George A. Hermann

Reversible asynergy. Histopathologic and electrographic correlations in patients with coronary artery disease.

Histopathologic-electrographic studies of ventriculography depicted nitroglycerin responsive and unresponsive asynergic areas were performed in 25 patients. Of 29 areas, 12 improved with nitroglycerin, showing < 10% muscle loss. Seventeen unimproved zones demonstrated significant fibrosis. Epicardial electrograms showed R waves in eight of nine improved zones. Of 11 unimproved zones, eight had Q waves.Histopathologic-electrographic data from five responders showed < 10% muscle loss, of whom four had epicardial R waves. Six unresponsive areas had significant fibrosis, with a QS over four.Thus, nitroglycerin responsive asynergic areas are generally comprised of histologically intact myocardium and are associated with epicardial R waves.

Relationship between regional myocardial perfusion and the presence, severity and reversibility of asynergy in patients with coronary heart disease.

SUMMARY In this study, the interrelationship of regional myocardial perfusion at rest and after exercise, the presence, severity and reversibility of asynergy and the severity of the corresponding coronary arterial obstruction was examined. Forty-five patients underwent exercise testing with thallium-201, cardiac catheterization including intervention (nitroglycerin) ventriculography and coronary arteriography. Of the 45 patients, 13 were normal by catheterization while 32 had coronary heart disease (CHD). Of the 32 with CHD, 21 had asynergy and 11 had normal ventricular contraction. Eighteen of 21 patients with asynergy also had a myocardial perfusion abnormality after exercise, while only three of the 11 without asynergy had a perfusion abnormality (P < 0.001). Of the 21 hypokinetic zones, only 67% had a myocardial perfusion abnormality, while all of the akinetic and dyskinetic zones had a perfusion defect (P < 0.025).Twenty-seven left ventricular zones demonstrated perfusion abnormalities after exercise, of which 19 had either normal or improved myocardial perfusion at rest. Fifteen of these 19 had reversible asynergy on nitroglycerin ventriculography while three had normal contraction. In contrast, the eight zones with myocardial perfusion defects, both at rest and with exercise, all had associated asynergy which was irreversible.A significant relationship was also observed between the severity of the coronary arterial obstruction, asynergy and a perfusion abnormality. Thus, of 39 myocardial zones supplied by 2 90% coronary arterial lesions, 24 had asynergy and 21 of these also had a corresponding myocardial perfusion defect. However, of the remaining 15 without asynergy, only three had a perfusion abnormality (P < 0.001). In addition, of 17 zones subserved by coronary vessels having 75-89% obstructive lesions, three of seven with asynergy had an associated perfusion abnormality, while none of the 10 without asynergy had a perfusion defect (P < 0.025).In summary, the findings of the present study indicate that there is a close interrelationship between the severity of a coronary arterial obstruction and both decreased regional myocardial perfusion and contraction in man. Myocardial perfusion, which is adequate at rest but abnormal with stress, is associated with less severe and reversible asynergy, while perfusion, which is abnormal even at rest, appears to be associated with more severe and irreversible asynergy.

Quantitative radionuclide angiography in the right anterior oblique view: comparison with contrast ventriculography.

Abstract Because the right anterior oblique view is widely accepted as the best “single” projection for assessing wall motion, the utility of this view during first pass radionuclide angiography was studied in 44 patients who also underwent contrast ventriculography and coronary arteriography. Of the 44 patients, 8 had a normal heart and 14 had coronary artery disease with normal wall motion on contrast ventriculography. All also had normal contraction on radionuclide angiography. On contrast ventriculography, 22 patients had coronary artery disease and asynergy involving 34 left ventricular segments. Of 17 segments localized to the anterior and apical asynergic areas on contrast ventriculography, 16 were accurately localized with radionuclide angiography. Similarly, of 17 inferior asynergic areas, 13 were also shown to be inferior on radionuclide angiography. In addition, quantitative assessment of the severity of asynergy using the hemiaxis method demonstrated a good correlation between asynergic severity as defined with radionuclide angiography and contrast ventriculography. Of 11 anterior areas, 7 defined as hypokinetic with contrast ventriculography demonstrated chordal shortening of 20.1 ± 5.2 percent (mean ± standard error of the mean) ( P P After appropriate background subtraction, determination of ejection fraction using radionuclide angiography showed a correlation of 0.839 between the left anterior oblique and right anterior oblique projections independent of the sequence of injection. In addition, ejection fraction determined with radionuclide angiography in the left ( r = 0.824) and right ( r = 0.801) anterior oblique views correlated well with ejection fraction assessed from contrast ventriculography. Thus, first pass radionuclide angiography performed in the right anterior oblique view is a sensitive noninvasive means of assessing the location and severity of asynergy as well as global left ventricular performance in patients with coronary artery disease.

