bluuebunny/crossref_metadata_2025_split huggingface dataset:
A previously unrecognized drug interaction between quinidine and digoxin
Authors: Reiffel J. A. , Leahey E. B. , Drusin R. E. , Heissenbuttel R. H. , Lovejoy W. , Bigger J. T. 
Published: October 2013

AbstractFollowing the development of digoxin radioimmunoassay, we noted that serum digoxin concentrations appeared to rise in patients given quinidine. To further evaluate this important possible interaction between digoxin and quinidine, charts from 863 cardiology patients were reviewed. Ninety two patients received both drugs after having been on digoxin alone; 38 were ineligible for the study because of insufficient data and 27 were excluded because of changing renal function and/or concomitant antiarrhythmic drug therapy, leaving 27. Serum digoxin increased in 25 of the 27 study patients (93%) during quinidine therapy; mean serum digoxin rose from 1.4 ng/ml before quinidine to 3.2 ng/ml during quinidine. Anorexia, nausea and/or vomiting developed in 16 patients (59%) during quinidine therapy, but disappeared in all 10 patients in whom digoxin alone was reduced in dose, suggesting that digoxin had a causative role in the appearance of these symptoms although they developed only after quinidine had begun. Three of thirteen patients with only atrial arrhythmias on digoxin prior to quinidine developed new ventricular premature depolarizations (VPD) after starting quinidine; two of these three as well as four patients with prior VPDs developed new ventricular tachycardia, ventricular fibrillation, asystole, or sudden death. When starting quinidine in patients who are taking digoxin, the clinical course, ECG and serum digoxin should be followed closely.
Aneurysm of the left atrial appendage
Authors: van der Hauwaert L. G. , Dumoulin M. , Daenen W. , Stalpaert G. 
Published: October 2013

AbstractA 2‐year old asymptomatic girl is presented in whom the chest x‐ray film led to the discovery of a grossly distorted cardiac shadow. Angiocardiography showed a giant aneurysm originating from the left atrium. At operation an intrapericardial aneurysm of the left atrial appendage, measuring 12 × 4 × 4 cm, was found. It communicated with the left atrium through an orifice measuring 3 cm. The aneurysm was excised.
Atrial bigeminy with block associated with bradycardia and paroxysmal atrial fibrillation — An important variant of the tachycardia‐bradycardia syndrome
Authors: Washington H. G. , Ward D. E. , Camm A. J. , Spurrell R. A. J. 
Published: October 2013

AbstractSerial 2‐channel 24 h dynamic ECGs in 7 patients who were referred with the “tachy‐brady” syndrome for consideration for permanent cardiac pacing revealed:1. atrial premature beats (APBs) which were conducted to the ventricles normally or aberrantly;2. intermittent atrial bigeminy with block towards the ventricles (this rhythm mimicked sinus bradycardia with ventricular rates of 38‐45 beats/min and the ectopic P waves were visible on only one of the ECG channels);3. paroxysms of atrial fibrillation initiated by closely coupled APBs.These findings suggested that both the ventricular bradycardia and the atrial fibrillation were caused by frequent APBs and that pacing therapy was unnecessary. Disopyramide was given to 5 patients resulting in suppression of the arrhythmia and relief of symptoms. In one patient there was spontaneous resolution and one patient refused treatment. This variant of the “tachy‐brady” syndrome can be successfully treated by suppression of abnormal atrial impulse formation without recourse to pacemaker implantation.
The superiority of mitral E point‐ventricular septum separation to other echocardiographic indicators of left ventricular performance
Authors: D'Cruz I. A. , Lalmalani G. G. , Sambasivan V. , Cohen H. C. , Glick G. 
Published: October 2013

AbstractM‐mode echocardiography, angiocardiography, and coronary arteriography were done in 40 patients with coronary heart disease, 12 with congestive cardiomyopathy, and 14 with no detectable cardiac or coronary abnormality. We measured mitral E point‐ventricular septum separation (EPSS) at the moment of the E peak; the previously described method measures EPSS as the vertical distance between the nadir of systolic septal motion and the subsequent mitral E peak. Angiocardiographic ejection fractions correlated better with EPSS (r = 0.83) than with left ventricular (LV) end‐diastolic internal diameter (r = 0.62), LV internal diameter systolic shortening fraction (r = 0.64), LV echocardiographic ejection fraction (r = 0.70), and LV posterior wall systolic thickening (r = 0.58). Patients with angiocardiographic ejection fractions below 55% usually had EPSS values over 10 mm by our method. Six false negatives and one false positive occurred. Our observations in patients with impaired LV performance suggest that LV dilatation, and especially dilatation of the LV outflow tract, is relatively more important than reduction in the amplitude of diastolic anterior mitral excursion in the production of high EPSS values. Although the usual method for measuring EPSS and ours are equally satisfactory, ours has certain theoretical advantages.
Human electropharmacology of the calcium antagonist dimeditiapramine (Ro 11‐1781) in coronary patients
Authors: Cocco G. , Strozzi C. , Chu D. 
Published: October 2013

