tbuckley/cabot-search huggingface dataset:
Exaggerated pressor response to treadmill exercise in chronic cocaine abusers with left ventricular hypertrophy.
Authors: C GCigarroa, J DBoehrer, M EBrickner, E JEichhorn, P AGrayburn
Journal: Circulation (1992)

BACKGROUNDChronic cocaine abuse has been associated with a high prevalence of left ventricular hypertrophy (LVH) in normotensive individuals at rest. This study was conducted to determine whether chronic cocaine abusers with LVH would manifest an exaggerated pressor response to treadmill exercise.METHODS AND RESULTSForty-nine normotensive chronic cocaine abusers underwent Bruce protocol treadmill exercise testing until they attained 85% maximum predicted heart rate. A peak exercise systolic blood pressure greater than or equal to 210 mm Hg was defined as abnormal. In addition, they underwent two-dimensional echocardiography and had left ventricular mass determined by the area-length method. LVH was defined as left ventricular mass greater than or equal to 105 g/m2 and a posterior wall thickness greater than or equal to 1.2 cm. Age- and race-matched control subjects also underwent echocardiography and exercise testing. Group differences in peak exercise blood pressure in cocaine abusers with LVH, cocaine a...
Autoregulation of cerebral blood flow in hypertensive patients. The modifying influence of prolonged antihypertensive treatment on the tolerance to acute, drug-induced hypotension.
Authors: SStrandgaard
Journal: Circulation (1976)

Autoregulation of cerebral blood flow (CBF) was studied by the arteriovenous oxygen difference method in 13 patients with untreated or ineffectively treated severe hypertension, nine patients with effectively treated, formerly severe hypertension, and ten normotensive controls. Resting mean blood pressure in these three groups was 145 +/- 17 (1 SD) mm Hg, 116 +/- 18 mm Hg, and 98 +/- 10 mm Hg, respectively. Blood pressure was decreased by trimethaphan infusion combined with head-up tilt. The lower limit of CBF autoregulation in the three groups was 113 +/- 17 mm Hg, 96 +/- 17 mm Hg, and 73 +/- 9 mm Hg, and the lowest tolerated blood pressure where mild symptoms of brain hypoperfusion were encountered was 65 +/- 10 mm Hg, 53 +/- 18 mm Hg, and 43 +/- 8 mm Hg. These pressures were all significantly higher (P less than 0.01) in the group of untreated or ineffectively treated hypertensive patients than in the normotensive group demonstrating a shift of CBF autoregulation in the former. The observations in effe...
The linear relation between oxygen consumption and pressure-volume area can be reconciled with the Fenn effect in dog left ventricle.
Authors: TNozawa, YYasumura, SFutaki, NTanaka, HSuga
Journal: Circulation Research (1989)

We studied the Fenn effect in 12 excised cross-circulated dog left ventricles in control contractility and in a contractility enhanced by dobutamine or depressed by propranolol. The additional oxygen consumption (Vo2) in an ejecting contraction compared with that found in an isovolumic contraction at a comparable end-systolic pressure was considered to constitute the cardiac Fenn effect. We examined whether this load-dependent Vo2 could be reconciled with the linear relation between Vo2 and pressure-volume area (PVA) common for both ejecting and isovolumic contractions that has so far been consistently observed and was presently confirmed. PVA is a specific area in the pressure-volume diagram, represents the total mechanical energy generated by each contraction, and consists of external mechanical work (EW) and mechanical potential energy. Because potential energy is common in the isovolumic and ejecting contractions producing the same end-systolic pressure, PVA of the ejecting contraction is greater by E...
The effect of free fatty acids on myocardial oxygen consumption during atrial pacing and catecholamine infusion in man.
Authors: SSimonsen, J KKjekshus
Journal: Circulation (1978)

