Zatebradine and exercise tolerance.
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Angina Pectoris↗
Biomedical subjects
H Boudoulas
Publications and source records attributed to H Boudoulas.
Effect of quinapril or metoprolol on heart rate variability in post-myocardial infarction patients.
The effect of quinapril or metoprolol on heart rate variability (HRV) indexes was studied in patients who had recovered from acute myocardial infarction. Patients with stable coronary artery disease and normal volunteers were used as controls. Sixty patients with uncomplicated myocardial infarction (aged 32 to 74 years [mean 56.7]) were randomized to quinapril (n = 25), metoprolol (n = 25), and placebo (n = 10). HRV was assessed 5 days (baseline) and 35 days after the onset of acute myocardial infarction. After the baseline studies, the post-myocardial infarction patients were treated with metoprolol (50 to 100 mg/day), quinapril (5 to 10 mg/day), or placebo. Twenty patients with stable coronary artery disease and 20 healthy volunteers, age- and sex-matched to myocardial infarction patients, were used as controls. Compared with placebo, quinapril and metoprolol increased HRV indexes significantly 35 days after the onset of myocardial infarction. HRV indexes were not statistically different between the 2 treatment groups. At baseline and after therapy, HRV was similar in patients with anterior or inferior wall myocardial infarction. HRV 35 days after the onset of myocardial infarction was not different from HRV in patients with stable coronary artery disease, but was decreased when compared with that in normal volunteers. Data suggest that quinapril has the same beneficial effect on HRV indexes as metoprolol in patients who have recovered from uncomplicated acute myocardial infarction.
Adrenergic beta-Antagonists↗
Comparison of thickness and distensibility in the carotid artery and descending thoracic aorta: in vivo ultrasound assessment.
Early atherosclerotic changes in the carotid artery and thoracic aorta have been examined by high-frequency ultrasound measuring of intimal-medial thickness and stiffness. Whether changes in stiffness and thickness occur in parallel and whether the determinants of stiffness and thickness in the two vessels are similar is unknown. To examine the relation between ultrasonographic measures of atherosclerosis in the carotid and the thoracic aorta, 146 patients aged 20 to 84 years (mean 54 years) were studied by both transesophageal echocardiography (TEE) and carotid duplex scanning. From two-dimensionally derived M-mode recordings of the thoracic aorta and high-frequency B-mode imaging of the common carotid, the intimal-medial thickness was measured along with diastolic and systolic diameters for calculation of stiffness. Interobserver and intraobserver variability of carotid and aortic intimal-medial thickness and diameter were low. There was a good relation between carotid and aortic intimal-medial thickness (r = 0.69; p=0.0001). Age was the major independent determinant of thickness in both vessels. Carotid and aortic stiffness, as measured by Peterson's elastic modulus, were less closely related (r=0.51; p=0.0001). Age was the only independent predictor of stiffness in both vessels. In conclusion, structural ultrasonographic manifestations of early atherosclerosis in the carotid artery and thoracic aorta are closely related. Large population studies measuring only carotid intimal-medial two-thickness may reflect atherosclerotic changes occurring throughout the vascular bed.
Adult↗
Spectrum of structural abnormalities in floppy mitral valve echocardiographic evaluation.
