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W E Adam

Publications and source records attributed to W E Adam.

At least 55 records · Page 3Linked to original sources
PubMed1987

[Radionuclide ventriculography--a noninvasive method of diagnosis and quantification of tricuspid valve insufficiency].

The diagnosis of tricuspid regurgitation (TR) is difficult to make by simple clinical methods or by invasive techniques. Contrast echocardiography and Doppler echocardiography have improved diagnostic results, but a golden standard is still not available. Radionuclide ventriculography (RNV) is a well-established method for the detection and quantification of a volume load on the left ventricle: the regurgitation fraction can simply be derived from the regurgitant index as the ratio of enddiastolic-endsystolic count-rate differences between the left and right ventricle. In left heart valvular regurgitation a regurgitant index exceeding the upper normal limit can be expected. This study was performed to evaluate the diagnostic accuracy of an abnormally low regurgitant index in detecting TR, which is accompanied by an isolated volume load on the right ventricle. A series of 33 patients with TR on physical examination and cardiac catheterization underwent RNV and was compared with 48 patients with right ventricular enlargement or pressure load on the right ventricle. In addition, the specificity of the method was evaluated in 470 consecutive patients with various forms of heart disease. In 18 out of 20 subjects with isolated TR a regurgitant index below the lower normal limit was found. The remaining 2 cases with minor TR had a regurgitant index within the normal range, which is 0.89 to 1.97 in this laboratory. In patients with additional volume load on the left ventricle, the sensitivity of the method was found to be low, as could be expected from the principle of the method. The time-activity curve over the liver was usually in phase with that recorded over the atria in subjects with TR. Therefore, the additional examination of a region of interest over the liver was particularly useful in these patients with concomitant aortic or mitral valve regurgitation. None of the 48 patients with right ventricular enlargement or pressure load on the right ventricle had a falsely positive result. A total of 17 out of 470 consecutive patients had a regurgitant index below the normal range; left ventricular function was severely impaired in 9 of these patients. The remaining subjects had a regurgitant index slightly below the lower normal limit. In conclusion, RNV has a high sensitivity in the diagnosis of TR in patients without left heart valvular regurgitation and a high specificity in patients without severely impaired left ventricular function and without left-to-right shunt through an atrial septal defect.(ABSTRACT TRUNCATED AT 400 WORDS)

Adult↗
PubMed1986

Diagnostic value of early and delayed 201Tl thyroid scintigraphy in the evaluation of cold nodules for malignancy.

We performed 201Tl thyroid scintigraphy using an early and delayed scanning technique in 34 patients exhibiting cold nodules on 99mTc scans. Of the 29 benign nodules, 27 were correctly diagnosed as being negative, i.e. 93% specificity. However, two of five malignant nodules failed to concentrate activity on both the early and delayed scans. The low sensitivity (60%) of this method for detecting carcinomas limits its clinical value in the routine diagnostic work-up of patients with suspected thyroid cancer. Our findings are in contrast to previous more optimistic reports.

Adult↗
PubMed1986

Haemodynamic response to exercise in patients with chest pain and normal coronary angiograms.

A series of 42 patients with chest pain but normal coronary angiograms and normal haemodynamics at rest were prospectively classified as typical angina (group 1, N = 9) or atypical angina (group 2, N = 16) or non-anginal chest pain (group 3, N = 17). All patients underwent radionuclide ventriculography and measurement of pulmonary artery pressure at rest and during maximum exercise. Comparison of data during exercise revealed significantly higher (P less than 0.025) left ventricular filing pressures as reflected by the diastolic pulmonary artery pressure in group 1 (29 +/- 5 mmHg) than in both group 2 (22 +/- 6 mmHg) and group 3 (22 +/- 5 mmHg). The rest-to-exercise change in left ventricular ejection fraction was variable and not significant in group 1 (62 +/- 6% vs 63 +/- 14%). By contrast, both group 2 and group 3 had significant increases (63 +/- 6% vs 69 +/- 10%, P less than 0.02 and 63 +/- 5% vs 68 +/- 5%, P less than 0.01). The classification as 'typical angina' was predictive of an abnormal (greater than 25 mmHg) filling-pressure response to stress. The positive and negative predictive values were 78% and 70%, respectively. The clinical classification was not a predictor of an abnormal (delta less than 5%) ejection-fraction response. No correlation between radionuclide and filling-pressure data could be established. The data suggest that the majority of patients assigned to group 1 manifested an impaired left ventricular function with exercise. This was primarily related to abnormalities in diastolic filling while the systolic performance was not consistently depressed.

Adult↗
PubMed1986

Interactions of vasodilators with calcium entry- and beta-blockers in patients with coronary heart disease.

