Combining antiarrhythmic drugs and implantable devices therapy: benefits and outcome

At least 50% of patients who received an ICD have been treated with antiarrhythmic drugs (AAD). The potential indications for combining antiarrhythmic drugs and ICD are generally the following: reduction of the number of episodes of ventricular tachycardia or ventricular fibrillation and therefore of the number of shocks, improving patient's quality of life and extending the battery life of the ICD, prevention of supraventricular arrhythmias and/or control of their rate, lengthening of the tachycardia cycle length to allow ventricular tachycardia conversion by antitachycardia pacing and reduction of the number of episodes of syncope. Although previous papers reported conflicting results about pharmacologic therapy in reducing the frequency of iCD shocks, some recent randomized prospective studies showed the efficacy of pharmacologic therapy in reducing the frequency of ICD shocks. The use of antiarrhythmic drugs can have also adverse effect: an increase in the defibrillation threshold, an increase in the pacing threshold and an increase in the VT cycle length leading to detection failure. We have also to consider that some advantages derived from antiarrhythmic drugs can be reached by the new devices with atrial sensing and pacing and/or the possibility of atrial defibrillation or by using catheter ablation as adjunctive therapy to ICD. For these reasons, the concomitant use of antiarrhythmic drugs and ICD should be evaluated in each patient in relation to specific clinical and electrophysiologic features including: the frequency, the rate and the clinical presentation of the ventricular arrhythmia, the effect of the selected drug on the defibrillation threshold, the defibrillation threshold at the implant, the effect of the selected drug on the ventricular function and the likelihood of proarrhythmic events.

Hypermnesia in unilateral neglect

Thirteen right brain-damaged patients who were found to neglect pictures presented on the left of a display were presented the same stimuli, intermixed with foils, in a yes-no recognition test. Fifty per cent of patients claimed to have already seen one or more of the previously neglected pictures. This demonstrates that visual information that fails to access consciousness in neglect patients does retain the ability to surface as explicit memory at a later stage.

Two-dimensional distortion of space representation in unilateral neglect: perceptual and response-related factors

The paper reports the results of an experiment in which left-neglect patients were required to point at the location they judged vertically to correspond (within the frame of the visual stimulus display they were given) with a cue that was variably located along a left-right axis lying proximally or distally with respect to the left-right axis over which they had to give their response. Patients were found to make rightward errors as in a similar, single-case study. The significant positive correlation between those errors and the degree of response bias on a manual-response version of the Milner Landmark Task suggests that rightward pointing errors made by left-neglect patients in conditions such as those set in the present experiment are due to a dysfunction selectively affecting an output-related component of space representation.

Antiarrhythmic benefits of dual chamber stimulation with rate-response in patients with paroxysmal atrial fibrillation and chronotropic incompetence: a prospective, multicentre study

BACKGROUND

While the haemodynamic benefits of DDDR pacing compared with DDD pacing in patients with brady-tachy syndrome and chronotropic incompetence (CI) are well demonstrated, the antiarrhythmic advantage is controversial and so far not clearly demonstrated.

AIM

We have performed a prospective, randomized, multicentre study to evaluate the efficacy of DDDR and DDD pacing modes in preventing paroxysmal atrial fibrillation (PAF) episodes in patients with brady-tachy syndrome and CI.

METHODS AND RESULTS

Seventy-eight patients were included in the study. All patients had a dual chamber pacemaker implanted and were randomly programmed to DDD or DDDR with a cross over (DDD --> DDDR or vice versa) at 3 months. The final evaluation was performed at 6 months by means of two self-administered symptom questionnaires to evaluate activity. Symptoms of palpitations were analysed and scored. The patients were less symptomatic with the DDDR mode. The number of mode-switch activations compared with symptomatic episodes of PAF confirmed the high rate of asymptomatic PAF episodes in patients with brady-tachy syndrome. We conclude that in a small but well defined population of patients affected by sick sinus syndrome with CI and severely symptomatic PAF, DDDR pacing compared with DDD pacing may offer an additional antiarrhythmic benefit and should be considered the primary mode of pacing.

Coronary flow reserve of normal left anterior descending artery in patients with ischemic heart disease: A transesophageal Doppler study

The aim of this study was to investigate the flow reserve of a normal left anterior descending coronary artery (LAD) in patients with coronary artery disease (CAD) of other epicardial vessels by Doppler transesophageal echocardiography (TEE). Thirty-one consecutive patients (age 59 +/- 8 years; 23 men) referred for TEE were considered. Eighteen patients had CAD and a 70% or greater LAD stenosis (group 1); 13 patients had right and/or circumflex CAD (>/=70% stenosis) and normal or minimally diseased LAD (group 2). Ten patients (age 54 +/- 11 years) with normal coronary arteries constituted group 3. Baseline and adenosine (0.160 microg/kg per minute intravenously over 60 minutes) flow velocities in the LAD were measured by pulsed Doppler examination during TEE. Peak and mean systolic and diastolic flow velocities were calculated. Adenosine/baseline peak and mean velocity ratios were used for evaluating blood flow reserve in the LAD. Heart rate and arterial pressure values were similar in the 3 groups at baseline and during adenosine infusion. Baseline and adenosine-related flow velocities were comparable in the 3 groups. Peak and mean diastolic velocity ratios were lower in groups 1 and 2 compared with group 3 (peak velocity ratio 1.68 +/- 0.81 and 1.93 +/- 0.35 vs 2.62 +/- 0.32, P <. 05; mean velocity ratio 1.71 +/- 0.86 and 2.01 +/- 0.41 vs 2.84 +/- 0.74, P <.05), whereas no differences were found between groups 1 and 2. No significant differences were found in systolic flow velocity ratios among the 3 groups. Patients with ischemic heart disease have a reduced diastolic flow velocity reserve in the LAD independent from the presence of significant LAD stenosis. Thus the adenosine TEE-Doppler study should be considered a screening test for CAD rather than for LAD disease.

Quantitative comparison of technetium-99m tetrofosmin and thallium-201 images of the thyroid and abnormal parathyroid glands

The aim of the study was to quantitatively compare the scintigraphic images of the thyroid and abnormal parathyroid glands obtained with technetium-99m tetrofosmin and thallium-201 in patients with hyperparathyroidism. Forty-six patients with hyperparathyroidism underwent (201)Tl (74 MBq), (99m)Tc-pertechnetate (74 MBq) and (99m)Tc-tetrofosmin (555-740 MBq) scintigraphy in a single session. Image analysis included the computation of the thyroid/background ratio in the whole study population and the parathyroid/background ratio, parathyroid/thyroid ratio and diagnostic sensitivity in 17 patients who underwent parathyroid surgery. The pertechnetate subtraction technique was used. (201)Tl and (99m)Tc-tetrofosmin showed a similar thyroid/background ratio (1.79+/-0.41 and 1.81+/-0. 47, respectively, P=NS); however, (99m)Tc-tetrofosmin showed a higher parathyroid/background ratio than (201)Tl (2.06+/-0.54 vs 1. 79+/- 0.50, P=0.007). Despite the superior quality of (99m)Tc-tetrofosmin images, both tracers showed identical sensitivity in detecting enlarged parathyroid glands in patients with primary hyperparathyroidism (89%) and in those with secondary hyperparathyroidism (50%).

