobus, M LWeisfeldt, J TFlaherty
Journal: Circulation (1987)

Reperfusion of ischemic myocardium has been postulated to result in a specific oxygen radical-mediated component of tissue injury. In a previous study we demonstrated improved recovery of ventricular function and metabolism when the superoxide radical scavenger superoxide dismutase was administered at the time of postischemic reflow. Studies in vitro, have suggested that superoxide toxicity might be mediated via the generation of more reactive hydroxyl radicals in an iron-catalyzed reaction. The present study was designed to test the hypothesis that myocardial reperfusion injury might be reduced by administration of the iron chelator deferoxamine at the time of reflow, most likely by preventing hydroxyl radical formation. Sixteen isolated Langendorff rabbit hearts, perfused within the bore of a superconducting magnet, were subjected to 30 min of normothermic (37 degrees C) total global ischemia followed by 45 min of reperfusion. At reflow eight treated hearts received a 10 ml bolus containing 50 mumol of ...
Premature pulmonic valve opening following sinus of Valsalva aneurysm rupture into the right atrium.
Authors: A EWeyman, J CDillon, HFeigenbaum, SChang
Journal: Circulation (1975)

Echocardiographic features of a patient with sinus of Valsalva aneurysm rupture into the right atrium are described. The aneurysm presented as a dense echo-producing mass in the right atrium which descended into the tricuspid orifice during diastole and withdrew back into the atrium during ventricular systole. Pulmonic valve exho motion demonstrated early diastolic pulmonic valve opening indicating an early right ventricular diastolic pressure rise exceeding simultaneous pulmonary artery pressure. Since the aorta is the only source of early diastolic pressure in excess of pulmonary artery pressure available to the right heart, this finding of early diastolic pulmonic valve opening indicated the presence of a fistula between the aorta and right heart. Other interesting echocardiographic features of this case are also presented.
Quantifying the HDL proteome by mass spectrometry: how many proteins truly associate with HDL?
Authors: Gunther Marsche
Journal: European Journal of Heart Failure (2018)

I read with great interest the article by Emmens and colleagues published in the European Journal of Heart Failure.1 The authors purposed to examine whether changes in the high-density lipoprotein (HDL) proteome of heart failure patients relate to a worse prognosis. Certainly, Emmens et al. have conducted a very interesting and valuable study, but some methodological issues need to be considered. Because of differences in HDL isolation techniques and poor purification of the isolated HDL fractions, the total 'list' of HDL proteins unfortunately varies dramatically from study to study, and it is not clear what proteins truly associate with HDL. When studying the HDL proteome, it requires highly purified fractions of HDL, using a two-step protocol, consisting of density gradient ultracentrifugation (d = 1.063–1.21 g/mL) or immunoprecipitation, followed by size exclusion chromatography to minimize contamination with low density lipoproteins and other lipidated plasma proteins that are co-isolated with HDL.2, 3 Emmens et al. used a calcium silicate matrix to separate lipoproteins from other plasma proteins, which is not sufficient to yield highly purified fractions of HDL. In addition, no quantitative raw data were provided, making it impossible for the reader to judge the quality of lipoprotein preparations and the abundance of the individual proteins. Therefore, it is not clear whether the identified proteins are HDL-associated. This work was supported by the Austrian Science Fund FWF (Grants P22976-B18 and W1241).
The effects of variations in conductivity and geometrical parameters on the electrocardiogram, using an eccentric spheres model.
Authors: YRudy, RPlonsey, JLiebman
Journal: Circulation Research (1979)

The effects of variations in the volume conductor properties of the torso on the electrocardiogram were studied by means of a theoretical eccentric spheres model. The model includes a blood cavity, cardiac muscle layer, pericardium, lung region, skeletal muscle layer, and subcutaneous fat. The source of the field is a double-layer spherical cap located within the myocardium. The following effects regarding the electrocardiogram (ECG) potentials were determined: (1) blood augments the potential, but less than predicted by simpler published models; (2) in anemia, high potentials are expected, whereas in polycythemia, voltages are reduced; (3) abnormally low lung conductivity (emphysema) causes low surface potentials whose magnitude is controlled by the low conductivity skeletal muscle layer; (4) low voltages result both from low and high pericardial conductivities; (5) the surface potential increases with increasing myocardial conductivity; (6) low skeletal muscle conductivity (Pompe's disease) causes high ...
Volatile anesthetics block intercellular communication between neonatal rat myocardial cells.
Authors: J MBurt, D CSpray
Journal: Circulation Research (1989)