Combinations of antianginal drugs may be used for an additive effect against angina, but also to off-set unwanted effects of one drug with another, either by direct effects or by a reduction of dosage of each drug. Based on earlier studies with separate drugs we have now examined the effect of 150 mg bupranolol combined with 40 mg isosorbide dinitrate (ISDN) in one retarded tablet, given twice daily. 22 patients with CHD entered the study, 11 of those with and 11 without signs of ischemia during exercise. In an acute radionuclide ventriculographic (RNV) study 2 h after the tablet, ejection fraction (EF) during exercise increased only in patients with exercise ischemia (+6%, p less than 0.001). In the other patients EF did not change. After 21 days of treatment echocardiographically determined end-systolic and end-diastolic diameters decreased, resulting in an increase of shortening fraction by 15.6% (p less than 0.05). Heart rate, systolic and diastolic pressure and ST-segment depression decreased significantly. In another acute RNV study the effect of a venous vasodilator, molsidomine 4 mg s.l., was examined after nifedipine 10 mg s.l. in 19 patients with CHD, 9 with and 10 without exercise ischemia. Differences between drugs were most prominent during exercise. In the nonischemic group EF rose by 6.6% after nifedipine (n.s.) and by 14% after molsidomine (p less than 0.01 against control). In the group with ischemia EF rose by 12.6% after nifedipine and by 17.4% after additional molsidomine, significant against control (p less than 0.01) as well as against nifedipine (p less than 0.05).(ABSTRACT TRUNCATED AT 250 WORDS)

Bupranolol↗
PubMed1986

Parametric imaging of experimentally simulated Wolff-Parkinson-White syndrome conduction abnormalities in dogs: a concise communication.

In order to test the diagnostic potential of phase analysis of radionuclide ventriculography (RNV) for localizing accessory bundles in Wolff-Parkinson-White (WPW) syndrome, 24 experimental runs were performed in three open chest instrumented dogs. After a baseline study, WPW syndrome was simulated by stimulation at seven different sites around the base of the ventricles, and RNV's were obtained. Subsequent data processing including Fourier transformation allowed the localization of the site of the first inward motion of the ventricles by an isophasic wave display. In sinus rhythm, the septum contracted first. During ectopic premature ventricular stimulation by triggering the atrial signal, the phase scan was altered only when the stimulus was applied earlier than 20 ms before the expected QRS complex during sinus rhythm. During stimulation with fixed frequency, only the left lateral positions of the premature stimulation were detected by phase analysis with a sensitivity of 86%. Neither the antero- or posteroseptal nor the right ventricular premature contraction pattern could be exactly localized.

Animals↗
PubMed1986

[Comparison of left ventricular end-diastolic volume determined by radionuclide ventriculography, by contrast-media ventriculography and by a geometry-independent method].

Ejection fraction and end-diastolic volume (EDV) are valuable parameters of left ventricular function. They can be measured by radionuclide ventriculography. This study examines EDV in comparison to two other methods. A comparison was made between EDV derived from radionuclide ventriculography (RNV), standard contrast ventriculography and a 'hybrid' method, which calculates EDV from ejection fraction, heart rate and thermodilution cardiac output. Two groups of patients were examined: 54 patients with various cardiac diseases by contrast and radionuclide ventriculography (RNV); and 18 patients with typical angina were examined by RNV at rest and during exercise three times: Control without medication, 20 minutes after 10 mg metoprolol i.v. and again 10 minutes after the second exercise and 10 mg isosorbide dinitrate sublingually. In comparison to contrast ventriculography RNV overestimated EDV by 27%, and in comparison to the hybrid method by 11% with satisfactory linearity. The extent of error increases with decrease of ventricular volume. The assumption that the two short axes of the left ventricle are equally long causes one quarter of total error. Errors caused by the algorithm delineating the borders of the left ventricle cannot be measured. For clinical purposes radionuclide ventricular EDV seems to yield satisfactory results.

Cineangiography↗
PubMed1986

Specification of regional wall motion abnormalities by phase analysis of radionuclide angiograms in coronary artery disease and non-coronary artery disease patients.