High-performance liquid chromatographic analysis of physiological amino acids in human brain tumors by pre-column derivatization with phenylisothiocyanate

A reversed-phase high-performance liquid chromatographic technique for the determination of free amino acids in five biopsies of human brain tumors (two meningiomas, one glioblastoma and two oligodendrogliomas) is described. The frozen tissues were homogenized, deproteinized with perchloric acid and neutralized with potassium hydroxide. Aliquots of the supernatant containing the physiological amino acids are used for pre-column derivatization with phenylisothiocyanate. The derivatized PTC-amino acids (phenylthiocarbamyl derivatives) are stable for a five day period if stored as a powder at -20 degrees C in an inert atmosphere and they can be analyzed on a reversed-phase column (PicoTag) using a gradient of two eluents with absorption detection at a wavelength of 254 nm. Good resolution of several amino acids (>30) is achieved within ca. 60 min. For most amino acids this method is suitable for an accurate measurement over a wide range of physiological concentrations (50-400 pmol) starting from a very small amount of sample.

Bladder obstruction in Hunter's syndrome

We report a case of bladder obstruction in a patient with Hunter's syndrome, presenting with acute painful symptomatology, due to the impossibility of voiding, which was diagnosed with ultrasonography and cystometrography. Intermittent catheterization with intravesical oxybutynin chloride lead to successful functional resolution of the obstruction.

Cardiac variant of Fabry's disease mimicking hypertrophic cardiomyopathy

A case of cardiac variant of Fabry's disease mimicking hypertrophic cardiomyopathy is reported. The diagnosis was obtained by biventricular endomyocardial biopsy showing severely hypertrophied myocardiocytes with large periodic acid-Schiff and Sudan black positive perinuclear vacuoles, shown at electromicroscopy to consist of lamellated cytoplasmic figures highly suggestive of Fabry's disease, and confirmed by diagnostic low activity of alpha-galactosidase A in the peripheral lymphocytes. Invasive approach was suggested by the occurrence of a long-standing atrial fibrillation that failed to determine deterioration of cardiac function. Differential diagnosis between hypertrophic cardiomyopathy and the cardiac variant of Fabry's disease is relevant for prognostic and therapeutic implications including the perspective of an enzyme replacement therapy.

Alterations in the CSB gene in three Italian patients with the severe form of Cockayne syndrome (CS) but without clinical photosensitivity

Cockayne syndrome (CS) is a rare autosomal recessive disorder characterized by postnatal growth failure, mental retardation and otherwise clinically heterogeneous features which commonly include cutaneous photosensitivity. Cultured cells from sun-sensitive CS patients are hypersensitive to ultraviolet (UV) light and, following UV irradiation, are unable to restore RNA synthesis rates to normal levels. This has been attributed to a specific deficiency in CS cells in the ability to carry out preferential repair of damage in actively transcribed regions of DNA. We report here a cellular and molecular analysis of three Italian CS patients who were of particular interest because none of them was sun-sensitive, despite showing most of the features of the severe form of CS, including the characteristic cellular sensitivity to UV irradiation. They all were altered in the CSB gene. The genetically related patients CS1PV and CS3PV were homozygous for the C1436T transition resulting in the change Arg453opal. Patient CS2PV was a compound heterozygote for two new causative mutations, insertions of an A at position 1051 and of TGTC at 2053, leading to truncated proteins of 367 and 681 amino acids. These mutations result in severely truncated proteins, as do many of those that we previously identified in several sun-sensitive CS-B patients. These observations confirm that the CSB gene is not essential for viability and cell proliferation, an important issue to be considered in any speculation on the recently proposed additional function of the CSB protein in transcription. Our investigations provide data supporting the notion that other factors, besides the site of the mutation, influence the type and severity of the CS clinical features.

Quantitative analysis of cancellation tasks in neglect

Patients with spatial neglect do not explore contralateral space effectively. Although cancellation tasks are used widely to assess this visual search deficit, their methods of analysis are not well established. We introduce logistic regression analyses for cancellation tasks in 7 patients with left neglect. We investigated the influences of spatial location, stimuli number, and target discriminability on the probability of canceling a target. As a group, neglect patients showed left and near neglect. They also explored and canceled targets further into contralateral space on arrays with fewer visual stimuli. Individual analyses revealed exceptions to these group patterns, such as two patients with far rather than near neglect. Only patients with relatively mild neglect canceled more targets when they were more easily discriminated from distracters. Logistic regression models accounted for 0.68 the variance in cancellation performances of the entire group. Shifting the unit of analysis from the proportion of targets canceled to the probability of detecting individual targets offers a powerful parametric method to analyze group and individual performances on cancellation tasks and can reveal functional dissociations in neglect.

Multisite stimulation in refractory heart failure

Since the early nineties, the employment of DDD pacing from a right ventricular site with a short AV delay in patients with severe heart failure has led to considerable conflicting results, so that the real benefit of this method remains to be defined even in selected patients, such as those with first-degree AV block, QRS duration > 140 ms due to left bundle branch block (LBBB), mitral regurgitation time > or = 450 ms and diastolic filling time < or = 200 ms. Indeed, the asynchronous activation induced by pacing the right apex is the most important limitation to the technique, particularly in patients without an LBBB pattern or in those with an incomplete LBBB pattern. Recent studies have also shown that pacing of the right interventricular septum provides no better results than pacing of the right apex, at least in selected patients with no LBBB pattern and no significant mitral regurgitation. Today, it has been suggested that permanent biventricular pacing could be proposed as a feasible and reliable approach to improving ventricular function through the synchronization of the septum and the apex of the left ventricle, particularly in patients with a marked delay in ventricular activation sequence. This technique may be performed by means of transvenous leads inserted through the coronary sinus into the cardiac veins to stimulate both ventricles simultaneously, starting from the right apex and left lateral wall. Consequently, this approach supplies a strong basis for initiating further studies to examine the chronic effects of left ventricular pacing in patients with severe heart failure. We also suggest that the new tissue Doppler imaging techniques could usefully be applied to accurately select candidates to biventricular pacing.

Cervical myelopathy in mucopolysaccharidosis type IV

We describe our experience with 8 Italian patients having mucopolysaccharidosis type IV, diagnosed between 1 and 10 years of life, who presented odontoid hypoplasia causing cervical myelopathy. We discuss the possibility of cranio-cervical stabilization in order to reduce the neurological complications.

Detection of synaptophysin-producing cells in human thymus by immunohistochemistry and nonradioactive in situ hybridization

We investigated human thymic tissue by immunohistochemistry and in situ hybridization for the presence of synaptophysin-producing cells. Our results indicate that anti-synaptophysin antibody detected immunoreactive material in nerve fibers around vessels located in major thymic septa, in a relevant number of cortical epithelial cells, and in scattered epithelial cells in the medulla. The epithelial nature of synaptophysin-positive cells was documented by the co-expression of cytokeratins as revealed by double immunofluorescence. In situ hybridization studies revealed the presence of synaptophysin mRNA in cells mainly located in the cortex, the specific fluorescent signals being localized in the cell cytoplasm. Western blot analysis using an affinity-purified polyclonal antibody revealed an immunoreactive band of about 38 kD in the extracts from unfractionated thymic tissue and from epithelial cell-enriched fractions. No staining was observed in isolated thymocytes. The expression of synaptophysin in epithelial cells of the thymic cortex suggests that this protein may be involved in secretory activities related to T-cell maturation.