The effect of myocardial uptake of free fatty acids (FFAu) on myocardial oxygen consumption (MVO2) in relation to increased heart rate and inotropic stimulation was determined in patients with coronary artery disease. Submaximal atrial pacing and isoproterenol stimulation increased MVO2 by 66% and 142%, respectively, at similar heart rates. Inhibition of lipolysis with beta-pyridyl carbinol almost abolished FFAu and reduced MVO2 significantly. Increased heart rate contributed 47% and FFAu 50% of the raised MVO2 attributed to inotropic stimulation was 30%. Augmentation of FFAu by triglyceride/heparin infusion increased MVO2 significantly above control levels, both during pacing and isoproterenol infusion. We conclude that MVO2 is closely correlated to FFAu, catecholamines sensitize the heart to FFA, and increased FFAu account for a major part of the increased MVO2 during catecholamine stimulation. The importance of reducing heart rate and lipolysis to reduce myocardial oxygen requirements is emphasized.
TCTAP C-056 Triple Vessel Coronary Artery Disease Involving Distal Left Main, CTO LAD, and Ostial LCX in An Elderly Patient : Challenges and Strategy
Authors: Kumutha Gobal, Hou Tee Lu, Adelyn Nisha Henry, Heng Shee Kim, Kim Fong Ng, Tee Choon Keong, Vicknesan Kulasingham, Mahadevan Gurudevan, Chuey Yan Lee
Journal: Journal of the American College of Cardiology (2021)
Platelet kinetic studies in patients with hyperlipoproteinemia: effects of clofibrate therapy.
Authors: L AHarker, WHazzard
Journal: Circulation (1979)

Studies of platelet and fibrinogen kinetics in 27 patients with hyperlipoproteinemia and 28 control subjects demonstrated shortened platelet survival and increased platelet turnover in seven patients with type III and 10 patients with type IV-V hyperlipoproteinemia (p less than 0.01). There was no correlation between platelet survival time and specific lipid levels, vascular disease, sex or age. Platelet kinetics were not significantly altered from control values in eight patients with familial hypercholesterolemia. Platelet aggregation studies and fibrinogen kinetic measurements did not differ in any of the hyperlipoproteinemic groups of patients from those in control subjects. Despite significant changes in plasma lipids induced by clofibrate, platelet survival was significantly extended only in patients with type IV-V hyperlipoproteinemia (p less than 0.05). These results are consistent with the hypothesis that atherogenesis in patients with types III--V hyperlipoproteinemia may be associated with a pr...
Evaluation of left ventricular function during upright exercise: correlation of exercise Doppler with postexercise two-dimensional echocardiographic results.
Authors: A AMehdirad, G AWilliams, A JLabovitz, R JBryg, B RChaitman
Journal: Circulation (1987)

The relationship of regional and global left ventricular function to aortic flow dynamics during exercise was determined in 14 normal subjects and 14 patients with coronary artery disease. Doppler and two-dimensional echocardiographic studies were performed before, during, and immediately after an exercise test by the Bruce protocol. Two-dimensional echocardiography was used to determine the ejection fraction and new wall motion abnormalities. The peak ejection velocity, stroke index, and cardiac index were calculated from the pulsed Doppler tracing. In normal subjects the ejection fraction increased significantly (p less than .001) from rest (0.51 +/- 0.07) to peak exercise (0.61 +/- 0.07), while the response in coronary patients was blunted (0.49 +/- 0.11 vs 0.48 +/- 0.16). Similarly, the change in peak ejection velocity throughout exercise in normal subjects (from 0.71 +/- 0.12 to 1.50 +/- 0.35 m/sec) was significantly (p less than .01) greater than that in patients with coronary artery disease (from 0...
Limitations of the echocardiogram in diagnosing valvular vegetations in patients with mitral valve prolapse.
Authors: P AChandraratna, ELangevin
Journal: Circulation (1977)

In order to assess the reliability of the echocardiogram in detecting valvular vegetations in patients with mitral valve prolapse (MVP), echocardiograms from 85 consecutive patients with mitral valve prolapse were reviewed. Eleven patients had thick shaggy echoes confined to the anterior mitral leaflet; eighteen patients had shaggy echoes on the posterior leaflet; and five had abnormal echoes on both the anterior and posterior leaflets. Only one patient had clinical evidence of infective endocarditis. Redundant leaflets which present multiple surfaces for the production of echoes may explain the abnormal echoes that were observed. Patients with echographic features suggesting mild prolapse less commonly exhibited shaggy leaflet echoes than those with more severe prolapse. Because a significant proportion (40%) of patients with MVP had shaggy echoes which closely resembled those seen in valvular vegetations, we feel that the echocardiogram is of limited value in diagnosing infective endocarditis in patient...
Regional blood flow, oxidative metabolism, and glucose utilization in patients with recent myocardial infarction.
Authors: JCzernin, GPorenta, RBrunken, JKrivokapich, KChen, RBennett, AHage, CFung, JTillisch, M EPhelps
Journal: Circulation (1993)