AbstractThe electrophysiological effect of dimeditiapramine (Ro 11‐1781), a Ca2+ antagonist, was evaluated in 20 patients with coronary heart disease. Electrophysiological measurements, including sinus cycle length, sinoatrial conduction time, intra‐atrial conduction time, atrial, atrioventricular, nodal and ventricular refractory periods and intraventricular conduction time were recorded before and after the intravenous administration of Ro 11‐1781. At a dose which is effective against cardiac arrhythmias, Ro 11‐1781 produced no statistically significant changes in the sinoatrial and intraventricular conduction time. Similarly, neither the sinoatrial nor the ventricular refractory period was affected. Ro 11‐1781, however, increased the atrioventricular conduction time and decreased the systolic blood pressure to a statistically significant extent. The tolerance was very good.
Concealed extrasystoles due to wenckebach conduction delay within the reentry loop
Authors: Kerin N. Z. , Levy M. N. , Goldberg L. B. , Rubenfire M. 
Published: October 2013

AbstractLong electrocardiographic strips were analyzed from an aged patient whose heart rhythm had periods of unifocal ventricular extrasystoles with fixed coupling intervals. Periods of gradual prolongation of the coupling interval finally led to omission of a ventricular premature beat. This sequence was repetitive and is considered to be the result of reentrant extrasystoles with a 3:2 Wenckebach type of conduction delay within the reentry loop. The mechanism of concealed conduction due to overlong propagation within the reentry loop is discussed.
Validity of myocardial oxygen consumption parameters
Authors: Baller D. , Bretschneider H. J. , Hellige G. 
Published: October 2013

AbstractThe purpose of this study was to examine any reported indices for estimating myocardial oxygen consumption (MV̇O2) under uniform experimental conditions at maximal variation of hemodynamics and MV̇O2. One hundred sixty‐two steady states were analyzed in 10 closed‐chest dog experiments. Myocardial blood flow was directly measured by a differential pressure catheter in the coronary sinus. The indirect values of MV̇O2 calculated from 24 indices were compared with directly measured MV̇O2. Throughout a wide range of hemodynamic states, the best correlate with MV̇O2 was found to be the additive parameter Et (r = 0.96). Any indices that do not incorporate potentially important changes of MV̇O2 related to both myocardial contractility and ventricular dimensions show unsatisfactory correlations with MV̇O2 at extreme changes of hemodynamics. Tension‐time index (TTI) correlates poorly with MV̇O2 (r = 0.63). This result is due to the neglect of contractility. Pressure‐heart rate product (P × HR) correlates with MV̇O2 with r = 0.86. Better results for TTI and P × HR, as reported in previous works, are reproducible by dividing our data into two groups of different inotropic states. At normal and moderate inotropic stimulation the correlation for TTI rises to r = 0.96, and for P × HR to r = 0.91. This augmentation is to be referred to the close relationship (r = 0.92) of peak ventricular pressure to maximum rate of pressure rise in this group. The additive parameter Et is the best, both at moderate (r = 0.97) and at maximal inotropic stimulation (r = 0.87), and is to be preferred for indirect estimation of MV̇O2. Results are discussed with regard to the clinical application of MV̇O2 indices.
A comparison of mathematical models for estimating right ventricular volumes in animals and man
Authors: Horn V. , Mullins C. B. , Saffer S. I. , Jones D. C. , Freeborn W. A. , Knapp R. S. , Nixon J. V. 
Published: October 2013