Effects of early treatment with captopril and metoprolol singly or together on six-month mortality and morbidity after acute myocardial infarction. Results of the RIMA (Rimodellamento Infarto Miocardico Acuto) study. The RIMA researchers

The RIMA (Rimodellamento Infarto Miocardico Acuto) study was designed to assess the relative effects of angiotensin-converting enzyme (ACE) inhibition by captopril, beta-blocker therapy by metoprolol, and their combination in patients with a first acute myocardial infarction on: 1. echocardiographically detected left ventricular remodeling; 2. prognosis. The second goal will be the argument of the present paper. Two-hundred fifty < or = 75 years consecutive patients (mean age: 58 yrs, males = 203) with acute myocardial infarction were randomly allocated to receive for > or = 3 months captopril (up to 75 mg/day, Group 1), metoprolol (up to 200 mg/day, Group 2) or captopril + metoprolol (Group 3) starting in the first 24 hours after the onset of symptoms. Intravenous beta-blockers in the acute phase of myocardial infarction and all other cardioactive drugs were allowed. The effect of the randomized therapy at six months from admission to the coronary care unit was considered in relation to: 1. recurrence of spontaneous cardiac events and of elective revascularization procedures; 2. adverse reactions (hypotension, atrioventricular block, cough, allergy, need of beta-blockers in Group 1, need for ACE inhibition in Group 2) requiring treatment modification based on physician's decision.

RESULTS

Definite follow-up data were available in 226 patients and 195/226 patients (86%) had a complete treatment period. In these patients (per protocol analysis), 37 spontaneous cardiac events occurred: cardiac death = 6, non-fatal reinfarction = 9, unstable angina requiring hospitalization = 16, congestive heart failure = 6. Moreover, seven patients received a coronary revascularization procedure. Events occurred in 11/67 patients from Group 1, 16/63 patients from Group 2, 10/65 patients from Group 3 (16% vs 25% vs 15%, p = 0.28). The multiple logistic regression analysis demonstrated an increased odds ratio (OR) for spontaneous cardiac events in patients from Group 2 (OR = 2.82, 95% Cl: 1.16-6.87: p < 0.05). Elective revascularization procedures were statistically less frequent in patients treated with metoprolol (Group 1 = 9%, Group 2 = 1.6%, Group 3 = 0%; Group 1 vs Groups 2 and 3; p = 0.03). The intention-to-treat analysis on the overall population (226 patients) confirmed the presence of a trend towards a higher risk in patients from Group 2 (OR = 2.1, 95% Cl: 0.96-4.59; p = 0.06). Adverse reactions were observed in 16 patients from Group 1, 6 patients from Group 2 and 15 patients from Group 3 (22% vs 10% vs 23%; Group 2 vs Groups 1 and 3; p = 0.08). At the multivariate regression analysis, a trend towards less adverse reactions in patients assigned to the beta-blocker therapy alone was confirmed (OR = 0.41, 95% Cl: 0.15-1.13; p = 0.07).

CONCLUSIONS

In a randomized early post-infarction treatment strategy, ACE inhibition with captopril alone or in combination with metoprolol demonstrated an increased protection against spontaneous cardiac events at six months in comparison with metoprolol alone. On the other hand, the beta-blocker treatment was associated with a lower number of elective revascularization procedures and appeared better tolerated than ACE inhibition.

Unilateral neglect and disambiguation of the Necker cube

Three groups of patients (right brain-damaged patients with or without left neglect, and left brain-damaged patients) and a group of healthy subjects, matched for age and educational level to the three groups of patients, were asked to report which of the two frontal surfaces of Necker cubes oriented in four different ways looked, at first sight, nearer to the viewer. The extent to which, and the way in which, disambiguation of the apparent perspective of Necker cubes occurred was found to vary across the four orientations and to be different in left-neglect patients compared with subjects of the other three groups. With normal subjects, the disambiguating factor is suggested to be a disposition to perceive the upper surface, which is nearly orthogonal to the frontal plane, as external to the cube. This would result from a navigation of the observer's spatial attention towards its target along a particular path that is altered in patients suffering from left neglect. It is suggested that comparison of the paths followed by the attentional vectors of normal subjects and left-neglect patients is potentially fruitful for a better understanding of the brain's normal mechanisms of spatial attention and of unresolved issues concerning the perception of the Necker cube.

Magnetic resonance spectroscopy study of low grade extra and intracerebral human neoplasms

In this study we report an in vitro 1H magnetic resonance spectroscopy (MRS) characterization of water soluble metabolites obtained from 17 low grade extra and intracerebral human tumors (8 meningiomas, 5 oligodendrogliomas, 2 subependimomas and 2 ependimomas). In addition, the in vivo localized 1H MRS results for 4 of the meningiomas are reported. The main metabolic features characterizing low grade tumors were investigated. Meningiomas are characterized by high Cho/Cr and Ala/Cr ratios; in many cases both in the in vitro and the in vivo spectra these ratios cannot be evaluated, due to the absence of the Cr metabolite. Low grade oligodendrogliomas are characterized by low Cho/Cr ratios. High amounts of myo-inositol are found in the spectra of ependimomas and subependimomas which are distinguished by different Cho/Cr ratio values and by a different Ala content.

Visual awareness and anisometry of space representation in unilateral neglect: a panoramic investigation by means of a line extension task

Ninety-one right brain-damaged patients with left neglect and 43 right brain-damaged patients without neglect were asked to extend horizontal segments, either left- or rightward, starting from their right or left endpoints, respectively. Earlier experiments based on similar tasks had shown, in left neglect patients, a tendency to overextend segments toward the left side. This seemingly paradoxical phenomenon was held to undermine current explanations of unilateral neglect. The results of the present extensive research demonstrate that contralesional overextension is also evident in most right brain-damaged patients without contralesional neglect. Furthermore, they show that in a minority of left neglect patients, the opposite behavior, i.e., right overextension can be found. The paper also reports the results of correlational analyses comprising the parameters of line-extension, line-bisection, and cancellation tasks, as well as the parameters relative to the Milner Landmark Task, by which a distinction is drawn between perceptual and response biases in unilateral neglect. A working hypothesis is then advanced about the brain dysfunction underlying neglect and an attempt is made at finding an explanation of neglect and the links between the mechanisms of space representation and consciousness through the study of the changes induced by unilateral brain lesions in the characteristics of space-coding neurons.

ABBREVIATIONS

C, control group; GN+91, full group of neglect patients; GN+27, group of neglect patients with relative left overextension; GN+14, group of neglect patients with relative right overextension; GN-43, full group of non-neglect patients; GN-9, group of non-neglect patients with relative left overextension; H canc, H cancellation task; LE, left extension; LE/RE, ratio of left-right extension; N+, neglect patients; N-, non-neglect patients; PB Land-M, perceptual bias on Landmark motor task; PB Land-V, perceptual bias on Landmark verbal task; RB Land-M, response bias on Landmark motor task; RB Land-V, response bias on Landmark verbal task; RE, right extension.

Perceptual and response bias in unilateral neglect: two modified versions of the milner landmark task

Perceptual and response bias in estimating the proportion of the two segments of prebisected lines were disambiguated in a group of 121 patients suffering from left neglect by means of two variants of the Milner Landmark task (Milner et al., 1993). The first variant, LANDMARK-V, required a verbal response; the second variant, LANDMARK-M, required manual pointing. The paper reports and discusses the results obtained on each task and their correlations, as well as the relationships between either kind of bias and the intrahemispheric location of the lesion. It is argued that besides their usefulness as a diagnostic tool the proposed variants of the Milner Landmark task provide results that are worth further investigation in their own right.

