456 research outputs found
Assessment of Coronary Flow Reserve During Angioplasty Using A Doppler Tip Balloon Catheter. Comparison With Digital Subtraction Cineangiography
Intracoronary blood flow velocity measurements with a Doppler probe and the radiographic assessment of myocardial perfusion with contrast media previously have been used to investigate regional coronary flow reserve. In the present study we applied both techniques in the same patients to measure the immediate improvement in coronary flow reserve as a result of angioplasty. In addition we compared papaverine induced hyperemia with reactive hyperemia following transient transluminal occlusion of a major coronary artery. In 13 consecutive patients with a single proximal stenosis, coronary flow reserve was measured preā and postangioplasty by digital subtraction cineangiography, while preā and postangioplasty Doppler measurements before and after papaverine were obtained in the proximal part of the stenotic vessel. After the last transluminal occlusion, reactive hyperemia recorded with the Doppler probe was also compared to the coronary flow reserve measurement obtained during papaverine induced hyperemia. As a result of the angioplasty, coronary flow reserve measured with the radiographic technique (mean Ā± SD) increased from 1.1 Ā± 0.4 to 2.2 Ā± 0.4 (P < 0.001), while coronary flow reserve measured with the Doppler probe (mean Ā± SD) increased from 1.2 Ā± 0.3 to 2.4 Ā± 0.4 (P < 0.001). Pharmacologically induced hyperemia measured with the radiographic technique and the Doppler probe were linearly related (r = 0.91 with a SEE 0.3) and confirmed the reliability of the intracoronary measurements. Using these two independent techniques, coronary flow reserve immediately after angioplasty was found to be substantially improved but still abnormal. In addition, the magnitude of hyperemia induced by papaverine was comparable to the reactive hyperemia following transluminal occlusion, although the latter measurement was recorded with the angioplasty catheter still across the dilated lesion. (J Interven Cardiol, 1988:1:1) Copyrigh
Absence of beneficial effect of intravenous metoprolol given during angioplasty in patients with single-vessel coronary artery disease
In a double-blind, randomized, placebo-controlled trial, the possible antiischemic effect of metoprolol during percutaneous transluminal coronary angioplasty was tested. Electrocardiograms, hemodynamics, and metabolism were studied in 27 patients with a stenosis in the left anterior descending coronary artery. Measurements took place before angioplasty, after each of four 1-minute occlusions and 15 minutes after the last balloon deflation. Patients were randomly given placebo or metoprolol (15 mg as a bolus intravenously, followed by an infusion 0.04 mg/kg/hr). At the end of the procedure, the rate-pressure product had decreased by 15% (NS) and 23% (p=0.001) in the placebo and metoprolol groups, respectively, mainly due to similar decreases in heart rate. Metoprolol tended to lower chest pain and reduce precordial ST-segment elevation due to angioplasty, but the effects were not statistically significant. Lactate, hypoxanthine, and urate release immediately after deflation was similar in both groups. Metoprolol reduced arterial plasma hypoxanthine throughout the procedure by about 30% (p ā¦ 0.02 vs. placebo). Thus, intravenous infusion of metoprolol did not significantly attenuate chest pain and ST-segment elevation, and failed to decrease cardiac lactate and oxypurine release. It did, however, reduce arterial hypoxanthine concentrations during angioplasty, possibly indicating that the beta-blocker inhibits extracardiac ATP catabolism.
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Curved track sprint characteristics in elementary school children
The management strategies of patients who underwent Mustard repair for transposition (of the great arteries were changed in the 1970s: infants became eligible for direct surgical repair, so Blalock-Hanlon atrioseptostomy could be avoided, and cold cardioplegia was introduced for myocardial preservation. Data are lacking, however, regarding whether these changes have had positive effects on the long-term outcome. We therefore conducted a follow-up study on all 91 patients who underwent a Mustard repair for transposition of the great arteries in our institution between 1973 and 1980 to assess the incidence and clinical importance of sequelae as well as health-related quality of life for these patients. Patients who were alive and could be traced through local registrar's offices received an invitation to participate in the follow-up study, which consisted of an interview, physical examination, echocardiography, exercise testing, and standard 12-lead and 24-hour electrocardiography. Patients operated on in the first 4 years had a significantly higher mortality rate and higher incidence of sinus node dysfunction than did patients operated on in the subsequent 4 years (25% vs 2% and 41% vs 3%, respectively). In contrast, the incidence of baffle obstruction necessitating reoperation was significantly higher in the second group. There were no significant differences in echocardiographic findings and exercise capacity between patients operated on in the first 4 years and in the subsequent 4 years. None of the patients had right ventricular failure; a mild degree of baffle leakage or obstruction was seen in 22% of the patients, and the mean exercise capacity was decreased to 84% +/- 16% of normal. The changes introduced between 1973 and 1980 have resulted in a considerable reduction of mortality and incidence of sinus node dysfunction but have also resulted in a more frequent need for reoperatio
