Gender differences in functional hemispheric asymmetry during processing of vowels as reflected by the human brain magnetic response

A number of findings indicate gender differences in language-related functional hemispheric brain asymmetry. To test if such gender-specific laterality is already present at the level of vowel-processing, the auditory evoked magnetic field was recorded in healthy right-handed male and female participants in response to the German synthetic vowels [a], [e] and [i]. Female participants exhibited stronger N100m responses than male participants over the left hemisphere. This observation was highly reliable across repeated experimental sessions. The present lateralization shows that previous findings suggesting a stronger left-hemispheric dominance for verbal material in males than in females can not be generalized to basic speech elements. Furthermore, the present results support the importance of controlling for gender ratio in studies of phonetic processing.

Experience with difficult keloids

A large number of treatment modalities have been used to treat keloid scars, with varying degrees of success. A modified combination therapy consisting of cryotherapy and intralesional triamcinolone injection has given good results in 43 patients, with complete resolution in 28% and significant improvement in 44%. We find it particularly useful for treating recurrent and/or difficult keloids.

Regression of left ventricular remodeling in chronic heart failure: Comparative and combined effects of captopril and carvedilol

BACKGROUND

This study evaluated the independent and combined effects of captopril and carvedilol on left ventricular remodeling in chronic heart failure. Although angiotensin-converting enzyme inhibitors and b-blockers are known to attenuate the remodeling process in chronic heart failure, a direct comparison of these agents has not been performed.

METHODS

We investigated 57 patients with mild to moderate chronic heart failure (48 ischemic, 9 nonischemic) who were randomized in a double-blind fashion to treatment with carvedilol or captopril at maximum doses of 25 mg twice daily for 3 months, followed by 3 months of combined treatment. Serial echocardiography, right heart catheterization, and treadmill exercise testing were performed at baseline, 3 months, and 6 months. After exclusions, 49 patients were evaluated during monotherapy and 48 during combination therapy.

RESULTS

Carvedilol monotherapy produced significant reductions in end-systolic volume, leading to a greater median increase in ejection fraction compared with captopril monotherapy (4.7% vs 1.5%, respectively; P <.05). Each drug caused similar reductions in left ventricular mass, chamber sphericity, and pulmonary artery wedge pressure during monotherapy and combined treatment. Adjunctive treatment with carvedilol produced a trend toward a greater increase in ejection fraction (4.3% vs 2.7%, respectively; P not significant) and significantly greater reductions in the wall thickening score index than with captopril (0.25 vs 0.08, respectively; P =.04).

CONCLUSIONS

Although angiotensin-converting enzyme inhibitor therapy did not alter left ventricular volume, treatment with carvedilol was associated with reductions in chamber volume; both drugs reduced left ventricular mass and sphericity. These beneficial effects on remodeling may help to explain the relative prognostic benefits of these therapies.

Effect of revascularization on left ventricular remodeling in patients with heart failure from severe chronic ischemic left ventricular dysfunction

Few data exist regarding the effect of revascularization on left ventricular (LV) geometry in patients with severe LV systolic dysfunction and viable myocardium. We hypothesized that patients with chronic ischemic LV dysfunction but viable myocardium will have improved LV geometry after revascularization, which in turn will improve long-term outcome. Accordingly, 70 patients with severe ischemic LV dysfunction (LV ejection fraction <0.35) were studied at rest. They then either underwent revascularization (n = 36) or were treated medically (n = 34). Fifty-four patients had viable myocardium, and 16 did not. They were evaluated for change in LV function and geometry (size and shape) a mean of 21 months later. Further follow-up was performed for a mean of 3.5 years to determine outcome. Patients with viable myocardium had improvement not only in regional and global function, but also in LV geometry (shape and size), which was independent of and incremental to the improvement in function. On long-term follow-up, change in LV end-systolic volume was the only multivariate discriminator between 15 patients who died and 55 who did not, irrespective of whether they had undergone revascularization. Thus, measurement of the effect of revascularization of viable myocardium in chronic ischemic heart disease should not only include improvement in resting regional and global LV function, but also LV geometry. Improvement in LV geometry contributes to better LV systolic function, which in turn is the best predictor of survival after revascularization.

A randomized, double-blind comparison of the efficacy and tolerability of once-daily modified-release diltiazem capsules with once-daily amlodipine tablets in patients with stable angina

A randomized, double-blind, parallel-group study comparing the efficacy and tolerability of once-daily diltiazem capsules with amlodipine tablets in patients with stable angina. After a run-in period of 1 to 3 weeks, 34 patients received once-daily diltiazem and 33 patients received amlodipine. Patients received either diltiazem, 240 mg/day, or amlodipine, 5 mg/day, for 2 weeks followed by diltiazem, 360 mg/day, or amlodipine, 10 mg/day, for 2 weeks. Standard treadmill exercise testing was the primary efficacy assessment. Patients also recorded incidence of angina attacks and use of glyceryl trinitrate spray. Both treatments gave significant improvement in time to onset of angina and time to maximal exercise. With the exception of amlodipine, 5 mg/day, both treatments gave significant increases in time to 1-mm ST segment depression. Diltiazem, 360 mg/day, gave a significant decrease in rate pressure product. There were no significant treatment differences in any of the exercise test parameters. Both treatments reduced incidence of angina attacks and use of glyceryl trinitrate spray. The incidence of edema was significantly less in patients receiving diltiazem. In conclusion, both treatments were effective in controlling patients' angina, but diltiazem was better tolerated, with a lower incidence of edema.

A prospective comparison of echocardiographic wall motion score index and radionuclide ejection fraction in predicting outcome following acute myocardial infarction

OBJECTIVE

To characterise echocardiographic wall motion score index (WMSI) as a surrogate measure of left ventricular ejection fraction (EF) following acute myocardial infarction (AMI) and to compare its prognostic value with that of EF measured by radionuclide ventriculography (RNV).

DESIGN

A prospective study to compare baseline echocardiographic WMSI with RNV EF in consecutive patients thrombolysed for AMI, both performed on the same day before discharge, and their relative prognostic values in predicting cardiac events.

SETTING

District general hospital coronary care unit and cardiology department.

PATIENTS

120 consecutive patients free of exclusion criteria thrombolysed for AMI and followed up for a mean (SD) of 13 (10) months.

INTERVENTIONS

None.

MAIN OUTCOME MEASURES

Correlation coefficients and receiver operating characteristic curve analyses plus cardiac event rates at follow up between RNV EF and echocardiographic WMSI.

RESULTS

WMSI correlated well with RNV EF. The best corresponding WMSIs for EFs 45%, 40%, and 35% were 0.6, 0.8, and 1.1, respectively. There were 42 cardiac events during follow up. Although both RNV EF and WMSI were strong univariate predictors of cardiac events, only WMSI independently predicted outcome in a multivariate model. All three WMSI cut offs significantly predicted events, while an RNV EF cut off of </= 45% v > 45% failed to reach significance.

