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Short-term effects of captopril on exercise tolerance in patients with chronic stable angina pectoris and normal left ventricular function.

A double-blind, placebo-controlled, crossover study was carried out to evaluate the short-term effects of captopril on exercise tolerance in 18 normotensive patients with chronic stable angina pectoris and normal left ventricular function. Captopril 25 mg (or placebo) was given twice, i.e. in the evening (10 p.m.) and the following morning (8 a.m.), prior to a maximal symptom-limited bicycle exercise test (11 a.m.). Captopril reduced the systolic and diastolic blood pressures at rest (p < 0.01) without causing any reflex tachycardia. The time to onset of S-T depression was prolonged (p < 0.05), and the maximal S-T depression was reduced (p < 0.02). No differences were found between captopril and placebo in total exercise duration or time to onset of angina. The effects of captopril on exercise-induced ischemia were demonstrated most clearly in patients who responded with a greater than 10 mm Hg fall in the resting systolic blood pressure. In conclusion, this study suggests that captopril has anti-ischemic properties, which may be of importance in the treatment of patients with chronic stable angina and normal left ventricular function. These beneficial effects probably relate to a reduction in afterload and myocardial wall stress and therefore a reduction in myocardial oxygen demand.

Adult↗

The evaluation of left ventricular function in childhood cancer survivors by pharmacological stress echocardiography.

Late cardiotoxicity after anthracycline chemotherapy for childhood cancer is well recognized sequelae. Many long-term survivors may have subclinical cardiac dysfunction undetectable at a baseline evaluation. Various tests have been utilized for the diagnosis of left ventricular impairment. Recently, low-dose dobutamine stress echocardiography has been proposed as a more sensitive screening test. We have applied low-dose dobutamine stress echocardiography (5-10 microg/kg/min) in 36 asymptomatic survivors (20 male/16 female aged 14.6+/-4.7 years) treated with a cumulative dose of 226+/-106 mg/m2 of doxorubicin. The median follow-up was 5 years. Control group consisted of 20 sex and age matched volunteers (12 male/8 female aged 12.6+/-4.9 years). We found significant differences in mean velocity of circumferential fibre shortening, myocardial performance index (Tei index), left ventricular posterior wall thickening and endsystolic wall stress at a baseline. The stress response was significantly blunted only in a patient group in the following parameters: endsystolic wall stress, isovolumic relaxation time and myocardial performance index. The threshold response was abnormal (0-5% improvement of a variable only) in 45% of subjects from a control group in one or two parameters. On the contrary, 63% of subjects from a patient group responded pathologically (the worsening of a variable) in one or more parameters. We have not found a good correlation between risk factors of late cardiotoxicity and stress changes of left ventricular function parameters. Low-dose dobutamine stress echocardiography is safe and feasible diagnostic tool in children and adolescents. Dobutamine significantly increases the differences in cardiac variables between healthy population and asymptomatic survivors for childhood cancer. In comparison to the controls, most asymptomatic patients revealed subclinical myocardial damage at test. The predictive value for the development of clinical symptoms and cardiac complications need to be assessed in a large prospective study.

Adolescent↗

Quantitative analysis of regional left ventricular function after myocardial infarction in the pig assessed with cine magnetic resonance imaging.

To assess the accuracy of quantitative analysis of global and regional wall motion and wall thickening of the left ventricle with cine magnetic resonance (MR), images obtained in eight pigs before and after myocardial infarction were compared with those obtained using gadolinium diethylenetriaminepentaacetic acid (Gd-DTPA)-enhanced multislice spin-echo MR imaging and determination of pathology. The region with abnormal wall motion and wall thickening, as determined with cine MR imaging, identified the same region of infarction as indicated by Gd-DTPA-enhanced spin-echo MR imaging and pathology. Within the infarcted region wall motion and wall thickening analyzed with the centerline method were significantly reduced. We conclude that the use of quantitative analysis of cine MR images accurately determines localization and extent of regional left ventricular dysfunction in the infarcted heart in vivo. This analysis using dedicated software including the centerline method allows sequential assessment of regional left ventricular function in normal and infarcted hearts.

Animals↗

Sex-associated differences in left ventricular function in aortic stenosis of the elderly.