AbstractVolume of 19 right ventricular canine casts and 11 right ventricular human casts were obtained by water displacement and compared to three different mathematical models for estimating right ventricular volumes by biplane cineangiography. In the canine studies, significant linear correlation coefficients were obtained using the longest measured length method (r = 0.92), the triangular modification of Simpson's rule (r = 0.93), and the elliptical modification of Simpson's rule (r = 0.93). The human studies resulted in similar significant correlation coefficients of 0.96, 0.97, and 0.97, respectively. Although the highest correlation with the lowest standard error of estimate was obtained using the triangular model, all three mathematical models produced volume estimations that fell within acceptable biological limits of accuracy.
Predictive value of thallium scintigraphy in coronary artery disease
Authors: Schicha H. , Rentrop P. , Facorro L. , Karsch K. R. , Blanke H. , Kreuzer H. , Emrich D. 
Published: October 2013

AbstractTo verify the predictive value of thallium exercise scintigraphy, 20 normal individuals and 60 patients with coronary artery disease (CAD) were examined, using a quantitative standard technique and receiver operating characteristic analysis. The sensitivity of thallium scintigraphy for the presence of CAD was 97% for patients with previous infarction and 85% for those without infarction. The sensitivity for the extent of CAD was 93% for vessels perfusing infarcted areas and only 67% for vessels without infarction. In patients without myocardial infarction, sensitivity for the number of diseased vessels decreased with increasing extent of CAD. An underestimation of hemodynamically significant stenoses was proven by a comparison with the results of exercise ventriculography.The predictive value of a normal scintigram at a high prevalence of CAD is as low as the predictive value of an abnormal scintigram at a low prevalence level (screening). Thallium scintigraphy is indicated in patients with a medium prevalence of CAD, e.g., in patients with atypical angina and in asymptomatic patients with pathologic ECG.
States of myocardial metabolism related to ischemia
Authors: Kammermeier H. , Giesen J. 
Published: October 2013

AbstractEnergy metabolism of the heart in ischemia is mainly characterized by oxygen deficiency and lack of lactate removal. However, under certain circumstances substrate deficiency might contribute to disturbances of energy supply as well. Capillary permeability was determined from tracer washout kinetics of isolated hearts. Regulation of mitochondrial respiration was estimated from the relationship of phosphorylation potential vs. oxygen consumption. The results obtained suggest that at least under experimental conditions substrate supply at the level of capillary exchange can be a rate‐limiting figure, as well as substrate supply at the mitochondrial level, i.e., NADH supply. The latter was inferred from the effects of cobalt and strontium ions on the regulation of respiration.
Segmental early relaxation phenomenon (SERP) versus exercise‐induced hypokinesia: A correlation study
Authors: Trieb G. , Sigwart U. , Mannebach H. , Gleichmann U. 
Published: October 2013

AbstractSixty‐one of five hundred thirty‐five patients (11%) with‐coronary heart disease (CHD) had a segmental early relaxation phenomenon (SERP). Thirty‐four patients had evidence of previous myocardial infarction (29 inferior and 5 lateral). Only 10 of 137 subjects (7%) with no evidence of CHD had a SERP. The review of coronary angiograms showed a high incidence of SERP in patients with left anterior descending coronary artery stenoses, particularly in the presence of additional high‐grade stenosis of the circumflex branch. Also SERP can be observed frequently in patients with triple‐vessel disease and inferior myocardial infarction. A circumscript SERP of the anterolateral or high septal wall is likely to be associated with ischemia of the corresponding myocardial segment; this hypothesis is supported by hemodynamic and angiographic measurements during exercise.An abnormal increase in left ventricular end‐diastolic pressure (LVEDP), augmentation of left ventricular end‐diastolic volume index (LVEDVI), and decrease in left ventricular ejection fraction (LVEF) with exercise was noted in 33 patients with SERP and normal resting left ventricular angiogram (Fig. 1).There is no adequate hypothesis to explain SERP in subjects without evidence of coronary heart disease. In some instances abnormal increase in LVEDP in the absence of significant coronary artery lesions was seen in these cases. Local metabolic disorders secondary to myocardial disease might be the underlying cause.
Diagnostics of ischemic heart disease: Influence of myocardial ischemia on AMP catabolite release and hemodynamics
Authors: de Jong J. W. , Verdouw P. D. , Remme W. J. , Simoons M. L. , Stam H. 
Published: October 2013