CONCLUSIONS

Although both RNV and echocardiographic WMSI strongly predicted cardiac outcome, WMSI, a cheaper and more readily available technique, is more discriminatory, especially in cases of mild left ventricular dysfunction following AMI.

Effect of aging on the prognostic significance of ambulatory systolic, diastolic, and pulse pressure in essential hypertension

BACKGROUND

This study compared the relative prognostic significance of 24 hour intra-arterial ambulatory systolic blood pressure (SBP), diastolic blood pressure (DBP), mean arterial pressure (MAP), and pulse pressure (PP) parameters in middle-aged versus elderly hypertensives.

METHODS AND RESULTS

A total of 546 subjects aged <60 years and 142 subjects aged >/=60 years who had undergone baseline pretreatment 24-hour intra-arterial ambulatory blood pressure monitoring were followed for 9.2+/-4.1 years. Multivariate analysis showed that in younger subjects, 24-hour, daytime, and nighttime DBP, MAP, and SBP, when considered individually, were positively related to morbid events; DBP parameters provided the best predictive values. In the group >/=60 years (elderly group), 24-hour, daytime, and nighttime PP and SBP were the most predictive parameters, whereas ambulatory DBP and MAP measurements failed to provide any prognostic value. When 24-hour values of SBP and DBP were jointly included in the baseline model, DBP (z=2.02, P=0.04) but not SBP (z=-0.43, P=0.67) was related to outcome in younger subjects, whereas in the elderly group, SBP (z=3.33, P=0.001) was positively and DBP (z=-1.75, P=0.07) was negatively related to outcome. Clinic blood pressure measurements failed to provide any independent prognostic value in either age group.

CONCLUSIONS

The relative prognostic significance of ambulatory blood pressure components depends on age; DBP parameters provided the best prognostic value in middle-aged individuals, whereas PP parameters were the most predictive in the elderly. This may reflect differing underlying hemodynamic mechanisms of hypertension in these age groups.

Humoral immune responses in different clinical forms of tuberculosis

To assess the antibody responses in different clinical forms of tuberculosis in an attempt to ascertain the specificity of such a response, so that it may be used as a diagnostic tool, 93 tuberculosis cases and 62 normal healthy controls were included in the study. All the cases were diagnosed as tuberculosis by clinical picture including radiological findings, blood picture, fine needle aspiration cytology (FNAC) or histopathological features, sputum examination or urine culture for acid-fast bacilli. IgM and IgG antibodies in the cases and controls were detected by ELISA using A60 antigen from M. bovis and compared with common diagnostic parameters of tuberculosis like presence of acid-fast bacilli in smear and tuberculin response. Antibody responses with A60 antigen has not been found to be specific and often failed to detect a new case.

Intravenous myocardial contrast echocardiography predicts recovery of dysynergic myocardium early after acute myocardial infarction

OBJECTIVES

We aimed to ascertain whether triggered intravenous myocardial contrast echocardiography (MCE) can predict functional recovery in patients with acute myocardial infarction (AMI) and to determine the optimal triggering interval in this setting.

BACKGROUND

Detection of myocardial viability early after AMI has both therapeutic and prognostic implications. Myocardial contrast echocardiography using intracoronary injections of contrast can detect viable myocardium, but there is little data on the use of recently developed intravenous MCE techniques for this purpose.

METHODS

Ninety-six patients with recent AMI (4.8 +/- 1.7 days) underwent echocardiography at baseline and six months later or three months after revascularization to determine regional function (score 1 = normal to 3 = akinetic). Myocardial contrast echocardiography was performed at baseline using intravenous injections of Optison. Triggering intervals of 1:1 (early) and 1:10 (delayed) cardiac cycles were used. Segments were deemed viable if they demonstrated homogeneous contrast opacification.

RESULTS

Of 400 akinetic segments at baseline, 109 (27%) improved during the follow-up period, and 375 (94%) were adequately visualized with MCE, of which 59 (16%) were homogeneously opacified by early and 125 (33%) by delayed MCE (negative predictive value for recovery of contractile function 74% and 84%, positive predictive value 29% and 47%, respectively). Independent predictors of functional recovery were delayed MCE (odds ratio [OR]: 4.0, p < 0.001), revascularization (OR: 6.0, p < 0.001), and log creatine kinase (OR: 0.5, p = 0.03). However, the presence or absence of >90% stenosis of the infarct-related artery did not influence the ability of triggered MCE to predict functional recovery.

CONCLUSIONS

Intravenous delayed triggered MCE can independently detect myocardial viability early after AMI.

Prognostic value of direct, continuous ambulatory blood pressure monitoring in essential hypertension

This study assessed the prognostic value of ambulatory vs. clinic blood pressure measurement in 688 hypertensives who had undergone pretreatment 24-hour intra-arterial ambulatory blood pressure monitoring. A total of 157 first events were recorded over a follow-up period of 9.2A+/-4.4 years. Ambulatory systolic or diastolic blood pressure parameters (whether 24-hour mean, daytime mean, or nighttime mean) or ambulatory pulse pressure provided independent prognostic information in conjunction with clinical variables. The most predictive models contained the ambulatory systolic blood pressure parameters. Age, male gender, South Asian origin, diabetes mellitus, and previous cardiovascular disease were additional independent predictors of events. In a subgroup of 295 uncomplicated patients, 24-hour ambulatory pulse pressure was an independent predictor of left ventricular mass index and maximal carotid intima-media thickness. Baseline clinic blood pressure parameters did not provide independent information for the prediction of events or target organ damage. Therefore, in this study, ambulatory blood pressure proved to be superior to clinic measurement for cardiovascular risk stratification. However, the routine use of ambulatory blood pressure monitoring is not currently recommended, mainly because of a lack of outcome trials based on the treatment of ambulatory blood pressure levels. (c)2001 by Le Jacq Communications, Inc.

Role of dobutamine echocardiography in detection of myocardial viability for predicting outcome after revascularization in ischemic cardiomyopathy

Coronary artery disease is the most common cause of heart failure in the Western world. Compared with medical therapy, surgical revascularization has been shown to improve survival rates in nonrandomized trials in patients with ischemic cardiomyopathy. However, perioperative mortality is high in this group of patients who do not demonstrate significant viable myocardium. Echocardiography during dobutamine infusion has been shown to reliably detect viable myocardium. Several studies have demonstrated its ability to provide high predictive value for recovery of both regional and global left ventricular function after revascularization. Indeed, nonrandomized studies also have indicated its value in predicting which patients with severe ischemic cardiomyopathy are likely to survive after revascularization. Dobutamine stress echocardiography has emerged as a safe and valuable technique for the assessment of myocardial viability and for the selection of patients for revascularization.

