Dramatic response to regorafenib in early glioblastoma progression: case report and review of the literature.

BACKGROUND: Glioblastoma (GBM) is a highly lethal disease despite integrated treatment comprising radiotherapy plus concomitant and adjuvant temozolomide, with a median overall survival of less than 15 months. For recurrent glioblastoma, there is yet no standard therapy, considering that Bevacizumab have failed to improve overall survival (OS) while regorafenib had a little benefit over standard chemotherapy. In addition, the disease control rate is almost exclusively stability, with a poor objective response rate. CASE REPORT: Here we present a case of rapid response to regorafenib in early glioblastoma progression at the end of adjuvant radiotherapy: after a single cycle of regorafenib the patient observed an impressive improvement in clinical condition, disappearance of headaches and a clear reduction of neoplastic tissue in MRI. A brief review about new radiological patterns in Magnetic Resonance Imaging (MRI) related to the introduction in clinical practice of antiangiogenic drugs and tyrosine kinase inhibitors has also been carried out. CONCLUSIONS: Regorafenib was certainly a first turning point in the second-line treatment of GBM, showing longer response rates and mostly disease stability than bevacizumab. A switch-maintenance strategy with tyrosine kinase inhibitors may represent a valid second-line therapeutic option.

Optimal target heart rate for exercise-induced T-wave alternans.

OBJECTIVES: This study was conducted to determine the optimal target heart rate (HR) for the use of exercise-induced T-wave alternans (TWA) as an index for risk of malignant ventricular tachyarrhythmias. BACKGROUND: Rate-dependent TWA is an index of vulnerability to ventricular tachyarrhythmias. However, false positive TWA was reported to occur in normal subjects at high HR. METHODS: Two groups were evaluated: Group I: 50 patients with malignant ventricular tachyarrhythmias, who received an implantable cardioverter-defibrillator (ICD); and Group II: 55 age-matched normal subjects. In both Groups, TWA was evaluated during symptom-limited bicycle exercise test. RESULTS: Peak HR during exercise test was 103 +/- 17 beats/min in Group I, versus 124 +/- 18 beats/min in Group II (P < 0.001). In Group I, 4 patients were excluded from analysis, due to high noise level or frequent ectopy during exercise. Out of the remaining 46 patients, TWA was present in 28 patients (61%), and absent in 18 (39%). In group II, TWA was present in four subjects (7%), and absent in 51 (93%). HR at the onset of TWA was 91 +/- 11/min in Group I, and 119 +/- 12/min in Group II (P < 0.001). Receiver operated characteristics curves demonstrated that a HR of 115 beats/min was the cutoff with the best sensitivity and specificity for TWA (100 and 96%, respectively). None of the patients in Group I developed TWA at HR > 115 beats/min, while two out of four in Group II had TWA at HR > 115/minutes. However, 13 patients in Group I who had no TWA were unable to exercise to a peak HR > 115 beats/min, compared to nine subjects in Group II. CONCLUSIONS: A target HR of 115 beats/min was highly sensitive and specific for determination of exercise-induced TWA as an index of risk of malignant ventricular tachyarrhythmias. However, a significant number of patients may not be able to achieve this target HR, resulting in an indeterminate test. The value of pharmacologic testing in this group should be assessed.

[Extramedullary primary cutaneous plasmacytoma. Description of a case] . / Plasmocitoma cutaneo primitivo extramidollare. Descrizione di un caso.

Primary cutaneous plasmacytomas of the chest wall are very rare. In this report we describe a case of a 70-years old man, affected by chronic obstructive pulmonary disease and renal failure. He was admitted because of a painful tumor on the right lateral chest wall: a transcutaneous fine needle aspiration and excisional biopsy revealed as a metastasis from lung cancer without clinical and or radiological evidence of pulmonary tumors and or other neoplasms. Because of failure of chemotherapy, the patient had undergone to bone marrow biopsy that it revealed medullary plasmacytosis < 5% plasma cells with a beta 2 microglobulin elevated. An other following excisional biopsy of a chest wall with immunocytochemistry revealed to be a cutaneous plasmacytomas. The patient was treated with local irradiation for a total dose of 40 cGy and systemic chemotherapy, stopped because of death by myocardial infarction. Cutaneous plasmacytomas appear to be more aggressive than non cutaneous extramedullary plasmacytomas; they should be separately categorized from them in future studies.

