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Biomedical subjects

A Zeiher

Publications and source records attributed to A Zeiher.

At least 19 recordsLinked to original sources
PubMed2001

Randomized comparison of coronary stent implantation under ultrasound or angiographic guidance to reduce stent restenosis (OPTICUS Study).

BACKGROUND: Observational studies in selected patients have shown remarkably low restenosis rates after ultrasound-guided stent implantation. However, it is unknown whether this implantation strategy improves long-term angiographic and clinical outcome in routine clinical practice. Methods and Results-- A total of 550 patients with a symptomatic coronary lesion or silent ischemia were randomly assigned to either ultrasound-guided or angiography-guided implantation of </=2 tubular stents. The primary end points were angiographic dichotomous restenosis rate, minimal lumen diameter, and percent diameter stenosis after 6 months as determined by quantitative coronary angiography. Secondary end points were the occurrence rates of major adverse cardiac events (death, myocardial infarction, coronary bypass surgery, and repeat percutaneous intervention) after 6 and 12 months of follow-up. At 6 months, repeat angiography revealed no significant differences between the groups with ultrasound- or angiography-guided stent implantation with respect to dichotomous restenosis rate (24.5% versus 22.8%, P=0.68), minimal lumen diameter (1.95+/-0.72 mm versus 1.91+/-0.68 mm, P=0.52), and percent diameter stenosis (34.8+/-20.6% versus 36.8+/-19.6%, P=0.29), respectively. At 12 months, neither major adverse cardiac events (relative risk, 1.07; 95% CI 0.75 to 1.52; P=0.71) nor repeat percutaneous interventions (relative risk 1.04; 95% CI 0.64 to 1.67; P=0.87) were reduced in the ultrasound-guided group. CONCLUSIONS: This study does not support the routine use of ultrasound guidance for coronary stenting. Angiography-guided optimization of tubular stents can be performed with comparable angiographic and clinical long-term results.

Blood Vessel Prosthesis Implantation↗
PubMed2001

Effects of atorvastatin on early recurrent ischemic events in acute coronary syndromes: the MIRACL study: a randomized controlled trial.

CONTEXT: Patients experience the highest rate of death and recurrent ischemic events during the early period after an acute coronary syndrome, but it is not known whether early initiation of treatment with a statin can reduce the occurrence of these early events. OBJECTIVE: To determine whether treatment with atorvastatin, 80 mg/d, initiated 24 to 96 hours after an acute coronary syndrome, reduces death and nonfatal ischemic events. DESIGN AND SETTING: A randomized, double-blind trial conducted from May 1997 to September 1999, with follow-up through 16 weeks at 122 clinical centers in Europe, North America, South Africa, and Australasia. PATIENTS: A total of 3086 adults aged 18 years or older with unstable angina or non-Q-wave acute myocardial infarction. INTERVENTIONS: Patients were stratified by center and randomly assigned to receive treatment with atorvastatin (80 mg/d) or matching placebo between 24 and 96 hours after hospital admission. MAIN OUTCOME MEASURES: Primary end point event defined as death, nonfatal acute myocardial infarction, cardiac arrest with resuscitation, or recurrent symptomatic myocardial ischemia with objective evidence and requiring emergency rehospitalization. RESULTS: A primary end point event occurred in 228 patients (14.8%) in the atorvastatin group and 269 patients (17.4%) in the placebo group (relative risk [RR], 0.84; 95% confidence interval [CI], 0.70-1.00; P =.048). There were no significant differences in risk of death, nonfatal myocardial infarction, or cardiac arrest between the atorvastatin group and the placebo group, although the atorvastatin group had a lower risk of symptomatic ischemia with objective evidence and requiring emergency rehospitalization (6.2% vs 8.4%; RR, 0.74; 95% CI, 0.57-0.95; P =.02). Likewise, there were no significant differences between the atorvastatin group and the placebo group in the incidence of secondary outcomes of coronary revascularization procedures, worsening heart failure, or worsening angina, although there were fewer strokes in the atorvastatin group than in the placebo group (12 vs 24 events; P =.045). In the atorvastatin group, mean low-density lipoprotein cholesterol level declined from 124 mg/dL (3.2 mmol/L) to 72 mg/dL (1.9 mmol/L). Abnormal liver transaminases (>3 times upper limit of normal) were more common in the atorvastatin group than in the placebo group (2.5% vs 0.6%; P<.001). CONCLUSION: For patients with acute coronary syndrome, lipid-lowering therapy with atorvastatin, 80 mg/d, reduces recurrent ischemic events in the first 16 weeks, mostly recurrent symptomatic ischemia requiring rehospitalization.