Enhanced detection of reversible perfusion defects by Tc-99m sestamibi compared to Tc-99m tetrofosmin during vasodilator stress SPECT imaging in mild-to-moderate coronary artery disease

OBJECTIVES

We prospectively compared dipyridamole single-photon emission computed tomography (SPECT) imaging with Tc-99m sestamibi and Tc-99m tetrofosmin for the detection of reversible perfusion defects in patients with mild-to-moderate coronary artery disease.

BACKGROUND

Tc-99m tetrofosmin has a lower first-pass myocardial extraction fraction compared to Tc-99m sestamibi and thus could underestimate mild perfusion defects.

METHODS

Eighty-one patients with 50% to 90% stenosis in one or two major epicardial vessels without previous myocardial infarction, and seven with <5% probability of coronary artery disease underwent dipyridamole SPECT imaging with both agents. The SPECT data were analyzed quantitatively.

RESULTS

Tc-99m sestamibi detected reversible perfusion defects in a greater number of segments (total 363 and 285, p < 0.001, and mean +/- SD, 2.2 +/- 3.0 and 1.8 +/- 2.5 per patient, p = 0.008, for Tc-99m sestamibi and Tc-99m tetrofosmin, respectively), demonstrated a larger extent of perfusion defect (mean +/- SD, 15.8% +/- 12.3% and 12.0% +/- 11.4%, p < 0.03, for Tc-99m sestamibi and Tc-99m tetrofosmin, respectively) and more often correctly identified patients with disease in more than one coronary artery (p = 0.02). There was better defect contrast with Tc-99m sestamibi (defect/normal wall count ratios were 0.60 +/- 0.15 vs. 0.73 +/- 0.14 for Tc-99m sestamibi and Tc99m tetrofosmin, respectively, p = 0.01, for reversible defects seen in identical segments with both agents; and 0.73 +/- 0.16 vs 0.79 +/- 0.17, respectively, p <0.01, for reversible defects detected with either agent alone). There was no significant difference in diagnostic sensitivity or image quality.

CONCLUSIONS

These differences between two commonly used tracers may have significant diagnostic and prognostic implications.

Value of dobutamine echocardiography for the assessment of myocardial viability for revascularization

Coronary artery disease accounts for a majority of heart failure cases in the western world. Many cardiologists believe that abnormal regional contractions in patients with coronary artery disease is equivalent to irreversibly damaged myocardium. Studies now challenge this long-held assumption. Data exist regarding the value of assessing myocardial viability in those patients with severe left ventricular dysfunction and coronary artery disease. This report discusses dobutamine echocardiography as a technique for assessing myocardial viability and for selecting patients for revascularization. (c)2001 by CHF, Inc.

Molecular dynamics of the anticodon domain of yeast tRNA(Phe): codon-anticodon interaction

We have studied the effect of codon-anticodon interaction on the structure and dynamics of transfer RNAs using molecular dynamics simulations over a nanosecond time scale. From our molecular dynamical investigations of the solvated anticodon domain of yeast tRNA(Phe) in the presence and absence of the codon trinucleotides UUC and UUU, we find that, although at a gross level the structures are quite similar for the free and the bound domains, there are small but distinct differences in certain parts of the molecule, notably near the Y37 base. Comparison of the dynamics in terms of interatomic or inter-residual distance fluctuation for the free and the bound domains showed regions of enhanced rigidity in the loop region in the presence of codons. Because fluorescence experiments suggested the existence of multiple conformers of the anticodon domain, which interconvert on a much larger time scale than our simulations, we probed the conformational space using five independent trajectories of 500 ps duration. A generalized ergodic measure analysis of the trajectories revealed that at least for this time scale, all the trajectories populated separate parts of the conformational space, indicating a need for even longer simulations or enhanced sampling of the conformational space to give an unequivocal answer to this question.

Comparison of left ventricular ejection fraction and volumes in heart failure by echocardiography, radionuclide ventriculography and cardiovascular magnetic resonance; are they interchangeable?

AIMS

To prospectively compare the agreement of left ventricular volumes and ejection fraction by M-mode echocardiography (echo), 2D echo, radionuclide ventriculography and cardiovascular magnetic resonance performed in patients with chronic stable heart failure. It is important to know whether the results of each technique are interchangable, and thereby how the results of large studies in heart failure utilizing one technique can be applied using another. Some studies have compared cardiovascular magnetic resonance with echo or radionuclude ventriculography but few contain patients with heart failure and none have compared these techniques with the current fast breath-hold acquisition cardiovascular magnetic resonance.

METHODS AND RESULTS

Fifty two patients with chronic stable heart failure taking part in the CHRISTMAS Study, underwent M-mode echo, 2D echo, radionuclude ventriculography and cardiovascular magnetic resonance within 4 weeks. The scans were analysed independently in blinded fashion by a single investigator at three core laboratories. Of the echocardiograms, 86% had sufficient image quality to obtain left ventricular ejection fraction by M-mode method, but only 69% by 2D Simpson's biplane analysis. All 52 patients tolerated the radionuclude ventriculography and cardiovascular magnetic resonance, and all these scans were analysable. The mean left ventricular ejection fraction by M-mode cube method was 39+/-16% and 29+/-15% by Teichholz M-mode method. The mean left ventricular ejection fraction by 2D echo Simpson's biplane was 31+/-10%, by radionuclude ventriculography was 24+/-9% and by cardiovascular magnetic resonance was 30+/-11. All the mean left ventricular ejection fractions by each technique were significantly different from all other techniques (P<0.001), except for cardiovascular magnetic resonance ejection fraction and 2D echo ejection fraction by Simpson's rule (P=0.23). The Bland-Altman limits of agreement encompassing four standard deviations was widest for both cardiovascular magnetic resonance vs cube M-mode echo and cardiovascular magnetic resonance vs Teichholz M-mode echo at 66% each, and was 58% for radionuclude ventriculography vs cube M-mode echo, 44% for cardiovascular magnetic resonance vs Simpson's 2D echo, 39% for radionuclide ventriculography vs Simpson's 2D echo, and smallest at 31% for cardiovascular magnetic resonance-radionuclide ventriculography. Similarly, the end-diastolic volume and end-systolic volume by 2D echo and cardiovascular magnetic resonance revealed wide limits of agreement (52 ml to 216 ml and 11 ml to 188 ml, respectively).