The effects of halothane and ethrane on gap junction-mediated intercellular communication and on membrane excitability were examined in cultured neonatal rat cardiac myocytes using whole-cell voltage-clamp and current-clamp techniques. Excitability was maintained at doses of both anesthetics that reversibly abolished current flow through junctional membranes. The degree of reduction of junctional conductance was a steep function of the dose of anesthetic; complete block occurred at lower aqueous concentrations of halothane than ethrane. The time course for loss of communication was rapid; 90% reduction of initial junctional conductance occurred in less than 15 seconds after exposure to 2 mM halothane or 4 mM ethrane. Recovery of junctional conductance and junctional permeability to intracellularly injected Lucifer yellow was rapid and complete on washout of the anesthetics. As junctional conductance was reduced by halothane or ethrane exposure, unitary conductance of the gap junctional channels remained c...
Ventricular arrhythmias in the subacute myocardial infarction period. High-resolution activation and refractory patterns of reentrant rhythms.
Authors: MRestivo, W BGough, Nel-Sherif
Journal: Circulation Research (1990)

Patterns of activation, functional conduction block, and effective refractory periods during reentrant activation were investigated in a 4-day postinfarction canine model using a 64-channel high-resolution (1 mm) bipolar electrode array. Lower resolution (3-10 mm) isochronal activation maps of the entire epicardial surface were constructed from 126 sites during the initiation and sustenance of reentry and showed reentrant wave fronts that circulated around arcs of functional conduction block. During initiation of reentry by premature stimulation, high-density recordings from these same regions showed that conduction block occurred abruptly, within 1 mm, and without prior decrement of the impulse. Electrograms recorded in proximity to the arc of block were comprised of two deflections: a local activation potential and an electrotonic potential reflecting activation 1 mm away; the reverse order of activation and electrotonus was observed on the opposite side of the arc of block. The occurrence of functional...
Quantitative analysis of potassium channel mRNA expression in atrial and ventricular muscle of rats.
Authors: J EDixon, DMcKinnon
Journal: Circulation Research (1994)

The expression of 15 different potassium channel genes in rat atrial and ventricular muscle was quantitatively compared by use of an RNase protection assay. Of these genes, only five, Kv1.2, Kv1.4, Kv1.5, Kv2.1, and Kv4.2, were expressed at significant levels in cardiac muscle. In comparisons of atrial and ventricular RNA samples, transcripts from the Kv1.2 and Kv4.2 genes showed the largest differences in relative abundance. There was an approximately twofold decrease in total Kv4 subfamily mRNA expression in atrial muscle relative to ventricular muscle and a 70% increase in total Kv1 subfamily mRNA. Variation of potassium channel mRNA expression within the left ventricular wall was also examined. There was a large gradient of Kv4.2 expression across the ventricular wall, and Kv4.2 expression in epicardial muscle was more than eight times higher than in papillary muscle. Other potassium channel genes were expressed at relatively uniform levels across the ventricular wall. The results suggest that transcr...
Regeneration of Epithelialized Digestive Continuity after Endoscopic Stenting for Circumferential Oesogastric Junction Necrosis Following Roux-EN-Y Gastric Bypass
Authors: S Ouazzani, D Lorenzo, M Fernandez, M Arvanitaki, D Blero, I El Moussaoui, J Closset, J Deviere, A Lemmers
Journal: Endoscopy (2021)

A patient who underwent a Roux-en-Y gastric by-pass after vertical gastroplasty for morbid obesity, presented with sepsis associated to complete oesogastric junction disunion with loss of luminal continuity. After surgical concertation, an endoscopic treatment with metallic stent was attempted to restore luminal continuity. After two cycles of endoscopic stenting during a total of 7 months, a neo-epithelialized digestive continuity, connecting the oesophagus to the remnant stomach, was observed, with no more leakage and excellent clinical evolution. After three successful dilation sessions of two stent-related strictures, the patient is fine and eats normally, without any dysphagia or sepsis.
Isolated left anterior descending coronary atherosclerosis: long-term comparison of internal mammary artery and venous autografts.
Authors: B WLytle, F DLoop, R LThurer, L KGroves, P CTaylor, D MCosgrove
Journal: Circulation (1980)

A consecutive series of 100 patients receiving left internal mammary artery grafts and a consecutive series of 100 patients receiving saphenous vein grafts as treatment of isolated left anterior descending coronary artery stenosis were reviewed to determine survival, graft patency, disease progression and New York Heart Association functional class. The mean follow-up was 67 months, and the mean catheterization interval was 20 months. Recommendations for revascularization can be made selectively to patients with critical isolated left anterior descending stenoses who have limiting symptoms and large areas of viable myocardium at risk.
The interaction of convection and diffusion in the transport of 131I-albumin within the media of the rabbit thoracic aorta.
Authors: ATedgui, M JLever
Journal: Circulation Research (1985)