BACKGROUNDMetabolic imaging with positron emission tomography (PET) can detect tissue viability in clinical infarct regions. With appropriate tracer kinetic models and serial  imaging, regional myocardial blood flow and rates of metabolism can now be quantified in patients with recent myocardial infarctions.METHODS AND RESULTSSerial  imaging with [13N]ammonia, [11C]acetate, and 18F-deoxyglucose was performed in 22 patients with recent infarctions to measure regional blood flow (in milliliters per gram per minute), glucose metabolism (in micromoles per gram per minute), and oxidative metabolism (in clearance rate per minute). Hypoperfused clinical infarct regions were classified as PET mismatch if 18F was increased relative to 13N activity or PET  if 13N and 18F activities were reduced concordantly. Blood flows differed significantly between normal, mismatch, and match segments (0.83 +/- 0.20, 0.57 +/- 0.20, and 0.32 +/- 0.12 mL.g-1.min-1, respectively). The relation between oxidative metabo...
Baroreflex control of renal sympathetic nerve activity is potentiated at early phase of two-kidney, one-clip Goldblatt hypertension in conscious rabbits.
Authors: HKumagai, HSuzuki, MRyuzaki, SMatsukawa, TSaruta
Journal: Circulation Research (1990)

Conscious normotensive and two-kidney, one-clip Goldblatt hypertensive rabbits were studied to determine the sensitivity of the arterial baroreflex control of renal sympathetic nerve activity (RSNA) and heart rate. The relations of the mean arterial pressure-RSNA and mean arterial pressure-heart rate were examined over a wide range of blood pressures produced by infusions of phenylephrine and nitroglycerin. The maximum slope obtained by logistic function analysis was considered to represent the baroreflex sensitivity. In the early hypertensive group (n = 8; mean arterial pressure +/- SEM, 88 +/- 2 mm Hg) on day 5 after renal clip application, the maximum slope of the mean arterial pressure-RSNA relation was -11.3 +/- 1.2, which was significantly greater than that of the sham normotensive group (-6.9 +/- 0.3, p less than 0.05). The maximum slope (-4.3 +/- 0.2) of the mean arterial pressure-RSNA relation in the late hypertensive group (n = 8; mean arterial pressure, 96 +/- 3 mm Hg) on day 21 after renal cli...
Coronary atherosclerosis is associated with left ventricular dysfunction and dilatation in aortic stenosis.
Authors: V IVekshtein, R WAlexander, A CYeung, TPlappert, M GSutton, PGanz, A PSelwyn, J ABittl
Journal: Circulation (1990)

Patients with aortic stenosis develop widely variable patterns of left ventricular hypertrophy and dysfunction. We postulated that coronary atherosclerosis (CAD) may be associated with impaired left ventricular function and chamber dilatation in patients with aortic stenosis. Left ventricular mass and volumes were quantified from two-dimensional echocardiography and correlated with coronary angiography in 78 patients with severe aortic stenosis and no previous myocardial infarction or regional wall motion abnormalities. Eighteen patients (group 1) had smooth coronary arteries, 25 patients had irregular coronary arteries with 50% or less stenosis (group 2), and 35 patients had obstructive CAD (group 3). Even though the calculated valve area was similar in all three study groups, group 1 patients had higher values for ejection fraction (65 +/- 9%, 51 +/- 17%, and 48 +/- 13%; p = 0.0002), systolic mass-to-volume ratio (9.2 +/- 3.9, 5.6 +/- 2.8, and 5.2 +/- 2.2; p = 0.0001), and cardiac index (2.9 +/- 0.7, 2....
Identification and functional significance of troponin I isoforms in neonatal rat heart myofibrils.
Authors: A FMartin, KBall, L ZGao, PKumar, R JSolaro
Journal: Circulation Research (1991)

We investigated the mechanism(s) responsible for differences in the effects of acidic pH on Ca2+ activation of the activity of adult and neonatal rat heart myofilaments. Studies on preparations of myofilaments reconstituted with adult troponin-tropomyosin (Tn-Tm) and either adult or neonatal thick filaments indicated that the difference in effect of acidic pH is related to differences in Tn-Tm and not other myofilament proteins. Immunoblotting analysis showed that development of the rat heart myofibrils is associated with isoform switching from slow skeletal TnI to cardiac TnI and from a slow mobility isoform of TnT (TnT1) to a faster Mr isoform (TnT2. Expression of slow skeletal TnI was associated with a relative insensitivity of myofilament Ca2+ activation to deactivation by acidic pH. Moreover, the effect of acidic pH on Ca2+ activation of ATPase activity of soleus myofibrils, which contain cardiac TnC and slow skeletal TnI, was essentially the same as the effect of acidic pH on rat cardiac myofibrils ...
Phorbol dibutyrate stimulates the release of diffusible endothelium-derived vasoconstrictor factor(s) from canine femoral arteries.
Authors: G MRubanyi, ALuisi, AJohns
Journal: Circulation Research (1991)