Aged↗
PubMed2001

[Anaplastic astrocytomas of the medulla oblongata. A rare differential diagnosis in orthostatic hypotension].

HISTORY AND PHYSICAL EXAMINATION: A 39-year-old women was admitted for evaluation of dizziness and hypotension. During standing the blood pressure dropped from 130/80 to 80/40 mmHg. Ten weeks before admission she had recurrent cerebral convulsions. Neurological evaluation showed a slight left hemiparesis. Computed tomography of the brain revealed a 1.5 +/- 1 cm cyst in the left tempral region. It was thought that the cause of the recurrent convulsions was alcohol abuse. During the next few weeks orthostatic hypotension increased and she was not able to work. INVESTIGATIONS: At admission abnormal findings included hypotension, horizontal nystagmus, and deviation of the soft palate to the right. After the patient was brought to an upright position during standardized passive tilt testing she showed a defect in the sympathetic limb of the baroreceptor reflex arc. Head magnetic resonance tomography showed a signal-enhancing tumour in the cervicomedullary region. TREATMENT AND CLINICAL COURSE: Before a planned biopsy could be performed the patient died of respiratory arrest. Postmortem examination revealed an anaplastic grade III astrocytoma extending form the pons to the medulla oblongata. CONCLUSION: Upright tilting leads to pooling of blood in the legs. One of the normal compensatory responses is a reflex tachycardia which our patient did not show as a sign of an afferent defect. Patients with orthostatic hypotension as a prominent symptom should be investigated with a standardized tilt test. In special patients, additional neurological investigations are necessary.

Adult↗
PubMed1991

Relation of technetium-99m pyrophosphate accumulation to time interval after onset of acute myocardial infarction as assessed by a tomographic acquisition technique.

Technetium-99m pyrophosphate (Tc-99m PYP) myocardial scintigraphy was performed in 110 clinically stable patients with acute or healed acute myocardial infarction (AMI). Tomography was performed 12 hours to 7 days (group A), 7 to 30 days (Group B), 1 to 6 months (Group C) and after greater than 6 months (group D) after AMI. All 40 patients in group A, 9 of 31 in group B, 1 of 22 in group C, and no patient (0 of 17) in group D had a pathologic Tc-99m PYP tomogram. Relative Tc-99m PYP accumulation within the area of infarction was measured as infarct zone to blood pool ratio, which decreased significantly (p less than 0.001) from group A (1.54 +/- 0.39) to group B (0.89 +/- 0.24), group C (0.8 +/- 0.19) and group D (0.76 +/- 0.13). These data were confirmed by sequential scintigraphy in 17 patients. It is concluded that a persisting Tc-99m PYP uptake is rarely found greater than 1 month after AMI using tomographic imaging techniques in clinically stable patients with coronary artery disease. Positive results on Tc-99m PYP tomography are a reliable indicator of AMI. Thus, Tc-99m PYP tomography is not only a sensitive but also a specific imaging technique for AMI, which might be especially useful for diagnosis of reinfarction.

Adult↗
PubMed1991

Digital angiographic impulse response analysis of regional myocardial perfusion. Estimation of coronary flow, flow reserve, and distribution volume by compartmental transit time measurement in a canine model.

