Ventricular Regional Wall Motion Abnormalities Research Articles

Transient myocardial dysfunction in a patient with subarachnoid haemorrhage

We report a patient of subarachnoid haemorrhage who presented with severe left ventricular dysfunction and marked electrocardiographic changes indistinguishable from acute myocardial infarction. Coronary arteriography showed normal anatomy and the ventricular regional wall motion abnormalities recovered spontaneously after 3 weeks. The implications of this association are discussed.

Cardiovascular consequences of correction of the anemia of renal failure with erythropoietin

The purpose of this study was to define the physiologic responses of the heart and peripheral circulation to chronic anemia using noninvasive measurements while eliminating confounding biochemical, pharmacologic and physiologic variables. Stable chronic hemodialysis patients were studied at the University Hospital based chronic dialysis unit and echocardiography laboratory before and after therapy with human recombinant erythropoietin (rHuEPO). Subjects included maintenance hemodialysis patients free of left ventricular regional wall motion abnormalities discernible by echocardiography, rhythm disturbance, significant valvular or ischemic heart disease. Two-dimensional echocardiograms and simultaneous targeted M-mode echocardiograms, phonocardiograms and externally acquired subclavian artery pulse tracings were used to measure whole blood viscosity, arterial blood gases and ionized calcium, complete blood count, electrolytes, creatinine, blood urea nitrogen (BUN), and inorganic phosphate. All measurements were made immediately post-dialysis before and after therapy with rHuEPO. The interval between pre- and post-rHuEPO studies was 8.3 +/- 2.3 months. We found that post-dialysis hematocrit rose from 24.7 +/- 0.9 to 36.4 +/- 0.9%, hemoglobin from 83 +/- 3 to 121 +/- 3 g/liter and whole blood viscosity from 2.87 +/- 0.11 to 3.71 +/- 0.18 centipoise (all, P < 0.001 after therapy with rHuEPO). The remaining biochemical measurements did not change. Heart rate fell from 83 +/- 3 to 77 +/- 3 beats/min (P = 0.013). Left ventricular preload and afterload were not statistically different before and after rHuEPO. Total vascular resistance rose from 1313 +/- 84 to 1568 +/- 129 dynes.sec.cm-5, P = 0.029. Cardiac output and cardiac index fell by 12 and 15% (P = 0.024 and 0.030), respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

Correlation between QTc interval duration and left ventricular systolic dysfunction in patients with acute myocardial infarction

QTc interval and left ventricular regional wall motion abnormality score (WMS) were asessed in 61 consecutive patients with 4-day-old acute myocardial infarction (AMI). There were 45 men and 16 women, aged 60.6 ± 8.7 years; 24 had anterior wall AMI and 37 had inferior wall AMI. Twentynine patients received thrombolytic treatment, which was presumably successful in 19. The longest QTc interval from a standard 12-lead electrocardiogram, corrected by Bazett's formula, was considered for the study. The WMS was evaluated echocardiographically. The authors found a statistically significant correlation between WMS and QTc interval duration; the correlation was stronger in patients with anterior AMI ( r = .9, P < .001) than in those with inferior AMI ( r = .66, P < .001). The WMS and QTc values were significantly lower in patients with successful thrombolytic treatment compared to those with unsuccessful thrombolysis ( P < .003 and P < .002, respectively). The authors could demonstrate no significant correlation between serum potassium concentration and the QTc interval. In patients with anterior AMI, QTc interval duration might represent an additional marker of left ventricular systolic dysfunction. It could also be used as an additional noninvasive criterion of coronary artery reperfusion in patients with AMI.

Regional ventricular wall motion abnormalities in tricuspid atresia after the fontan procedure