Multicenter trial on prognostic value of inducible ischemia, assessed by dobutamine stress echocardiography and exercise electrocardiography test, in patients with uncomplicated myocardial infarction, treated with thrombolytic therapy

BACKGROUND

Thrombolysis has reduced early and longterm mortality by about 20%; sometimes, however, there is a re-occlusion of the infarct related artery or an unsuccessful thrombolysis. In these situations, there is a possible increase in detrimental events in the follow-up.

OBJECTIVES

The aim of the study was to compare the prognostic value of dobutamine echocardiography (DET) and ECG exercise test (EET) in pts submitted to thrombolysis.

METHODS

One hundred and fifty-one pts, with acute uncomplicated myocardial infarction, were enrolled. The pts were able to perform EET and had a sufficient echocardiographic window; 58 had anterior myocardial infarction (38%), 79 had inferior (52%), 2 had lateral (1%), 12 had non-Q (8%). EET was performed with an initial load of 25 Watt, and thereafter, 25 W every two minutes. DET was performed with step-wise infusion every three minutes (5, 10, 20, 30 and 40 mcg/kg/min.). If the target heart rate was not reached, a further dose of 40 mcg/kg/min. together with atropine 0.25-1 mg was administered, in the absence of signs and symptoms of ischemia.

RESULTS

During a mean (+/- SD) follow-up period of 8 +/- 4.5 months (range 1-23), 16 spontaneous events happened (4 deaths, 5 non-fatal re-infarctions, 7 unstable angina). One-hundred and three EET (68%) were negative for ongoing ischaemia, while 48 were positive, 79 DET (52%) were negative for ongoing ischaemia and 72 were positive (48%). Statistical results: DET and EET had a sensitivity of 41% and 54%, a specificity of 57% and 74%, a positive predictive value of 7% and 14%, a negative predictive value of 91% and 95%, an accuracy of 56% and 73%. Kaplan-Maier survival curves demonstrated that patients with Peak Wall motion > 1.8 and EET score > 3, had the higher risk of spontaneous events.

CONCLUSION

A few spontaneous events happened in the follow-up. These data demonstrate that patients treated with thrombolysis are not at high risk of spontaneous events. DET and EET, therefore, have had a high negative predictive value. For this reason, we can conclude that pts with negative tests can be considered at low risk and do not need any further investigations.

ECG changes during dobutamine stress test and spontaneous recovery of contractility in patients with myocardial infarction

Recent reports suggest a relationship between ECG changes and myocardial viability during dobutamine stress echocardiography in patients with myocardial infarction. The aim of the study was to analyze the predictive value of T-wave normalization and ST segment elevation during low- (10 mucg/Kg/m') and high-dose (40 mucg/Kg/m') dobutamine stress test for late spontaneous recovery of function in patients with a first uncomplicated Q-wave myocardial infarction.

METHODS

Seventy eight consecutive patients (59 +/- 9 yrs; males = 67; anterior MI = 41, inferoposterior MI = 37 pts) underwent baseline 2D echo and dobutamine stress test at 9 +/- 2 days from onset of symptoms and they were free of cardiac events during the first three months after myocardial infarction. T-wave normalization (negative T-wave becoming > or = 1 mm upright in > or = 2 leads) and ST segment elevation (> or = 0.1 mm in > or = 2 leads) at low- and high-dose dobutamine infusion were compared with an improvement of contractility in the infarct area detected echocardiographically at three months. A wall motion score decrease in infarct area > or = 2 was the criterion for recovery of contractility.

RESULTS

ST segment elevation occurred in 19/78 patients at low dose (24%) and in 45/78 patients at high dose (58%). Late recovery of contractility in the infarct area was observed in 38/78 patients (49%). The positive and negative predictive values of ST segment elevation for late recovery of contractility were, respectively, 63-56% at low dose and 47-48% at high dose. A baseline negative T-wave in > or = 2 leads was present in 56 patients, and 27 (48%) showed recovery of contractility at three months. T-wave normalization occurred in 14 patients at low-dose (25%) and in 29 patients at high-dose dobutamine infusion (52%). The positive and negative predictive values of T-wave normalization were, respectively, 71-59% at low dose and 62-67% at high dose. Both ECG markers were present in 10/56 patients at low dose and in 19 patients at high dose. The positive and negative predictive values, respectively, were 70-57% at low dose and 58-57% at high dose. At univariate analysis, neither the ECG changes alone nor their combination during dobutamine stress testing were shown to be significant predictors of recovery of function.

CONCLUSIONS

Our study demonstrates that in patients with a first uncomplicated Q-wave myocardial infarction, the T-wave normalization and/or the ST segment elevation occurring during early dobutamine stress testing are not reliable predictors of late spontaneous recovery of contractility in the infarct area.

In vivo single voxel 1H MRS of glial brain tumors: correlation with tissue histology and in vitro MRS

Eighteen patients affected by glial brain tumors were examined by localized single voxel magnetic resonance spectroscopy (1H MRS). For all patients histological diagnosis was obtained after stereotactic biopsy or surgical removal of the tumor. Histological nuclear atypia, tumor cellularity, necrosis, vascular proliferation and percentage of Ki-67 positive cells in the total cell populations were evaluated. It was found that some of the in vivo 1H MRS parameters were related to the histological features of the tumor. In particular, the Choi/Cri metabolite ratio obtained from the neoplastic tissues paralleled the Ki-67 cell proliferation index. For some of the patients 1H and 13C in vitro high resolution magnetic spectroscopy of surgical specimens was also carried out. 1H MRS of aqueous extracts from different biopsy specimens of the same tumor furnished fine biochemical information on intratumor heterogeneity. The degree of histological vascular proliferation of the tumor was correlated to the presence of cholesteryl esters in the 13C spectrum of the lipid fraction of surgical specimens.

Different clinical and prognostic significance of painful and silent myocardial ischemia detected by exercise electrocardiography and dobutamine stress echocardiography after uncomplicated myocardial infarction

Prevalence and prognostic significance of painful and silent ischemia detected by exercise electrocardiography (ECG) and dobutamine stress echocardiography (DSE) were evaluated in 407 consecutive patients recovering from acute myocardial infarction. Painful ischemia assessed by both tests was not associated with different clinical characteristics of patients; on the other hand, it identified a higher risk subgroup compared with silent ischemia during exercise ECG but not during DSE.

Value of automatic processing and reliability of stored data in an implanted pacemaker: initial results in 59 patients

Stored data in implantable pacemakers have rarely been used as a diagnostic tool because of the complexity. Our group has developed software called AIDA, providing an automatic interpretation of data stored in memories of the Chorus (ELA medical) pacemaker. We compared the results of AIDA analysis to surface ECG Holter interpretation in 59 patients (age 75 +/- 9 years). In 33 cases, neither AIDA nor the Holter found any anomaly. Eleven patients demonstrated episodes of supraventricular tachycardia (SVT), confirmed by AIDA in ten patients; AIDA failure was due to nonsustained episodes of SVT not inducing mode switch. Loss of atrial sensing, pacemaker-mediated tachycardia, and ventricular extrasystoles were detected by AIDA in ten patients. Traditional Holter missed three cases. This initial study confirms that stored pacemaker data, automatically interpreted can provide reliable information over a 24-hour period.

Prognostic value of left ventricular volume response during dobutamine stress echocardiography

AIMS

An abnormal left ventricular volume response during dobutamine echocardiography identified patients with severe coronary artery disease. The aim of the study was to assess the prognostic value of left ventricular volume changes during dobutamine stress echocardiography in 136 patients.

