bluuebunny/crossref_metadata_2025_split huggingface dataset:
Mechanism of nitroglycerin‐Induced hypoxemia
Authors: Weygandt Glenn R. , Kopman Ercument A. , Ludbrook Philip A. 
Published: March 2007

AbstractWe and others have previously demonstrated a consistent significant decline in arterial oxygen tension (PaO2) after sublingual nitroglycerin in premedicated and unpremedicated patients both with and without coronary artery disease and/or obstructive ventilatory disease. Thus, in our 19 patients, PaO2 fell by an average of 17% (12 mm Hg), mean systemic arterial pressure by 19% (17 mm Hg), pulmonary arterial pressure by 38% (6 mm Hg), pulmonary arterial occlusive pressure by 62% (5.3 mm Hg), and cardiac index by 16% (0.37 liter/min/m2) [P < 0.001 for each] after nitroglycerin. Previous experimental studies suggest that the mechanism for the reduction of PaO2 may be relief of hypoxic pulmonary vasoconstriction with an increase in perfusion to poorly ventilated or nonventilated regions of the lungs. To examine this possibility, pulmonary vasodilatation was precluded by administration of a pulmonary vasoconstrictor (phenylephrine) simultaneously with nitroglycerin in nine patients with coronary artery disease. No significant change was observed in systemic or pulmonary arterial pressure, pulmonary arterial occlusive pressure, or systemic and pulmonary vascular resistance, and PaO2 did not decline. In ten other patients with coronary artery disease, the intrapulmonary right‐to‐left shunt fraction was determined before and after sublingual nitroglycerin; only a minimal increase in shunt fraction of 1.4% was observed, quantitatively insufficient to account for the observed decline in PaO2, thus excluding a predominant effect of nitroglycerin on nonventilated alveoli as a cause of the hypoxemia. We conclude that the reduction of PaO2 after nitroglycerin administration is attributable to pulmonary vasodilatation with a relative increase in perfusion of poorly ventilated lung units.
Internal mammary arteriography: A new catheter technique by right brachial approach
Authors: Singh Ram N. 
Published: March 2007

AbstractA technique for catheterization of both internal mammary arteries (IMAs) by right brachial approach is described. A special preformed catheter was used in 75 patients with coronary artery disease, including ten patients with direct IMA grafts. No complications occurred.The IMAs were studied to examine the question of their usefulness in direct myocardial revascularization. There were individual variations in the size of IMAs with poor correlation to age (r=−0.432) and body surface area (r=0.517). Seventy percent of the women had adequate IMAs. The IMA diameter was equal to or larger than the left anterior descending coronary artery (LAD) in 72% and the right coronary artery (RCA) in 34% of comparisons.Of the ten patients with direct IMA grafts, three instances of large side branches were seen. These branches appeared to carry large flows at the expense of the grafted coronary artery.Preoperative internal mammary arteriography should be done if the use of this vessel is contemplated in direct myocardial revascularization to assure the use of an IMA of adequate caliber compared to the recipient coronary artery. The side branches should be meticulously ligated during the operation.
A simple device to reproduce the spatial orientations of the thorax and transducer for serial M‐mode and two‐dimensional echocardiograms
Authors: Wong Maylene , Shah Pravin M. 
Published: March 2007

AbstractWe have described a device consisting of three circular levels for locating the spatial orientations of the thorax and a transducer that can be used to reproduce the path of the sonic beam through the heart.
Coronary angiography post first myocardial infarction in the asymptomatic or mildly symptomatic patient: Clinical, angiographic, and prospective observations
Authors: Mautner Richard K. , Phillips John H. 
Published: March 2007

AbstractThe role of coronary arteriography In the asymptomatic or mildly symptomatic post first myocardlal infarction patient is controversial. Thirty‐one class 0–1 patients (Canadian Heart Association Grading System) underwent coronary arteriography within six months (mean 67 days) of their first myocardlal Infarction. Coronary arteriography revealed three‐vessel disease in nine (29%), two‐vessel disease in ten (32%), single‐vessel disease in ten (32%), and normal coronary arteries in two (6%). No pattern had left main disease, and two (6%) had teft main equivalent disease. In 12 patients with single‐vessel disease or normal coronary arteries there were no morbid events over a mean follow‐up period of 26 months. In the 19 with multivessel disease, eight (40%) developed a cardiac event during a mean follow‐up period of 11.4 months. These Included one who elected to undergo immediate aortocoronary bypass surgery, two with unstable angina, three acute myocardial infarctions, and two deaths. Based on these date and a review of the literature, a scheme Is proposed for the subsequent evaluation and treatment of this patient group.
Hemodynamic effects of disopyramide at rest and during exercise in normal subjects
Authors: Thadani Udho , Manyari Dante , Gregor Peter , Olowoyeye John , Leach Alan , West Roxroy O. , Parker John O. 
Published: March 2007