Objectieves. The purpose of this study was to determine whether wall motion abnormalities are present before or after the Fontan procedure in patients with a univentricular heart of the left ventricular type with an absent right atrioventricular valve connection (tricuspid atresia) and to assess the impact of such abnormalities on ventricular performance and clinical outcome.Background. Normal systolic and diastolic ventricular (unction is critical for a successful Fontan repair. However, there have been no previous studies addressing the relation between regional ventricular function and hemodynamic factors.Methods. Thirty-seven pediatric patients were studied with biplane ventricular cineangiography. There were 20 male and 17 female patients whose mean age at the time of the Fontan operation was 6.5 ± 3.5 years (range 2.5 to 15.6). Eighteen patients were studied preoperatively, 25 at >1 year postoperatively and 6 serially. Wall motion was assessed by a centerline method. Normal ranges for wall motion and other variables were established from 25 normal subjects.Results. Wall motion abnormalities were observed in 2 of 18 patients preoperatively and in 11 of 25 patients postoperatively. Age at operation and ventricular volumes did not differ between postoperative patients who had normal (group I, 14 patients) or abnormal (group II, 11 patients) wall motion. However, ventricular mass and the mass/volume ratio were significantly greater and systolic variables and cardiac index were significantly lower in group II versus group I. Two patients in group I were considered to have a clinically poor outcome (persistent heart failure), and five in group II had heart failure, including one who died late.Conclusions. These observations suggest that postoperative regional wall motion abnormalities in this setting are not rare, may be related to excessive hypertrophy and may contribute to cardiac dysfunction and a poor clinical outcome.

Influence of reperfusion induced by thrombolytic treatment on natural history of left ventricular regional wall motion abnormality in acute myocardial infarction

Although several studies have investigated left ventricular (LV) function after reperfusion inter ventions, it is still unclear whether benefits result from successful therapy or whether such benefits only reflect the natural history of a subgroup of patients with acute myocardial infarction (AMI). This study evaluates the unique effect of thrombolytic therapy on the natural history of regional LV wall motion dysfunction. One hundred seventy-six patients with AMI were studied: 82 patients (group A) underwent conventional treatment and 94 (group B) thrombolytic therapy. LV regional improvement, evaluated by changes in echo score between admission and predischarge examination, was present more frequently in group B (28%) than in group A (17%). Furthermore, improved patients in group B had higher admission echo scores (7.5 ± 3.5 vs 6.3 ± 3.1), a prevalence of anterior AMI (68 vs 30.1%) and a higher rate of coronary patency (92 vs 58% in patients who had no improvement). In group A patients the rate of coronary patency was similar in those who did (46.1%) and did not have (36.1%) improvement. Observations at 12 to 18 months showed similar data in group A patients and in group B patients without improvement, whereas a marginal additional improvement was observed in group B patients who had in-hospital improvement. These observations demonstrate that LV function recovery is more frequent and marked in treated than in untreated patients. Follow-up results suggest a prolonged beneficial effect of thrombolytic treatment on LV function. The highest rate of coronary patency in improved group B patients underline the role of reperfusion on natural history of LV dysfunction after AMI.

Ischemia-induced regional wall motion abnormality is improved after coronary angioplasty: Demonstration by dobutamine stress echocardiography

Objectives. The purpose of this study was to examine whether dobutamine stress echocardiography can detect reversal of ischemia-induced left ventricular regional wall motion abnormality immediately after percutaneous transluminal coronary angiopiasty.Background. Although angioplasty is routinely performed as a means of coronary revascularization, at present there is a question whether this results in an immediate improvement in ischemia-induced left ventricular regional function.Methods. Thirty-five patients underwent dobutamine stress echocardiography 24 h before and 24 to 48 h after angiographically successful coronary angioplasty. Only patients with normal wall motion at rest were included. Dobutamine infusion was begun at 5 μg/kg per min and increased at 5-min intervals (10, 20, 30, 40 μg/kg per min). Echocardiographic images were stored into cine loops and analyzed off line with simultaneous comparison of images acquired at baseline, 5 μg/kg per min, peak infusion and recovery. Echocardiographic images were interpreted independently, without knowledge of other data, by two experienced cardiologists using the 16-myocardial segment model.Results. Before angioplasty, dobutamine stress echocardiography induced wall motion abnormalities in 31 patients (88%). Wall motion score at peak dobutamine infusion improved in 28 (90%) of the 31 patients after angioplasty. Wall motion score at peak dobutamine infusion for the group improved from 20 ± 3 before angioplasty to 17 ± 2 after angioplasty (p < 0.001). There was no change in the rate-pressure product achieved for the group before and after angioplasty (20,038 ± 6,415 beats/min × mm Hg before versus 20,775 ± 5,435 after angioplasty, p = NS). Before angioplasty, dobutamine stress echocardiography induced angina in 13 patients (37%), whereas angina occurred only once after angioplasty. Electrocardiographic changes diagnostic of ischemia occurred seven times, all before angioplasty.Conclusions. We conclude that dobutamine stress echocardiography is an excellent method to demonstrate an immediate improvement in stress-induced regional left ventricular dysfunction in the distribution of the vessel undergoing successful angioplasty.