A system impulse response function that describes the kinetics of radiographic contrast material transit through the coronary circulation was calculated from 175 selective digital angiograms of normal and stenotic arteries in 10 dogs during rest and hyperemia. The goal of the study was to determine if the flow and distribution volume characteristics of the epicardial coronary arteries and the myocardial microcirculation could be stimulated by specific mathematical compartments of a lagged normal density model impulse response function in which the flow/distribution volume ratio is the inverse of the mean transit time. The arterial compartment mean transit time correlated with flow (r = 0.75); however, the correlation was significantly improved in individual dogs (r = 0.83 +/- 0.13; p less than 0.005) and was highly dependent on the length of the conduit vessel. The microcirculation compartment mean transit time was distributed as two populations with respect to flow. There was a linear correlation during hyperemia (r = 0.87) and a nonlinear relation during rest, which was characteristic of an autoregulating system. Resting values of microcirculation compartment mean transit time correlated with coronary flow reserve (r = 0.84) and differed significantly between vessels that were normal and those with subcritical stenosis, critical stenosis, or total occlusion (p less than 0.01 for all comparisons). The estimated microcirculation compartment distribution volume increased from a minimum of 4.0 +/- 1.5 ml/100 g myocardium in normal vessels with resting flow to 11.2 +/- 3.5 ml/100 g during hyperemia. These data suggest that the model compartments functionally describe the physiological behavior of their anatomic analogues and permit the quantification of microcirculatory autoregulation from a single measurement at rest without provoking hyperemia.

Algorithms↗
PubMed1991

[Immunoscintigraphy using 111Indium-labeled antimyosin in suspected myocarditis].

111Indium-monoclonal antimyosin scans were carried out in 21 patients with suspected myocarditis, confirmed by reduced ejection volume, pericardial effusion and clinical follow up in 12 patients. Coronary heart disease was excluded angiographically in all cases. Quantitative evaluation of myocardial 111In-antimyosin accumulation 48 hours after injection showed a pathological uptake in 10/12 patients with increased heart/lung ratios (Q48 greater than 1.58). Ratios were also elevated in 2 patients with cardiomyopathy, 2 suffering from vasculitis and 1 with dermatomyositis. Four patients without proven cardiac disease had normal ratios (Q48 less than or equal to 1.58). Examination after 24 hours was of limited value, depending on the residual blood pool activity. Visual analysis of the scans showed a high interobserver variation despite a positive correlation with quantitative analysis (48 h p.i.: r = 0.72; p less than 0.001), and is not recommended. The results show the value of the 111In-antimyosin scan as a screening method prior to myocardial biopsy. However, scintigraphy cannot definitely elucidate the cause of myocardial damage. Therefore, myocardial biopsy is still recommended after positive antimyosin scans.

Adolescent↗
PubMed1989

Digital angiographic impulse response analysis of regional myocardial perfusion: linearity, reproducibility, accuracy, and comparison with conventional indicator dilution curve parameters in phantom and canine models.

The system mean transit time (Tsys) of the impulse response function describing contrast material transit through the coronary circulation was determined from serial digital angiographic images. The linearity, reproducibility, and relations with regional myocardial perfusion and conventional time-density curve parameters, time to peak concentration (TPC), and exponential washout rate (k) were assessed in a dynamic flow x-ray phantom (n = 46) and in six open-chest dogs (n = 102) while coronary flow was altered by stenosis and/or hyperemic stimuli. In the phantom studies, the inverse of the system mean transit time (Tsys-1) closely predicted flow/volume (r = 0.99, slope = 0.99). In dogs, Tsys-1 was independent of the shape of the contrast bolus injection (single or double-peaked), class of contrast agent (ionic or nonionic), the type of hyperemic stimulus (dipyridamole, dipyridamole plus norepinephrine, transient total occlusion, or ionic contrast media), and was highly reproducible between adjacent myocardial regions served by the same artery (r = 0.98 +/- 0.01). There was a strong correlation between Tsys-1 and regional coronary flow for stenotic and/or hyperemic vessels (r = 0.94, distribution volume = 14.9 ml/100 g) over a wide range (0-514 ml/min/100 g). Tsys-1 performed better than conventional time-density curve parameters TPC-1 and k for predicting phantom flow/volume ratios and regional myocardial blood flow in the dog. These data suggest that both digital coronary angiography and coronary contrast transit can be modeled as linear systems and that impulse response analysis may provide accurate and reproducible estimates of regional myocardial blood flow.