CONCLUSION

These results suggest that ejection fraction measurements by various techniques are not interchangeable. The conclusions and recommendations of research studies in heart failure should therefore be interpreted in the context of locally available techniques. In addition, there are very wide variances in volumes and ejection fraction between techniques, which are most marked in comparisons using echocardiography. This suggests that cardiovascular magnetic resonance is the preferred technique for volume and ejection fraction estimation in heart failure patients, because of its 3D approach for non-symmetric ventricles and superior image quality.

Tissue harmonic imaging: a new method for predicting left ventricular thrombus?

We report a case of spontaneous echocardiographic contrast in the left ventricle visualized by transthoracic second harmonic imaging, but not by fundamental imaging, and subsequent thrombus formation.

Discrete breathers: exact solutions in piecewise linear models

Exact breather solutions are constructed in piecewise linear (PWL) versions of the discrete nonlinear Schrodinger and Klein-Gordon equations. These solutions correspond to intersections of stable and unstable manifolds of relevant fixed points in associated 2D mappings, an exact construction of which is possible due to the PWL nature of the models. Such exact solutions give us insight into several aspects of breather properties. The problem of dynamical stability of the breathers is mentioned as an instance, detailed results on which will be presented in a future paper.

Racial variation in cardiovascular morbidity and mortality in essential hypertension

OBJECTIVES

To perform a longitudinal comparison of morbidity and mortality among white, south Asian and Afro-Caribbean hypertensive patients in relation to baseline demographic characteristics and clinic and ambulatory blood pressure variables.

DESIGN

Observational follow up study.

SETTING

District general hospital and community setting in Harrow, England.

PATIENTS

528 white, 106 south Asian, and 54 Afro-Caribbean subjects with essential hypertension who had undergone 24 hour ambulatory intra-arterial blood pressure monitoring.

INTERVENTIONS

Follow up for assessment of all cause morbidity and mortality over a mean (SD) of 9.2 (4.1) years.

MAIN OUTCOME MEASURES

Non-cardiovascular death, coronary death, cerebrovascular death, peripheral vascular death, non-fatal myocardial infarction, non-fatal stroke, coronary revascularisation.

RESULTS

South Asians had the highest all cause event rate of 3.46, compared with 2.50 (NS) and 0.90 (p = 0.002) events/100 patient-years for whites and Afro-Caribbeans, respectively. This was because of an excess of coronary events (2.86 v 1.32 events/100 patient-years in south Asians v whites, respectively; p = 0.002). Age (p < 0.001), sex (p < 0.001), race (south Asians : whites, hazard ratio 1.79; p = 0.008), diabetes (p = 0.05), previous history of cardiovascular disease (p < 0.001), and 24 hour ambulatory systolic blood pressure (p = 0.006) were independent predictors of time to a first event. Clinic blood pressure did not provide additional prognostic information.

CONCLUSIONS

South Asian origin was an independent predictor of all cause events, mainly because of an excess of coronary events in this group. Ambulatory but not clinic blood pressure was of additional value in predicting subsequent morbidity and mortality.

Power doppler harmonic imaging: a feasibility study of a new technique for the assessment of myocardial perfusion

BACKGROUND

The aim of the study was to assess the feasibility of a new technique, power Doppler harmonic imaging (PDHI), for assessing myocardial perfusion through a venous injection of microbubbles, with the use of a new ultrasound contrast agent.

METHODS AND RESULTS

Fifteen patients with known coronary artery disease and a resting perfusion abnormality on Tc-99m sestamibi single-photon emission computed tomography (SPECT) underwent PDHI at rest during intravenous injections of 2 to 3 mL of Sonovue (Bracco SpA, Milan, Italy), a new second-generation ultrasound contrast agent. Myocardial perfusion was determined to be present or absent by use of a 5-segment model by 2 blinded observers for both PDHI and SPECT. Of a total of 75 possible myocardial segments, 7 (9%) were not analyzed because of obvious artifacts on PDHI. SPECT showed perfusion defects in 40 of the remaining 68 segments, whereas PDHI showed 39 defects. There was high concordance between the 2 imaging modalities for the presence (93%) as well as the location (96% for the anteroseptal region, 93% for the inferoposterior region, and 87% for the apical region) of the defects.

CONCLUSIONS

These preliminary results suggest that PDHI is a feasible technique for the detection of resting myocardial perfusion defects in patients with coronary artery disease after a venous injection of a new second-generation ultrasound contrast agent.

Can nuclear cardiology really help in the emergency departments of the 21st century?

The cardiac troponins are a highly sensitive and specific marker for myocardial damage and have been shown to be useful in the management of patients with acute coronary syndromes. However, some patients with significant ischaemia have no myocardial damage, and therefore negative troponins, despite high risk of subsequent events. Furthermore as a result of the time delay before the troponins can be measured in the peripheral blood, serial sampling is required to rule out myocardial damage. Nuclear perfusion imaging provides an instantaneous assessment of perfusion at the time of injection which is not dependent of on myocardial necrosis, but the presence of flow heterogeneity. Thus these two techniques provide complementary information for the assessment of patients with chest pain and non-diagnostic electrocardiograms, and early perfusion imaging offers the possibility of more rapid assessment and decision making than is possible with troponins.

Improved efficacy and safety of controlled-release diltiazem compared to nifedipine may be related to its negative chronotropic effect

The objective of this study was to assess the safety and efficacy of long-acting preparations of two commonly used calcium antagonists with particular reference to their effects on heart rate. Twenty patients with chronic stable angina were recruited to a double-blind, double-dummy crossover study of controlled-release diltiazem (diltiazem CR) versus sustained-release nifedipine (nifedipine SR) and underwent clinical assessment, symptom and adverse event reporting, and repeated treadmill exercise tests over a 10- to 11-week period. The main outcome measures were heart rate at rest and exercise, incidence of angina and nitroglycerin use, treadmill exercise performance (duration, time to angina, time to 1-mm ST-segment depression, heart rate at equivalent maximal exercise, and maximal ST-segment depression), and adverse events. Diltiazem CR significantly reduced heart rate at rest and equivalent exercise and incidence of angina and nitroglycerin use compared with nifedipine SR. Exercise duration time to angina and time to 1-mm ST-segment depression (but not maximal ST-segment depression) were all significantly improved by diltiazem CR. Diltiazem CR also caused significantly fewer adverse events than nifedipine SR. Calcium antagonists with negative chronotropic effects (eg, diltiazem CR) are safer and more efficacious as monotherapy in chronic stable angina than dihydropyridines (eg, nifedipine SR) even when a long-acting formulation of the latter is used.

Dobutamine echocardiography predicts functional outcome after revascularisation in patients with dysfunctional myocardium irrespective of the perfusion pattern on resting thallium-201 imaging

OBJECTIVE

To evaluate whether the predictive value of dobutamine echocardiography for assessing contractile reserve was altered by differing patterns of regional myocardial perfusion.