Fourier transform of gated radionuclide ventriculograms (RNV) permits the quantitative evaluation of regional wall motion abnormalities (RWMA) regarding both regional magnitude (amplitude display) and regional time sequence of contraction (phase display). In this study, an attempt was made to further specify coronary artery disease (CAD) and non-CAD RWMA detected on consecutive exercise RNV in 17 patients (pts) with proven severe CAD; or on resting RNV in 24 pts with transmural myocardial infarction (MI) compared with 27 pts after treatment with daunorubicin (DAU). RWMA were defined objectively from parametric images by a decrease of the sectorial amplitude by more than 2 s.d.s of normal as determined by quantification of RNV studies of 20 normal individuals. In 15 out of 17 CAD pts (88%) and in 19 out of 24 MI pts (79%), a significantly decreased regional amplitude was found. Importantly, in all abnormal CAD and MI amplitude scans (100%), a significantly abnormal phase delay in the same region could be noted. In five out of 27 pts on DAU (18%) an apical hypokinesis could be verified. In comparison with CAD pts, however, the phase distribution was normal in all these DAU pts. Thus, standardized phase analysis of RNV data provides a powerful tool for specifying RWMA. It allows a highly specific separation of RWMA caused by exercise-induced ischemia, MI, or DAU.

Adult↗
PubMed1986

[Value and reliability of blood pool scintigraphy in liver hemangiomas].

In a prospective study the importance and reliability of blood-pool scanning were checked. 40 patients were investigated. In 36 patients sonographical evidence of one or more hemangiomas was shown. 4 patients with 11 primary or secondary tumors in the liver were taken as control group. All tumors could be verified by histology or CT. Differentiation between hemangiomas and other space-occupying lesions (benign and malignant tumors) was possible with high accuracy. We found a sensitivity of 100% in hemangiomas larger than 4 cm, a sensitivity of 78% in hemangiomas larger than 3 cm and a sensitivity of 69% in hemangiomas larger than 2 cm. Falsely positive results were not observed. In conclusion, blood-pool scanning of the liver is a reliable method in the differential diagnosis of hemangiomas.

Adult↗
PubMed1985

An evaluation of the diagnostic efficacy of phase analysis of data from radionuclide ventriculograms in patients with Wolff-Parkinson-White syndrome.

It has been suggested that phase analysis of radionuclide ventriculograms may be of value for detecting and localising the abnormal sequence of ventricular contraction secondary to Wolff-Parkinson-White (WPW) syndrome. The present study was undertaken to test this hypothesis. The space--time sequences of right- and left-ventricular action obtained from radionuclide ventriculograms obtained during rest studies were evaluated in 8 patients with WPW syndrome (confirmed by 12-lead surface electrocardiography) and compared to those of 14 normal subjects. All of the latter showed a consistent ventricular activation pattern, i.e. the first site of ventricular activity in the upper septal region followed by a second site either at the base of the left ventricle or located apically. It was possible to diagnose 11 of the 14 normal subjects (specificity, 79%) and 7 of the 8 patients (sensitivity, 88%). The 4 patients who had been classified as having a left-sided accessory bundle by surface electrocardiography were likewise diagnosed by phase analysis, as were the 2 patients with a confirmed right-sided bypass tract. Two patients with septal posterior accessory pathways could not be identified by phase analysis. Furthermore, cases with an activation pattern which closely resembled that of the 2 patients with right-sided accessory bundles were found to be normal from their ECGs. It is now necessary to evaluate phase analysis against invasive electrophysiological methods in such patients.

Electrocardiography↗
PubMed1985

Effects of molsidomine on regional contraction and global function of the left ventricle.

Fifteen consecutive patients (mean age 54 years) with proven coronary heart disease were studied with radionuclide ventriculography. After resting and exercise control studies, repeat studies were performed after administration of 4 mg of molsidomine sublingually and again after administration of 10 mg of metoprolol intravenously. Rest to exercise ejection fraction (EF) decreased significantly. This was significantly attenuated by molsidomine and by metoprolol. In a subset of nine patients with exercise ischemia, EF showed significant (p less than 0.05) improvement after molsidomine administration (46.7 +/- 13.7% to 57.1 +/- 16.7%), which was diminished to 54.4 +/- 10.5% after metoprolol administration. In the subgroup without exercise ischemia, molsidomine increased the EF to a lesser extent (47.3 +/- 12.7% to 52.6 +/- 13.4%, p less than 0.05). After administration of metoprolol the EF decreased below the control level (44.4 +/- 10.6%). Regional Fourier amplitudes accentuated the differences between the two groups. We conclude that molsidomine and metoprolol improve left ventricular function in patients with coronary heart disease and ischemia during exercise. In patients with reduced left ventricular function without signs of ischemia, molsidomine improves function as well and should be used additionally, if beta blockers are indicated for other reasons.

Adult↗
PubMed1985

Limitations of radionuclide ventriculography in the non-invasive diagnosis of coronary artery disease. A correlation with right heart haemodynamic values during exercise.