AbstractThe hemodynamlc effects of disopyramide phosphate, 2.0 mg/kg body weight, given intravenously over a period of five minutes were studied at rest and during exercise in ten patients without clinical or anglographlc evidence of heart disease.Following disopyramide, the resting cardiac index was lower (4.0 ± 0.6 vs 4.3 ± 0.6 iners/min/m2, mean ± 1 SO, P <0.05), while left ventricular end‐dlastollc pressure (16 ± 4 vs 11 ± 4 mm Hg, P <0.001), pulmonary arterial (PA) mean pressure (20 ± 5 vs 17 ± 5 mm Hg, P <0.05), and brachlal arterial (BA) mean pressure (105 ± 8 vs 96 ± 7 mm Hg, P <0.05) were higher than the pre‐infuslon resting values. During exercise, there was no change in left ventricular end‐diastollc pressure while cardiac index rose from 4.0 ± 0.6 to 6.5 ± 0.6 itters/mln/m2 (P <0.001) and left ventricular stroke work index increased from 62 ± 19 to 84 ± 22 gm/beat/m2 (P <0.001). The normal hemodynamlc response during exercise after disopyramide despite the apparent depression of left ventricular function at rest probably reflects the positive inotroplc effect of enhanced sympathoad‐renergic activity.
Cross‐sectional echocardiographic visualization of abnormal systolic motion of the left ventricle in mitral valve prolapse
Authors: D'Cruz Ivan A. , Shah Shirish , Hirsch Leroy J. , Goldbarg Alberto N. 
Published: March 2007

AbstractIn 11 of 34 patients with typical mitral valve prolapse on the M‐mode echocardlogram, cross‐sectional echocardiography in the apical four‐chamber view revealed a characteristic abnormality not previously described. In mid‐ to late‐systole the ventricular septum contracted vigorously, forming a bend or sharp convexity toward the left ventricle, while motion of the posterolateral basal left ventricle was diminished and delayed. This finding was not encountered In 35 other patients with innocent systolic murmurs, or in 15 patients with mitral regurgitation of etiologies other than mitral valve prolapse. This abnormal pattern of left ventricular contraction on cross‐sectional echocardiography occurred with equal frequency In patients with holoaystollc and late‐systolic prolapse; it was seen more frequently In patients with severe prolapse than In those with mild to moderate prolapse.
Evaluation of thallium‐201 imaging in nontransmural ischemia and infarction
Authors: Haider Bunyad , Oldewurtel Henry A. , Moschos Christos B. , Lee Won K. , Regan Timothy J. 
Published: March 2007

AbstractTo assess the validity of thallium‐201 myocardial imaging in the diagnosis of non‐transmural ischemia and infarction, the proximal left anterior descending coronary artery was partially occluded for 60 minutes with a balloon‐tip catheter in intact anesthetized dogs in a basal state or during atrial pacing. In vivo sclntigrams of myocardium were compared with those obtained in the isolated heart and in the incised ventricle spread flat. None of the animals with partial occlusion wtth or without pacing demonstrated abnormal scintiscans in vivo. Removal of background by isolating the heart increased positive images to 30%; positive images were associated wtth an isotope count ratio between ischemlc and normal muscle of less than 0.67. Removal of superimposed nonischemic muscle in the heart enface increased image detection after pacing to 11 of 15. Since animals with subendocardlal scar failed to demonstrate a “cold area” in vivo, unfavorable geometry as well as extent and degree of ischemia appear to be important Thus, thallium radioactivity in superimposed and adjacent myocardium, as well as background, may limit the detection of nontransmural ischemia and scar.
Cimetidine (Tagamet) combined with steroids and H1 antihistamines for the prevention of serious radiographic contrast material reactions
Authors: Myers Gene E. , Bloom Frederick L. 
Published: March 2007

