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 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

A simple, noninvasive radionuclide technique which measures the severity of valvular regurgitation has been developed. The technique compares right and left ventricular stroke volume indices (change in counts between diastole and systole over the left and right ventricles) from 45 degrees LAO gated cardiac blood pool scans. In 14 control subjects, the left-to-right ventricular stroke index ratio was near unity (1.15 +/- 0.15 [SD]). In 26 patients with mitral and/or aortic regurgitation it was larger (range 1.36--5.30, mean 2.44). Comparison between the stroke index ratio and qualitative angiographic estimates of regurgitation revealed good agreement (F = 45.5, p less than 0.001). Gated cardiac blood pool scans permit noninvasive assessment of the severity of valvular regurgitation.
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PMID:Measurement of aortic and mitral regurgitation by gated cardiac blood pool scans. 44 49

Left ventricular (LV) intramyocardial markers (MM) were used to study the effects of intravenous verapamil on LV pump function and diastolic filling dynamics. Verapamil (0.1 mg/kg bolus followed by 0.005 mg/kg/min) was administered to 10 patients with severe coronary artery disease 4 years after coronary bypass grafting and implantation of 7 tantalum markers into the LV. MM were filmed at 100 frames/sec (biplane 30 degrees RAO/60 degrees LAO). The digitized biplane MM coordinates were transformed into 3-dimensional coordinates and maximal projection area was defined. LV volumes were calculated frame-by-frame and ejection fraction and peak filling rate derived. Pressure-volume relations were calculated in early-, mid-, and end-diastole. Verapamil caused a slight rise in end-diastolic pressure (12 to 14 mmHg, p less than 0.001) and end-diastolic volume (142 to 152 ml; p less than 0.005) and a fall in max dP/dt (1732 to 1570 mmHg/s; p less than 0.01) reflecting the drug's negative inotropic action. Verapamil reduced LV systolic pressure (136 to 126 mmHg; p less than 0.01), diastolic aortic pressure (74 to 68 mmHg; p less than 0.001) and peripheral resistance (1496 to 1348 dynes.s.cm-5; p less than 0.025); cardiac index was increased (2.7 to 2.9 l/min/m2; p less than 0.05), as were ejection fraction (47 to 49%; p less than 0.02) and stroke volume (67 to 75 ml; p less than 0.001). Great cardiac vein flow increased as well (88 to 102 ml/min; p less than 0.005).(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Effects of intravenous verapamil on left ventricular systolic function and diastolic filling dynamics in patients with coronary artery disease: analysis of intramyocardial markers. 326 99

As a new method for regional wall motion analysis, the tomographic functional images, including "coronal", "sagittal" and "four-chamber" sections, were produced by applying the fundamental Fourier analysis using gated cardiac pool emission computed tomography (POOL-SPECT). Segmental wall motion was qualitatively assessed from the functional images in 10 normal subjects and in 48 patients with myocardial infarction. The results were compared with those assessed by gated blood pool planar images (modified LAO 45), two-dimensional echocardiography (2DE) or contrast left ventriculography (LVG). The following results were obtained. 1. POOL-SPECT imaging could separate the ventricle in three dimensions from the neighboring cardiovascular system by avoiding the overlapping blood pool to make accurate recognition of regional wall motion. 2. The functional tomograms had greater clinical efficacy in the diagnosis of infarcted segments than did the conventional equilibrium method, with high sensitivity (93/99, 93.9%), specificity (128/141, 90.8%) and accuracy (221/240, 92.1%), especially in the apical and inferoposterior portions. 3. Tomographic functional imaging facilitated estimating segmental cardiac performance from spatial and temporal aspects. The amplitude image which expresses regional stroke volume was readily available to detect hypokinesis and akinesis. The phase image of the initial cardiac movement was very useful for diagnosing dyskinesis. 4. In comparing the qualitative analysis with 2DE or LVG, complete agreement was observed in 80% (128/160) and 85.1% (149/175) of segments, though POOL-SPECT imaging showed underestimations in 11% of the segments. In conclusion, POOL-SPECT can be performed repeatedly without potential risks and the tomographic functional images derived from application of Fourier analysis to POOL-SPECT images are very useful for qualitative and three-dimensional analysis of regional wall motion. Thus, this technique may be a promising procedure in clinical investigations, obviating the disadvantages of conventional methods.
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PMID:[Qualitative determination of infarct segment by Fourier analysis using gated cardiac pool emission computed tomography]. 350 41