Safety, hemodynamic profile, and feasibility of dobutamine stress technetium myocardial perfusion single-photon emission CT imaging for evaluation of coronary artery disease in the elderly
OBJECTIVES: Cardiovascular disease is the leading cause of morbidity and
mortality in the elderly. The evaluation of coronary artery disease by
exercise stress testing is frequently limited by the patient's inability
to exercise. Although pharmacologic stress testing with dobutamine is an
alternative, the safety of dobutamine myocardial perfusion scintigraphy in
the elderly has not been previously studied. PATIENTS AND METHODS: We
studied the safety and feasibility of dobutamine (up to 40
microg/kg/min)-atropine (up to 1 mg) stress myocardial perfusion
scintigraphy using technetium single-photon emission CT imaging in 227
patients > or = 70 years old (mean +/- SD age, 75 +/- 4 years). A control
group of 227 patients < 70 years old (mean age, 55 +/- 11 years; matched
for gender, prevalence of previous infarction, beta-blocker therapy, and
severity of resting perfusion abnormalities) was studied to assess
age-related differences in the safety and the hemodynamic response. A
feasible test was defined as the achievement of the target heart rate
and/or an ischemic end point (angina, ST-segment depression, or reversible
perfusion abnormalities). RESULTS: No myocardial infarction or death
occurred during the test. The target heart rate was achieved more
frequently in the elderly patients (87% vs 79%; p < 0.05). The elderly
patients had a higher prevalence of supraventricular tachycardia (7% vs
1%; p < 0.005) and premature ventricular contraction (74% vs 32%; p <
0.005) during the test, as compared to the younger patients. There was a
trend to a higher prevalence of ventricular tachycardia (5% vs 2%) and
atrial fibrillation (3% vs 0.4%) in the elderly patients. Arrhythmias were
terminated spontaneously by termination of dobutamine infusion or by
administration of metoprolol. Independent predictors of supraventricular
tachyarrhythmias and ventricular tachycardia were older age (p < 0.001;
chi(2), 9.8) and myocardial perfusion defect score at rest (p < 0.01;
chi(2), 6.8) respectively, by using a multivariate analysis of clinical
and stress test variables. Elderly patients had a higher prevalence of
systolic BP drop > 20 mm Hg during the test (37% vs 12%; p < 0.05). The
test was terminated due to hypotension in 2% of the elderly patients and
in 1% of the control group. Age was the most powerful predictor of
hypotension (p < 0.005; chi(2), 10.3). The test was considered feasible in
216 elderly patients (95%) and in 209 patients of the control group (92%).
CONCLUSION: Dobutamine-atropine stress myocardial perfusion scintigraphy
is a highly feasible method for the evaluation of coronary artery disease
in the elderly. Elderly patients have a higher risk for developing
hypotension and supraventricular tachyarrhythmias during a dobutamine
stress test. However, dobutamine-induced hypotension is often asymptomatic
and rarely necessitates the termination of the test
Long-term prognostic value of dobutamine stress 99mTc-sestamibi SPECT: single-center experience with 8-year follow-up
PURPOSE: To determine the long-term prognostic value of dobutamine stress
technetium 99m (99mTc)-labeled sestamibi single photon emission computed
tomography (SPECT) in patients with limited exercise capacity. MATERIALS
AND METHODS: Clinical data and SPECT results were analyzed in 531
consecutive patients. Follow-up was successful in 528 (99.4%) patients; 55
underwent early revascularization and were excluded. Normal or abnormal
findings were considered in the absence or presence of fixed and/or
reversible perfusion defects. A summed stress score was calculated to
estimate the extent and severity of perfusion defects. Univariate and
multivariate Cox proportional hazards regression models were used to
identify independent predictors of late cardiac events. The incremental
value of myocardial perfusion scintigraphy over clinical variables in
predicting events was determined according to two models. The probability
of survival was calculated by using the Kaplan-Meier method. RESULTS:
Findings were abnormal in 312 patients. During 8.0 years +/- 1.5 of
follow-up (range, 4.5-10.6 years), cardiac death occurred in 67 patients
(total deaths, 165); nonfatal myocardial infarction, in 34; and late
revascularization, in 49. The annual rates for cardiac death, cardiac
death or infarction, and all events were 0.9%, 1.2%, and 1.5%,
respectively, after normal findings and 2.7%, 3.4%, and 4.4%,
respectively, after abnormal findings (P <.05). In a multivariable Cox
proportional hazards model, not only an abnormal finding but also the
summed stress score provided incremental prognostic information in
addition to clinical data. The hazard ratio for cardiac death was 1.09
(95% CI: 1.01, 1.18) per 1-unit increment of the summed stress score.
CONCLUSION: The incremental prognostic value of dobutamine stress
99mTc-sestamibi SPECT over clinical data was maintained over an 8-year
follow-up in patients with limited exercise capacity
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