METHODS AND RESULTS

Endpoints were defined as spontaneous cardiac events at follow-up. Left ventricular end-diastolic and end-systolic volume changes (abnormal response: < 10% and < 20% decrease, respectively) were compared with other clinical and stress test variables. During 18 +/- 7 months of follow-up, 31 cardiac events occurred: 12 hard events (cardiac death [n = 6], myocardial infarction [n = 6]) and 19 soft events (unstable angina [n = 16], congestive heart failure [n = 3]). End-diastolic volume response (P = 0.006), diabetes (P = 0.008), inducible wall motion abnormalities (P = 0.024), end-systolic volume response (P = 0.039) and inducible angina (P = 0.038) were related to a greater likelihood of cardiac events. The Cox regression analysis revealed end-diastolic volume response (odds ratio: 3.0; CI 1.44-6.32) and diabetes (odds ratio: 2.7; CI 1.28-5.69) to be independent predictors of spontaneous cardiac events. Diabetes (odds ratio: 4.0; CI 1.26-12.80) and < 40% baseline ejection fraction (odds ratio: 2.21; CI1.14-4.29) were independent predictors of hard events.

CONCLUSION

An abnormal end-diastolic volume response during dobutamine stress echocardiography identifies patients with an unfavourable outcome; they should be considered for more accurate prognostic stratification.

Low-grade adenocarcinoma of endolymphatic sac mimicking jugular paraganglioma at clinical and neuroradiological examination

We report a case of low-grade adenocarcinoma of endolymphatic sac origin mimicking jugular paraganglioma at clinical and neuroradiological examination. The lesion occurred in a 72-year-old male who presented with a long-standing history of right-sided hearing loss and a few-week history of progressive facial nerve palsy and right aural pain. At histology, the tumor was composed of pseudoglandular spaces with papillary infoldings. Lumina contained colloid-like material. The lesion was surgically removed with suboccipital approach following endoarterial embolization. This study emphasizes that low-grade adenocarcinomas of endolymphatic sac origin extending to posterior cranial fossa and jugular paraganglioma may be indistinguishable preoperatively at clinical and radiological levels.

Long-term haemodynamic and antiarrhythmic benefits of DDIR versus DDI pacing mode in sick sinus syndrome and chronotropic incompetence

AIMS

The aim of this Italian multicentre study was to evaluate the haemodynamic and antiarrhythmic effects of DDIR versus DDI pacing mode in sick sinus syndrome with chronotropic incompetence.

METHODS

Seventy-nine patients were implanted with a dual chamber rate-responsive pacemaker (Medtronic 7075) and centrally randomised to DDI or DDIR pacing mode. After six months, the pacing modality was crossed over. Follow-up included clinical data, rest ECG, echocardiography, Holter monitoring and exercise testing in DDIR.

RESULTS

a) Haemodynamic effects. Comparing postimplant exercise testing in DDIR mode with preimplant tests, peak heart rate increased from 96 +/- 17 to 115 +/- 17 bpm (+20%, p < 0.0001), total work capacity from 7.0 +/- 3.5 to 8.8 +/- 4.3 minutes (+26%, p < 0.0001), peak oxygen uptake from 1238 +/- 406 to 1453 +/- 423 ml/min (+17%, p < 0.001) and oxygen uptake at anaerobic threshold from 977 +/- 343 to 1222 +/- 415 ml/min (+25%, p < 0.001). These benefits persisted unchanged during one-year follow-up. b) Antiarrhythmic effects. After six months, paroxysmal atrial fibrillation recurrence significantly decreased in the whole population: group I (DDI) 20.7 vs 48.3%, p < 0.02; group II (DDIR) 21.2 vs 36.4%, p < 0.05; group I + II (DDI + DDIR) 21.0 vs 41.9%, p < 0.001. After one year no significant differences were found between DDI and DDIR. Group I: DDI 23.8 vs DDIR 28.6%, ns; group II: DDI 22.7 vs DDIR 18.2%, ns.

CONCLUSION

DDIR vs DDI significantly improves short- and long-term haemodynamic performance. Dual chamber pacing shows a significant reduction of paroxysmal atrial fibrillation recurrence, regardless of rate responsiveness.

Dual modulation of Na/H antiport by atrial natriuretic factor in rat aortic smooth muscle cells

The aim of the present work was to study the effect of the atrial natriuretic factor (ANF) on the Na/H antiport in rat aorta smooth muscle cells, evaluated as intracellular pH (pHi) recovery after an acid load with ammonium chloride. The Na/H antiport was studied using a fluorescent probe, sensitive to pHi, 2',7'-bis(carboxyethyl)-5(6)-carboxyfluorescein. Our data indicate that ANF modulates the activity of the Na/H antiport in both a dose- and time-dependent manner. Hormone concentrations of 10(-10) M activate the antiport, increasing both the rate of recovery and the set point by approximately 0.2 pH units. This effect is mediated by diacylglycerol as a result of phospholipid hydrolysis by a phospholipase C, even if an involvement of adenosine 3',5'-cyclic monophosphate (cAMP) cannot be ruled out. ANF (10(-7) M) inhibits the antiport, decreasing both the rate of recovery and the set point by approximately 0.3 pH units, because of guanosine 3',5'-cyclic monophosphate production. Both inhibition and stimulation of pHi by ANF were more pronounced when the hormone was given before the acid load, perhaps because of the longer time exposure. We present new hypotheses on the mechanism of action of this paracrine/autocrine factor.

Unilateral neglect and space constancy during passive locomotion

Space constancy was investigated in seven blindfolded left-neglect patients by driving them along routes involving one or two, left or right, 90 degrees turns. At the end of each route patients had to indicate its starting point while still blindfolded. On average, no considerable left/right differences were found in pointing accuracy. The entailments of this finding for the understanding of neglect phenomena are briefly discussed.

Localised proton MR spectroscopy of brain metabolism changes in vegetative patients

We examined 14 vegetative brain-injured patients with proton magnetic resonance single-volume spectroscopy (1H MRS) at 1.5 T to establish whether there were changes in relative concentrations of N-acetyl aspartate (NAA), choline (Cho) and creatine (CR) metabolites from those found in healthy brains. Spectra were obtained from two different (2 x 2 x 2 cm) volumes of interest in the left and in the right frontal cortex, normal on MRI. All spectra revealed abnormalities compared with normal spectra obtained from age-matched control subjects. Values outside the normal range for at least one of the metabolite ratios were observed in all patients. Cho/Cr was markedly higher and NAA/Cho and NAA/Cr were markedly lower than in the control subjects. At different times six patients regained awareness and the ability to obey commands, and four were re-examined; changes in metabolite ratios were observed, which were different in individual patients. The NAA/Cho ratio reaches statistical significance in discriminating between the patients with a poor outcome (death or prolonged vegetative state) and those who regained awareness; the dividing line appears to be at a value of about 1.6.