AbstractCimetidine has recently proved useful in the prophylaxis of certain allergic and other hlstamlne‐medlated reactions [1–6, 25]. We have encountered a patient who had a serious cutaneous and respiratory reaction to Renografln‐76 during cardiac catheterizatlon. For the four days preceding his second catheterizatlon, the patient was treated with prednlsone, 30 mg daily, dlphenhydramlne, 25 mg orally, three times a day, intravenous dlphenhydramlne, 25 mg, three times a day, and Solu‐Cortef, 500 mg, intravenously, every six hours. Despite this preparation, he developed an intense reaction to Renografln‐76, which did not respond to further doses of Solu‐Cortef and dlphenhydramlne in the catheterlzation laboratory. Cimetidine, 300 mg, in 100 ml of D5W over 15 minutes, rapidly reversed the entire cutaneous and respiratory phenomenon.In the future, strong consideration should be given to using Cimetidine, in its intravenous form, as a routine medication in angiographlc laboratories where radio‐graphic contrast materials (ROM) are used. It may be helpful as a pretreatment for recognized RCM reactive patients when catheterlzation Is essential.
Hypercontractile cardiac state mimicking hypertrophic subaortic stenosis
Authors: Erdin Robert A. , Abdulla Abdulla M. , Stefadouros Miltiadis A. 
Published: March 2007

AbstractIdlopathic hypertrophic subaortte stenosis (IHSS) is a disease manifested as a spectrum of various clinical and laboratory findings. We present the case of a patient with classical clinical and hemodynamlc findings of IHSS who lacked all of the typical echocardlographlc features of the disease. The case emphasizes the need for diligent use of bedside physical examination and vasoactlve manipulation of systolic murmurs whenever functional left ventricular outflow tract obstruction is suspected, since it can occasionally be missed by echocardlography.
Preliminary experience with reversal of venoatrial flow in the diagnosis of tricuspid regurgitation
Authors: Midwall Jay , Untereker William , Richard Augusto , Gorlin Richard , Teichholz Louis Evan , Herman Michael V. 
Published: March 2007

AbstractPresent methods of assessing trlcuspld regurgttation are often unreliable. We present preliminary data concerning a new angiographic method for identification of tricuspid regurgttation which evaluates direction of flow of contrast media during right ventricular (RV) systole in the Inferior vena cava (IVC) and hepatic veins following right atrial or IVC angiography.Group I consisted of 15 patients who had tricuspid regurgttation by conventional criteria. AIM 5 patients exhibited reversal of venoatrial flow by right atrial or inferior vena cava angiography. In a control group (group III) of 20 patients who do not have clinical tricuspid regurgttation, one patient demonstrated retrograde flow. Group II consisted of 11 patients wtth mttral valve disease and mild to moderate pulmonary hypertension. All 11 had no conventional evidence of tricuspid regurgttation; however, all 11 had the pathophysiologlc potential for tricuspid regurgttatlon. Five of 11 had reversal of venoatrial flow during RV systole, suggesting the presence of clinically inapparent tricuspidIn conclusion, preliminary data suggest that angiographic reversal of venoatrial flow may be both sensitive and specific for the presence of tricuspid regurgttation. Further investigation wtth comparison to RV angiography and real‐time echocardiography should be performed.
Clinical significance and characteristics of exercise‐induced ventricular tachycardia
Authors: Codini Michele A. , Sommerfeldt Lorraine , Eybel Carl E. , Messer Joseph V. 
Published: March 2007

AbstractForty‐seven patients (0.08%) from a total of 5,730 consecutive patients undergoing treadmill stress tests developed one or more episodes of ventricular tachycardia. Forty patients had heart disease, coronary artery disease being the leading cause. Rest ECG was normal in 12 patients and showed long QT (>440 msec) in 16 patients. Ventricular tachycardia was brief and self‐terminating, requiring D/C cardloverston In only one patient. “Exertional hypotension” preceded ventricular tachycardia In 16 of 34 patients. There was poor correlation (r=0.16) between the rate of ventricular tachycardia (VT) and the underlying heart rate. Only four episodes of VT were Initiated by R on T premature ventricular beats.In summary, exercise‐Induced ventricular tachycardia 1) Is a rare complication of treadmill stress test and occurs In patients with heart disease; 2) is frequently preceded by “exertional hypotension;” and 3) Is not related to the R on T phenomenon. The high incidence of prolonged QT may indicate a role for the autonomic nervous system in its pathogenesis.
Effect of intraarterial injection of heparin on the complications of percutaneous arterial catheterization in infants and children
Authors: Rao P. Syamasundar , Thapar Mohinder K. , Rogers James H. , Strong William B. , Lutcher C. Larry , Nesbit Robert R. , Wray Charles H. 
Published: March 2007