Phase I dose escalation study of gemcitabine and paclitaxel plus colony-stimulating factors in previously treated patients with advanced breast and ovarian cancer.

Gemcitabine and paclitaxel (PTX) are among the most active new drugs in advanced breast and ovarian cancer. In this Phase I study, we used fixed doses of gemcitabine administered on days 1 and 8 and escalating doses of paclitaxel on day 1 of a 21-day cycle in patients with pretreated metastatic breast or ovarian cancer. The dose of gemcitabine was fixed at 1,000 mg/m2; PTX was commenced in the first small patient group at a dose of 90 mg/m2, which was then escalated in subsequent groups by 30 mg/m2 per step. From the third dose level onwards, all patients received granulocyte colony-stimulating factor 300 microg by subcutaneous injection on days 5 and 6, and granulocyte macrophage colony-stimulating factor on days 15-18. Cohorts of at least 3 patients were treated at each dose level. Dose escalation was stopped if at least a third of the patients in a given cohort had dose-limiting toxicity (DLT), which was defined as grade 4 neutropenia or thrombocytopenia, or grade 3-4 non-haematological toxicity. The maximum tolerated dose (MTD) was defined as the dose level immediately below that causing DLT in one-third of the patients or more. Evaluation of the tumour response was performed every three cycles. Forty-five patients (31 with breast cancer, 14 with ovarian cancer) were treated at seven different dose levels. Only at the seventh PTX dose level was DLT observed after the first course of therapy: three grade 4 neutropenia, one grade 4 thrombocytopenia, and one grade 4 anaemia. DLT occurred in 5/6 patients at at PTX dose of 270 mg/m2; therefore dose escalation was stopped at that level and the dose immediately before it (PTX 240 mg/m2) was considered as the MTD and recommended for further studies. No toxic deaths occurred. Grade 3-4 uncomplicated neutropenia was observed in four patients. Three had uncomplicated grade 3-4 thrombocytopenia. One patient had grade 3 and one grade 4 anaemia. Nonhaematological side effects were generally mild. Among 30 evaluable patients with metastatic breast cancer, four complete responses (CR) (13%) and 12 partial responses (PR) (40%) were observed, for an overall response rate of 53% (95% confidence interval (CI) 34-72). The median duration of response was 31 weeks. Among 13 evaluable patients with advanced ovarian cancer, one CR (8%) and five PRs (38%) were observed, for an overall response rate of 46% (95% CI 19-78). The median duration of response was 32 weeks. Our study shows that gemcitabine and PTX can be administered in combination in patients with breast and ovarian cancer without unexpected toxicities and with encouraging therapeutic results.

Phase I-II study of gemcitabine and paclitaxel in pretreated patients with stage IIIB-IV non-small cell lung cancer.

Gemcitabine and paclitaxel are among the most active new agents in non-small cell lung cancer (NSCLC) and are worth considering for second-line chemotherapy. In this phase I-II study, we combined gemcitabine and paclitaxel for second-line treatment of advanced NSCLC. Gemcitabine doses were kept fixed at 1000 mg/m2 on day 1 and 8, and paclitaxel doses were escalated from 90 mg/m2 on day 1 of the 21-day cycle. Thirty-seven patients were treated at six different dose levels. Grade 4 neutropenia was dose-limiting toxicity (DLT), since it occurred in two out of six patients treated at paclitaxel 240 mg/m2; the paclitaxel dose level just below (210 mg/m2) was selected for phase Il evaluation. Non-hematologic toxicity was mild. One complete response (CR) (3%) and 13 partial responses (PR) (36%) were observed in 36 evaluable patients for an overall response rate of 39% (95% C.I., 23-57%). Median duration of response was 35 weeks (range, 8-102). All of the observed objective responses occurred in the 19 patients who had previously responded to the first-line therapy. Median survival was 40 weeks (range, 8-108 weeks). The combination of gemcitabine and paclitaxel is a feasible, well-tolerated, and active scheme for second-line treatment of advanced NSCLC; further evaluation, at least in selected patients, such as those previously responding to first-line chemotherapy, is definitely warranted.

The long QT syndrome and torsade de pointes.