Dobutamine-induced ST-segment elevation in patients with acute myocardial infarction and the role of myocardial ischemia, viability, and ventricular dyssynergy

We analyzed the relation between dobutamine-induced Q-wave ST-segment elevation and regional contraction during low (5 to 10 microg/kg/min) and high doses (20 to 40 microg/kg/min) of dobutamine in a series of 391 dobutamine echocardiographic tests performed 10 +/- 2 days after a first uncomplicated acute myocardial infarction (AMI). ST-segment elevation was defined as > or = 1 mm new or additional J-point elevation with a horizontal or upsloping ST segment lasting 80 ms. Wall motion score index at rest was derived using a 16 segment-4 grade score model. Patients with dobutamine-induced ST-segment elevation had a higher wall motion score index at rest (anterior wall AMI: 1.67 +/- 0.27 vs 1.43 +/- 0.30, p = 0.0001; inferior wall AMI: 1.44 +/- 0.27 vs 1.30 +/- 0.18, p = 0.0001) and similar incidence and extent of myocardial viability and homozonal ischemia in comparison with those without ST-segment elevation. The sensitivity, specificity, and accuracy of dobutamine-induced ST-segment elevation for detecting residual homozonal ischemia were 51%, 55%, and 54%, respectively, in patients with anterior wall AMI, and 42%, 68%, and 58%, respectively, in patients with inferior wall AMI. In conclusion, dobutamine-induced ST-segment elevation is not associated with higher incidence and extent of viable or jeopardized myocardium but rather to a greater extent of wall motion abnormalities at rest. Thus, this finding does not represent a clinically reliable discriminator for selecting patients for coronary angiography and possible revascularization procedures.

Brain perfusion SPET and proton magnetic resonance spectroscopy in the evaluation of two systemic lupus erythematosus patients with mild neuropsychiatric manifestations

The diagnosis of central nervous system (CNS) involvement appears to be a major problem in systemic lupus erythematosus (SLE), especially when the clinical signs are non-specific or neuroimaging is unremarkable. Two SLE patients with mild neuropsychiatric manifestations were studied with magnetic resonance imaging (MRI), single photon emission tomography (SPET) and localized proton magnetic resonance spectroscopy (H-1 MRS). MRI was normal in both patients. SPET revealed areas of hypoperfusion in both patients. H-1 MRS demonstrated metabolic abnormalities in the regions corresponding to the hypoperfused areas. A correlation between H-1 MRS and SPET was noted: patients with mild neuropsychiatric SLE may have disturbances evident on SPET and H-1 MRS in the presence of normal anatomy on MRI, suggesting that CNS involvement in SLE has very strong physiological and neurometabolic components in individual patients.

Steroid-eluting electrodes prevent chronic pacing threshold rise in the atrial chamber after oral propafenone administration

The aim of the study was to evaluate chronic atrial pacing threshold increase after oral propafenone therapy. Fifty patients affected by advanced AV block and sick sinus syndrome were studied at least 6 months after pacemaker implantation, before and after oral propafenone therapy (450-900 mg/day based on body weight). The patients were subdivided into three groups as to the type of electrode implanted, all three unipolar: group I (20 patients) Medtronic CapSure 4003, group II (13 patients) Medtronic Target Tip 4011, group III (17 patients) Medtronic 4057 screw-in leads. In all cases, Medtronic unipolar pacemakers were implanted with the same noninvasive autothreshold measurement method. Propafenone and 5-OH-propafenone blood levels were measured 3-5 hours after drug administration. The packing autothreshold was measured at 0.8, 1.6, and 2.5 V by reducing the pulse width. After propafenone, groups II and III showed a statistically significant threshold rise (P ranging from < 0.01 to 0.05), whereas no significant difference was found in group I. Propafenone and 5-OH-propafenone blood vessels did not show any significant difference among the three groups. Strength-duration curves were drawn for the three groups before and after propafenone: at baseline the curves shifted to the left with the steep part above the knee, clearly favoring CapSure over the other two groups. After propafenone, the curves shifted to the right, with the flat par progressively more evident in groups II and III. In the atrial chamber, steroid-eluting leads prevented threshold increase after propafenone therapy, in contrast with a significant threshold rise with conventional porous and screw-in leads.

Reliability of a new algorithm for automatic mode switching from DDDR to DDIR pacing mode in sinus node disease patients with chronotropic incompetence and recurrent paroxysmal atrial fibrillation

To evaluate the safety and efficacy of a new algorithm for automatic mode switching (AMS) from DDD-DDDR to DDIR, 26 patients, 16 females and 10 males, mean age 73 +/- 6 years of age, affected by sinus node disease, chronotropic incompetence, and recurrent paroxysmal atrial fibrillation (PAF) received the Medtronic Thera DR pacemaker. The device continuously calculates, in ms, the running average of the intrinsic atrial rate (MAR) and compares the current atrial interval (CAI) with the stored MAR. When the CAI is greater than the MAR it increases by 8 ms, and when the CAI is less than the MAR, it decreases by 23 ms. When MAR < or = 330 ms (182 beats/min), tachycardia is detected and AMS is activated. All patients had clinical evaluation, 12-lead ECG, Holter monitoring, and exercise testing after implantation and every 3 months for 1 year. The results were compared with the data stored in the pacemaker memory: AMS episodes number; the histogram of the last 14 episodes; and atrial electrogram recording. Twenty-two Holter recordings in 13 patients showed PAF and in all of them AMS occurred simultaneously. AMS lasted between 10 seconds and 20 hours, and MAR ranged from 195-400 beats/min. No episode of PAF and no AMS were recorded in 39 Holter recordings in 22 patients. Appropriate AMS was confirmed in five patients by stored atrial electrogram and in nine by 12-lead ECG and pacemaker event markers. Mean atrial sensing was 2.13 +/- 1.04 mV during PAF and 3.18 +/- 1.46 mV during sinus rhythm. No PAF episode and no AMS were recorded during exercise testing. In conclusion, this new algorithm was very reliable, sensitive, and specific.

Usefulness of dipyridamole transesophageal echocardiography in the evaluation of myocardial ischemia and coronary artery flow

High-dose dipyridamole transesophageal stress echocardiography has recently been proposed as a useful and safe method to assess myocardial ischemia in patients with poor transthoracic acoustic window. It has also been shown that transesophageal echocardiography (TEE) allows the study of coronary blood flow reserve (CBFR) in the left anterior descending artery (LAD). The aim of our study was to assess whether the morphologic information and pathophysiologic data on CBFR and myocardial ischemia can be collected by a single stress TEE without comprimizing its feasibility, safety and accuracy. We studied, 29 patient with known or suspected CAD (previous myocardial infarction or angina) (Group A), and as a control group, we studied 11 patients with mitral disease or mitral prostheses (Group B). All patients underwent the coronary angiography. None of Group B patients showed significant coronary artery stenosis (> 70%). In baseline conditions left ventricular wall motion and LAD coronary blood flow velocity (CBFV) were also evaluated. The following CBFV parameters were measured: maximal diastolic velocity (MaxDV), mean diastolic velocity (MnDV), maximal systolic velocity (MaxSV), mean systolic velocity (MnSV). The ratios of dipyridamole to rest maximal and o mean to diastolic velocities (MaxDV-Dip/Max DV-rest; MnDv-Dip/MnDV-rest) were measured as indexes of CBFR. No side effects were observed and the test could be completed in all patients (feasibility 100%). Wall motion analysis was adequate in all patients (feasibility 100%). Comparison between wall motion analysis was obtained and angiographic findings shown that the overall sensitivity and specificity of TEE were 84% and 93% respectively. Sensitivity for one, two and three vessel disease was 60%, 70% and 100%, respectively. LAD CBFV was adequately recorded in 85% of patients. CBFR parameters showed a significant difference between the two groups (Max DV-Dip/Max DV-rest: 1.67 +/- 0.7 vs. 2.73 +/- 0.6, P < 0.001); comparison between Group B patients and those of Group A with angiographically documented LAD stenosis showed a statistically significant difference in CBFR parameters (MaxDV-Dip/MnDV-rest, 2.73 +/- 0.6 vs. 1.65 +/- 0.7, P < 0.001, MnDV-Dip/MnDV-rest, 2.56 +/- 0.5 vs. 1.69 +/- 0.6 < 0.001). We conclude that transesophageal stress echocardiography is a useful method to study CAD and that it is possible to assess both morphologic and pathophysiologic information during a single examination.