BACKGROUND: In aortic stenosis, the response of the left ventricle to pressure overload varies from compensated hypertrophy to overt heart failure. The determinants of left ventricular adaptation are poorly understood. METHODS AND RESULTS: Left ventricular function was compared to assess the role of sex in 34 women and 29 men 60 years or older with both hemodynamic and echocardiographic data characteristic of severe aortic stenosis and no important coronary artery disease. Despite a similar degree of left ventricular outflow obstruction in women versus men (aortic valve area 0.54 +/- 0.20 versus 0.59 +/- 0.19 cm2, NS), the left ventricle of women had a greater fractional shortening (37 +/- 12 versus 25 +/- 12%, p = 0.001), achieved a smaller end-systolic chamber size (1.82 +/- 0.64 versus 2.17 +/- 0.65 cm/m2, p = 0.04), and generated more pressure (210 +/- 35 versus 182 +/- 29 mm Hg, p = 0.001) with a greater maximum positive dP/dt (2.153 +/- 794 versus 1,595 +/- 384 mm Hg/sec, p = 0.02). The men had a lower cardiac index (2.12 +/- 0.59 versus 2.49 +/- 0.63 l/min/m2, p = 0.02), higher mean pulmonary artery pressure (35 +/- 13 versus 27 +/- 10 mm Hg, p = 0.01), and shorter ejection period (340 +/- 40 versus 370 +/- 40 msec, p = 0.02). Women and men were equally symptomatic. Supernormal left ventricular ejection performance was present in 41% of the women and only 14% of the men (p = 0.002). This subgroup of women had a small, thick-walled chamber (end-diastolic radius to thickness ratio, 1.58 +/- 0.52 versus 2.45 +/- 0.51 in control women, p = 0.01) with low end-systolic wall stress. Subnormal ejection performance was present in 64% of the men and only 18% of the women (p = 0.002). This subgroup of men had an increased chamber size and high end-systolic wall stress compared with control men. Greater left ventricular mass was present in men compared with women (211 +/- 55 versus 179 +/- 55 g/m2, p = 0.03). CONCLUSIONS: Sex is a factor in left ventricular adaptation to valvular aortic stenosis in adults 60 years or older.

Aged↗

Left ventricular functional response to moderate and intense exercise.

The left ventricular (LV) volume and ejection fraction (EF) response to upright exercise was assessed on 15 normal subjects during cycle ergometry. Measures of cardiac function and gas exchange were made at rest, at 85% of the ventilatory anaerobic threshold (VAT; WL1), and at peak exercise (WL2). EF increased from rest (58 +/- 12%) during WL1 (66 +/- 10%), reaching significantly higher values at WL2 (69 +/- 8%; p less than .05). End-diastolic volume increased from rest during WL1 (136 +/- 36 ml vs. 118 +/- 32 ml; p less than .05), becoming significantly higher than rest during WL2 (141 +/- 41 ml). End-systolic volume was unchanged from rest (51 +/- 25 ml) during submaximal exercise (50 +/- 20 ml), but it decreased significantly during WL2 (44 +/- 21 ml; p less than .05). The systolic pressure/end-systolic volume ratio increased from 3.0 +/- 1.7 (rest) to 5.8 +/- 3.0 at WL2 (p less than .05). These results suggest that the Frank-Starling mechanism is operative throughout exercise, particularly during exercise below the VAT. LV performance after the VAT is further augmented by increased contractility with continued, yet diminished, utilization of the Frank-Starling mechanism.

Adult↗

Percutaneous transvenous mitral commissurotomy for rheumatic mitral stenosis with impaired left ventricular function: an echocardiographic follow-up study.

Sixty consecutive patients of rheumatic mitral stenosis who underwent percutaneous transvenous mitral commissurotomy were evaluated and followed up for 3 months in order to study the effect of the procedure on left ventricular ejection fraction and to elucidate the pathophysiology of impaired left ventricular function. The response in 16 patients (26.7%) with left ventricular dysfunction (ejection fraction less than 50%) was compared to that in 44 patients with normal left ventricular ejection fraction. Patients with left ventricular dysfunction had relatively larger left ventricular end-diastolic (84 +/- 15 vs. 76 +/- 14 ml) and end-systolic (45 +/- 11.5 vs. 35 +/- 12 ml) volumes. Percutaneous transvenous mitral commissurotomy was successful in all patients. Mitral valve area increased in all patients, from 0.8 +/- 0.2 cm2 to 1.82 +/- 0.37 cm2. After commissurotomy there was a trend towards increase of the left ventricle end-diastolic volumes in both groups of patients. Left ventricular ejection fraction also marginally increased in both groups. A reduced left ventricular compliance due to thickened and fibrotic mitral valve apparatus and excessive afterload due to increased systemic vascular resistance because of low output are possible mechanisms for left ventricular dysfunction in patients with mitral stenosis.

Adolescent↗

Acute changes of global and regional left ventricular function immediately after direct myocardial revascularization.

Direct myocardial revascularization (DMR) has been proposed to treat patients with severe coronary artery disease who are not amenable for classical revascularization techniques such as percutaneous coronary intervention (PCI) or bypass surgery (CABG). Although recent reports suggest its benefit in alleviating patients' complaints in the long term, there is still a paucity of data on the immediate impact on regional and global myocardial functioning following this treatment. In this overview we discuss our own experience and provide a summary of other data currently available.

Coronary Disease↗

Improvement of left ventricular function after renal transplantation in a patient with uremic cardiomyopathy: report of a case.