Posterior displacement of the mitral valve with billowing into the left atrium has been the major echocardiographic criterion used for the diagnosis of mitral valve prolapse (MVP). However, the current criteria are limited by the influence of hemodynamic factors on the degree of prolapse, whereas complications such as mitral regurgitation, endocarditis, and need for surgery have been associated with redundancy or thickening of the leaflets. Sixty-eight normal subjects (mean age, 40 years; range, 18 to 76 years) were compared with 58 patients with MVP (mean age, 37 years, range, 18 to 83 years). Leaflet displacement across the annular plane in the parasternal long-axis view was mandatory for the diagnosis of MVP. Transthoracic echocardiographic measurements of anterior and posterior leaflet thickness, leaflet length, and chordal length were made from the parasternal long-axis view and the mitral annular diameter, from the apical four-chamber and two-chamber views. The MVP group had greater anterior thickness (4.1 +/- 0.4 mm vs 5.3 +/- 0.7 mm; p = 0.0001), posterior thickness (3.2 +/- 0.4 mm vs 4.7 +/- 0.9 mm; p = 0.0001), anterior length (22.8 +/- 2.0 mm vs 25.7 +/- 1.7 mm; p = 0.0001), posterior length (12.8 +/- 1.0 mm vs 15.7 +/- 2.5 mm; p = 0.0001), chordal length (25.6 +/- 2.7 mm vs 28.0 +/- 2.5 mm; p = 0.0001), and annular diameter (29.1 +/- 1.5 mm vs 31.3 +/- 2.6 mm; p = 0.0001). Of the MVP group, >80% had at least one abnormality identified and >50% had at least two abnormalities. In addition, patients with MVP with significant regurgitation had greater anterior thickness (5.2 +/- 0.7 mm vs 5.8 +/- 0.8 mm; p = 0.015), posterior thickness (4.5 +/- 0.9 mm vs 5.3 +/- 0.7 mm; p = 0.024), posterior length (15.1 +/- 1.6 mm vs 17.9 +/- 4.2 mm; p = 0.004), and annular diameter (36.0 +/- 2.0 mm vs 33.3 +/- 2.1 mm; p = 0.0001). The majority of patients with floppy mitral valves resulting in MVP have structural abnormalities that may be defined by echocardiography. A spectrum of floppy valve structure is demonstrated by echocardiography, with mitral regurgitation occurring more frequently in patients with multiple and more severe anatomic abnormalities. In addition to the presence of prolapse and regurgitation, the assessment of leaflet thickness, leaflet length, annular diameter, and chordal length is fundamental to the definition and stratification of patients with MVP associated with the floppy mitral valve.
Adolescent↗
Effects of simvastatin and ciprofibrate alone and in combination on lipid profile, plasma fibrinogen and low density lipoprotein particle structure and distribution in patients with familial combined hyperlipidaemia and coronary artery disease.
BACKGROUND: Hypolipidaemic agents do not usually normalize all of the multiple lipoprotein abnormalities in patients with familial combined hyperlipidaemia (FCHL). The effect of the simvastatin-ciprofibrate combination in comparison with each drug alone on the lipoprotein abnormality patterns was studied in patients with FCHL and coronary artery disease (CAD). METHODS: Sixty patients (53 men and seven women), mean age 52 years (range 36-60 years), were studied. After a 4-week placebo period, patients were randomly assigned to three groups. The first group (n = 20) received simvastatin (20 mg daily), the second group (n = 20) ciprofibrate (100 mg daily) and the third group (n = 20) the combination of both drugs for a 12-week period. Parameters measured were as follows: plasma fibrinogen, total cholesterol, triglycerides, low density lipoprotein (LDL), very low density lipoprotein, intermediate density lipoprotein, and high density lipoprotein cholesterol, as well as LDL subfraction distribution and structure by density gradient ultracentrifugation. Apoproteins (apo) B and AI were assessed by immunoturbidometry. RESULTS: At baseline, apoB, LDL cholesterol and triglycerides were increased, whereas LDL particles were small and dense. ApoB was significantly reduced by all three interventions. Drug combination and ciprofibrate significantly reduced plasma fibrinogen (-24 and -25%, respectively; P < 0.001) and triglycerides (-51 and -49%, respectively; P < 0.001). Drug combination and simvastatin significantly reduced LDL cholesterol (-25 and -22%, respectively; P < 0.001) compared with ciprofibrate (-10%; P < 0.01). Ciprofibrate and drug combination increased LDL particle size (parameter K -0.24 versus -0.61 and -0.30 versus -0.62, respectively; P < 0.001), whereas simvastatin had no significant effect on LDL particle size. The cholesterol content of LDL particles was reduced with ciprofibrate and the drug combination only in the dense LDL particles (LDL3-5) and increased in the light (LDL1-2) subfractions, whereas simvastatin reduced the cholesterol content of all LDL subfractions except LDL2. Ciprofibrate and drug combination reduced the triglyceride content of all LDL subfractions. CONCLUSION: Combined treatment with simvastatin and ciprofibrate effectively reduced plasma fibrinogen, triglycerides, total and LDL cholesterol and increased LDL particle size in patients with FCHL and CAD. These effects might induce a clinical benefit for these patients.