A consecutive series of 56 patients with chest pain but no evidence of previous myocardial infarction was prospectively studied by radionuclide ventriculography to determine the value of global and regional radionuclide indices in detecting coronary artery disease. The results were correlated with the clinical judgment of chest pain, the results of the exercise electrocardiogram, and the right heart haemodynamic measurements during exercise. As a result of the criteria for entry, the study group was representative of the population seen in such a clinical setting. Only 25% of patients had coronary artery disease. The predictive power of radionuclide ventriculography was limited. The conventionally used criterion that normal subjects have an increase in left ventricular ejection fraction of at least 5% with exercise provided only 78% sensitivity and 57% specificity. Fourier analysis and visual interpretation of radionuclide studies wrongly diagnosed three out of 10 patients with extensive disease requiring surgery. These results suggest that radionuclide ventriculography is of limited value in the non-invasive diagnosis of coronary artery disease.

Adult↗
PubMed1985

[Isotopic methods].

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Arrhythmias, Cardiac↗
PubMed1984

[Radionuclide ventriculography in aortic and mitral valve insufficiency. Pre- and post-operative studies of valve replacement surgery].

Radionuclide ventriculography (RNV) is now a well-established procedure for the noninvasive evaluation of cardiac hemodynamics, including the detection and quantification of valvular regurgitation. 46 patients undergoing aortic or mitral valve replacement were examined by RNV pre- and postoperatively. The specificity of RNV in the diagnosis of aortic or mitral incompetence was high. All cases of moderate to severe aortic regurgitation were identified. This, however, was not true for mitral incompetence. A significant overlap between the left atrium and the left ventricle in the LAO view is held responsible for this decrease in sensitivity. The quantification of aortic regurgitation and the assessment of left ventricular function by RNV appears to hold promise in the preoperative workup. This diagnostic approach yields important additional information, which may be essential in the appropriate timing of surgical intervention. Aortic valve replacement for incompetence as well as for stenosis was accompanied by a significant improvement in global left ventricular ejection fraction. No postoperative change in ejection fraction was found in cases of mitral incompetence, while a slight increase was observed following operative therapy for mitral stenosis. The radioisotope findings were correlated to the results obtained by cardiac catheterization and noninvasive techniques such as echocardiography. The place of RNV in the pre- and postoperative management of valvular heart disease is delineated in this paper. It is of special value in the evaluation of aortic incompetence and may be an important diagnostic adjunct in the approach to the patient with mitral valve disease or aortic stenosis.

Adult↗
PubMed1982

Radionuclide ventriculography: a noninvasive method for the detection and quantification of left-to-right shunts in atrial septal defect.

The present investigation was undertaken to assess a new scintigraphic method for the diagnosis of left-to-right shunts due to atrial septal defect based on the differing stroke volumes of left and right ventricles and to compare it with oxymetric data. Radionuclide ventriculography was carried out after injection of 20 mCi 99mtechnetium-labeled red blood cells. Time-activity curves were obtained from the left and right ventricular regions, and the ratio (A) of end-diastolic-end-systolic count rate differences for the left and right ventricles was calculated. The left-to-right shunt (in percent of the pulmonary flow rate) is then given as 100 X (1 - A/1.43; 1.43 being the previously determined mean value of A in 66 normal patients. In 16 patients with an atrial septal defect and/or partial anomalous pulmonary venous connection a correlation of r = 0.81 was found between those shunts determined by the scintigraphic method and those calculated by oxymetric data. The specificity of the method and the sensitivity in detecting left-to-right shunts exceeding 30% are high. The method is practical and already widely used for determination of ejection fraction end-diastolic volume and other factors. The combination of this technique with other methods for shunt diagnosis such as gamma-fit analysis may prove of special value.

Heart↗
PubMed1982

Regional evaluation of the left ventricular wall motion by radionuclide ventriculography.

ECG gated radionuclide ventriculography was performed in 85 patients with heart disease. From the analysis of time activity curves of each pixel, sets of parametric scans were displayed. Of 496 parametric scans, 192 were normal and 304 showed wall motion abnormalities. There was good correlation between the individual parametric scans (r greater than or equal to 0.815) and between parametric scans and contrast ventriculograms (r greater than or equal to 0.631) in the occurrence and extent of regional wall motion abnormalities. The highest sensitivity was revealed by the peak filling rate (relaxation velocity) scan. The best specificity was shown by scans using the amplitude and phase of the first Fourier element. Good results were obtained by a combination of four parametric images. The ability of the phase scan to detect local dyskinesis may be better than that of the contrast ventriculogram. Changes in parametric scans were related to, but preceded, impairment of left ventricular function (r greater than or equal to 0.513), It is concluded that parametric scans provide a reliable, objective and non-invasive method for regional evaluation of left ventricular function, of great use in the diagnosis of local wall motion abnormalities and their effect on the heart performance.

Adolescent↗