AbstractThe purpose of this study was to answer the questions: What is the correlation between adenosine monophosphate (AMP) breakdown and hemodynamic changes caused by myocardial ischemia? Can AMP catabolites released by the heart be used to diagnose ischemic heart disease?We studied changes in metabolism and hemodynamics in the intact ischemic pig heart and the isolated, perfused rat heart made hypoxic or ischemic. We measured the AMP catabolites adenosine, inosine, and hypoxanthine, which were released by the oxygen‐deprived heart.Inosine is a sensitive (and early) indicator of wall‐thickness changes in the ischemic pig heart. In addition to a change in lactate metabolism, myocardial inosine production is a good marker for myocardial ischemia because it correlates well with carbohydrate extraction and ventricular function, and because these occlusion‐induced changes are relatively large. We tried unsuccessfully to develop a model to study interventions during myocardial ischemia in which the pig served as its own control.
Role of nuclear cardiology in differentiating scar from ischemic myocardium
Authors: Schmidt D. H. , Hellman C. K. , Johnson W. D. 
Published: October 2013

AbstractFor 10 years, patients with abnormal ventricular function (sometimes with ejection fractions under 10%) have generally been offered surgery. Significant improvement in ejection fraction, or in wall motion in a specific segment, has often been observed postoperatively. In the past, simple and effective means to differentiate preoperatively which areas will improve (ischemic myocardium) from those which will not (scar tissue) have not been available. Several radionuclide techniques have been used to study the problems, including use of radio‐labeled particles, 201thallium, 133xenon, and first‐pass radionuclide angiography with and without nitroglycerin intervention. Only the last technique has proven reliable in predicting postoperative improvement in wall motion.Thirty patients have been studied with routine catheterization and first‐pass radionuclide angiography and all had significant wall motion abnormalities preoperatively. Preoperative radionuclide angiograms with nitroglycerin have been compared with postoperative radionuclide angiograms. The images of the RAO radionuclide angiogram were divided into six segments for analysis of wall motion by trisecting the long axis of the left ventricle. Results show that nitroglycerin accurately predicts improvement in ejection fraction with surgery. In terms of wall motion, approximately 50% of akinetic segments improve and 65% of hypokinetic segments improve both with nitroglycerin and revascularization.To summarize, nitroglycerin predicts wall motion improvement with 80% sensitivity and 90% specificity. These data suggest that nitroglycerin radionuclide angiography is a safe, noninvasive technique for differentiating ischemic viable muscle from scar tissue.
Ten‐year experience of 359 epicardial pacemaker systems: Complications and results
Authors: Oldershaw P. J. , Sutton M.G. , Ward D. , Jones S. , Miller H. 
Published: October 2013

AbstractIn the last ten years (1970–1980) 457 patients underwent permanent pacemaker insertion in the Brompton Hospital. Our practice has been somewhat atypical in that the majority of these patients had epicardial leads, initially using a Cordis intramural sutured electrode (85 patients), and subsequently a Medtronic sutureless electrode (274 patients). Our initial experience with these electrodes was satisfactory, but more recently it has become apparent that the long‐term morbidity and complication rate is high. The respective complication rates being 25% and 18% for sutured and sutureless epicardial electrodes. In this study, lead complications were defined as those requiring lead replacement, and problems most commonly encountered were high voltage threshold, infection, and lead fracture. Unless there are specific indications for epicardial pacing it is now our policy to treat patients requiring permanent pacing with endocardial systems. Our complication rate with this technique (90 patients) is significantly lower (9%).
Myopotential inhibition of ventricular synchronous pacemaker
Authors: Lazar A. V. , Massumi A. , Hall R. J. 
Published: October 2013

AbstractUnlike ventricular inhibited demand pacemakers, myopotential inhibition of ventricular synchronous pacemaker is a less well recognized phenomenon. We describe a case of slowing of the pacing rate of an Intermedics Cyberlith pulse generator in the R‐synchronous mode, below the programmed rate from myopotential inhibition.
The cardiac fibrous skeletal ring model: Simple, inexpensive method to illustrate normal and abnormal cardiac anatomy three dimensionally
Authors: Chun P. K. C. 
Published: October 2013

AbstractA novel, innovative, simple, and inexpensive graphic method is proposed to facilitate illustrating the variety of cardiovascular pathology. Six‐ring plastic container holders, resected selectively, or circles carefully drawn to represent the cardiac fibrous skeleton, enable visualization of the cardiac pathology three‐dimensionally without notations. Given 9 axioms, this systematic technique is easy to learn and teach, enabling a nonartistic neophyte to understand complex, cardiac anatomic perspectives and diagram specific cardiac anomalies.
Left ventricular emptying dynamics in patients with asymmetric septal hypertrophy and concentric hypertrophic cardiomyopathy
Authors: Peters J. , Bhargava V. , Johnson A. , Mangiardi L. , Slutsky R. 
Published: October 2013