Effects of low‐dose adenosine on myocardial performance after coronary artery bypass surgery

The effect of a non-hypotensive dose of adenosine infusion on myocardial performance after coronary artery bypass surgery was examined. Upon arrival at the intensive care unit, 16 patients (14 males, 2 females; mean age 64.5, range 46-71) were randomized to a blinded infusion of either low-dose adenosine (n = 8) or placebo (n = 8). The infusion continued at a rate corresponding to 30 micrograms.kg-1.min-1 of adenosine into the right ventricle over 4 h. Data were collected from the arterial line, thermodilution pulmonary artery catheter, transoesophageal echocardiogram (TEE), and 12-lead ECG on six occasions: before infusion, hourly during the infusion, and 1 h after terminating the infusion. Mean arterial blood pressure did not differ between the adenosine and placebo groups at any measurement point. Heart rate increased by approximately 15% during the first hour of adenosine infusion. Cardiac index increased by approximately 50% during infusion of adenosine and cardiac index remained higher while systemic vascular resistance remained lower in the adenosine-treated group during infusion. The E/A ratio (ratio between peak left ventricular inflow blood velocities during early filling and atrial contraction) was significantly higher in the adenosine-treated group after treatment for 1 h while the area injection fraction did not differ between groups at any time. The number of patients with ischaemic events as judged from ECG and from left ventricular regional wall motion abnormalities (RWMA) as visualized by TEE did not differ between groups (ECG: one patient in the adenosine group and one patient in the placebo group-RWMA: four patients in the adenosine group versus three in the placebo group).(ABSTRACT TRUNCATED AT 250 WORDS)

Left ventricular shape is the primary determinant of functional mitral regurgitation in heart failure

Objectives. The aim of this study was to examine the temporal association between the onset of functional mitral regurgitation and the development of changes in left ventricular shape, chamber enlargement, mitral anulus dilation and regional wall motion abnormalities during the course of evolving heart failure.Background. Despite extensive characterization, the exact etiology of functional mitral regurgitation in patients with chronic heart failure remains unknown.Methods. Heart failure was produced in seven dogs by multiple sequential intracoronary microembolizations. Serial changes in left ventricular chamber volume and shape were evaluated from ventriculograms. Changes in mitral anulus diameter and ventricular regional wall motion abnormalities were evaluated echocardiographically. The presence and severity of mitral regurgitation were determined with Doppler color flow mapping. Measurements were obtained at baseline and then biweekly until mitral regurgitation was first observed.Results. No dag had mitral regurgitation at baseline but all developed mild to moderate regurgitation 12 ± 1 weeks after the first embolization. The onset of mitral regurgitation was not associated with an increase in left ventricular end-diastolic volume relative to baseline (58 ± 3 vs. 62 ± 3 ml), mitral anulus diameter (2.4 ± O.1 vs. 2.4 ± 0.1 cm) or wall motion abnormalities of left ventricular wall segments overlying the papillary muscles. In contrast, the onset of mitral regurgitation was accompanied by significant changes in global left ventricular shape evidenced by increased end-systolic chamber sphericity index (0.22 ± 0.02 vs. 0.30 ± 0.01) (p < 0.01) and decreased end-systolic major axis/ minor axis ratio (1.71 ± 0.05 vs. 1.43 ± 0.04) (p < 0.001).Conclusions. These data indicate that transformation of left ventricular shape (increased chamber sphericity) is the most likely substrate for the development of functional mitral regurgitation.

Effect of electroconvulsive therapy on the electrocardiogram and echocardiogram.