The LQTS is a prime example of how molecular biology, ion channel, cellular, and organ physiology, coupled with clinical observations, promise to be the future paradigm for advancement of medical knowledge. Both the congenital and acquired LQTS are due to abnormalities (intrinsic and/or acquired) of the ionic currents underlying cardiac repolarization. In this review, the continually unraveling molecular biology of congenital LQTS is discussed. The various pharmacological agents associated with the acquired LQTS are listed. Although it is difficult to predict which patients are at risk for TdP, careful assessment of the risk-benefit ratio is important before prescribing drugs known to be able to cause QT prolongation. The in vivo electrophysiological mechanism of TdP in the LQTS is described using, as a paradigm, the anthopleurin-A canine model, a surrogate for LQT3. In the LQTS, prolonged repolarization is associated with increased spatial dispersion of repolarization. Prolongation of repolarization also acts as a primary step for the generation of EADs. The focal EAD induced triggered beat(s) can infringe on the underlying substrate of inhomogeneous repolarization to initiate polymorphic reentrant VT, sometimes having the characteristic twisting QRS configuration known as TdP. The review concludes by discussion of the clinical manifestations and current management of both the congenital and acquired LQTS. The initial therapy of choice for the large majority of patients with the congenital LQTS is a beta-blocking drug. This therapy seems to be effective in LQT1 and LQT2 patients, but may not be as effective in LQT3 patients. Other therapeutic options include pacemakers, cervicothoracic sympathectomy, and the implantable cardioverter defibrillator. Recent molecular genetic studies have suggested several genotype specific therapies; however, long-term efficacy data are not available.

Analysis of interleukin-2/interleukin-2 receptor system in advanced non-small-cell lung cancer.

AIMS AND BACKGROUND: The purpose of the study was to investigate the IL-2/IL-2 receptor system in patients with advanced non-small-cell lung cancer (NSCLC). PATIENTS AND METHODS: Sera from 40 subjects and 80 patients with stage III and IV NSCLC were assayed for soluble interleukin-2 receptor (sIL-2R) and interleukin-2 (IL-2) by the enzyme-linked immunosorbent assay. Circulating CD25+ cells were analyzed by flow cytoflorimetry. The data were related to clinical status by comparing the levels of sIL-2R and IL-2 at diagnosis and during the treatment. RESULTS: The mean sIL-2R concentrations of the NSCLC patients were significantly higher than the control population (P=0.0001); the patients with metastatic disease had significantly higher levels than those with locally advanced disease (P=0.02). No correlation was seen between circulating CD25+ cells and sIL-2R levels. Disease progression was associated with an increase in sIL-2R levels and a decline in IL-2; the sIL-2R/IL-2 ratio showed a gradual increase with tumor progression. CONCLUSIONS: Our study demonstrates in a large series of patients that in advanced NSCLC there is an imbalance of the IL-2/IL-2 receptor system. Furthermore, circulating sIL-2R levels and the sIL-2R/IL-2 ratio may be useful as markers of disease activity and treatment response, suggesting a potential prognostic value.

Catheter entrapment in the mitral valve apparatus requiring surgical removal: an unusual complication of radiofrequency ablation.

We describe a patient with Wolff-Parkinson-White syndrome in whom a steerable catheter became entrapped in the mitral valve apparatus, during radiofrequency ablation. Treatment consisted of surgical removed of the catheter. The occurrence of this previously unreported complication stresses the need for on-going monitoring of risk and benefits of electrophysiological interventions.

Radiofrequency ablation for cardiac arrhythmias causing postcardiac injury syndrome.

We report 2 cases of exudative left pleural effusion following radiofrequency catheter ablation of cardiac arrhythmias complicated by cardiac perforation. We suggest that radiofrequency ablation may be a previously unsuspected cause of postcardiac injury syndrome.

Risk stratification for recurrent tachyarrhythmias in patients with paroxysmal atrial fibrillation and flutter: role of signal averaged electrocardiogram and echocardiography.

The value of signal-averaged P-wave electrocardiogram and echocardiography for predicting recurrent atrial tachyarrhythmias was prospectively investigated in 60 patients presenting with paroxysmal atrial fibrillation or flutter. All patients were followed up for 1 year after restoration of sinus rhythm. A stepwise discriminant function analysis was used to identify variables predicting recurrent atrial tachyarrhythmias. Analyzed variables included signal-averaged P-wave duration in 3 bipolar orthogonal leads (X,Y,Z) and their vector magnitude, as well as left and right atrial dimensions and volumes. During follow-up, 25 patients had recurrent atrial tachyarrhythmias, while 35 did not. Using discriminant function analysis, the left atrial antero-superior dimension was found to be the only variable predicting the recurrence of atrial tachyarrhythmias (p < 0.0038) and was able to correctly classify 65% of the study patients. It was concluded that, in patients with paroxysmal atrial fibrillation or flutter, the traditionally used determination of left atrial dimension was the variable most closely associated with a high risk for recurrent tachyarrhythmias. The signal-averaged P-wave duration did not improve tachyarrhythmia prediction.