Adult↗
Left atrial dysfunction after orthotopic heart transplantation.
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Atrial Function, Left↗
Frequency of HLA antigens in Graves' hyperthyroidism and mitral valve prolapse.
BACKGROUND AND AIMS OF THE STUDY: An association between Graves' hyperthyroidism (G) and mitral valve prolapse (MVP) has been reported, but possible genetic linkage between the two disorders has not. METHODS: One hundred and five patients (pts) with G were studied after therapy, in a euthyroid state. MVP (auscultatory plus echocardiographic findings) was present in 33 pts (31%). Frequency of human lymphocyte antigens (HLA) in pts with G and in pts with G plus MVP was compared to 170 normal subjects (NL). There was no difference in HLA-A antigens among the three groups. RESULTS: The frequency of HLA B-15 was greater in pts with G plus MVP (18.9%) compared to NL (3%) and to G without MVP (4.2), p < 0.01. The frequency of HLA-B39 was greater in G without MVP (13.8%) compared to NL (4.1%), p < 0.01. The HLA DRB1*1601-2 was more frequent in G with (30.3%) or without (29.2%) MVP compared to NL (13.5%), p < 0.01. The frequency of HLA DRB1*1401-10 and DQA1*0104 were greater in NL (16.5%) compared to G with (3.0%) or without (4.2%) MVP, p < 0.01. CONCLUSIONS: The data confirmed previous observations that the frequency of MVP is high in pts with G. Further, the data indicated a possible genetic linkage between the two abnormalities.
Adolescent↗
Pressure-diameter relation of the human aorta. A new method of determination by the application of a special ultrasonic dimension catheter.
BACKGROUND: Pressure-diameter relation of the aorta provides important information about the elastic properties of the vessel. However, owing to methodological limitations, data regarding this relation are limited in conscious humans. In the present study, we assessed a new method for the direct estimation of the elastic properties of the aorta in conscious humans by simultaneous acquisition of instantaneous aortic pressure and diameter. METHODS AND RESULTS: With this method, instantaneous diameter of the thoracic aorta was acquired by a newly designed intravascular catheter developed in our institution that incorporates an ultrasonic displacement meter at its distal end. Instantaneous aortic pressure was acquired simultaneously at the same aortic level with a catheter-tip micromanometer. Aortic pressure-diameter loops were derived from computer analysis of data. After in vitro and animal testing, elastic properties of the aorta were investigated in coronary artery disease (CAD) patients (n = 15) and compared with those of control subjects (n = 10). Aortic distensibility was less in the CAD group than in the control group (1.73 +/- 0.33 versus 3.95 +/- 1.09 x 10(-6) x cm2 x dyne-1, P < .001). Compared with control subjects, the mean value of the slope of the pressure-diameter loops was significantly greater in the CAD group (38.89 +/- 8.75 versus 19.62 +/- 5.46 mm Hg.mm-1, P < .001), whereas the mean value of the intercept was lower in this latter group of patients (-785.60 +/- 177.55 versus -313.43 +/- 126.41 mm Hg, P < .001). An excellent correlation was found between the slope of pressure-diameter loop and age in the group of control subjects (r = .827). Ninety-three percent of the patients with CAD had values above the upper 95% confidence limits of the control subjects (P < .001). In a third group of patients (n = 16) in whom assessment of pulse wave velocity was also included in the study of the elastic properties of the aorta, pulse wave velocity had a strong inverse correlation with aortic distensibility (r = -.95) and a strong positive correlation with the slope of the pressure-diameter loop (r = .97). CONCLUSIONS: This new method of determination of pressure-diameter of the aorta enables an accurate and reliable evaluation of the elastic properties of the aorta in conscious humans and may be useful for a profound study of human aorta mechanics.