AbstractThrombotto complications of percutaneous arterial Catheterization still remain a significant and serious problem in infants and children. Systemic heparlnlzation has been recommended for prevention of these complications. The purpose of this study was to evaluate the effect of Intraarterial injection of heparin In reducing thrombotic complications following percutaneous femoral artery Catheterization. One hundred sixteen consecutive patients (ages four months to 20 years) studied by the Desllets‐Hoffman modification of Seldlnger's technique of femoral artery Catheterization were randomly allocated to the control or heparin groups using a double‐blind technique. At the completion of the Catheterization, 0.1 ml/kg of placebo or heparin (1,000 units/ml) was injected into the common iliac artery prior to removal of the catheter and sheath. Segmental plethysmography was performed in both lower extremities prior to and after the Catheterization, and a plethysmography index (PI) was calculated.The age and sex distribution, diagnoses, number, type, and site of previous Catheterization, hemoglobin, platelet count, the amount of flush solution and the heparin contained therein, size of the catheter and sheath used, number of arterial punctures, and the length of the time in the artery were similar In the two groups (P > 0.1). Thrombln time and activated partial thromboplastin time were measured prior to the use of flush solution and prior to angtography, and these remained essentially unchanged In the two groups. The PI in the control group (97.5 ± 32) was not significantly different (P > 0.1) from that of the heparin group (97.7 ± 32). Similarly, the six to 24 month postcatheterlzatlon plethysmography data show no differences (P > 0.1). The number of patients with reduced Ipsilateral posterior tlbial and dorsalls pedls pulses was also similar (P > 0.1). None of the patients in either group required thrombectomy. The low incidence of arterial complications in our patients when compared with other studies may be related in part to use of a sheath, which is not called for in original Seldinger technique. The data suggest that full‐dose heparin administration does not significantly alter arterial complications following percutaneous femoral artery catheterization, especially in childern over five years of age.
Treatment of unstable angina pectoris with percutaneous transluminal coronary angioplasty (ptca)
Authors: Meyer Jürgen , Schmitz H. , Erbel R. , Kiesslich T. , Böcker‐Josephs B. , Krebs W. , Braun P. C. , Bardos P. , Minale C. , Messmer B. J. , Effert S. 
Published: March 2007

AbstractPercutaneous transluminal coronary angioplasty (PTCA) was performed in 40 patients (34 male, 6 female; 51.0 ± 8.5 years) with the typical clinical picture of unstable angina. All had a short history of pain (2.9 ± 2.0 months), angina at rest, transient ST and/or T wave changes during this period, and little or no enzyme elevations. The patients had a total of 41 stenoses (39 single, one double; one main‐stem, 26 left anterior descending, 14 right coronary artery). The degree of the stenoses was 95.5 ± 4.9% (area method) and 81.8 ± 10.7% (diameter method). PTCA was successfully performed in 26 cases (63%), reducing the stenoses to 61.5 ± 12.4% (area method) and 39.1 ± 10.0% (diameter method). One patient (2.5%) received an immediate bypass operation because of an acute vessel occlusion. Eleven of the 14 not successfully treated patients received an aortocoronary bypass within the next three to 35 days. All still had symptoms of unstable angina. Three patients refused operation. Their treatment consisted of nitroglycerin, beta‐blockers and nifedipin.Seventeen of the 26 successfully treated patients were restudied after 4.9 ± 1.7 months. The degree of stenosis had risen to 69.2 ± 17.4% (area method). While the stenoses in 12 patients were equal or less than before PTCA, stenosis recurred in five cases. Two patients were successfully retreated.PTCA can be performed with a good early success rate and a low complication rate in patients with unstable angina. Relief of pain and improvement of blood supply to the jeopardized myocardium can be provided immediately and with a limited amount of expense. The method can therefore be regarded as appropriate first‐stage treatment in such patients.
Right ventriculography as a valid method for the diagnosis of tricuspid insufficiency
Authors: Ubago José L. , Figueroa Alvaro , Colman Thierry , Ochoteco Alberto , Rodriguez Miguel , Durán Carlos MG 
Published: March 2007