PATIENTS

31 consecutive patients with symptomatic congestive heart failure (left ventricular ejection fraction < 35%) caused by coronary artery disease.

SETTING

A district general hospital.

METHODS

Thallium-201 perfusion imaging and low dose dobutamine (5-15 microg/kg/min) echocardiography were performed and resting echocardiography was repeated three months after revascularisation. Perfusion pattern and systolic wall thickening were compared using a 12 segment left ventricular model.

RESULTS

Of the 273 severely dysfunctional segments, 106 (39%) showed a normal perfusion and 167 (61%) an abnormal pattern. After revascularisation, recovery occurred in 71 of the segments with a normal perfusion pattern, and in these a dobutamine response was observed in 61 (86%); recovery also occurred in 56 segments with a mild to moderate abnormality of perfusion, and in these a dobutamine response was seen in 46 (81%) (NS). After revascularisation, the positive and negative predictive values for recovery of dysfunctional segments, where the majority were abnormally perfused, were 88% and 86%, respectively. Systolic wall thickening score indices improved from (mean (SD)) 3.21 (0.58) to 2. 6 (0.66) (p < 0.001) after revascularisation in dobutamine responsive patients (n = 24) compared with patients who did not show a dobutamine response (2.86 (0.65) and 3.13 (0.56), p = 0.61, respectively).

CONCLUSIONS

Dobutamine echocardiography predicted improvement of dysfunctional myocardium after revascularisation irrespective of the resting perfusion pattern seen.

Why cardiac magnetic resonance imaging will not make it

Coronary artery disease is currently the largest killer in the western world, and is estimated to become the leading cause of death worldwide by the year 2020. The question therefore is whether magnetic resonance imaging currently has a place in the already extremely well equipped armamentarium of cardiac testing. Although it is promising, its clinical use is somewhat limited by high cost and low availability of equipment and trained personnel. The absence of portable systems for cardiac application make cardiac magnetic resonance imaging in the emergency room, at the patient's bedside or in the doctor's office impossible. The comparison of the cardiac magnetic resonance imaging with proven and cost-effective techniques like echocardiography and nuclear imaging will be decisive in terms of the choice of imaging modalities in cardiology.

Prediction of coronary and cerebrovascular morbidity and mortality by direct continuous ambulatory blood pressure monitoring in essential hypertension

BACKGROUND

The goal of this study was to assess the prognostic value of ambulatory versus clinic blood pressure measurement and to relate cardiovascular risk to ambulatory systolic and diastolic blood pressure levels.

METHODS AND RESULTS

The study population consisted of 688 patients 51+/-11 years of age who had undergone pretreatment 24-hour intra-arterial ambulatory blood pressure monitoring on the basis of elevated clinic blood pressure. A total of 157 first events were recorded during a 9.2+/-4.1-year follow-up period. The predictive value of a regression model containing age, sex, race, body mass index, smoking, diabetes mellitus, fasting cholesterol level, and previous history of cardiovascular disease was significantly improved by the addition of any ambulatory systolic or diastolic blood pressure parameter (whether 24-hour, daytime, or nighttime mean) or pulse pressure, whereas inclusion of baseline clinic blood pressure variables did not enhance the prediction of events. The most predictive models contained the ambulatory systolic blood pressure parameters. In the model containing 24-hour mean ambulatory systolic blood pressure (P=0.001), age (P<0.001), male sex (P<0.001), South Asian origin (P=0.008), diabetes mellitus (P=0. 05), and previous cardiovascular disease (P<0.001) were additional independent predictors of events. Whereas 24-hour ambulatory systolic blood pressure was linearly related to the incidence of both coronary and cerebrovascular events, 24-hour ambulatory diastolic blood pressure exhibited a positive linear relationship with cerebrovascular events but a curvilinear relationship with coronary events.

CONCLUSIONS

Ambulatory blood pressure is superior to clinic measurement for the assessment of cardiovascular risk; there is no reduction in coronary risk at lower levels of ambulatory diastolic blood pressure.

Improved endocardial visualization with second harmonic imaging compared with fundamental two-dimensional echocardiographic imaging

BACKGROUND

Endocardial visualization is suboptimal by fundamental imaging in at least 30% of patients. Second harmonic imaging was developed for visualization of myocardial contrast agents. We have hypothesized that endocardial visualization may improve with harmonic imaging compared with fundamental imaging.

METHODS AND RESULTS

Accordingly, 40 consecutive patients with poor endocardial visualization by conventional echocardiography in at least 1 left ventricular segment (22-segment model) in the 4 standard views randomly underwent fundamental and harmonic imaging without contrast. The images were separately and randomly analyzed by 2 observers. Endocardial visualization was scored as 0, not visualized; 1, poorly visible; and 2, well visualized. Endocardial visualization indexes were also calculated. More segments were assigned a score of 0 (P <. 001) and 1 (P <.001) by fundamental compared with harmonic imaging, whereas harmonic imaging demonstrated more segments with a score of 2 (P <.001) compared with fundamental imaging. Endocardial visualization indexes were significantly better by harmonic imaging in the parasternal long axis (P <.005), short axis (P <.001), and apical 4- (P <.0001) and 2-chamber views (P <.0001). Similar results were obtained by a second observer. Agreement between the 2 observers regarding improvement, deterioration, or no change in score between harmonic and fundamental imaging was 88% (kappa = 0. 76). Interobserver and intraobserver agreements for systolic wall thickening scores also significantly improved with harmonic compared with fundamental imaging (P <.001).

CONCLUSION

Second harmonic imaging is superior to fundamental imaging for endocardial visualization in patients with suboptimal fundamental imaging.

The carvedilol hibernation reversible ischaemia trial; marker of success (CHRISTMAS). The CHRISTMAS Study Steering Committee and Investigators

BACKGROUND

Carvedilol improves left ventricular (LV) function when heart failure is due to LV systolic dysfunction, but the magnitude of the response is heterogeneous among patients with coronary disease, possibly reflecting the presence or volume of hibernating myocardium.

AIMS

The primary objective of the study is to determine whether the presence of hibernating myocardium predicts the magnitude of improvement in LV ejection fraction in response to carvedilol among patients with heart failure and LV systolic dysfunction due to coronary disease.

METHODS

The study is a prospective, randomised, parallel-group, double-blind, multi-centre study comparing carvedilol and placebo over a period of approximately 6 months in the above patient population. The primary end-point is the comparison of the mean change, from baseline to the final visit, in radionuclide-determined LV ejection fraction among patients on placebo with those on carvedilol stratified according to the presence of hibernating myocardium. Hibernating status will be determined by a combination of echocardiographic and myocardial perfusion (technetium-99m sestamibi) imaging.