Although electrocardiographic (ECG) ST segment depression is commonly induced by electroconvulsive therapy (ECT) for depression, it is unknown whether this reflects segmental myocardial ischemia, as is true under most circumstances, or a direct effect of central nervous system stimulation on cardiac repolarization in the absence of ischemic left ventricular regional wall motion abnormalities. We evaluated the association between ECG changes and left ventricular regional wall motion abnormalities detected by the echocardiograms performed before and after ECT in 11 patients. Immediately after ECT, three patients' ECGs revealed 1-mm downsloping or horizontal ST segment depression, one had a nonspecific ECG change (peaked T waves), and the ECG remained normal in seven. All patients had normal baseline echocardiograms. After ECT, at a time when the product of arterial blood pressure and heart rate was 100% above baseline values, five patients developed new left ventricular regional wall motion abnormalities that were confined to hypokinesia; no patient developed myocardial infarction or angina after ECT. Three patients with regional wall motion abnormalities developed ECG ST segment depression after ECT (sensitivity 60%), one had a nonspecific ECG change (peaked T waves), and the ECG of one patient remained normal. In conclusion, ECT may induce ECG changes with simultaneous regional wall motion abnormalities at a time when arterial blood pressure and heart rate are markedly elevated, findings that are highly suggestive of "demand" myocardial ischemia. In this small series, ECG or echocardiographic abnormalities did not predict clinical cardiac morbidity.

Elevations of CK-MB Following Pulmonary Embolism: A Manifestation of Occult Right Ventricular Infarction

To determine the frequency and etiology of elevations of CK-MB in patients with pulmonary emboli, we studied 52 patients with well-documented emboli and the absence of known ischemic heart disease or ECG changes suggestive of acute infarction. All patients were evaluated with serial CK-MB determinations at 8-h intervals. All patients with elevations of CK-MB had noninvasive cardiac evaluations. Four (7.7 percent) of the 52 patients had a rising and falling pattern of CK-MB that satisfied enzyme criteria of acute infarction. Three of these four also manifested classic echocardiographic features of right ventricular infarction. None of the four had evidence of left ventricular regional wall motion abnormalities or dysfunction. Of the 48 patients without elevations of CK-MB, only two had segmental right ventricular dysfunction. These findings suggest that pulmonary emboli can induce right ventricular infarction in some (7.7 percent) patients even when patients with a history of coronary artery disease and/or ECG changes of infarction are excluded. Conversely, the diagnosis of pulmonary embolism should be considered in patients when right ventricular infarction is diagnosed.

Evolution of stress echocardiography.

Interest in stress echocardiography began with M-mode recordings of the left ventricle. Kraunz and Kennedyz0 looked at left ventricular wall motion at rest and with exercise in 1970. This study involved normally contracting chambers. Shortly thereafter investigators began noticing that abnormal wall motion could be detected with M-mode echocardiography. Jacobs et all5 noted detection of left ventricular regional wall motion abnormalities with M-mode echocardiography in 1973. Other papers continued to document the ability of M-mode echocardiography to identify regional left ventricular dysfunc

EFFECT OF ELECTROCONVULSIVE THERAPY ON THE ELECTROCARDIOGRAM AND ECHOCARDIOGRAM

Although electrocardiographic (ECG) ST segment depression is commonly induced by electroconvulsive therapy (ECT) for depression, it is unknown whether this reflects segmental myocardial ischemia, as is true under most circumstances, or a direct effect of central nervous system stimulation on cardiac repolarization in the absence of ischemic left ventricular regional wall motion abnormalities. We evaluated the association between ECG changes and left ventricular regional wall motion abnormalities detected by the echocardiograms performed before and after ECT in 11 patients. Immediately after ECT, three patients' ECGs revealed 1-mm downsloping or horizontal ST segment depression, one had a nonspecific ECG change (peaked T waves), and the ECG remained normal in seven. All patients had normal baseline echocardiograms. After ECT, at a time when the product of arterial blood pressure and heart rate was 100% above baseline values, five patients developed new left ventricular regional wall motion abnormalities that were confined to hypokinesia; no patient developed myocardial infarction or angina after ECT. Three patients with regional wall motion abnormalities developed ECG ST segment depression after ECT (sensitivity 60%), one had a nonspecific ECG change (peaked T waves), and the ECG of one patient remained normal. In conclusion, ECT may induce ECG changes with simultaneous regional wall motion abnormalities at a time when arterial blood pressure and heart rate are markedly elevated, findings that are highly suggestive of demand myocardial ischemia. In this small series, ECG or echocardiographic abnormalities did not predict clinical cardiac morbidity.