[Bronchoalveolar lavage in lower respiratory tract infections in patients with bronchopulmonary carcinoma. Our experience]. / Il lavaggio broncoalveolare nelle infezioni delle basse vie respiratorie nei pazienti con carcinoma broncopolmonare. Una nostra esperienza.

UNLABELLED: In order to evaluate the usefulness of the endoscopic procedures with BAL, we conducted a study on 92 patients with diagnosis of lung cancer, underwent to chemotherapy, identifying pathogenic species involved and the antibiotic sensibility and antibiotic resistance. Moreover, to evaluate possible modifications of alveolar cell population in neutropenic patients, we studied the specimens from BALs performed via fibreoptic bronchoscopy. METHODS: The cellular pattern of BALs in terms of concentration of total cells, concentrations of alveolar macrophages (AMs), of polymorphonucleates (PMNs) and lymphocytes (Ls) were compared in neutropenic and non-neutropenic patients. RESULTS: In the statistical analysis of our study we found a correlation, statistically significant, between patients with neutropenic episodes on the previous chemotherapy courses and incidence of LTRI. The mean concentrations x 100,000/ml of BAL fluid of total alveolar cells, AMs, PMNs and Ls were significantly lower, after chemotherapy, in group of neutropenic patients than in non neutropenic patients, respectively. CONCLUSIONS: In this study we found that during neutropenia the alveolar cell population was quantitatively deficient, confirming the hypothesis, proposed by other authors, of "lung aplasia" as a consequence or a concomitant event of chemotherapy-induced marrow toxicity.

Nonsustained ventricular tachycardia in ischemic heart disease: when and which pharmacological treatment?

Nonsustained ventricular tachycardia is not uncommon both in the presence and absence of organic heart disease and in the latter situation, is usually not associated with an increased risk. However, in patients with ischemic heart disease, especially in the post-infarction period, nonsustained ventricular tachycardia is associated with an increased risk of sudden, and possibly non-sudden, cardiac death. Several non-invasive and invasive tests have been utilized, individually or in combination, to risk stratify those patients. Left ventricular ejection fraction, the signal averaged electrocardiogram, and especially programmed ventricular stimulation have been commonly utilized to identify those patients at high risk for malignant tachyarrhythmias and to evaluate the potential benefit from antiarrhythmic treatment. At present, however, there is no consensus as to the best strategy to identify and treat high risk patients. Several ongoing multicenter clinical trials may eventually provide such guidelines. In the meantime, an algorithm for the management of those patients is suggested.

Transient myocardial ischemia detected by Holter monitoring during the early post-infarction period.

BACKGROUND: On the basis of extensive studies concerning the prognostic value of Holter monitoring in patients with angina, we evaluated the clinical outcome of patients with transient ischemic episodes soon after myocardial infarction. METHODS: The incidence and clinical significance of myocardial ischemia, detected in the acute phase of myocardial infarction, were evaluated in 87 patients. Twenty-four-hour Holter recordings were obtained on the 2nd, 4th, 6th, and 12th hospital day. RESULTS: Myocardial ischemia was detected during at least one of the four recording periods in 28 patients (32%). A total of 157 ischemic episodes were documented. The proportion of recordings that showed transient myocardial ischemia progressively declined from 20% on the 2nd day to 5% on the 12th post-infarction day. Of the 157 ischemic episodes, 132 (84%) were silent and 25 (16%) were symptomatic. Transient ST-segment elevation was present in 99 of the 157 episodes (63%), while transient ST-segment depression occurred in the remaining 58 of the 157 cases (37%). One or more in-hospital cardiac events (reinfarction, acute pulmonary edema, ventricular tachycardia or fibrillation, cardiac death) were more frequent in patients with (group I) than in those without (group II) transient myocardial ischemia [nine out of 28 (32%) versus six out of 59 (10%); P < 0.03]. At follow-up (mean 11.5 +/- 2 months) the incidence of cardiac events (angina, reinfarction, heart failure, ventricular tachycardia or fibrillation, revascularization procedures, cardiac death, sudden death) was comparable in the two groups [four out of 24 (17%) versus 10 out of 49 (20%); NS]. Predischarge exercise testing, performed in 64 patients (74%), showed myocardial ischemia in 50%; the percentage did not vary significantly between group I and group II patients. Moreover, a positive exercise test was not predictive of major cardiac events at follow-up. CONCLUSION: Transient myocardial ischemia, frequently silent, is not uncommon in the acute phase of myocardial infarction and progressively decreases during the in-hospital stay. Its recognition in the subacute phase of myocardial infarction may lead to the identification of a subset of patients at the highest risk of early major complications, who may benefit from aggressive diagnostic and therapeutic strategies.