RESULTS

255 patients have undergone screening tests of which 207 have been randomised so far. The study intends to randomise 400 patients and the first report of results is expected in 2000.

CONCLUSIONS

As far as we are aware this is the first randomised controlled trial to investigate the effects of treatment in patients stratified according to the presence of hibernating myocardium. The study will provide insights into the prevalence of myocardial hibernation, its natural history, and its influence on prognosis as well as the interaction between the presence of hibernating myocardium and the effects of treatment with carvedilol.

The role of neurohormonal antagonists in hibernating myocardium

Hibernating myocardium is characterized by chronic reduction of myocardial blood flow due to obstructive coronary artery disease, causing reversible left ventricular dysfunction and flow-metabolism mismatch. The condition is unstable and increasing demand may lead to further left ventricular dysfunction or necrosis causing death or worsening heart failure. Recognition of the condition is difficult and requires complex cardiac imaging protocols. Treatment protocols are also poorly defined. This review addresses both the diagnostic and therapeutic aspects of hibernating myocardium.

Myocardial viability on echocardiography predicts long-term survival after revascularization in patients with ischemic congestive heart failure

OBJECTIVES

This study was conducted to evaluate the effect of revascularization on survival in patients with congestive heart failure (CHF) due to ischemic left ventricular (LV) systolic dysfunction based on the presence of myocardial viability (MV).

BACKGROUND

There are insufficient data regarding the survival benefit of revascularization in patients with CHF due to ischemic LV systolic dysfunction.

METHODS

Follow-up was obtained in 87 consecutive patients with CHF due to ischemic LV systolic dysfunction (New York Heart Association [NYHA] class II-IV; LV ejection fraction <0.35) who underwent low-dose dobutamine echocardiography (DE). MV within each of 12 myocardial segments representing the LV was defined as having either: 1) normal function or mild dyssynergy at rest; 2) severe resting dyssynergy that improved on DE, or 3) worsening of function on DE except in the case of akinesia.

RESULTS

At a mean follow-up of 40+/-17 months, 37 patients had received revascularization on the basis of clinical grounds, and there were 22 (25%) cardiac-related deaths. Multivariate Cox regression analysis revealed that when patients with at least five segments showing MV underwent revascularization, mortality was reduced by an average of 93% (confidence interval of 22% to 99%), which was associated with improvement in NYHA class as well as LV ejection fraction. Patients with less than five segments showing MV who underwent revascularization (and thus, showing mostly scar), and those with at least 5 segments demonstrating MV who were treated medically, had a much higher mortality.

CONCLUSIONS

Revascularization produces a clear survival benefit in patients with CHF due to ischemic LV systolic dysfunction who have a significant region of the LV demonstrating MV. These data may have wide-ranging implications in the management of patients with coronary artery disease whose main clinical presentation is CHF.

The prognostic value of a normal Tc-99m sestamibi SPECT study in suspected coronary artery disease

BACKGROUND

Myocardial perfusion is widely used for risk stratification of patients with suspected or known coronary artery disease (CAD). Recent years have seen an increasing demand for screening of such patients. The value of a normal stress thallium-201 scanning is well established. The advent of technetium 99m-sestamibi single photon emission computed tomography (SPECT) has enhanced the profile of nuclear cardiology even further as a reliable test for screening. However, in spite of previous reports, there is paucity of large-scale data regarding the prognostic value of a normal Tc 99m-sestamibi scanning result.

METHODS

The aim of our study was to assess the incidence of cardiac death and non-fatal myocardial infarction in patients with an intermediate probability of coronary artery disease (CAD). A total of 473 patients with normal stress Tc-99m-sestamibi SPECT were monitored for 30+/-16 (6 to 56) months to assess serious cardiac events. There were 272 men and 201 women, with a mean age of 56+/-2 years, of whom 89% had symptoms suggestive of CAD, 65% had an abnormal exercise electrocardiography, 6% had known CAD, and 5% had a high risk of CAD. The average workload was 9.14 metabolic equivalents, peak exercise heart rate was 93%+/-13% of the age predicted target.

RESULTS

The annualized mortality rate was 0.2% (95%CI 0.02% to 0.7%) and no infarctions occurred in this group.

CONCLUSIONS

A normal stress Tc-99m-sestamibi is highly predictive of a benign outcome, even in patients with intermediate probability of CAD.

Carvedilol prevents remodeling in patients with left ventricular dysfunction after acute myocardial infarction

OBJECTIVE

The aim of the study was to assess the effects of carvedilol, a vasodilating nonselective beta-blocker, on the indexes of left ventricular remodeling after acute myocardial infarction in those with left ventricular dysfunction.

METHODS AND RESULTS

Forty-nine patients with predischarge left ventricular ejection fraction <45% after acute myocardial infarction were evaluated in a double-blind, randomized, placebo-controlled, parallel group study (selected from the database of the Carvedilol Heart Attack Pilot Study: CHAPS). Patients received medication after thrombolysis and continued to do so for 6 months. Two-dimensional echocardiography was performed before discharge (7 to 10 days after admission) and at 3 months after acute myocardial infarction. Analysis of variance showed that wall thickness opposite the site of infarction decreased from (mean +/- SD) 12.3 +/- 2.1 mm to 11.0 +/- 2.4 mm with carvedilol compared with 11.6 +/- 1.9 mm to 12.2 +/- 1.9 mm with placebo (P =.01). Left ventricular mass changed from 235 +/- 74 g to 217 +/- 64 g with carvedilol compared with 227 +/- 80 g to 252 +/- 85 g with placebo ( P =.02). Carvedilol prevented alteration of sphericity index (ratio of long and short axis of left ventricle) that changed from 1.65 +/- 0.29 to 1.66 +/- 20 with carvedilol compared with 1.58 +/- 0.33 to 1.39 +/- 0.19 with placebo (P =.02); alteration was also prevented of wall thickening abnormality at infarct site, which changed from 9.2 +/- 3.1 cm2 to 9.1 +/- 3.5 cm 2 with carvedilol compared with 10.3 +/- 3.3 cm2 to 13.5 +/- 4.6 cm2 with placebo (P =.002).

CONCLUSION

Carvedilol administered early after acute myocardial infarction results in attenuation of left ventricular remodeling in patients with persistent left ventricular dysfunction before discharge.

Biodistribution, radiation dosimetry and pharmacokinetics of 111In-antimyosin in idiopathic inflammatory myopathies

In view of the established role of 111In-antimyosin in the detection of heart muscle pathology, radiation dose estimates were made for this substance. Biodistribution and biokinetic data were obtained from our studies, which failed to show abnormal uptake of 111In-antimyosin in localized sites of skeletal muscle involvement in patients with idiopathic inflammatory myopathies.