Right ventricular systolic function during exercise with and without significant coronary artery disease

To evaluate the effects of exercise and coronary artery disease on right ventricular (RV) systolic function, rest and exercise biplane RV angiograms were recorded in 20 patients undergoing diagnostic cardiac catheterization. Thirteen patients had exercise angiograms of sufficient quality to undergo analysis and were classified into 2 groups. Group 1 had no or only mild coronary artery disease; group 2 had significant coronary artery disease as manifested by new, exercise-induced, left ventricular regional wall motion abnormalities. RV systolic pressure increased in both groups during exercise: 33 to 57 mm Hg in group 1 (p = 0.0002) and 33 to 55 mm Hg in group 2 (p = 0.0004). Pulmonary resistance did not change in group 1 during exercise but increased in group 2 (3.2 to 4.8 Wood units, p = 0.04). RV ejection fraction increased slightly, but not significantly, during exercise in group 1, but decreased in group 2 (73 vs 58% with exercise [p = 0.01]). The change in RV ejection fraction from rest to exercise correlated closely with the change in pulmonary resistance from rest to exercise (r = −0.89, p < 0.0001). RV regional wall motion analysis demonstrated a generalized decline in regional ejection fraction in group 2 during exercise, even in patients without right coronary artery disease. In conclusion, there is a decline in RV ejection fraction during exercise in patients with significant coronary artery disease. The generalized reduction in regional RV ejection fraction coupled with the close correlation with the change in pulmonary resistance suggests that increased afterload, rather than RV ischemia, is the cause.

Quantitative assessment of transient left ventricular asynergy in coronary artery disease

The purpose of this study was to determine the diagnostic value of quantitative two-dimensional echocardiography during transesophageal atrial pacing in assessing the presence and severity of coronary artery disease. Apical four- and two-chamber views were registered at rest and at different pacing rates. Computerized quantitative evaluation of left ventricle wall motion was performed. On the basis of left ventricle wall motion analysis data of 22 individuals with no coronary pathology, as assessed by angiography and with negative exercise ECG and transesophageal atrial pacing ECG test, nomograms for assessment of wall motion abnormalities and for calculation of asynergy area as a measure of wall motion abnormality extent were obtained. The method revealed new transient wall motion abnormalities during pacing or exacerbation of old ones present at rest in 83 of the 89 patients with angiographically proven coronary artery stenosis greater than or equal to 70% and in 3 of the 32 controls with no changes in their coronary angiograms. Thus, it showed high sensitivity (93%), specificity (91%), predictive value of positive result (96%), predictive value of negative result (83%), and efficiency of the test (93%). These values appeared to be higher than those calculated for transesophageal atrial pacing ECG, recorded simultaneously with echocardiographic images (81, 87, 95, 62, and 83%, respectively) and for exercise ECG test which was performed in 66 coronary patients and in 29 controls (68, 86, 92, 54, and 74%, respectively). The extent of pacing-induced left ventricular regional wall motion abnormalities appeared to be directly correlated to the extent of coronary artery disease.(ABSTRACT TRUNCATED AT 250 WORDS)

Thoracic Epidural Anesthesia Improves Global and Regional Left Ventricular Function During Stress-Induced Myocardial Ischemia in Patients With Coronary Artery Disease

The aim of the present investigation was to study the effects of high thoracic epidural anesthesia (TEA), including the cardiac sympathetic segments, on ischemic ST-segment changes and left ventricular global and regional wall motion abnormalities. Ten patients with a two- or three-vessel coronary artery disease, all treated with the beta-adrenergic blocker metoprolol because of severe stable angina pectoris, performed two identical exercise stress tests, the first without TEA (control exercise) and the second with TEA (TEA exercise). Before each stress test, intravenous metoprolol was given to achieve maximal or near maximal beta-adrenoceptor blockade. Systolic and diastolic arterial pressures (radial artery cannula), heart rate, and rate-pressure product, as well as global and regional ejection fractions, using equilibrium radionuclide angiography in the left anterior oblique projection, were measured at rest and during maximal exercise. ST-segment analysis (V3 or V5) was performed, and the regional wall motion score was calculated at control exercise and TEA exercise. Intravenous metoprolol or intravenous metoprolol plus TEA at rest did not cause any significant changes of any of the variables. During TEA exercise, systolic arterial pressure, diastolic arterial pressure, and rate-pressure product, but not heart rate, were significantly lower compared to control exercise. The global and anterolateral ejection fractions were significantly higher (52.8% versus 46.5% and 53.2% versus 46.0%, respectively, P less than 0.05), and the regional wall motion score was significantly lower (8.8 versus 11.8, P less than 0.01) during TEA exercise than during control exercise. ST-segment depression was significantly lower during TEA exercise (-1.03 versus -1.84 mV, P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Comparison of contrast angiography and two-dimensional echocardiography for the evaluation of left ventricular regional wall motion abnormalities after acute myocardial infarction