Risk stratification for arrhythmic events in patients with nonischemic dilated cardiomyopathy and nonsustained ventricular tachycardia: role of programmed ventricular stimulation and the signal-averaged electrocardiogram.

OBJECTIVES: This study investigated prediction of arrhythmic events by the signal-averaged electrocardiogram (ECG) and programmed stimulation in patients with nonischemic dilated cardiomyopathy. BACKGROUND: Risk stratification in patients with nonischemic dilated cardiomyopathy remains controversial. METHODS: Eighty patients with nonischemic dilated cardiomyopathy and spontaneous nonsustained ventricular tachycardia underwent signal-averaged electrocardiography (both time-domain and spectral turbulence analysis) and programmed stimulation. All patients were followed up for a mean of 22 +/- 26 months. RESULTS: Sustained monomorphic ventricular tachycardia was induced in 10 patients (13%), who all received amiodarone. The remaining 70 patients were followed up without antiarrhythmic therapy. Of the 80 patients, 15% had abnormal findings on the time-domain signal-averaged ECG, and 39% had abnormal findings on spectral turbulence analysis. Time-domain signal-averaged electrocardiography had a better predictive accuracy for induced ventricular tachycardia than spectral turbulence analysis (88% vs. 66%, p < 0.01). During follow-up, there were 9 arrhythmic events (5 sudden deaths, 4 spontaneous ventricular tachycardia/fibrillation) and 10 nonsudden cardiac deaths. Cox regression analysis showed that no variables predicted arrhythmic events or total cardiac deaths. The 2-year actuarial survival free of arrhythmic events was similar in patients with or without abnormal findings on the signal-averaged ECG or induced ventricular tachycardia. CONCLUSIONS: In patients with nonischemic dilated cardiomyopathy, 1) there is a strong correlation between abnormal findings on the time-domain signal-averaged ECG and induced ventricular tachycardia, but both findings are uncommon; and 2) normal findings on the signal-averaged ECG, as well as failure to induce ventricular tachycardia, do not imply a benign outcome.

Incidence and prediction of induced ventricular tachyarrhythmias in idiopathic dilated cardiomyopathy.

The value of time-domain and spectral turbulence analyses of the signal-averaged electrocardiogram (SAECG) for predicting induction of sustained monomorphic ventricular tachycardia (VT) was prospectively investigated in 70 patients with idiopathic dilated cardiomyopathy. Sustained VT was induced in 9 patients (13%). The prevalence of abnormal time-domain and spectral analyses was 16 and 37%, respectively. The total predictive accuracy of time-domain and spectral analyses for VT induction was 86 and 67%, respectively (p < 0.01). The predictive accuracy of time-domain and spectral analysis was similar in patients without an intraventricular conduction defect (94 and 84%, respectively). However, the predictive accuracy of time-domain was higher than that of spectral analysis in patients with an intraventricular conduction defect (65 vs 25%; p < 0.05). The poor concordance between spectral analysis and programmed stimulation results was mainly due to the high number of false-positive recordings in the presence of an intraventricular conduction defect (9 of 20 cases). With the use of stepwise discriminant function analysis, an abnormal time-domain SAECG was the only variable predicting the induction of sustained VT (p < 0.0003). In dilated cardiomyopathy, an abnormal time-domain SAECG and induced sustained VT are rare, both time-domain signal-averaged electrocardiography and spectral analysis have a high predictive accuracy for VT induction in patients without an intraventricular conduction defect, and spectral analysis does not improve VT prediction in those with a conduction defect.

Combined time-domain and spectral turbulence analysis of the signal-averaged ECG improves its predictive accuracy in postinfarction patients.