Animals↗
Effect of vasa vasorum flow on structure and function of the aorta in experimental animals.
BACKGROUND: It is known that vasa vasorum flow contributes substantially to the nutrition of the outer layers of the thoracic aorta. This investigation was undertaken to test the hypothesis that impairment of vasa vasorum flow would alter the structure of the aortic wall and change the elastic properties of the aorta. METHODS AND RESULTS: The periaortic fat that contain the vasa vasorum for the ascending aorta was removed in seven anesthetized dogs, and the results were compared with those obtained from six weight-matched sham-operated control dogs. Aortic pressures, aortic diameters, and aortic distensibility were obtained before and 30 minutes and 15 days after removal of the periaortic vasa vasorum network. Aortic pressures were measured directly with a fluid-filled catheter. Aortic diameters were measured simultaneously with aortic pressures with an elastic, air-filled ring connected to a transducer. Aortic distensibility was calculated by the formula 2 x pulsatile change in aortic diameter/(diastolic aortic diameter x pulse pressure). Histology was performed in transverse blocks of aortic wall at the end of the experiment in both groups. The efficacy of the technique for the interruption of vasa vasorum blood supply to the aortic wall was demonstrated by histology in four additional animals that were killed without removal of vasa vasorum (two animals) and immediately after vasa vasorum removal (two animals). At baseline, heart rate, aortic pressures, aortic diameters, and aortic distensibility were similar in the two groups. A significant decrease in aortic distensibility was observed 30 minutes and 15 days after removal of the vasa vasorum in the experimental group (baseline, 3.453 +/- 1.023; 30 minutes, 2.521 +/- 0.760; 15 days, 1.586 +/- 0.488 10(-6).cm2.dyn-1; F = 9.532, P < .001). No changes were observed in aortic distensibility in the control group during the experiment. Histology of the aorta revealed medial necrosis, alterations of the elastin fibers, and a trend (P = .055) for altered collagen-to-elastin ratio in a region occupying more than the one (outer) half of the media of the experimental group animals. No changes were observed in the control group. CONCLUSIONS: The findings of the present study demonstrated that interruption of vasa vasorum flow led to an acute decrease in the distensibility of the ascending aorta. Moreover, structural changes of the aortic wall and further deterioration of the elastic properties of the aorta occurred 15 days after vasa vasorum removal.
Animals↗
Coronary artery fistulas in adults: incidence, angiographic characteristics, natural history.
The incidence, angiographic characteristics, and natural history of coronary artery fistulas in patients undergoing diagnostic cardiac catheterization have not been well defined. Of 33,600 patients who had diagnostic cardiac catheterization, 34 (0.1%) had coronary artery fistula. Nineteen fistulas originated from the right, 11 from the left anterior descending, and 4 from the circumflex coronary arteries, respectively. The mean ratio of pulmonary to systemic flow was 1.19 +/- 0.33. Only one patient with coexistent atrial septal defect had a pulmonic to systemic flow ratio > 1.5. Right and left heart pressures, with the exception of three patients in whom left ventricular end-diastolic pressures was > 12 mm Hg, were within normal limits. During a mean follow-up period of 6.3 years (range 2-14 years), there were no complications related to coronary artery fistula. It was concluded that the incidence of coronary artery fistulas detected during diagnostic coronary angiography is very low. Coronary artery fistulas originate predominantly from the right coronary artery and are not associated with hemodynamic abnormalities or other congenital heart diseases. The prognosis of coronary artery fistulas in adults is good.
Adult↗
Left atrial volumes and function in orthotopic cardiac transplantation.