Regional left ventricular wall motion abnormalities were assessed using 2-dimensional echocardiography and contrast ventriculography within 12 hours of the onset of chest pain in 20 patients with acute myocardial infarction (AMI); 10 patients had anterior infarctions and 10 had inferior. End-diastolic and end-systole sinus beats from right anterior oblique contrast ventriculograms were analyzed using the center-line chord technique with both a standard overlap method of chord assignment and a nonoverlap method. Echocardiograms were obtained in parasternal long- and short-axis and apical 2- and 4-chamber views and analyzed using a 16-segment scoring system to derive anterior and infero-posterolateral wall motion indexes using both overlap (10 segments for anterior, 8 inferior) as well as nonoverlap (9 segments anterior, 7 inferior) methods of segment assignment. There was a significant inverse correlation between the standard (nonoverlap) echocardiographic analysis and the standard (overlap) angiographic analysis for infarct regions (y = −0.43 × + 1.11, r = −0.59, p < 0.05). Fifteen of 18 patients with angiographic infarct regional score <- −1 standard deviation/ chord had an echocardiographic index ≥1.5, while 15 of 16 patients with echocardiographic regional infarct index ≥1.5 had an angiographic score <-−1 standard deviation/chord. Correlation between the 2 methods for noninfarct territories was poor (r = −0.34) because the angiographic method assesses hyperkinesis while the echocardiographic method does not. For noninfarct regions, 13 of 16 patients with an angiographic score >−1 standard deviation/chord had an echocardiographic index <1.5, while 13 of 15 patients with an echocardiographic regional index of <1.5 had an angiographic score >−1 standard deviation/chord. In comparing overlap and nonoverlap methods, significant differences were found for noninfarct regions but not for infarct regions for both echocardiographic and angiographic analyses. Data indicate that 2-dimensional echocardiography, which is non-invasive and more easily repeatabte for serial studies, yields similar results to contrast angiography for the assessment of regional wall motion abnormalities after AMI.

Follow-up Study of Morbidity in Patients with Angina Pectoris and Normal Coronary Angiograms and the Value of Investigation for Esophageal Dysfunction

A postal questionnaire was used to assess the symptoms, use of medical facilities, and employment status of patients with angina pectoris and normal coronary angiograms following cardiac catheterization. In a retrospective study of 187 patients, 66 had left ventricular dysfunction demonstrated by abnormal regional wall motion and 121 had normal left ventricular function. At follow-up twelve to forty-six months following catheterization, 89% with left ventricular dysfunction and 82% with normal ventricular function had continued to experience chest pain. There was no significant change in the admission rate to hospital because of chest pain or the proportion of patients who were working, after catheterization as compared with before, in either group. Some patients with left ventricular regional wall motion abnormalities appeared to have progressive left ventricular dysfunction. In a prospective study of 63 patients, detailed investigation of esophageal function was performed. Twenty-two patients had left ventricular wall motion abnormalities. The majority of the 41 patients with normal left ventricular wall motion had esophageal abnormalities that were treated appropriately. At follow-up six to twenty-four months following catheterization significantly fewer patients with normal left ventricular function continued to experience chest pain compared with those with left ventricular dysfunction. Following catheterization the hospital admission rate fell significantly and the proportion of patients working increased significantly in the group with normal left ventricular function. The hospital admission rate and employment status of patients with left ventricular dysfunction did not change significantly following angiography. These findings suggest, therefore, that investigation for and treatment of esophageal dysfunction should be performed in patients with angina pectoris, normal coronary angiograms, and normal left ventricular function.

Ischemia—silent or manifest: does it matter?