The purpose of this study was to analyze the effect of the tumor-promoting phorbol ester 12,13-dibutyrate (PDBu) on the synthesis/release of nonprostanoid endothelium-derived vasoactive factors. In bioassay experiments (in the presence of 10(-5) M indomethacin), infusion of PDBu (10(-9)-10(-7) M) through a femoral artery (donor) segment with endothelium evoked further, concentration-dependent contraction of superfused canine coronary artery bioassay rings without endothelium (already contracted with 10(-7) M PDBu). Removal of the endothelium from the donor segment abolished further contractions of the bioassay ring to 10(-9) M PDBu and significantly depressed the contractile responses to 10(-9) and 10(-7) M PDBu infused through the donor segment. The inactive phorbol ester 4 alpha-phorbol 12,13-didecanoate had no effect on vascular preparations mounted in the bioassay system. Selective exposure of the bioassay tissue to 10(-7) M PDBu completely inhibited its responsiveness to basally released endothelium-...
Can serial exercise testing improve the prediction of coronary events in asymptomatic individuals
Authors: R AJosephson, EShefrin, E GLakatta, L JBrant, J LFleg
Journal: Circulation (1990)

An abnormal ST segment response to treadmill exercise has a low predictive value for future coronary events (angina pectoris, nonfatal myocardial infarction, or cardiac death) in apparently healthy individuals. To determine whether the conversion from a normal to an abnormal ST segment response might identify individuals at high risk for a future coronary event, we analyzed the results of serial exercise tests performed at 2-4-year intervals in 726 male and female volunteers, aged 22-84 years (mean, 55.1 years), from the Baltimore Longitudinal Study of Aging (BLSA). All subjects were free of cardiovascular disease at entry by history, physical examination, and resting 12-lead electrocardiogram. Over a mean overall follow-up of 7.4 years, coronary events occurred in 34 of 178 (19.1%) of those with an abnormal ST response to exercise versus 30 of 548 (5.5%) in those with a normal response (p = 0.001). Angina pectoris was the most common presenting coronary event regardless of ST segment exercise response. A...
Postoperative left anterior hemiblock and right bundle branch block following repair of tetralogy of Fallot. Clinical and etiologic considerations.
Authors: C NSteeg, EKrongrad, FDavachi, F OBowman, J RMalm, W MGersony
Journal: Circulation (1975)

Previous reports have indicated an incidence of right bundle branch block (RBBB) and left anterior hemiblock (LAH) pattern varying from 8-22% following corrective surgery in patients with tetralogy of Fallot. Among 207 patients with tetralogy of Fallot operated on at our institution, 8.7% developed an ECG pattern of RBBB and LAH. These patients were followed for 1-13 years (mean 6.2 years) for a total of 111 patient years. All patients are alive and none have had documented late atrioventricular dissociation, syncope, or other symptoms. Transient heart block was present in one patient in the immediate postoperative period but has not recurred. This group of patients differs significantly from other series in which such an ECG pattern was associated with a marked increase in morbidity and mortality. These data and the experimental evidence suggest that two distinct groups of patients exist: 1) a group in which this ECG pattern is secondary to lesions within the bundle of His and 2) a group in which the pat...
Coronary Artery Stents
Authors: Jassim Al Suwaidi
Journal: JAMA (2000)