Effects of previous myocardial infarction on measurements of reactive hyperemia and the coronary vascular reserve

The measurement of coronary vascular reserve by the reactive hyperemic response to ischemia has been advocated as a practical method of assessing the physiologic significance of coronary stenoses. Because the concept of measuring coronary blood flow during maximal vasodilation assumes a normal arteriolar network and viable myocardium, the presence of previous myocardial infarction may cause a significant decrease in the coronary reserve unrelated to the severity of a coronary stenosis itself. To determine the potential importance of this effect, rest and hyperemic coronary blood flow were measured in 14 dogs in the regions subtended by the left anterior descending and left circumflex coronary arteries. One hour occlusion of the left anterior descending artery followed by reperfusion was performed in 10 dogs; the 4 remaining dogs in which no occlusion was performed served as control animals (group 3). One week later, rest and hyperemic blood flow measurements were repeated in all 14 dogs. Of the 10 dogs undergoing left anterior descending artery occlusion, 5 had a large infarct (group 1) and 5 had a small infarct (group 2). In group 1 in the 1 week study, both the coronary reserve in the left anterior descending artery zone and the ratio of the coronary reserve in this zone and the left circumflex artery zone decreased compared with values before occlusion (from 425 +/- 134 to 150 +/- 34% and from 1.56 +/- 0.40 to 0.68 +/- 0.31, respectively; both p = 0.007).(ABSTRACT TRUNCATED AT 250 WORDS)

Diagnostic accuracy of salivary scintigraphic indices in xerostomic populations.

PURPOSE Three decades of work to enhance the diagnostic accuracy of salivary scintigraphy have generated various plausible decision criteria. This study evaluates four commonly cited numeric indices in studies of xerostomic populations and how accurately they identify Sjögrens syndrome, chronic sialadenitis, radiation sialadenitis, and drug effects and distinguish each from the other. METHODS Stimulated dynamic salivary scintigraphy was performed on 295 xerostomic patients and on 31 controls. The nonparametric area under the receiver operating characteristic curves expressed the diagnostic accuracy of the following scintigraphic indices: the parotid:submandibular ratio of unstimulated glandular activity, the peak:baseline uptake ratio, its time of occurrence, and the stimulated excretion fraction. RESULTS The stimulated excretion fraction distinguished Sjögrens syndrome and radiation sialadenitis from healthy states with respective accuracies of 0.78 and 0.90. The maximum diagnostic payoff in Sjögrens syndrome occurred at a cutoff of 73%, yielding a 73% rate of test sensitivity and a 73% rate of specificity. The other three indices were not useful. Even the stimulated excretion fraction performed indifferently or poorly in most other diagnostic tasks. CONCLUSIONS In the scintigraphic examination of xerostomic and healthy populations, an acceptable diagnostic utility of the stimulated excretion fraction was evident only in Sjögrens syndrome and radiation sialadenitis. When presented with differential diagnostic alternatives not involving radiation sialadenitis, none of the four numeric indices performed acceptably.

New myocardial perfusion imaging agents: Description and applications

Myocardial perfusion imaging is the most commonly performed procedure in nuclear cardiology. Thallium-201 has been the agent of choice due to its favorable physiologic kinetics: the initial myocardial uptake corresponds to the regional blood flow distribution because of high extraction efficiency during the first transit and the ability to redistribute over time is useful to distinguish scar from ischemia. The physical characteristics of thallium, however, are not ideal for nuclear imaging because of low energy photopeaks, long half-life, and the need for a cyclotron for its production. On the other hand, technetium-99m has very favorable physical characteristics such as a photopeak that has an optimal energy for imaging, a short half-life, and in addition the agent is generator-produced. Thus it is natural to search for technetium-99m-labelled agents for myocardial perfusion imaging to overcome the poor physical characteristics of thallium-201. In this paper, we review the background, technical aspects, clinical application, and future direction.

Cystadenofibroma of the ovary

A case of bilateral papillary cystadenofibroma of the ovaries is presented, and certain clinical and pathologic features of the tumor are summarized. The initial clinical, histologic, cytologic, and histochemical features of this case were suggestive of estrogenic activity engendered by the tumor. Postoperative cytologic data, however, tended to refute this suggestion. Rigorous diagnostic and logical criteria should be fulfilled before assigning a cause-and-effect relationship to any such lesion and a coexisting endocrinologic aberration.

Local characteristics of the normal and asynergic left ventricle in man.

