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Long-term successful coronary artery angioplasty in polycythemia vera
No full textIn a 65-year-old man with Polycythemia Vera, invalidating angina pectoris was associated with severe narrowing of the right coronary artery. After percutaneous coronary angioplasty (PTCA) the patient became symptom free and remained so for 12 months, while receiving an antiplatelet agent, a calcium antagonist and nitrate. Coronary angiography repeated after a year, because of reappearance of angina, documented good patency of the treated artery and some progression of a narrowing involving another coronary vessel. This is the first reported case of long-term success of PTCA in Polycythemia Vera, a disease exposed to a high risk of thrombosis and, possibly, of restenosis. It is undefined whether medical treatment contributed to the anatomical and clinical results. As far as a single case can say, Polycythemia Vera might not represent a prohibitive background for coronary PTCA
Ineffectiveness of angiotensin converting enzyme inhibition (enalapril) on overt and silent myocardial ischemia in vasospastic angina and comparison with verapamil
No full textDoppler assessment of left ventricular filling pattern in silent ischemia in patients with Prinzmetal's angina
No full textSpontaneous angina is an ideal condition in which to study left ventricular (LV) dysfunction induced by acute myocardial ischemia. In 6 patients with Prinzmetal's angina, LV diastolic function during 16 episodes of spontaneous angina was studied by simultaneous recordings of electrocardiographic (ECG), echocardiographic and hemodynamic parameters. In particular, pulsed Doppler echocardiography measured peak velocity of early (E) and late (A) transmitral flow and E/A ratio, as indexes of relative early versus late LV filling. During the ischemic attacks, the time sequence of pulsed Doppler echocardiographic and ECG changes showed 3 distinct phases: (1) "waxing phase: transmitral flow changes with minimal ECG modifications (E/A = 0.85 +/- 0.1); (2) "steady" phase: maximal ECG changes (E/A = 0.9 +/- 0.1); and (3) "waning" phase: regression of the ECG changes (E/A = 1.26 +/- 0.15). In each phase, E/A ratio showed a significant difference from the baseline value (E/A = 1.17 +/- 0.2) as a result of changes in E, suggesting that myocardial ischemia affects mainly the early phase of diastole. In the waxing phase, LV diastolic dysfunction preceded systolic abnormalities, as documented by a significant reduction of E/A ratio in the absence of alterations in LV ejection fraction, as well as in systemic arterial and pulmonary wedge pressures. Finally, all the recorded parameters were consistent with LV "contractile rebound" occurring in the waning phase and affecting both diastole and systole
Coronary vasomotor and therapeutic influences of propranolol and nifedipine on the spontaneous component of mixed angina
No full textIn 24 patients with spontaneous and effort-related angina (mixed angina), propranolol (80 mg q.i.d.) was significantly more beneficial than nifedipine (20 mg q.i.d.) on the number, duration and severity of the spontaneous manifestations. In some cases nifedipine elicited a paradoxical response. These patterns are unlikely to have resulted from different influences on the myocardial oxygen demands, since heart rate was steady before the occurrence of ischaemia and systemic arterial pressure was equally reduced in all patients. Sublingual nifedipine (10 mg) was tested in 12 patients and the residual lumen diameter of significant (greater than 50%) coronary stenoses (quantitative angiography) was unchanged in one, enhanced in seven and reduced in four of them. Lumen variations ranged from +1.59 to -1.2 mm and correlated closely with the results of oral nifedipine treatment. Propranolol (0.1 mg kg-1 i.v.) was tested in the other 12 cases and in none did variations of stenosis lumen diameter exceed 0.3 mm. These observations indicate that: in a number of lesions a portion of pliable wall may offer a compliant substrate for vasomotor influences; this may be the major factor whereby coronary obstructions cause spontaneous, besides effort-related angina; nifedipine is effective on the former manifestation provided that it does not promote stenosis constriction; propranolol may result in benefit through bradycardia facilitating coronary flow in diastole and reducing the baseline metabolic demands, to elevate the threshold of ischaemia during transient impedance to flow
Comparison of nifedipine, propranolol and isosorbide dinitrate on angiographic progression and regression of coronary arterial narrowings in angina pectoris
No full textCalcium antagonists and beta blockers may retard or inhibit atherogenesis. This study investigated whether nifedipine or propranolol influences coronary atherosclerosis in humans. In selected patients with effort angina and proven coronary artery disease, the cineangiographic pattern after 2-year therapy with nifedipine (group 1, 39 patients), propranolol (group 2, 36 patients) or isosorbide dinitrate (group 3, 38 patients) was compared to that before treatment. The disease evolved to a different extent in the 3 groups. Patients with evidence of progression of old narrowings and appearance of new narrowings were significantly fewer in group 1 (31% and 10%) than in group 2 (53% and 34%) and group 3 (47% and 29%). The number of stenoses with evidence of progression was significantly smaller after nifedipine (14), and larger after propranolol (39) compared with group 3 (24). Thus, nifedipine seemed more protective than the other 2 drugs against coronary atherosclerosis. The coronary risk factors were normal in the nifedipine group and remained so with treatment, suggesting that they were dissociated from influences on atherosclerosis. The evolution, as judged by the number of narrowings with progression, appeared significantly (p less than 0.01) worse with propranolol than with isosorbide dinitrate. Propranolol caused unfavorable modifications of serum lipids; there was a 28% increase in total triglycerides and a 25% decrease in high density lipoprotein cholesterol at 12 months in group 2
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
[Greater efficacy of propranolol versus nifedipine in angina with 2 components, that results in varying influence on coronary vasomotility]
No full textIn 24 patients with stable spontaneous and effort-related angina, ischemic episodes at rest were not preceded by changes in circulatory variables (heart rate, systemic and pulmonary arterial pressures) that may raise myocardial oxygen consumption. We interpreted these episodes as caused by critical and reversible coronary flow reduction at the site of a stenotic lesion, and evaluated the clinical efficacy of nifedipine and propranolol in the treatment of this condition. Propranolol fully abolished or reduced the number of spontaneous ischemic episodes in a significantly larger number of patients than did nifedipine; it was also effective in several cases in whom nifedipine had failed or had even caused a paradoxic effect. Quantitative angiographic evaluation of the influence of nifedipine (Group 1, 12 patients, 10 mg sublingually) and propranolol (Group 2, 12 patients, 0.1 mg/kg intravenously) on the residual lumen diameter of 1 significant coronary stenosis in each patient showed that after nifedipine, the lumen was unchanged in 1, augmented in 7, and reduced in 4 cases; variations ranged between +1.59 and -1.2 mm, and their direction correlated closely with the influence of oral nifedipine on the episodes of spontaneous ischemia; and in no case did treatment with propranolol vary the stenosis lumen by more than 0.3mm. In this form of angina, a number of lesions seem to offer a compliant substrate for vasomotion and, possibly, for critical changes in flow. The vasomotor influences of nifedipine on these lesions are variable as well as the efficacy of the drug on the manifestations of ischemia at rest.(ABSTRACT TRUNCATED AT 250 WORDS
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