Algorithms↗
PubMed1987

[Hemodynamic effect of intravenous diltiazem and nifedipine in acute myocardial infarct. A randomized study].

In a prospective, randomized trial of 28 patients with acute myocardial infarction nifedipine or diltiazem were administered intravenously and hemodynamic parameters and drug plasma levels measured for 24 hours. Both drugs lowered arterial blood pressure and peripheral resistance. Only diltiazem reduced heart rate and the heart rate x arterial pressure product, as pointer to a reduction in myocardial oxygen consumption. On the other hand, nifedipine is more likely to cause a (reflex) increase in heart rate. In no patient was there evidence of drug-induced hemodynamic impairment. Left ventricular filling pressure was reduced in those patients in whom it had been elevated. While a steady-state plasma concentration was quickly reached with nifedipine, in some patients diltiazem infusion produced a continuous rise in plasma concentration and, in two patients with posterior-wall infarction, high-grade a-v block (reversible after discontinuation of the drug). The results indicate that under ECG control both drugs can be used intravenously without much risk. The hemodynamic profile of diltiazem (reduction in peripheral resistance and heart rate) would seem to be particularly favorable in acute infarction, while nifedipine is preferred in acute infarction plus hypertension. The possible effect on a-v conduction is to be watched on intravenous administration of diltiazem, while in normotensive patients nifedipine may cause an undesirable (reflex-mediated) sympathetic activation.

Adult↗
PubMed1987

Early clinical evaluation of the intravenous treatment of acute myocardial infarction with anisoylated plasminogen streptokinase activator complex.

50 consecutive patients with acute myocardial infarction and symptoms of less than 4 hours duration were treated with anisoylated plasminogen streptokinase activator complex (APSAC) 30U intravenously as a bolus injection over 5 minutes. An open infarct-related artery was found in 32 patients (64%) when the first coronary angiography was taken 66 +/- 21 minutes after APSAC. Complete reperfusion was subsequently seen in 10 of 18 patients with an occluded infarct-related artery 74 +/- 16 minutes after injection of APSAC. Thus, a patient infarct-related artery was seen in 42 patients (84%) within 68 +/- 20 minutes. A control coronary angiography was performed in 37 patients (74%) after 25 +/- 19 days. Reocclusion was found in 5 patients. The minimal cross-sectional area of the residual coronary stenosis increased from 1.3 +/- 0.9 mm2 to 1.8 +/- 1.9 mm2. Patients with residual thrombi after coronary thrombolysis (n = 13) demonstrated an increase of the minimal cross-sectional area of the residual stenosis from 1.2 +/- 0.8 to 2.6 +/- 2.3 mm2, whereas those without residual thrombi showed only minor changes of the minimal cross-sectional area (1.3 +/- 0.9 to 1.2 +/- 1.2 mm2). Thus, APSAC demonstrated a high patency rate and a low reocclusion rate after intravenous administration. The prolonged fibrinolytic activity of APSAC leads to a further regression of the residual coronary stenosis among patients with coronary thrombi after reperfusion.

Adult↗
PubMed1986

Coronary thrombolysis during acute myocardial infarction by intravenous BRL 26921, a new anisoylated plasminogen-streptokinase activator complex.

The safety and fibrinolytic efficacy of a new anisoylated plasminogen-streptokinase activator complex (APSAC) was tested in 50 patients with acute myocardial infarction (AMI) less than 4 hours in duration. APSAC (30 mg) was given intravenously as a bolus injection 151 +/- 47 minutes after clinical symptoms. Coronary angiography was then performed to assess coronary artery patency: 28 patients had an inferior AMI and 22 an anterior AMI. A patent infarct-related artery was found in 32 patients (64%) on first coronary angiography 66 +/- 21 minutes after administration of APSAC. Subsequent reperfusion was observed in 10 patients after 74 +/- 16 minutes (84%). Bleeding complications or hematomas were observed in 18 patients, of whom 3 required blood transfusions. Marked hypofibrinogenemia was observed within 24 hours in most patients. A control coronary angiogram was recorded in 37 patients (74%) after 25 +/- 19 days and showed reocclusion in 5 patients.

