Left main coronary artery aneurysm: a case report and review of the literature

Left main coronary artery aneurysm is an uncommon feature of coronary artery disease in adults. We describe the case of a large aneurysm in a 58-year-old patient undergoing cardiac catheterization for effort angina and inducible myocardial ischemia. Specific considerations about the underlying causes and therapeutic options are discussed.

Early and long-term results of stenting of diffuse coronary artery disease

Diffuse coronary artery disease (CAD) is considered unfavorable for interventional procedures; however, the results of stenting of diffuse CAD have not been completely characterized. We performed stenting in 100 consecutive patients with diffuse CAD, defined as significant stenosis >20 mm (n = 59 patients), multiple significant stenoses in the same artery (n = 23 patients), or significant narrowing involving the whole length of the coronary artery (n = 18 patients). Angiographic success was achieved in 103 arteries (100%) and clinical success was obtained in all 100 patients. There were no deaths; no patient had stent closure, acute myocardial infarction, or required emergency coronary artery bypass surgery. All 100 patients had >6 months follow-up (mean 18 +/- 7 months, range 7 to 31); 77 (77%) remained asymptomatic, and 5 (5%) had acute myocardial infarction, of whom 2 died (2%). In-stent restenosis was observed in 12 patients (12%) and repeat angioplasty was performed in 10. Including those patients who underwent repeat angioplasty, 89 (89%) maintained clinical improvement and 95 (95%) were alive and free of bypass surgery during follow-up. Life-table analysis showed 86% freedom from death, myocardial infarction, and target lesion revascularization at 28 months. Thus, selected patients with diffuse CAD may be treated with satisfactory acute and long-term results by stent implantation.

Apoptosis in recent myocardial infarction

PURPOSE

Apoptosis is considered a common pathological feature in acute myocardial infarction (MI) and heart failure; however its role in the later phases post MI has not been characterized. The goal of our study was to investigate by pathological examination human hearts at 20 to 30 days post MI and identify signs of ongoing cell apoptosis.

MATERIALS AND METHODS

Two hearts were collected at autopsy from patients who died 20 to 30 days from the onset of MI (Cases 1 and 2). Gross anatomy and light microscopy examination of the hearts was performed to define the infarcted area and the infarct-related artery. The in situ end-labeling of DNA fragmentation (TUNEL) was performed to identify apoptotic cells and the apoptotic rate (AR) was calculated.

RESULTS

There were no signs of acute necrosis in any of the specimens examined. A high number of myocardiocyte were positive at TUNEL examination in specimens obtained at sites of infarction, mean AR = 44%, but not in specimens derived from the same patients at regions remote from the MI, AR = 0.

CONCLUSIONS

High grade apoptosis is present at sites of infarction and not in regions remote from the infarcted area in the later phases post MI. These data support persistent myocardiocyte loss and identify a possible explanation of progressive left ventricular dysfunction in the subacute phases of MI.

[Platelet glycoprotein IIB-IIIA receptor inhibitors in patients with ischemic heart disease]

Glycoprotein IIb-IIIa receptor inhibitors are the newest anti-platelets drugs currently used in patients with coronary artery disease. We examined mechanisms of their action and different pharmacokinetic and pharmacodynamic characteristics of the four glycoprotein IIb-IIIa antagonists evaluated in randomized, controlled and multicenter trials. We reviewed results of these trials in the settings of percutaneous revascularizations procedures or unstable coronary syndromes. Platelet glycoprotein IIb-IIIa receptor inhibitors reduced incidence of cardiac death and myocardial infarction during the short- and midterm, and benefit was greater in: a) patients undergoing coronary angioplasty with or without stent implantation, particularly in the presence of unstable angina, diabetes or complex and diffuse coronary artery disease; b) as a direct therapy of unstable coronary syndromes, particularly in patients with refractory angina, diabetes and elevated Troponin; more recently they have been used as adjuvant therapy in acute myocardial infarction. Infusion of these drugs was not associated with higher rates of major bleedings.

Gemcitabine-induced atrial fibrillation: a hitherto unreported manifestation of drug toxicity

BACKGROUND

Gemcitabine is an antimetabolic drug for solid tumors. Although its pharmacokinetics as well as its side-effects are well known, paroxysmal atrial fibrillation associated to the administration of this drug has not yet been described.

PATIENTS AND METHODS

We describe the case of a 78-year-old man with pancreatic adenocarcinoma who presented repeated paroxysmal atrial fibrillation episodes 18-24 hours after every gemcitabine infusion which resolved with antiarrhythmic drugs. This clinical history was positive for a remote brief episode of atrial fibrillation, which resolved spontaneously, and the patient had no predisposing factors for supraventricular arrhythmias (systemic hypertension, diabetes or coronary artery disease).

RESULTS

Cardiac work-up revealed only a mild mitral-valve prolapse and complete right bundle branch block. During the arrhythmia episodes no other precipitating factors were reported. The close temporal relationship of the arrhythmia to drug administration and the recurrence of arrhythmia upon rechallenge allowed to hypothesize an intrinsic pro-arrhythmic effect of gemcitabine or its metabolite 2',2'-difluorodeoxyuridine.

CONCLUSIONS

The occurrence of atrial fibrillation during the administration of gemcitabine may be considered as a cardiac arrhythmia drug-related toxicity. This side-effect of gemcitabine infusion is a previously unreported sign of drug toxicity; therefore, a high level of awareness to this problem is warranted when this drug is administered.

Signal detection and noise suppression using a wavelet transform signal processor: application to ultrasonic flaw detection

The utilization of signal processing techniques in nondestructive testing, especially in ultrasonics, is widespread. Signal averaging, matched filtering, frequency spectrum analysis, neural nets, and autoregressive analysis have all been used to analyze ultrasonic signals. The Wavelet Transform (WT) is the most recent technique for processing signals with time-varying spectra. Interest in wavelets and their potential applications has resulted in an explosion of papers; some have called the wavelets the most significant mathematical event of the past decade. In this work, the Wavelet Transform is utilized to improve ultrasonic flaw detection in noisy signals as an alternative to the Split-Spectrum Processing (SSP) technique. In SSP, the frequency spectrum of the signal is split using overlapping Gaussian passband filters with different central frequencies and fixed absolute bandwidth. A similar approach is utilized in the WT, but in this case the relative bandwidth is constant, resulting in a filter bank with a self-adjusting window structure that can display the temporal variation of the signal's spectral components with varying resolutions. This property of the WT is extremely useful for detecting flaw echoes embedded in background noise. The detection of ultrasonic pulses using the wavelet transform is described and numerical results show good detection even for signal-to-noise ratios (SNR) of -15 dB. The improvement in detection was experimentally verified using steel samples with simulated flaws.

Effect of deep-trap level on transverse acoustoelectric voltage measurements

The effect of trapped charges on the transverse acoustoelectric voltage (TAV) is investigated with the aim of extending the use of TAV measurements to the study of semiconductors with high defect density. Even if surface acoustic wave frequencies are as high as 100 MHz, charge trapping can influence the TAV. This has been verified by two particular experiments performed on Si/SiO(2) structures with high density of interface states. A theoretical model is proposed to explain the effects of the presence of deep-trap levels on the TAV. Novel boundary conditions for the acoustoelectric equations are introduced and an approximate solution for the TAV amplitude is presented. The model is used to define a novel procedure for the determination of interface-states' density using TAV versus bias voltage measurements.