Early ventricular filling and therefore passive left atrial emptying may be impaired in patients with cardiac transplantation. As a result, left atrial function may be an important factor in maintaining stroke volume in recipients of orthotopic cardiac transplants. Left atrial volumes maximal (mitral valve opening), minimal (mitral valve closure), and onset of atrial systole (P wave on electrocardiogram) were determined by echocardiography using the biplane area-length method in 12 patients after cardiac transplantation and 12 control subjects. Maximal and minimal left atrial volumes and left atrial volumes at onset of atrial systole were larger in patients who had cardiac transplantation than in control subjects (89.8 vs 41.8 cm3, 48 vs 15.2 cm3, and 70.4 vs 27.0 cm3, respectively; p < 0.01). In patients undergoing cardiac transplantation, good correlations were found between left atrial maximal volume and left ventricular mass (r = 0.56) and between left atrial maximal volume and mean pulmonary capillary wedge pressure (r = 0.81). Left atrial passive emptying volume (maximal minus volume at P wave), was not statistically different between the two groups (19.3 in patients receiving transplants vs 14.7 cm3 in control subjects), but left atrial stroke volume (beginning atrial systole to minimal) was larger in patients receiving transplants than in control subjects (22.4 vs 11.8 cm3, respectively; p < 0.001). Thus left atrial contraction contributed 42% to the left ventricular stroke volume in patients who had cardiac transplantation but only 17% in control subjects (p < 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
Atrial Function, Left↗
Exercise-induced QRS changes (Athens QRS score) in patients with coronary artery disease: a marker of myocardial ischemia.
Previous studies have shown a good correlation between exercise-induced changes of Q-, R-, and S-waves (Athens QRS score) and the number of the obstructed coronary arteries. The present study was undertaken to test the hypothesis that abnormal Athens QRS score is related to exercise-induced myocardial ischemia. Patients who had exercise radionuclide ventriculography (n = 150) or thallium-201 scintigraphy (n = 124) within 1 month of cardiac catheterization were studied. Athens QRS score was calculated based on the exercise-induced changes of the Q-, R-, and S-waves. Changes in Athens QRS score were compared to the number of obstructed coronary arteries, segmental contraction abnormalities, and exercise-induced myocardial perfusion defects. Athens QRS score and coronary artery disease: The Athens QRS score was decreased as the number of obstructed coronary arteries increased (normal coronary arteries 3.7 mm, confidence interval 1.0 to 3.9, one vessel disease 1.2 mm, two vessel disease -0.6 mm, three vessel disease -1.3 mm, p < 0.001). Athens QRS score and segmental contraction abnormalities: The Athens QRS score decreased as the number of segmental contraction abnormalities increased (no segmental contraction abnormalities 2.5 mm, confidence interval 1.0 to 3.9, one segmental contraction abnormality -0.4 mm, two segmental contraction abnormalities -1.5 mm, three segmental contraction abnormalities -2.6 mm, p < 0.001). Athens QRS score and reversible myocardial perfusion defects: The Athens QRS score was decreased as the number of exercise-induced myocardial perfusion defects increased (no perfusion defect 2.4 mm, confidence interval 0.9 to 3.9, one perfusion defect -0.7 mm, two perfusion defects -2.6 mm, three perfusion defects -3.3 mm, p < 0.001). Abnormal values of the Athens QRS score were better correlated with the number of exercise-induced segmental contraction abnormalities or the myocardial perfusion defects than the number of obstructed coronary arteries (p < 0.001). Exercise-induced changes in Athens QRS score were directly related to the number of obstructed coronary arteries, to exercise-induced segmental contraction abnormalities and to exercise-induced myocardial perfusion defects. However, Athens QRS score changes were more closely related to the number of exercise-induced segmental contraction abnormalities or to the exercise-induced myocardial perfusion defects than to the number of obstructed coronary arteries. The data suggest that exercise-induced QRS changes, Athens QRS score are related to exercise-induced myocardial ischemia.
Coronary Angiography↗
Left atrial performance indices in chronic mitral valve disease.