AbstractWe studied the dynamics of left ventricular (LV) emptying in 8 patients with asymmetric septal hypertrophy (ASH), 6 patients with concentric hypertrophic cardiomyopathy (CHC), and 6 normal controls. Four patients with ASH had resting systolic gradients >20 mmHg, all had significant post premature ventricular contraction (PVC) systolic pressure gradients. LV volume (V) was obtained by frame‐by‐frame analysis of cineangiograms. End‐diastolic volume was similar for all groups; end‐systolic volume was significantly less in ASH and CHC patients than in normals. Maximum dV/dt was similar in ASH and CHC, and significantly greater than normals. Total systolic contraction time (SCT), i.e., time from peak volume to last cine frame at minimum volume, was similar for all groups, but the time required to eject 90% of stroke volume (90%T), as a fraction of SCT, was shorter for ASH (0.52±0.07) and CHC patients (0.51 ±0.05) than normals (0.67±0.07) (p < 0.05 vs myopathy groups). In the sinus beat following a PVC, however, this ratio decreased significantly in normals and CHC patients, but did not change in ASH patients. We conclude that ASH and CHC have similar exaggerated systolic LV ejection dynamics in the basal state; the failure of ASH patients with post‐PVC systolic outflow gradient to reduce 90% T/SCT post PVC may reflect obstruction to LV emptying.
Chromatin changes of endothelial cells in umbilical arteries in smokers
Authors: Asmussen I. 
Published: October 2013

AbstractFine granular spots within the nucleus of endothelial cells have been demonstrated in umbilical arteries from newborns. These nuclear changes were predominantly found in vessels from newborns delivered by heavy smoking mothers (≥ 10 cigarettes per day) χ2 = 8.28, p < 0.005. Similar nuclear changes have until now only been reported in man in relation to tumors or other pathological conditions. The vessels showed signs of increased cellular turnover compatible with the findings in experimental atherosclerosis. The nuclear changes thus could be interpreted as an alteration of nuclear activity.
The relationship of low voltage on the electrocardiogram and chronic obstructive pulmonary disease
Authors: Sorbello A. , Giudice J. C. , Papa L.A. 
Published: October 2013

AbstractA retrospective analysis was performed to analyze the relationship between low voltage on the electrocardiogram and chronic obstructive pulmonary disease. Subjects were 250 patients who had both pulmonary function tests and an electrocardiogram at UMDNJ‐John F. Kennedy Memorial Hospital from the years 1975–1980. Low voltage was detected in only 13 of 250 patients. An attempt to define the relationship between the incidence of low voltage on the electrocardiogram and the severity of airway obstruction, as judged by the reduction in the FEV1, was unsuccessful. Concomitantly, a relationship could not be established between the incidence of low voltage and the degree of hyperinflation, as judged by the residual volume. In conclusion, the electrocardiographic evidence of low voltage does not represent either a sensitive or a specific finding for patients with chronic obstructive lung disease. It cannot be construed as either a useful or predictive parameter in the diagnostic evaluation of these patients.
Temperature Dependence of the Properties of Water and Its Solutes, Including the Supercooled Region
Authors: Sluyters Jan H. , Sluyters‐Rehbach Margaretha 
Published: October 2013

AbstractAn earlier study on the properties of supercooled water and some solutes obtained by simple graphical extrapolation of data available in the literature, determined above the freezing point, led to the hypothesis that water could have a temperature of structural arrest at t0=−30 °C for H2O and −22 °C for D2O. From the present investigation of many more properties of a widely varied nature, this discovery is confirmed throughout. The method is compared with the classical logarithmic Arrhenius and van′t Hoff methods that predict t0 always to occur at 0 K, and with the more recently used power law dependence method. With the latter, extrapolated plots intersect the temperature axis at or near to a value of ts=−45 °C, that is, systematically more negative than t0. It is argued that this ts value, which is the so‐called singularity temperature, is likely to be an artefact. It is suggested that, instead of using modified van ’t Hoff or Arrhenius relationships to describe temperature dependences in the full temperature range, polynomials in (t−t0) should be used.