It is demonstrated that right ventricular volumes can be measured accurately by biplane cineangiography using the Simpson's rule or various area-length methods. In order to validate the single plane approach a biplane (30 degrees RAO-60 degrees LAO) right ventricle (RV) cineangiography was performed in 10 adults investigated for chest pain without coronary artery disease or any other heart disease. RV volumes (EDV: end-diastolic; ESV: end-systolic; SV: stroke volume) and EF (ejection fraction) were measured by biplane and single plane analysis with the same area-length method using the pyramide with triangular base as geometric model (Ferlinz). The results are: RVEDV (ml/m2) biplane (B) 81 +/- 10, monoplane (M) 82 +/- 11; RVESV (ml/m2) B 33 +/- 6, M 35 +/- 8; RVSV (ml/m2) B 48 +/- 8, M 47 +/- 10; RVEF (%) B 59 +/- 6, M 57 +/- 8. Equations of linear regression show the following correlations: RVEDV R = 0.82 p less than 0.01; RVESV R = 0.77 p less than 0.01; RVSV R = 0.92 p less than 0.001; RVEF R = 0.85 p less than 0.01. Authors conclude to a good enough correlation between monoplane and biplane analysis especially for RVSV and RVEF. They underline the great variability of individual values.
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PMID:[Measurement of right ventricular volume by cineangiography. Validation of monoplane analysis compared with biplane]. 361 5

To evaluate the frequency of right ventricular dysfunction following recovery from myocardial infarction (MI) and the relationship of segmental right ventricular (RV) wall motion abnormalities to left ventricular (LV) function or location of coronary arterial stenosis, biplane right and left ventricular cineangiograms were obtained in 100 consecutive patients (4 +/- 3 months post MI). Thirty (group A) had anterior MI and significant stenosis or obstruction of left anterior descending artery (LAD). The remaining 70 patients had inferior MI. They were divided into three groups according to the site of the main coronary stenosis or obstruction and corresponding LV akinesia: right coronary artery (RCA) proximal to the acute marginal artery (RMA), (group B: 32 patients), RCA distal to the RMA (group C: 18 patients), left circumflex artery (LCF), (group D: 18 patients). RV and LV end-diastolic volume index (EDV), end-systolic volume index (ESV), stroke volume (SV) and ejection fraction (EF) have been determined. RV segmental wall motion was assessed in RAO and LAO projection by determining the percentage of systolic shortening (+ delta R) along 11 hemiaxes. Mean axial shortening (delta R) of the RV inferior and free walls were considered. When compared with that in 10 normal subjects, RV end-diastolic volume (RVEDV), RV end-systolic volume (RVESV) were increased and RV ejection fraction (RVEF) was lower in patients with anterior or inferior MI. Inferior delta R exhibited comparable sequential changes in the three groups of inferior MI and similar LVEF alteration.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Right ventricular function in healed myocardial infarction in man. A cineangiographic assessment. 400 47

When cardiac hypokinesis in myocardial infarction is analyzed by means of phase analysis of radionuclide (RI) angiography, there are some cases in which the amount of regional wall movement of the left ventricle does not so decline, but the phase delay of regional wall movement is great. Hence, a simulation experiment was performed with a computer to evaluate the influences of regional phase delay on cardiac work. It was assumed that the radius of the model of the left ventricle varies from 3 cm in the late diastolic phase to 2 cm in the late systolic phase, and that in the initial 1/3 time of diastole, the radius alters by 90% of the change. One cardiac cycle (360 degrees) was divided into 60 fractions (1 fraction = 6 degrees), 0 degree being the end of diastole and 180 degrees the end of systole. An ischemic area was supposed to cover S% of the whole volume of the left ventricle, its amount of regional wall movement being P% of the normal area, and the phase delay being R degrees. By varying S, P and R, and taking weighted means of volume curves and normal ones, their assumed volume curves of the left ventricle were computed. Stroke volume (SV) and ejection fraction (EF) obtained from these curves were compared to those obtained from the normal curves, and were expressed in percentage (%SV, %EF). The influences of the changes of S, P and R on the volume curve and on the cardiac work were examined. Then the count curves of the left ventricle (LV) were obtained by gated RI angiography in 22 cases of myocardial infarction and 8 healthy controls, and LV regional wall movements were examined by means of the Fourier analysis. The circular volume was partitioned from the center into eight sections on the LV image of LAO 45 degrees, and the amount of wall movement and the phase delay of each section were evaluated from the count curves of each section. The following results were obtained. %SV and %EF declined with sole occurrence of regional phase delay. Occurrence of the regional phase delay flattened the slope of the volume curve of the initial diastolic phase and formed shoulders on this curve. This was observed also on the count curves actually determined from cases with myocardial infarction. When regional wall movement was markedly decreased, the influence of the regional phase delay on the pattern of the volume curve was slight even if the phase delay was extensive.(ABSTRACT TRUNCATED AT 400 WORDS)
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PMID:[Effect of regional phase delay on left ventricular performance studied by radionuclide angiography]. 667 76