The predictive accuracy of time-domain (TD) late potential analysis of the signal-averaged electrocardiogram in postmyocardial infarction (MI) is limited by the high incidence of false positives in inferior MI. However, frequency-domain spectral turbulence (ST) analysis suffers from a high incidence of false positives, especially in anterior MI. A prospective study was conducted of 262 patients with acute MI to investigate the hypothesis that combined TD and ST analyses of the signal-averaged electrocardiogram could improve its predictive accuracy for serious arrhythmic events in the post-MI period. Abnormal TD criteria were RMS40 less than 25 microV at 25 Hz plus RMS40 less than 16 microV at 40 Hz, and abnormal ST criteria were a turbulence score of 3 or 4. Seventeen patients had arrhythmic events during 10.5 +/- 2.4 months of follow-up evaluation (13 sudden cardiac death judged to be due to arrhythmia and 4 nonfatal sustained ventricular tachycardia). The total predictive accuracy of combined TD and ST (92%) was higher than TD (87%), whereas ST had the lowest total predictive accuracy of 78%. The negative predictive accuracy of all three analyses was high (96-97%). However, the positive predictive accuracy of TD (28%) was higher than ST (14%). Combined TD and ST significantly improved the positive predictive accuracy of the test to 35% in the total group and to 40% in patients with first anterior or inferior MI. The best results were obtained in patients with first anterior MI, where the positive predictive accuracy of combined analysis was 50%.

Time-domain and frequency-domain analyses of the signal-averaged ECG in patients with ventricular tachycardia and ischemic versus nonischemic dilated cardiomyopathy.

The value of time-domain and frequency-domain (spectral turbulence) analyses of the signal-averaged electrocardiogram was investigated to predict induced sustained monomorphic ventricular tachycardia (VT). Two groups of patients with spontaneous nonsustained VT and left ventricular ejection fraction less than 50% were enrolled: 70 patients with idiopathic dilated cardiomyopathy (group 1) and 70 patients with ischemic heart disease (group 2). Sustained VT was induced in 9 cases (13%) in group 1 and 16 (23%) in group 2. The prevalence of abnormal time-domain and spectral turbulence analysis was 16 and 37%, respectively, in group 1 and 27 and 51%, respectively, in group 2 (NS). In group 1, the predictive accuracy of time-domain and spectral turbulence analysis for induced VT was 86 and 67%, respectively (P < .01). In group 2, the predictive accuracy of the two techniques for induced VT was, respectively, 79 and 66% (NS). In both groups, the predictive accuracy of time-domain analysis was higher than that of spectral turbulence analysis in patients with intraventricular conduction defect (IVCD): 65 versus 25%, respectively, in group 1 (P < .01), and 81 versus 44%, respectively, in group 2 (P < .05). However, the predictive accuracy of time-domain and spectral analyses was similar in patients without IVCD: 94 versus 84%, respectively, in group 1, and 77 versus 74%, respectively, in group 2. Thus, in patients with dilated cardiomyopathy, (1) the etiology does not affect the predictive accuracy of time and frequency domain and frequency-domain analyses have high predictive accuracy in patients without IVCD; and (3) spectral turbulence analysis does not improve VT prediction in patients with IVCD.

Spontaneous myocardial ischemia and the signal-averaged electrocardiogram.

The effects of transient myocardial ischemia on the signal-averaged electrocardiogram were investigated in 13 patients with coronary artery disease and spontaneous angina undergoing 3-channel ambulatory electrocardiography. Ischemia was seen as ST elevation in 2 patients or ST depression in 11; it was anterior in 5 patients, inferior in 4 and undefined in 4. Signal-averaged electrocardiograms with noise levels less than or equal to 1 microV were obtained from Holter tapes during 54 of 61 ischemic attacks recorded in the study group (88%), and compared with 54 tracings recorded within 60 minutes of the index attacks. Baseline tracings were normal in 8 patients (62%), showed a long QRS duration in 2 (15%), and both a long QRS duration and a late potential in the remaining 3 (23%). Comparison of recordings at baseline and during ischemic attacks revealed no significant changes in signal-averaged electrocardiographic parameters. Absence of significant differences was also noted when analysis was performed according to the type of ischemic attacks (associated with ST elevation [n = 14] or ST depression [n = 40]), their location (anterior [n = 21] or inferior [n = 23]), their duration (greater than 10 minutes [n = 29] or less than or equal to 10 minutes [n = 25]), and their magnitude (greater than 2 mm [n = 18] or less than or equal to 2 mm [n = 36]). It is concluded that spontaneous transient myocardial ischemia, independent of its type, location, duration and magnitude, does not generate a substrate for late potentials on the signal-averaged electrocardiogram.