METHODS

After intravenous administration of 74 MBq (2 mCi) 111In-antimyosin, gamma camera scintigraphy was performed in 12 adult patients with inflammatory muscle disease and in 2 control patients. Six whole-body scans were performed over 72 h, and uptake of 111In-antimyosin in organs was quantified using an attenuation-corrected conjugate counting method. Residence times in source organs were used with MIRDOSE software to obtain radiation dose estimates. Pharmacokinetic parameters were derived from serial whole-blood and plasma 111In concentrations.

RESULTS

The tracer cleared slowly from the circulation, and highest organ uptakes were found in the marrow and liver; kidneys showed the highest concentrations. Uptake was also evident in spleen, the facial image and male genitalia.

CONCLUSION

For a typical administered activity of 74 MBq 111In-antimyosin, the kidneys receive the highest dose (58 mSv), and the effective dose is 11 mSv. Radioactivity was cleared from plasma at an average rate of 136 mL/h, and the mean steady-state distribution was approximately 5 L plasma.

Comparison of safety and efficacy of carvedilol and metoprolol in stable angina pectoris

In a double-blind, randomized, 3-month multicenter study, the safety and tolerability and the antianginal and anti-ischemic efficacy of carvedilol 25 to 50 mg twice daily were assessed in comparison with metoprolol 50 to 100 mg twice daily in younger and elderly patients with stable angina. After a 7-day placebo run-in at the end of which a symptom-limited bicycle ergometric exercise was performed, 368 patients were randomly allocated to the parallel treatment groups. After 4 weeks of therapy with a low dose, a further exercise test was performed and patients were titrated in single-blind fashion to the higher dose if the increase in total exercise time was < 1 minute, and there was no safety concern. After a further 8 weeks of treatment a third exercise test was performed. Carvedilol low dose/high dose was shown to be at least as safe and well tolerated as metoprolol low dose/high dose both in younger and elderly patients. There were no hitherto unknown adverse events and no marked change in the types of events after increase of the doses. Early adverse events after treatment initiation or uptitration were equal with both medications, indicating no particular risk associated with carvedilol's vasodilatory action. No rebound phenomena were observed. Both drugs showed good antianginal and anti-ischemic efficacy, with marked increases on uptitration including patients > or = 65 years of age. However, in the doses selected, which appeared equipotent with respect to beta blockade, carvedilol's improvement of time to 1-mm ST-segment depression was statistically significantly greater than that of metoprolol. This could be due to its additional vasodilatory or antioxidative actions. Based on the safety and efficacy data of the present study, use of the higher of the 2 recommended doses of carvedilol and metoprolol appears justified in younger and elderly patients without adequate therapeutic control at lower doses.

Value of ambulatory intra-arterial blood pressure monitoring in the long-term prediction of left ventricular hypertrophy and carotid atherosclerosis in essential hypertension

The aim of this study was to compare the abilities of clinic and ambulatory blood pressure (BP) to predict the long term occurrence of left ventricular hypertrophy and carotid atherosclerosis in uncomplicated hypertensive patients. Two hundred and ninety-five patients who had undergone 24-h ambulatory intra-arterial BP monitoring on the basis of an elevated clinic BP, attended follow-up at a mean of 10.2 (+/- 3.5) years later. This consisted of a history, physical examination, risk factor profile and serum cholesterol level. Echocardiography and carotid ultrasonography were also performed to determine left ventricular mass index and maximal intima-media thickness (IMTmax), a measure of carotid atherosclerosis severity. The factors most strongly correlated with both left ventricular mass index and IMTmax were age, 24-h mean pulse pressure and 24-h mean systolic BP. Age, 24-h mean systolic BP and body mass index were independent correlates of left ventricular hypertrophy (R2 = 17%), whereas age, 24-h mean pulse pressure and pack years were independent predictors of carotid atherosclerosis (R2 = 34%). Clinic BP did not feature in the final model for the long term prediction of cardiovascular end-organ damage. These findings promote a role for ambulatory BP monitoring in guiding aggressiveness of drug therapy in an attempt to limit potential target organ damage.

Denaturation of supercoiled DNA: a Monte Carlo study

A theoretical investigation of the denaturation characteristics of a supercoiled DNA has been presented employing a Metropolis Monte Carlo algorithm to examine the overall melting profiles of a supercoiled plasmid as the temperature is varied. We show that in contrast to a previously presented algorithm, this much simpler method is sufficient to explain almost all the overall denaturation characteristics and it also correctly calculates the detailed denaturation probabilities of each base pair at various degrees of supercoiling. We also present for the first time a theoretical investigation of the alkaline denaturation of a supercoiled plasmid. Although one can qualitatively reproduce the denaturation profiles using the present Monte Carlo algorithm, the agreement with experiment is not as good as in the case of thermal denaturation. The possible sources of discrepancy between theory and experiment have been discussed.

Carriage rate of group B streptococci in pregnant women and evaluation of different isolation media

A study was conducted in 507 pregnant women of different parities, trimesters of pregnancy and age groups for finding out the colonisation rate of group B streptococci either in throat or vagina or from both sites. Incidence of carriage rate in throat was 4.73%, in vagina 9.66% and in both sites 12.03%. Age, parity, gestational period of women were not found to have any significant influence on the colonisation rate at different sites. Isolation rate of the organism was greatly enhanced using two selective media for isolation compared to using single selective medium or combination of non-selective media and a single selective medium.

Cardiovascular outcome in white-coat versus sustained mild hypertension: a 10-year follow-up study

BACKGROUND

The aim of this study was to compare the risk conferred by white-coat versus sustained mild hypertension for the development of cardiovascular disease.

METHODS AND RESULTS

Patients (n=479) who underwent 24-hour intra-arterial ambulatory blood pressure monitoring on the basis of a persistently elevated clinic systolic blood pressure of 140 to 180 mm Hg were followed up for the development of subsequent cardiovascular events during a 9.1+/-4. 2-year period. White-coat hypertension, defined as a clinic systolic blood pressure of 140 to 180 mm Hg associated with a 24-hour ambulatory systolic blood pressure <140 mm Hg and diastolic blood pressure <90 mm Hg, was present in 126 patients, and the remainder had sustained mild hypertension. A subgroup of patients without complications underwent follow-up echocardiography and carotid ultrasound. White-coat hypertensives were younger (44+/-12 versus 52+/-10 years, respectively; P<0.001) and had a significantly lower incidence of cardiovascular events (1.32 versus 2.56 events per 100 patient-years, respectively; P<0.001) than sustained hypertensives. Multivariate analysis revealed age (P=0.002), sex (P=0.007), race (P=0.001), smoking (P=0.005), and the presence of white-coat hypertension (hazard ratio, 0.29; 95% CI, 0.09 to 0.90; P=0.04) to be independent predictors of subsequent cardiovascular events. Subgroup analysis in patients without complications revealed a lower incidence of left ventricular hypertrophy and lesser degrees of carotid hypertrophy in the white-coat group.