The significance of ventricular asynergy in determining medical prognosis and surgical risk in patients with coronary artery disease and its delineation by ventriculography have been of increasing interest. To determine the underlying histopathologic and electrographic features of left ventricular asynergy, 39 patients undergoing open heart surgery were studied. Thirty-six histopathologic specimens were obtained in 31 patients (26 as transmural needle biopsies and 10 as aneurysm resections). In four normally contracting areas and 12 hypokinetic areas, neither fibrosis nor early changes of myocardial damage was evident. In contrast, of eight akinetic areas there was more than 50 per cent muscle loss in four and from 30 to 35 per cent muscle loss in three, in only one area was there less than 10 per cent muscle loss. Of 12 dyskinetic zones there was more than 75 per cent muscle loss in 10 zones, 35 per cent in one and no pathologic abnormalities in one. Epicardial electrograms were obtained from 35 areas in 29 patients. Of 10 normally contracting ventricles, in one, pathologic Q waves were demonstrated only over the inferior area. Progressive increases in the severity of asynergy were associated with a progressive increase in frequency of initial abnormal Q waves. In only one of nine hypokinetic areas were epicardial Q waves exhibited, but they were present in six of 10 akinetic and five of six dyskinetic areas. Both histopathologic and electrographic data were available from 20 asynergic areas in 16 patients. Initial epicardial R waves were associated with normal biopsy specimens in seven of eight hypokinetic areas. Of seven akinetic areas, initial R waves were associated with 30 to 35 per cent muscle loss in three; of four areas with initial Q waves, there was a 35 per cent muscle loss in one and more than 50 per cent muscle loss in three. Similarly, of five dyskinetic segments, a QS pattern was associated with more than 75 per cent fibrosis in four. In one dyskinetic area there was an intial R wave in association with a normal appearing biopsy specimen. In summary, a good correlation exists between the severity of asynergy by ventriculography, the degree of muscle loss and the presence of epicardial Q waves. However, a significant amount of histologically and electrographically normal myocardium may be present even in severely asynergic areas.

Quantification of absolute luminal diameter by computer-analyzed digital subtraction angiography: an assessment in human coronary arteries.

Determination of absolute lumen diameters has been shown to be useful in predicting the functional importance of a coronary stenosis. In this study, both single-plane and orthogonal biplane digital subtraction angiograms were obtained in human cadaver coronary arteries. A single absolute diameter was calculated at the site of greatest narrowing in 20 segments by two automated computerized algorithms. Minimum and maximum diameters at the site of the stenosis were measured from pathologic sections prepared after pressure fixation. Method 1, which determines the edges by means of the first derivative of the videodensity curve, derived absolute diameters that fell between the pathologic minimum and maximum in 10 of 20 segments. Method 2, which determines the edges by an average of the first and second derivatives of the videodensity change, derived absolute diameters that fell between the pathologic minimum and maximum diameters in 15 of 20 segments. Method 1 correlated well with the maximum pathologic diameter (r = .76) and less well with the minrmum pathologic diameter (r = .67). Method 2 correlated very well with the maximum pathologic diameter (r = .79) and also correlated well with the minimum pathologic diameter (r = .74). As would be expected, the computerized algorithms tended to overestimate the minimum pathologic diameter and to underestimate the maximum pathologic diameter. In six segments, two orthogonal views were analyzed; no further accuracy was discernible over single-plane determinations. Thus quantitative coronary angiography by digital subtraction angiography is sufficiently accurate to be of use in the measurement of the severity of a coronary stenosis.

Assessment of coronary artery stenoses by digital subtraction angiography: A pathoanatomic validation

Automated computer assessment of coronary stenoses from digital subtraction angiographic images comparing geometric and videodensitometric algorithms was performed. Digital subtraction angiograms were acquired on a 512 X 512 X 8 bit pixel matrix at 8 frames/second. Fifteen segments from nine human cadaver coronary arteries, with lesions ranging from 0% to 97%, were analyzed. Hand injections of radiopaque dye were made during the pulsatile infusion of saline solution at physiologic pressures and flows. Individual frames best demonstrating a lesion were digitally magnified and the stenosis was measured; the operator identified only the segment of interest. The artery was then injected with a rapidly hardening gel during the same rate of infusion as that used during image acquisition. Histologic sections were cut at 2 mm intervals after fixation and elastic stains applied. Photographs of the section comparable to the site determined from the angiogram were taken, and hand planimetry by a blinded investigator was performed. There was an excellent correlation between histopathology and videodensitometry (r = 0.93; p less than 0.0001). The two geometric algorithms studied also had very good correlations (r = 0.90 and 0.84) with pathology. Two experienced angiographers, despite excellent agreement with each other, had lower correlations with pathology than any of the three computer algorithms studied (r = 0.79 and 0.83, respectively), although this difference did not attain statistical significance. This in vitro model simulating in vivo conditions validates the use of automated videodensitometric and geometric computer algorithms to interpret coronary angiography and assess severity of stenosis.