Carbochromen increases coronary flow and cardiac output. A previous study has advanced the hypothesis that the latter may be due to afterload reduction. Fourteen patients with coronary heart disease have now been studied by means of radionuclide angiocardiography. Gated blood pool angiocardiographic data were collected in basal conditions and, without moving the patient, 80 mg of carbochromen were administered i.v. Data were collected again, following infusion, during 3'-6'(1) and 7'-10'(2) periods. Changes in the following parameters have been evaluated: LV ejection fraction (EF), LV ejection rate (ER), system pressure (BP), heart rate (HR), cardiac output index (CO), stroke volume index (SV), LV end-diastolic volume index (EDV), systemic vascular resistance index (SVR), regional LV wall motion. During period 1 a significant decrease was observed in BP and SVR, the other parameters remaining unchanged. During period 2 there was a significant increase in CO, SV, EF, ER and a significant decrease in SVR. BP was unchanged. No changes were ascertained in HR and EDV. Eight patients, in basal conditions, showed asynergy in the LAO projection. Three of these patients showed improved wall motion during period 2. A possible central action of carbochromen should be pointed out. This conclusion can be drawn by observing the increase in the pump indexes, while BP and SVR show a decrease and EDV and HR no change. The left ventricular wall motion improvement observed in some of the cases confirms the possibility that carbochromen is capable of improving cardiac contractility. This effect may follow the regional myocardial perfusion increase.
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PMID:Haemodynamic effects of carbochromen. 698 2

Using a method for determination of absolute volumes, including correcting for attenuation, we have explored the ability of the method to determine stroke volume in humans by radionuclide techniques. Thermodilution cardiac output determinations and multigated equilibrium blood-pool scintigraphy in the LAO view were performed simultaneously in twenty patients in which no evidence of intracardiac shunts or valvular disease was present. The correlation was good between the attenuated radionuclide and thermodilution stroke volume (r = 0.80, s.e.e. of estimate = 12 ml; SVtd = 2.31 x SVr + 18 ml). When correction for attenuation was made, the correlation improved (r = 0.96, s.e.e. = 6 ml) and approached the line of identity (SVtd = 0.99 x SVr + 1.2 ml). The correlation was also good between radionuclide cardiac output, corrected for attenuation, and the thermodilution cardiac output (r = 0.89, s.e.e. = 0.36 l/min; COtd = 0.86 x COr + 0.67 l/min). Thus our method of correction for attenuation in the determination of absolute left-ventricular volumes has been shown to provide a reliable, noninvasive means of calculating stroke volume and cardiac output in humans, without the use of geometric assumptions or regression equations.
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PMID:Influence of attenuation on radionuclide stroke volume determinations. 710 24

The stroke count ratio (SC ratio: SCL/SCR) for left to right ventricular enddiastolic-endsystolic count differences was obtained from LAO multi-gated cardiac blood pool scintigrams for quantitative assessment of valvular regurgitation and shunts. SC ratio, 1.48 +/- 0.24 (mean +/- S.D.) in 21 normal subjects, was decreased in 7 patients with atrial septal defects (ASD) and in one with isolated tricuspid regurgitation (TR), and increased in 15 patients with aortic regurgitation (AR) and in 6 with mitral regurgitation (MR). In post-surgical reassessment of 3 patients, the ratio was restored in normal range. Comparison between SC ratio and angiographic estimates of regurgitation revealed good agreement. Regurgitant fraction (RF) in AR or MR and shunt ratio (SR) in ASD were calculated by the formula: RF = 1-1.48/SC ratio, and SR = 1-SC ratio/1.48, respectively. These were derived by assuming that an excess of stroke counts was due to regurgitant or shunt flow and that the coefficient in counting ventricular radioactivity was 1.48. Agreement was found between RF or SR measured by this formula and by the invasive method. This method permits noninvasive quantitation in patients with valvular regurgitation and shunts without complicated computer procedures.
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PMID:[Analysis of left to right ventricular stroke count ratio by gated radionuclide angiocardiography: detection and quantitation of valvular regurgitation and shunts (author's transl)]. 726 83

At present right ventriculography data cannot be accurately estimated owing to the absence of software for quantitative analysis of the right ventricle (RV) volumes and function. The aim of this study was to use existing software for left ventriculography analysis to estimate right ventricular volumes and function in patients without coronary lesions and in those with coronary artery disease (CAD). Thirty-two patients without significant lesions of coronary arteries and 20 patients with CAD were examined with left ventriculography and right atriography. Each examination was performed in 2 projections: 30 degrees right anterior oblique (RAO 30 degrees) and 60 degrees left anterior oblique (LAO 60 degrees) projections. Correction factor (CF) was obtained by finding the ratio between stroke volumes of the left and right ventricles. The mean CF was 0.9243+/-0.2887 for patients without CAD and 0.8758+/-0.2232 for patients with CAD. Such calculation is the easiest and quite accurate method of determining RV volumes and function by using existing software of quantitative angiographic analysis.
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PMID:Quantitative angiographic analysis of right ventricular global function in normal incidences and in patients with coronary artery disease. 1579 2


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