The interaction of convection and diffusion in the transport of 131I-labeled albumin within the wall of rabbit thoracic aorta was studied in vessels excised at in vivo length. They were pressurized with a solution containing no tracer and immersed in a solution containing labeled albumin. The label then entered the wall tissue via the adventitia and had to diffuse against the convective flux which occurred from the lumen to the adventitia. Experiments were performed on intact and deendothelialized vessels pressurized to 70 and 180 mm Hg. At the end of each experiment the vessels were subjected to sequential frozen sectioning parallel to the lumenal surface. The radioactivity of the 20-micron-thick sections was determined and expressed as a tissue:labeled solution concentration ratio. Transmural profiles of these ratios were thus obtained. The steady state was found to be achieved by about 90 minutes. When the convection was enhanced by removal of the endothelium, the average ratios were lower than when th...
Value of the P-wave signal-averaged ECG for predicting atrial fibrillation after cardiac surgery.
Authors: J SSteinberg, SZelenkofske, S CWong, MGelernt, RSciacca, EMenchavez
Journal: Circulation (1993)

BACKGROUNDAtrial fibrillation (AF) is a commonly encountered arrhythmia in clinical practice, and it occurs frequently after cardiac surgery. The P-wave signal-averaged (SA) ECG noninvasively detects atrial conduction delay. Prior studies have described greater P-wave prolongation in patients with a history of AF, but prospective studies have not been performed.METHODS AND RESULTSConsecutive patients undergoing cardiac surgery were enrolled. The P-wave SAECG was recorded before surgery from three orthogonal leads using a sinus P-wave template and a cross-correlation function. The averaged P wave was filtered with a least-squares-fit filter and combined into a vector magnitude, and total P-wave duration was measured. Patients were observed after cardiac surgery for the development of AF. One hundred thirty patients were enrolled, and 33 (25%) developed AF 2.6 +/- 2.0 days after surgery. Patients with AF more often had left ventricular hypertrophy on ECG (P < .05) and had a lower ejection fraction (P < .05)...
Factors modifying the early nondiuretic vascular effects of furosemide in man. The possible role of renal prostaglandins.
Authors: G DJohnston, W RHiatt, A SNies, N APayne, R CMurphy, J GGerber
Journal: Circulation Research (1983)

Animal experiments have suggested that salt-balance, prostaglandin synthesis, and renal function are important determinants of the nondiuretic vascular effects of furosemide. To investigate the influence of these factors in humans, we studied 10 normal volunteers and five anephric patients. The volunteers were studied on three occasions: when on a 10 mEq/day sodium diet, on a 250 mEq/day sodium diet, and on a 10 mEq/day sodium diet with indomethacin, 200 mg/day. The anephric patients were studied immediately after dialysis. Plethysmographic methods were used to measure venous capacitance and blood flow in the calf before, and at 5, 10, and 15 minutes after furosemide, 80 mg, iv. Blood was obtained before and 15 minutes after furosemide for determination of plasma renin activity by radioimmunoassay and of plasma 6-keto-prostaglandin F1 alpha by chromatography-mass spectrometry. We found that furosemide significantly increased venous capacitance in the calf of the normal volunteers on a low salt diet. Indom...
Thrombolytic effects of recombinant fibrolase or APSAC in a canine model of carotid artery thrombosis.
Authors: F SMarkland, G SFriedrichs, S RPewitt, B RLucchesi
Journal: Circulation (1994)

BACKGROUNDThrombolytic agents used clinically rely on the activation of plasminogen to plasmin. Plasmin possesses multiple actions including increasing thrombin activity and activation of platelets. Thus, after successful thrombolytic therapy, arterial hyperactivity and reocclusion may be the result of a predominant plasmin-induced thrombogenic action at the site of the residual thrombus. Fibrolase, a direct-acting fibrinolytic enzyme from southern copperhead snake venom, induces rapid clot lysis in vitro. Fibrolase does not rely on plasminogen activation or any other bloodborne components for activity and is not inhibited by any of the rapidly acting serine proteinase inhibitors in blood.METHODS AND RESULTSWe investigated the efficacy of fibrolase to lyse an occlusive thrombus formed in the carotid artery of the anesthetized dog. Electrolytic injury was initiated in both the right and left carotid arteries. Thirty minutes after both arteries were occluded, each vessel was infused with either fibrolase (4...
Sotalol in patients with Wolff-Parkinson-White syndrome.
Authors: K PKunze, MSchlüter, K HKuck
Journal: Circulation (1987)