Clinical expressions of myocardial ischemia are protean and include angina and symptoms related to ventricular systolic and diastolic dysfunction and arrhythmia. The consequences of ischemia are also variable and range from no immediate adverse effects to sudden death, myocardial infarction and severe impairment of cardiac performance and heart failure. However, myocardial ischemia can occur without any clinical manifestations and can be clinically totally silent. There is a multitude of evidence for the existence of “silent” myocardial ischemia (1). Reversible left ventricular regional wall motion abnormalities, either stress-induced or spontaneous, in the absence of angina, provide evidence for silent myocardial ischemia. Global and regional myocardial lactate production, a metabolic marker of ischemia, has been documented in the absence of angina. Reversible myocardial thallium perfusion defects at rest or during dipyridamole or exercise stress occur rather frequently without associated angina. On the basis of wall motion abnormalities, metabolic dysfunction, reversible scintigraphic perfusion defects and ischemic changes on the stress electrocardiogram (ECG), the incidence rate of silent myocardial ischemia has been estimated to be approximately 34% in patients with coronary artery disease (2). However, recently popularized ambulatory electrocardiography in studies to detect ischemia have revealed a much higher incidence of silent ischemia (3). It has been documented that ST segment shifts, both depression and elevation. on the ambulatory ECG correlate well with other markers of myocardial ischemia (4). Electrocardiographic monitoring has revealed that in patients with stable exertional angina resulting from obstructive coronary artery disease, approximately 70% of episodes of ischemia are asymptomatic. In postinfarction patients and in patients with

Fourier classification images in cardiac nuclear medicine

At present, the diagnosis of cardiac left ventricular regional wall motion abnormalities (RWMA) in nuclear medicine is aided mainly by phase images and amplitude images, which picture the spatial distribution of the phase and of the amplitude of the first harmonics of pixel time activity curves, respectively. However, they do not utilize other information contained in the original radionuclide images, and they do not offer a direct diagnostic interpretation of the data. The proposed Fourier classification images (FCI) overcome these deficiencies. Their pixel intensities express directly the diagnostic class of RWMA. The FCI pixel intensities are functions of pixel coordinates, Fourier features of pixel time activity curves, and their distribution parameters, and they are not limited by the first harmonics model. The derivation of the pixel classifier includes normalization transformation of coordinates and activities. Fourier analysis of raw image data, and teaching the computer by examples of already diagnosed cases with the help of discriminant analysis. FCI offer direct and robust diagnosis of RWMA, superior to that derived from phase and amplitude images, especially in the detection of mild RWMA.

Comparison between vertical parallel hole collimator and 30� rotating slant hole collimator for assessing global and regional left ventricular function by radionuclide angiography

Left ventricular ejection fraction (LVEF) and regional wall motion abnormalities were determined in 40 patients (30 with coronary artery disease and 10 with valvular heart disease) using equilibrium radionuclide angiography. Scintigraphic acquisitions were collected in random order with 2 different collimators as follows: in anterior face (AF), left anterior oblique (25 degrees-45 degrees LAO) and 70 degrees LAO, with a vertical parallel hole collimator (VTC), and in 25 degrees-45 degrees LAO and 65 degrees-80 degrees LAO with a 30 degrees rotating slant hole collimator (RSHC), with the slant of the collimator directed towards the cardiac apex in both projections. Results were compared to contrast ventriculography (CV) performed in the 30 degrees right anterior view (3 segments: anterior, apical, inferior) and in a 60 degrees left anterior oblique view (3 segments: septal, apical and lateral). Radionuclide LVEF in both series was closely correlated with contrast ventriculographic LVEF (r = 0.89, VTC vs CV and r = 0.87, RSHC vs CV, respectively). Regional wall motion analysis was only performed among the 30 patients suffering from coronary heart disease. Eight contrast angiographic studies were normal and 22 abnormal. Global sensitivity and specificity were 100% and 63% with the VTC (3 false positives) and 91% and 87% with the 30 degrees RSHC (2 false negatives and 1 false positive, P = ns). Agreement for the localisation of the regional wall motion abnormalities between CV and radionuclide angiography was 70.6% with the VTC and 71.2% with the RSHC (P = ns).(ABSTRACT TRUNCATED AT 250 WORDS)