The improvement of heart function in a patient on hemodialysis with dilated cardiomyopathy by renal transplantation is herein reported. The patient was a 35-year-old woman. Hemodialysis had been initiated 3 months before, but she experienced difficulty with hemodialysis maintenance and exhibited congestive heart failure. The ejection fraction (EF) was decreased to 36.6% in the echocardiogram, and an intracardiac biopsy of the right ventricle showed myofiber degeneration and interstitial edema upon examination by light microscopy. She then underwent renal transplantation, and the postoperative recovery was almost uneventful. The cardiothoracic ratio decreased rapidly to around 40% after 1 month, although her body weight increased. The ejection fraction increased to 50% in the echocardiogram. An intracardiac biopsy of the right ventricle revealed disoriented myofibers, but myofiber degeneration improved, and no interstitial edema was present upon examination by light microscope. The electron microscopy showed that the intracellular edema had disappeared and other degenerative changes had also improved. The patient was discharged on the 44th postoperative day, with a serum creatinine of 1.3 mg/dl.

Adult↗

Left ventricular function in asthmatic children chronically treated with theophylline evaluated by exercise Doppler echocardiography.

To evaluate the chronic effects of theophylline on cardiac function, M-mode and pulsed Doppler derived variables were measured at rest and the suprasternal continuous wave Doppler measurement of ascending aortic flow was used during treadmill exercise testing. Subjects consisted of 13 children with stable asthma (mean 11.7 +/- 2.2 years) who were treated with theophylline for at least one year and 16 age-matched, untreated normal volunteers. In the resting state, the chronic administration of theophylline seemed to produce a slight increase in percent fractional shortening, outflow peak velocity and atrial contribution to ventricular filling in the asthmatic children as compared to normals, but these changes were not statistically significant. The asthmatic children showed significantly lower values than the controls in exercise induced changes in the peak velocity, stroke index and cardiac index, but not in the heart rate. Therefore, chronic administration of theophylline appears to have a minimal effect on resting cardiac function, but a possibly deleterious effect on the cardiac response to exercise testing.

Adolescent↗

Simultaneous measurement of left ventricular function and perfusion.

A new radiopharmaceutical, methylisobutyl isonitrile (MIBI), has been developed as a technetium-99m-labelled alternative to thallium 201 for myocardial imaging. By virtue of the high specific activity of 99mTc, some 600 MBq may be administered as a 0.3 ml bolus, permitting the acquisition of a first-pass nuclear angiogram at rest and at peak exercise. The agent was assessed in ten sequential patients referred for routine cardiac catheterisation, who also underwent an exercise electrocardiographic (ECG) test. Good quality nuclear angiograms, planar perfusion and tomographic perfusion images were obtained; the results correlated well with the catheterisation data. Of 30 myocardial segments for which wall motion was judged normal/abnormal from the nuclear angiogram, results concordant with contrast studies were obtained in 27 (90%). In the case of the 50 segments analysed from the perfusion images, concordant results were obtained in 43 (86%) from the planar studies and in 42 (84%) from the tomographic studies. All normal segments were classified correctly.

Adult↗

Relation between flow grade after thrombolytic therapy and the effect of angioplasty on left ventricular function: a prospective randomized trial.

Recent intervention trials during myocardial infarction demonstrated no benefit from emergency angioplasty after thrombolytic therapy when compared with either delayed percutaneous transluminal coronary angioplasty (PTCA) or a conservative strategy. However, it is possible that subgroups of patients may benefit from early intervention with angioplasty. We performed a prospective randomized trial in patients with a patent infarct-related artery after thrombolytic therapy to determine whether initial flow grade is related to infarct-zone function and whether patients with ineffective reperfusion (greater than 90% stenosis or Thrombolysis in Myocardial Infarction [TIMI] flow less than or equal to 2) might benefit from immediate PTCA. Thrombolytic therapy was administered to 170 patients at a mean of 2.1 +/- 0.5 hours after onset of myocardial infarction. A patent infarct-related artery that was suitable for angioplasty was present in 89 patients who comprised the study group; after randomization, 47 of 50 patients with a patent infarct-related artery had successful emergency PTCA 3.8 +/- 1.5 hours after onset of symptoms, and 39 were scheduled for delayed (18 to 48-hour) PTCA. Reocclusion occurred before the scheduled (delayed) procedure in eight patients (20.5%), and was symptomatic in six. Infarct-region function (by the centerline method) measured initially, before discharge, and at 4 months was similar in both groups; improvement was significant (p less than 0.001) at discharge when compared with initial values with no further change at 4 months. However, patients with ineffective reperfusion had greater hypokinesia initially (p less than 0.05) compared with those with effective reperfusion (less than or equal to 90% stenosis plus TIMI flow 3). Moreover, independent of the timing of PTCA, improvement was greater before discharge in patients with ineffective reperfusion (p less than 0.05) with a trend also evident at 4 months. Importantly, 42 of 51 patients (82%) with a residual lumen less than 0.4 mm after thrombolysis had some improvement in function at discharge; this compared with a previous study in which patients with a similar degree of stenosis (without PTCA) had no improvement. Moreover, reocclusion occurred before scheduled (delayed) PTCA in 37% of patients with greater than 90% stenosis compared with only 5% in those with less than or equal to 90% stenosis (p = 0.02). Thus flow grade is an important determinant of myocardial function in patients with a patent artery after thrombolytic therapy and is predictive both of improvement in wall motion after PTCA and early reocclusion.(ABSTRACT TRUNCATED AT 400 WORDS)

Angioplasty, Balloon, Coronary↗