CONCLUSIONS

These findings indicate a relatively benign outcome in white-coat hypertension compared with sustained mild hypertension.

Hepatitis D infectivity profile among hepatitis B infected hospitalised patients in Calcutta

450 hospitalised cases of hepatic and non hepatic disorders and 100 normal individuals were examined for serum Hepatitis B Surface antigen and Delta Virus antigen by ELISA to find out its association with different clinical disorders. 105 patients (23.3%) and 2 control (2%) were positive for HBsAG. 60 cases with jaundice (26%) were HBsAg positive. 65% of HBsAg positive jaundiced patients had serum bilirubin level more than 2 mg per dl with a mean SGPT level of 488 iu/L. Only two cases were positive for HDV antigen among 60 HBsAg positive jaundice patients indicating a lower rate of prevalence of infection (3.3%). 62 (59%) out of 105 HBsAg positive cases did not show any history of blood transfusion or surgical interference indicating a positive HBV transmission through needle prick during investigative procedures.

Influence of background correction in the estimation of myocardial uptake of 99mTc labelled perfusion imaging agents

The effects of different corrections for background activity in the estimation of low organ uptake of radiopharmaceuticals have been examined using myocardial perfusion imaging agents. Estimates of myocardial uptake of 99mTc-labelled MIBI and tetrofosmin were made both at rest and after exercise. Patients were given one or other of the agents (12 MIBI; 17 tetrofosmin) and the measurements at rest and after exercise were made within a week of each other using a planar gamma camera method incorporating an attenuation-corrected, geometric mean technique. Myocardial uptakes were estimated using two different background corrections and also with no background subtraction. Mean values were in the range 1.3 to 3.0% and showed that, for both agents, uptakes estimated with and without background correction could differ by a factor of two. Although the study was not designed to compare myocardial uptakes of the two agents, a background correction which accounted separately for activity in tissue over- and under-lying the heart resulted in similar mean values for tetrofosmin (1.7% both at rest and after exercise) and for MIBI (1.8% rest; 1.9% exercise). For both agents, no significant difference was observed between myocardial uptakes at rest and after exercise measured at about two hours post-injection.

Safety, tolerability, and antiischaemic efficacy of ITF-296, a nitric oxide donor, in patients with chronic stable angina

A double-blind, placebo-controlled, parallel-group, dose-escalation study was performed to evaluate ITF-296, a new nitric oxide donor, in chronic stable angina. Twenty-four male patients underwent exercise electrocardiography in conjunction with echocardiography on three separate occasions within 2 weeks. After two reproducibility tests, the third exercise test was immediately preceded by a 30-min intravenous infusion of either placebo or 0.3, 1.0, or 3.0 microg/kg/min of ITF-296, with six patients in each treatment group. During ITF-296 infusion, systolic blood pressure decreased by a mean of 12 mm Hg compared with a 2 mm Hg increase in the placebo group [difference, -14; 95% confidence interval (CI), -23 to -6 mm Hg]. ITF-296 administration was followed by consistent increases in total exercise time, time to angina threshold, and time to 1-mm ST-segment depression. The mean change in total exercise time was 39 s on placebo and 94 s on ITF-296 (mean difference, 54 s; 95% CI, -48 to 157 mm Hg). The 1.0- and 3.0-microg/kg/min doses increased exercise time by >2 min with no important change in peak rate-pressure product compared with baseline. The trends exhibited in this small preliminary study were consistently pharmacologically plausible and indicate that ITF-296 shows potential antiischaemic efficacy in patients with chronic stable angina.

Independent prognostic value of the extent and severity of systolic wall thickening abnormality at infarct site after thrombolytic therapy

BACKGROUND

The prognostic value of systolic wall thickening abnormality after acute myocardial infarction in the thrombolytic era is not clearly known.

METHODS AND RESULTS

Accordingly, 119 consecutive patients with acute myocardial infarction who underwent thrombolysis were investigated with exercise electrocardiography and rest echocardiography at predischarge evaluation and were followed up for cardiac events. During a mean follow-up period of 19 months, 43 patients had cardiac events. Multivariate analysis with clinical, exercise electrocardiographic, and rest echocardiographic parameters showed that the independent predictors of cardiac events were systolic wall thickening score at the site of infarct (p = 0.02), end-systolic volume (p = 0.03), and exercise time (p = 0.02). The only independent predictor for both recurrent ischemic (death, unstable angina, and reinfarction) and nonischemic events (congestive heart failure and ventricular tachycardia) was systolic wall thickening score at the site of infarct (p = 0.02 and p = 0.007, respectively).

CONCLUSIONS

Systolic wall thickening abnormality at rest is an important independent predictor of cardiac events in patients who have undergone thrombolysis after acute myocardial infarction.

Assessment of myocardial perfusion and contractile function by inotropic stress Tc-99m sestamibi SPECT imaging and echocardiography for optimal detection of multivessel coronary artery disease

OBJECTIVE

To assess whether inotropic stress myocardial perfusion imaging, echocardiography, or a combination of the two could enhance the detection of multivessel disease, over and above clinical and exercise electrocardiographic data.

DESIGN

100 consecutive patients investigated by exercise electrocardiography and diagnostic coronary arteriography underwent simultaneous inotropic stress Tc-99m sestamibi SPECT (MIBI) imaging and echocardiography. MIBI imaging and echocardiographic data were analysed using a 12 segment left ventricular model, and each segment was ascribed to a particular coronary artery territory. The presence of perfusion defects with MIBI imaging or of wall thickening abnormality with echocardiography in at least two coronary artery territories at peak stress was taken as diagnostic of multivessel disease. Arteriographic evidence of > or = 50% stenosis was considered significant.

RESULTS

56 patients had multivessel disease. The sensitivity of the combination of MIBI imaging and echocardiography for detecting this was greater than either MIBI imaging or echocardiography alone (82%, 68%, and 68%, respectively; p = 0.005). Clinical and exercise electrocardiographic variables gave an R2 value of 18.2% for predicting multivessel disease. The addition of either MIBI imaging (R2 = 29.2%; p = 0.002) or echocardiography (R2 = 28.8%; p < 0.001) enhanced the detection of multivessel disease, and the inclusion of both had further incremental value (R2 = 34.8%; p = 0.003). Age (p = 0.03), MIBI imaging (p = 0.007), and echocardiography (p = 0.001) were independent predictors of multivessel disease.

CONCLUSIONS

The assessment of both myocardial perfusion and contractile function by simultaneous inotropic stress MIBI imaging and echocardiography optimises the non-invasive detection of multivessel disease.