In vivo 1H MRS and in vitro multinuclear MR study of human brain tumors

Localized in vivo 1H MR spectra of four patients with brain tumors and in vitro multinuclear (1H, 13C and 31P) MR characterization of water soluble and lipid components of the same tumors after surgical removal are reported herein. The in vivo spectra of the neoplastic regions of all patients showed N-Acetyl-Aspartate/Choline (NAA/Cho), Choline/Creatine (Cho/Cr) and N-Acetyl-Aspartate/Creatine (NAA/Cr) metabolite ratios markedly different from those of the controlateral healthy tissue. In vitro 1H MR measurements allowed for the identification of a much larger number of metabolites than those measured in vivo. Indeed, well resolved 1H, 13C and 31P MR spectra were obtained for water soluble and lipid components in all cases. Our data confirm that some metabolites observed in vitro could be specific markers of brain tumors.

An electrophysiological study of calcium entry during normal human T-lymphocyte activation

Our aim was to observe whether normal human T-cells respond to mitogenic stimulation with large whole-cell inward currents (composed of identifiable single-channel contributions) when [Ca2+]i is not markedly lowered but instead kept normal or moderately low, as has been reported in human leukaemic Jurkat T-cell line and T-cell clones [Kuno et al. (1986) Nature 323, 269-73; Kuno and Gardner (1987) Nature 326, 301-304; Gardner (1990) Annu. Rev. Immunol. 8, 231-252]. Whole-cell patch recordings showed no such currents in cells otherwise normally responding to depolarisation with the macroscopic IK described in T-lymphocytes and thus deemed viable, in agreement with the notion that Ca2+ influx in normal T-cells enterily depends on depletion of internal stores [Putney (1986) Cell Calcium 7, 1-12; Putney (1990) Cell Calcium 11, 611-624].

[Evaluation of the absorption of polycyclic aromatic hydrocarbons by analysing 1-hydroxypyrene in the urine of the workers in a factory of graphite electrodes]

A group of 288 workers of a graphite electrode manufacturing plant (33 of whom were not classified as either exposed or non-exposed) participated in a biological monitoring programme of exposure to PAHs via determination of 1-hydroxypyrene in end-of-shift urine. A highly significant difference (p < 0.000001) was observed in the mean urinary values of the metabolite in the 132 subjects classified as exposed compared to the 123 not exposed, which was not influenced by by confounding factors. The maintenance workers group showed mean urinary levels of 1-hydroxypyrene similar to the production department workers who were exposed to pitch. Among the exposed the use of a mask with filters for organic fumes reduced absorption of PAHs and significantly reduced urinary excretion of 1-hydroxypyrene (p < 0.005). The test also proved to be sensitive in discriminating the subjects exposed to low doses of PAHs, as the results obtained in laboratory workers showed. After comparing their data with the proposals for Biological Limit Values for 1-hydroxypyrene, the authors stress the usefulness of this biological monitoring tool in exposure to PAHs for the assessment of cancer risk, as provided for by Law No. 626/94.

[Prognostic value of echo-dobutamine test in patients with ischemic heart disease: comparison with exercise test]

BACKGROUNDS

The aim of the study was to assess the relative prognostic accuracy of dobutamine echocardiography (TED) vs maximal bicycle exercise electrocardiography (TE) in patients with proven coronary artery disease.

METHODS

One hundred and thirty consecutive patients (70 patients with uncomplicated recent myocardial infarction, 19 asymptomatic patients with previous myocardial infarction and 41 patients with stable angina pectoris and previous myocardial infarction or previous myocardial revascularization procedure) underwent TED (incremental dobutamine infusion: 5 to 40 ncg/kg/min, continued with atropine 0.25 to 1 mg iv if necessary) and TE on different days and in random order. Criteria for positivity were: new or worsening regional dyssynergy for TED; ST segment shift > or = 1 mm from baseline for TE. End points were defined as spontaneous events (cardiac death, myocardial infarction and unstable angina) and total events (spontaneous events plus myocardial revascularization procedures).

RESULTS

During 15.4 +/- 7.9 (range 1-33) months of follow-up, 33 events occurred: cardiac death (1), myocardial infarction (4) unstable angina (21) myocardial revascularization (7). Sensitivity, specificity, positive and negative predictive value, prognostic accuracy were similar for TED and TE (P = NS). Cumulative event-free survival curves as a function of TED and TE results were both statistically significant. A Cox stepwise regression analysis identified TED positivity obtained without atropine administration as the best predictor of spontaneous and total events (Odds ratio 5.33 and 4.38, respectively). Cumulative survival curves obtained by the combination of TED and TE results were statistically different (P < 0.05 and P < 0.001 for spontaneous and total events, respectively) and showed a poor clinical outcome in patients with both tests or only TED positive. TED correctly predicted clinical outcome in 24/39 patients in whom there was disagreement between the two tests.

CONCLUSIONS

In patients with proven coronary artery disease, TED and TE have a similar accuracy for predicting clinical outcome. Where a discrepancy is seen between the two tests, TED appears to have a slightly higher prognostic value.

[Multiplane transesophageal echocardiography and adenosine in the study of coronary blood reserve]

BACKGROUND

Coronary blood reserve is the capacity of coronary vessels to vasodilate and thereby to increase the blood flow, when the heart needs more energy. However, when a coronary stenosis occurs, the capacity to vasodilate is reduced or completely diminished. It is then necessary to use all the tools useful in evaluating the functional conditions of the coronary vessels. Above all, the intracoronary Doppler technique is used to measure the velocity of blood flow. Our purpose was to evaluate a non-invasive tool "Multiplane Transesophageal Echocardiography" in the study of velocity of the anterior descendent artery before and after adenosine infusion.

METHODS

At first, we studied 28 patients (pts), which we divided in two groups: Group A, 18 pts 59.38 +/- 8.23 mean age, 15 M. and 3 F., with anterior descending disease; Group B 10 pts, 59.20 +/- 8.48 mean age, 7 M. and 3 F, without significant stenosis (> 75%). Echocardiography examinations were performed with a 5 MHz multiplane probe, connected to a 1000 Hewlett Parkard echocardiography. Before the test, Diazepam 1 mg i.v. and Lidocaine spray were administered to the patients. We introduced the transesophageal probe and after choosing the best position of the aortic short axis view, we studied the anterior descending artery and measured the maximum and mean diastolic and sistolic velocities (V.MAX D., V.MN.D., V.MAX S., V.MN.S.).

RESULTS

Transesophageal echocardiography allowed us to study the anterior descending artery in 95% of pts. There were no side effects, except for one pt affected by severe bradicardia. In Group B there was an increase of the diastolic and sistolic velocity after adenosine infusion, resulting twice greater they the rest values. The adenosine/rest velocities ratios were statistically significant (V.MAX D. p < 0.02) (V.MN.D. p < 0.03).

CONCLUSION

Our results demonstrated an higher capacity of the Multiplane Transesophageal Echocardiography in studiing coronary blood reserve. We used adenosine, as a vasodilator drug, because of its short half-life and because it can be replatedly infused. The flow velocity values increased up to more than twice the rest values only in normal subjects.