We evaluated the effects of intravenous and long-term oral sotalol treatment in 17 patients with an accessory atrioventricular (AV) pathway. All patients had a history of symptomatic supraventricular tachycardia. During electrophysiologic study intravenous (1.5 mg/kg body weight) and oral (240 to 320 mg/day) sotalol caused significant increases of sinus cycle length, AV nodal conduction time, and refractory periods of atrial and ventricular myocardium and accessory pathway. AV reciprocating tachycardia, which was inducible and sustained in 15 patients at control, was still inducible after intravenous sotalol in 14 patients, including one in whom it was not inducible at control. However, tachycardia became nonsustained in 10 patients. In seven patients who underwent repeat drug testing while on oral sotalol, results were the same as after intravenous sotalol. Sixteen patients were followed-up for 36 months (median value). Fifteen of them were clinically free of symptoms or experienced marked improvement, d...
Platelet function studies in heart disease. VI. Enhanced platelet aggregate formation activity in congestive heart failure: inhibition by sodium nitroprusside.
Authors: JMehta, PMehta
Journal: Circulation (1979)

We studied 11 patients with congestive heart failure and 10 normal volunteers for in vivo platelet aggregate formation activity. The patients with heart failure had significantly (p less than 0.01) more circulating platelet aggregates than the normal volunteers. During sodium nitroprusside infusion, the number of circulating platelet aggregates declined to normal levels and in vitro platelet aggregation responses to epinephrine and adenosine diphosphate were also suppressed significantly (p less than 0.01). This was associated with a 30% decline in systemic vascular resistance and a 28% increase in cardiac output. In other in vitro experiments, sodium nitroprusside was found to have direct, dose-related platelet aggregation inhibitory actions. This study suggests that an increase in vascular resistance in certain heart failure patients may in part be related to an increase in circulating platelet aggregates. Direct inhibition of platelet aggregation by sodium nitroprusside may be a mechanism of its benefi...
Effect of hypoxia on the sinoatrial node, atrium, and atrioventricular node in the rabbit heart.
Authors: JSenges, TMizutani, DPelzer, JBrachmann, USonnhof, WKübler
Journal: Circulation Research (1979)

We used intracellular microelectrodes to study the effects of hypoxia on the isolated, superfused sinoatrial (SA) node, atrium, and atrioventricular (AV) node of the rabbit heart. Hypoxia decreased the rate of spontaneous impulse initiation in SA nodal fibers by decreasing the slope of diastolic depolarization. With gradually decreasing Po2, the sinus rate was reduced; concomitantly, the corrected sinus node recovery time after rapid atrial stimulation was much less affected demonstrating marked prolongation only under severe anoxic conditions. Hypoxia decreased the amplitude of action potentials of the SA node and of the AV node but not of the atrium. SA and AV nodal conduction were slowed by hypoxia; intraatrial conduction was not significantly affected. AV nodal conduction block occurred at lower atrial rates, and the effective refractory period of the AV node was prolonged. Inhomogeneity of SA and AV nodal impulse propagation often was observed in the presence of hypoxia. This was associated with conc...
The SUPPORT Project and Improving Care for Seriously III Patients-Reply
Authors: William A. Knaus
Journal: JAMA (1996)

<h3>In Reply.</h3> —The encouraging experiences reported by Dr Frank and Ms Campbell helped shape the SUPPORT intervention. Our different findings may result from our randomized trial design, our retaining established physician-patient relationships, or our more rigorous evaluation design. We welcome the opportunity to respond to Dr Dougherty and clarify a major public misinterpretation of SUPPORT's findings—that physicians were ignoring patients' wishes. SUPPORT demonstrated a failure of communication between clinicians and patients, not a failure of physicians to listen to patients. This is also a response to Dr Donnelly's suggestion that the SUPPORT intervention should have been more prescriptive. We designed the intervention to be as forceful as possible given the evaluation design of the study and the concerns of the institutional review boards that all care be under the control of the attending clinician. We agree with Dr Godec that, as part of any comprehensive approach to this problem, financial
Role of adrenoceptors and dopamine receptors in modulating left ventricular diastolic function.
Authors: R MLang, J DCarroll, SNakamura, HItoh, S IRajfer
Journal: Circulation Research (1988)

Although both dopamine and dobutamine are potent positive inotropic agents, multiple studies indicate that dopamine may produce a rise in left ventricular (LV) filling pressure, while dobutamine often has the opposite effect. To ascertain the pharmacological and hemodynamic mechanisms responsible for the elevation in LV filling pressure observed with dopamine, we administered incremental infusions (2, 4, and 6 micrograms/kg/min) of dopamine to 18 open-chest, anesthetized dogs in the presence and absence of rauwolscine (selective alpha 2-adrenoceptor antagonist) (n = 7), terazosin (selective alpha 1-antagonist) (n = 6), and domperidone (selective dopamine2 antagonist) (n = 5), while measuring pressures in the LV and left atrium and changes in dimension in the LV short-axis (with ultrasonic piezo crystals). Dobutamine (2, 4, and 6 micrograms/kg/min) was infused in five additional dogs before and after administration of rauwolscine. The time constant of isovolumic pressure decay, peak lengthening rate (mm/se...