AbstractThe value of right ventriculography in the diagnosis of tricuspid insufficiency (Tl) is often questioned because of (1) the high incidence of premature ventricular contractions (PVCs) during injection and (2) interference of the catheter in the valve closure mechanism. In 168 patients a commercially available, not preshaped, balloon‐tipped catheter was used for right ventriculography. To avoid the induction of PVCs, the catheter tip was placed in the middle third of the diafragmatic wall of the right ventricle, and the balloon was inflated, becoming trapped by the trabeculae. In this position the catheter's side holes should be located in the inflow chamber. To ensure this correct position, and therefore lack of ectopic beats during angiography, a saline test injection was performed previously in every case. With this technique the incidence of PVCs during ventriculography was only 7.7%. In all but one case, such beats were isolated. The 168 patients were divided into three groups according to their likelihood of experiencing tricuspid interference by the catheter group 1 included 41 patients with a normal heart or with coronary artery disease. No one from this group had Tl. Of group II, 28 patients with right ventricular pressure or volume overload or cardiomyopathy, only 2 had Tl, both with a previous clinical diagnosis of regurgitation. Group III contained 99 patients with rheumatic heart disease. Thirty‐five of them showed angiographic Tl, and 24 of these had this diagnosis confirmed either clinically or at surgery. It is felt that this technique of right ventriculography, with its low incidence of PVCs and slight interference with tricuspid closure, is a valid method for the objective study of the tricuspid valve.
Anomalous origin of the right coronary artery from the left anterior descending: Angiographic diagnosis in a patient with coronary artery disease
Authors: Simkoff William L. , Murphy Edward S. , Demots Henry , Khonsari Siavosh , Abbruzzese Pietro 
Published: March 2007

AbstractThe coronary angiographic findings of an individual whose right coronary artery originates from the proximal left anterior descending coronary artery are described.
Anomalous origin of the left coronary artery from the right pulmonary artery associated with complex congenital heart disease
Authors: Driscoll David J. , Garson Arthur , McNamara Dan G. 
Published: March 2007

AbstractThe rare coexistence of anomalous origin of the left coronary artery from the main pulmonary artery with other cardiac malformations prompts us to report an unusual case of anomalous origin of the left coronary artery from the right pulmonary artery associated with complete atrioventricular canal, patent ductus arteriosus, and coarctation of the aorta. It is important to recognize the presence of an anomalous origin of the left coronary artery in complex congenital heart disease since the coronary artery anomaly will increase the morbidity of the associated congenital cardiac malformation. Conversely, correction of the associated congenital cardiac defect may decrease the pulmonary artery pressure resulting in reduced left coronary artery flow, myocardial ischemia, and death.
Angled views in the evaluation of the right coronary artery
Authors: Gomes Antoinette S. , Esposito Vincent A. , Grollman Julius H. , O'Reilly Ronald J. 
Published: March 2007

AbstractThe use of cranial and caudal angulated views in the angiographic evaluation of the right coronary artery (RCA) was assessed in 61 patients. Each patient had a standard LAO and RAO view, followed by one or more angled views. The standard LAO view showed the area about the origin of the posterior descending artery (PD0) adequately in 33 of 46 patients (72% ), and the mid and distal portions of the posterior descending artery (PDm&d) adequately in 26/46 (56% ). The standard RAO view showed the PD0 adequately in only 17/46 (37% ) and the PDm&d adequately in 41/46 (89% ).With the LAO cranial view, however, the PD0 was seen well in 45/46 (98% ), and PDm&d was seen well in 44/46 (96% ). The RAO angled views, although of more limited utility, also afforded improved visualization of the distal segments of the RCA.We recommend the use of angled views in the evaluation of the right coronary artery, as these views, particularly the LAO cranial view, afford improved visualization of the distal segments of the RCA.