Intracoronary stents are now used for the majority of patients undergoing percutaneous coronary revascularization, and the body of scientific knowledge about stents has expanded rapidly in the last several years.To review the evidence supporting the widespread use of intracoronary stents.The MEDLINE database was searched for articles from 1990 through January 2000 using the indexing terms stents, coronary artery disease, and angioplasty. Additional data sources included bibliographies of articles identified on MEDLINE, bibliographies in textbooks on percutaneous coronary interventions, and preliminary data presented at recent national and international cardiology conferences.We selected for review studies that assessed the effects of stenting on the immediate and long-term outcome of patients undergoing percutaneous coronary revascularization. If data from randomized controlled trials were not available for specific patient subsets or lesion characteristics, observational studies were included.The methodologic characteristics of studies in coronary stenting were extracted and summarized according to key components of research design, including lesion type, location, and adjunctive therapy used. Studies were classified according to the strength of the available data into proven and unproven indications for stent use.Coronary artery stents increase the safety of interventional procedures, increase procedure success rates, and decrease the need for emergency coronary artery bypass graft surgery.Intracoronary stents have become an essential component of the catheter-based treatment of coronary artery disease. The evidence indicates that elective stenting, rather than provisional stenting or balloon angioplasty alone, improves clinical outcomes in the months following percutaneous coronary revascularization in a wide variety of clinical settings and lesion types. JAMA. 2000;284:1828-1836.
T Cells as the Future of Cancer Therapy
Authors: Antoni Ribas
Journal: Cancer Discovery (2021)

In the next 10 years, gene-engineered T-cell therapies have the potential to provide broad benefit for the treatment of patients with cancer. Advances in immunology, molecular biology, and bioengineering allow the design of gene-engineered T cells that actively target metastatic lesions, specifically recognize and kill cancer cells, and maintain long-term immunologic memory.
Systolic anterior motion of the mitral valve in the absence of asymmetric septal hypertrophy.
Authors: G SMintz, M NKotler, B LSegal, W RParry
Journal: Circulation (1978)

Asymmetric septal hypertrophy (ASH) is considered the unifying link in the spectrum of hypertrophic cardiomyopathies. ASH and mitral valve systolic anterior motion (SAM) are the two most important echocardiographic criteria for the diagnosis of idiopathic hypertrophic subaortic stenosis (IHSS). Ten patients found have SAM without ASH were studied. Septal thickness, thickening, and excursion were normal. Seven patients had left ventricular ejection times (LVET) measured before and after amyl nitrite inhalation. In six of them, corrected LVET increased by more than 40 msec. Four patients underwent diagnostic cardiac catheterization. Resting or provocable left ventricular outflow tract (LVOT) gradients were demonstrable in all four patients. The echocardiographic features in patients with SAM alone, ASH and SAM, and ASH alone were compared. compared. LVOT measurements in patients with SAM alone (2.2 +/- .4 cm) and ASH and SAM (2.1 +/- .5 cm) were similar and narrower than in patients with ASH alone (2.8 +/- ...
Heterosexual Transmission of HIV
Authors: Stephen E. Godfrey
Journal: JAMA (1992)

<h3>To the Editor.</h3> —The study by Padian et al<sup>1</sup>of female-to-male transmission of human immunodeficiency virus (HIV) unfortunately did not consider specific sexual behavioral practices among the comparative cases of male-to-female transmission, even though examination of associated risk factors was said to be an objective. The only mention of anal intercourse was with regard to the one possible case of female-to-male transmission reported. The reader was left with the inference that all the comparative cases of male-to-female transmission occurred through vaginal intercourse because it was not stated otherwise. However, Dr Padian herself was the lead author in an earlier report<sup>2</sup>in<i>JAMA</i>on male-to-female transmission of HIV in which anal intercourse specifically was considered and was found to discriminate significantly between seronegative and seropositive women to the extent that women who engaged in this practice were 2.3 times more likely to acquire infection than women who did not.
Attenuation of arterial baroreflex control of heart rate by left ventricular receptor stimulation in the conscious dog.
Authors: M JHolmberg, A JGorman, K GCornish, I HZucker
Journal: Circulation Research (1983)

The purpose of this investigation was to determine whether left ventricular receptor stimulation attenuates the arterial baroreflex control of heart rate in the conscious dog and to determine the role of cardiac efferent sympathetic and parasympathetic pathways in any interaction observed. Mean arterial blood pressure-heart rate function curves, which characterized arterial baroreflex control of heart rate, were constructed before (control) and during an infusion of veratrine into the left circumflex coronary artery. Peak sensitivity, the maximum absolute slope along the mean arterial blood pressure-heart rate curve, and heart rate range (maximum minus minimum heart rate) were reduced during intracoronary infusion of veratrine. The mean arterial blood pressure-heart rate relationship also was shifted to a lower pressure during intracoronary infusion of veratrine. In order to study the role of cardiac efferents in this interaction, we constructed mean arterial blood-pressure-heart rate curves during cholin...