Adult↗
PubMed1986

Echocardiographic findings in patients with proved pulmonary embolism.

Echocardiographic studies were performed in 105 patients with acute and recurrent pulmonary emboli. Pulmonary embolism was confirmed by pulmonary angiography (n = 48), autopsy (n = 6), and lung perfusion scintigraphy (n = 51). Seventy of 93 patients (75%) displayed a dilated right ventricle, 38 of 91 patients (42%) had reduced left ventricular cavity dimension, 41 of 82 patients (50%) had a decreased EF slope of the mitral valve, and 78 of 101 patients (77%) showed dilatation of the right pulmonary artery. The motion of the interventricular septum was abnormal in 41 of 93 patients (44%). Right-sided thrombi were seen in 13 patients within the right pulmonary artery (n = 11) and in the right ventricle (n = 3); in one patient they were found in the superior vena cava, in the innominate vein, and the right atrium. Two patients suffered from right-sided endocarditis. Thus echocardiographic changes were frequently found in patients with proved pulmonary emboli. The echocardiographic findings of right-sided cardiac and pulmonary artery abnormalities indicate hemodynamically active pulmonary emboli.

Acute Disease↗
PubMed1986

Quantitative assessment of temporal and spatial ventricular wall motion in normal and infarcted human left ventricles.

A new integrated method for quantitating temporal and spatial systolic wall motion heterogeneity was developed and applied in 15 normal subjects and 26 patients with previous myocardial infarction (MI). After frame by frame digitizing, right anterior oblique left cineventriculograms (LV) were analyzed with 90 spaced radii. For each radius shortening fractions at sequential systolic time points relative to end diastole were correlated with corresponding normalized time points using linear regression method, yielding the radial correlation coefficient (r) and the radial regression slope (b) for temporal and spatial information. High radial r values with small standard deviations were observed in normal LV (0.972 +/- 0.016) and in non-MI regions (0.964 +/- 0.018), indicating temporally homogeneous radial shortening. A significant temporal heterogeneity in wall motion was demonstrated in MI regions (0.480 +/- 0.304) (p less than 0.001). In comparison with normal b values (0.449 +/- 0.106), there were decreased b values in MI regions (0.203 +/- 0.211) (p less than 0.001) and increased b values in non-MI regions (0.695 +/- 0.213) (p less than 0.001), suggesting hypokinetic and compensative hyperkinetic contraction in corresponding regions. Thus, temporal and spatial wall motion throughout systole could be assessed quantitatively by the present computer-assisted method with two simple integrated parameters.

Adult↗
PubMed1986

Derivation of spatial information from biplane multidirectional coronary angiograms.

UNLABELLED: Modern biplane multidirectional isocentric X-ray equipment delivers the image information necessary for spatial computations from two simultaneous 2-dimensional coronary angiographic pictures. Using the tools of analytical geometry, the spatial position of well definable points in the fields of view of the two image-intensifiers can be calculated from their corresponding projections knowing the geometrical properties of the system stands. The method developed is independent of the angle between the projections and is applicable even if hemiaxial views are used. The mathematical formulas necessary for these spatial computations are derived. By means of calculating the radiological magnification factor, the method was validated using a wire with known diameter as reference object. 360-diameter measurements of the wire filmed in 18 different simultaneous biplane projections resulted in a mean error of 3.14%. In addition, catheter measurements of routine coronary angiograms yielded a mean diameter of 2.64 +/- 0.19 mm (mean +/- SD, real diameter 2.66 mm). CONCLUSION: Using this algorithm, a reliable determination of spatial coordinates of distinct points of interest is possible as prerequisite for absolute quantitative measurements from biplane angiograms.

Angiocardiography↗