Multidimensional left atrial (LA) performance indices have not been extensively studied in chronic mitral valve disease. LA maximal volume, stroke volume (LA volume at atrial systole minus LA minimal volume), LA ejection fraction (stroke volume/volume at atrial systole) and A-wave velocity, were measured in 14 patients with mitral stenosis (mean mitral valve area 1.5 cm2); 14 patients with chronic mitral regurgitation all in sinus rhythm; and were compared to 20 age and sex matched normal control subjects using biplane transthoracic echo and pulsed Doppler. Although LA volumes--maximal and at onset of atrial systole--were greater in mitral regurgitation and mitral stenosis (p < 0.01) compared to normal subjects, LA ejection fraction was not statistically different among the three groups. LA stroke volume was greater in mitral regurgitation and mitral stenosis compared to normal subjects, p < 0.01. LA kinetic energy (LAKE) = 1/2 mv2 (m = LA stroke volume x 1.06, blood's specific gravity, v = A wave velocity) was increased in mitral stenosis and mitral regurgitation compared to normal subjects (p < 0.001). An inverse correlation (r = 0.66, p < 0.01) was present between LAKE and mitral valve area in mitral stenosis. It is concluded that LA function, a complex interplay of multiple factors, requires multidimensional methods of analysis beyond standard measurements of size and volume, which provide additional insight into normal LA function, and better definition of LA function changes involved in the natural history of chronic mitral valve disease.
Adult↗
HLA-DQA1 and -DQB1 gene haplotypes in familial cardiomyopathy.
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Adult↗
Effects of recipient atrial contraction on mitral valve motion in orthotopic cardiac transplantation.
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Adult↗
Anti-beta-receptor antibodies in familial cardiomyopathy: correlation with HLA-DR and HLA-DQ gene polymorphisms.
The presence of beta-receptor autoantibodies and their relationship to restriction fragment length polymorphisms of the human leukocyte antigen (HLA) class II genes were studied in 42 affected and unaffected members of a family with a heritable disorder of the conduction system and cardiac muscle. Antibodies were detected in 34% of all members (59% of affected and 22% of unaffected; p < 0.01). Significant differences between affected and unaffected individuals and between anti-beta-receptor antibody positive and negative individuals were noted in the prevalence of polymorphisms obtained with Taq I for the HLA-DR beta and HLA-DQ alpha genes. In affected individuals, there was a strong positive correlation between these polymorphisms and the presence of anti-beta-receptor antibodies. These results suggest that autoimmune mechanisms under the control of the class II genes play an important role in the pathogenesis of familial cardiomyopathy.
Arrhythmias, Cardiac↗
Left atrial myopathy in idiopathic dilated cardiomyopathy.
To investigate whether left atrial systolic dysfunction in dilated cardiomyopathy is the result of left atrial dilatation, atrial involvement in the myopathic process, or both, 20 patients with aortic stenosis, 14 patients with idiopathic dilated cardiomyopathy, and 10 normal control subjects were studied. Left atrial volumes (cubic centimeters) were echocardiographically measured at mitral valve opening (maximal), mitral valve closure (minimal), and onset of atrial systole (P wave of the electrocardiogram) with the biplane area-length method. Atrial systolic function was assessed by calculating the active emptying fraction, equal to (volume at onset of atrial systole minus minimal volume)/volume at onset of atrial systole. Heart rate was similar in patients with aortic stenosis and dilated cardiomyopathy (83 +/- 11 vs 86 +/- 15 beats/min, respectively). Maximal volume was similar in patients with aortic stenosis (74.8 +/- 26.4 cm3) and dilated cardiomyopathy (79.7 +/- 25.3 cm3) but greater (p < 0.0001) than in control subjects (46.4 +/- 11.9 cm3). Active emptying fraction was inversely related to volume at onset of atrial systole and to tension at end of atrial systole (aortic stenosis r = -0.61 and r = -0.81, respectively; dilated cardiomyopathy r = -0.79 and r = -0.66, respectively). At any given level of volume at onset of atrial systole and tension at end of atrial systole, however, active emptying fraction was lower in patients with dilated cardiomyopathy compared with those with aortic stenosis.(ABSTRACT TRUNCATED AT 250 WORDS)
Aortic Valve Stenosis↗