[Use of high doses of atropine during dipyridamole echocardiography: safety and efficacy of the combined test]

BACKGROUND

Recent reports demonstrated an increased accuracy of dipyridamole echocardiography test with the intravenous infusion of 0.25 to 1 mg of atropine in 1-4 consecutive administrations at the end of the test. The effect of higher doses of atropine during dipyridamole echocardiography, potentially able to further increase heart rate and myocardial oxygen consumption, has not been evaluated. The aim of the study was to evaluate the effect of high doses of atropine during dipyridamole echocardiography and to investigate the possible pharmacological interference between dipyridamole and atropine.

METHODS

One-hundred consecutive patients (M = 81, F = 19; mean age 58 yrs) without inducible wall motion abnormalities at 14th minute of a high-dose (0.84 mg/Kg in 10') dipyridamole echocardiography test were studied. Seventy-five patients referred to the test in pharmacological wash-out were randomly divided in three groups: 25 patients (Group 1) received 10 mcg/Kg of atropine in 60"; 25 patients (Group 2) received 15 mcg/Kg of atropine in 120"; 25 patients (Group 3) received 20 mcg/Kg of atropine in 120"; moreover, 25 patients with a full-dose oral beta-blocker therapy (Group 4) received 20 mcg/Kg of atropine in 120". Atropine was infused during the 15th and 16th minute of the test. Heart rate (HR) changes and new wall motion abnormalities induced by atropine were considered and compared for each Group. In 60 patients (15 randomly selected from each Group) the effect on mean HR and R-R interval (msec) of the same dose of atropine infused during dipyridamole echocardiography was evaluated in resting conditions 24 hours apart.

RESULTS

The dipyridamole-atropine test was well tolerated and accomplished in all patients. HR increased significantly in all Groups of patients in comparison with pre-atropine HR values (Group 1: +14 +/- 8 b/m', p < 0.0001; Group 2: +19 +/- 8 b/m', p < 0.0001; Group 3: +22 +/- 9 b/m', p < 0.0001; Group 4: +19 +/- 8 b/m', p < 0.0001; Groups 2, 4 vs Group 1: p = 0.03, Group 3 vs Group 1: p = 0.002). No patients in Group 1 (0%), 3 patients in Groups 2 and 3 (12%), and 5 patients in Group 4 (20%) showed new wall motion abnormalities after atropine infusion (Group 4 vs Group 1: p = 0.06). Effects of atropine on HR and mean R-R interval were significantly more pronounced in resting conditions than during dipyridamole test (HR: +25 +/- 11 vs +18 +/- 9 b/m', p < 0.001; R-R: -256 +/- 122 vs -127 +/- 68 msec, p < 0.0001).

CONCLUSIONS

High doses of atropine during dipyridamole echocardiography test are safe and more effective for induction of new wall motion abnormalities than usual doses, particularly in patients tacking beta-blockers. The likelihood of an antagonistic mechanism between atropine and endogenous, dipyridamole-induced adenosine on sinus node is supported from our results.

Prognostic value of high dose dipyridamole echocardiography in patients with chronic coronary artery disease and preserved left ventricular function

OBJECTIVES

The prognostic value of dipyridamole echocardiography was assessed in patients with chronic coronary artery disease and preserved left ventricular function.

BACKGROUND

Few data are available on the prognostic value of dipyridamole echocardiography in patients with a low risk of cardiac events.

METHODS

Two hundred sixty-eight consecutive patients with stable, proven or suspected coronary artery disease and ejection fraction > or = 0.40 underwent high dose (up to 0.84 mg/kg body weight) dipyridamole echocardiography. In 204 patients definite exercise electrocardiographic (ECG) results were also available.

RESULTS

During a mean (+/- SD) follow-up period of 16 +/- 8 months (range 6 to 36), 33 spontaneous events occurred: 15 "hard" events (cardiac death [n = 6], myocardial infarction [n = 9]) and 18 "soft" events (unstable angina). Events occurred more frequently in patients with positive findings on dipyridamole echocardiography (59% vs. 3%, p < 0.001; hard events 24% vs. 2%, p < 0.01). A positive response at the low dose (up to 0.56 mg/kg) identified patients with a high incidence of hard events (7 of 16 patients, sensitivity 50%, specificity 96%). In patients with an exercise ECG, a comparable sensitivity for cardiac events was found (89% vs. 93%, p = NS), but dipyridamole echocardiography was more specific (91% vs. 61%, p < 0.01). A positive response on the low work load exercise ECG (< 8 min) and a positive response to low dose dipyridamole echocardiography had similar accuracy (82% vs. 90%, p = NS). Cox analysis identified dipyridamole echocardiography as the best predictor of cardiac events (odds ratio [OR] 20.9, 95% confidence interval [CI] 10.8 to 37.9); the highest risk of hard events was found in patients with a positive response to low dose dipyridamole echocardiography (OR 25.4, 95% CI 12.2 to 54.1).

CONCLUSIONS

In patients with chronic coronary artery disease and a low incidence of cardiac events, dipyridamole echocardiography was effective in prognostic stratification, and positive low work load exercise ECG results were a reliable predictor of subsequent events. Consequently, dipyridamole echocardiography should be considered a complementary tool in the presence of high work load positivity or ambiguous exercise ECG results.

Tamoxifen and quercetin interact with type II estrogen binding sites and inhibit the growth of human melanoma cells

The mechanism of the antiproliferative activity of tamoxifen on melanoma cells in vitro and in vivo is poorly understood, as it is not mediated by the antiestrogenic properties of tamoxifen. Using a whole-cell assay and nuclear and cytosolic radio-binding experiments with [3H]-estradiol as tracer, we found that MNT1, M10, and M14 melanoma cell lines as well as primary tumors expressed type II estrogen binding sites that bind tamoxifen and the flavonoid quercetin with similar affinity (KD 10-25 nM). Cell count and clonogenic assay showed both compounds to inhibit melanoma cell growth in a concentration-dependent manner in the range of concentrations between 1 nM and 1 microM. Neither the pure antiestrogen ICI-182780 nor the 3-rhamnosylglucoside of quercetin, rutin, bound to type II estrogen binding sites or inhibited cell growth. Our results suggesting that tamoxifen and quercetin can inhibit melanoma cell growth by interacting with type II estrogen binding sites help explain the reported effectiveness of tamoxifen, particularly in estrogen-receptor-negative tumors, and stress the potential role of quercetin in the treatment of melanoma.

Cellular basis of ventricular remodeling after myocardial infarction in rats

The remodeling of the spared non-ischemic left ventricular myocardium after different time intervals from the occlusion of the left coronary artery was examined in rats. In the presence of large infarcts, ventricular failure developed two to three days after surgery, because of chamber dilation and thinning of the wall, resulting in an average 7.5-fold increase in diastolic stress on the surviving myocardium. Mural thinning of the ventricular wall remote from and bordering the infarction occurred through side-to-side slippage of myocytes and capillaries within the wall. Although an average hypertrophic growth of 22% of the spared myocytes has been found, this amount of hypertrophy was insufficient to restore normal myocardial function. Long-term cardiac restructuring after infarction was characterized by the persistence of chamber dilatation and thinning of the ventricular wall. In addition to the side-to-side slippage, lengthening of the myocytes was an important cause of ventricular changes. As the reactive hypertrophy of the unaffected ventricle was insufficient to re-establish the ratio of ventricular mass to chamber volume, the diastolic stress remained elevated and decompensated eccentric ventricular hypertrophy developed. The anatomical remodeling of the spared left ventricular myocardium is an important conditioning factor in the short- and long-term outcome of ischemic cardiomyopathy.