Coronary Computed Tomography Angiography-Derived Plaque Quantification in Patients With Acute Coronary Syndrome.

This study investigated the discriminatory value of quantitative atherosclerotic plaque markers derived from coronary computed tomography angiography (cCTA) in patients with first acute coronary syndrome (ACS) compared with patients with stable coronary artery disease (CAD). Forty patients (56.9 ± 9.

Prognostic implications of coronary CT angiography-derived quantitative markers for the prediction of major adverse cardiac events.

Objective: To evaluate quantitative markers derived from coronary CT angiography (coronary CTA) for the prediction of major adverse cardiac events (MACE).

Materials And Methods: Pooled data from two centers in the US and Europe were retrospectively analyzed. Forty-six patients (65.

Coronary CT angiography-derived quantitative markers for predicting in-stent restenosis.

Objective: To evaluate quantitative markers derived from coronary CT angiography (coronary CTA) performed prior to percutaneous coronary intervention (PCI) with stent placement for predicting in-stent restenosis (ISR) as defined by quantitative coronary angiography (QCA).

Materials And Methods: We retrospectively analyzed the data of 74 patients (60 ± 12 years, 72% male) who had undergone dual-source coronary CTA within 3 months prior to a PCI procedure that included stent placement. Quantitative markers of the target vessel were derived from coronary CTA: Total plaque volume (TPV), calcified and non-calcified plaque volumes (CPV and NCPV), plaque burden (PB in %), remodeling index (RI), and lesion length (LL).

Imaging coronary artery disease and the myocardial ischemic cascade: clinical principles and scope.

On a subcellular level, atherogenesis is characterized by the translocation of proatherogenic lipoproteins into the arterial wall. An inflammatory response involving complex repair mechanisms subsequently causes maladaptive vascular changes resulting in coronary stenosis or occlusion. The chronology of the underlying processes occurring from atherosclerosis to myocardial ischemia affect the selection and interpretation of diagnostic testing.

Transient Ischemic Dilation of the Left Ventricle on SPECT: Correlation with Findings at Coronary CT Angiography.

Unlabelled: Transient ischemic dilation (TID) in the setting of abnormal stress-rest cardiac SPECT myocardial perfusion imaging (MPI) has been linked with increased cardiovascular risk. However, the significance of TID in the setting of an otherwise normal SPECT MPI study has not been clearly established. In this study, cardiac CT was used to evaluate the prevalence of atherosclerotic lesions and the severity of coronary artery stenosis in patients with TID of the left ventricle with or without associated myocardial perfusion defects on SPECT MPI.

CT detection of myocardial blood volume deficits: dual-energy CT compared with single-energy CT spectra.

Background: The performance of dual-energy CT (DECT) for the detection of myocardial blood volume deficits has not systematically been compared with single-energy CT (SCT) spectra.

Objective: We evaluated the accuracy for detection of myocardial blood volume deficits in DECT and SCT compared with 99m-Tc-Sestamibi-SPECT (single-photon emission CT) during rest and stress.

Methods: 47 patients underwent rest/stress SPECT myocardial perfusion imaging and cardiac DECT on a dual-source CT scanner.

Reproducibility of left and right ventricular mass measurements with cardiac CT.

Background: Cardiac CT provides volumetric data that enables characterization of the myocardium.

Objective: We evaluated intraobserver, interobserver, and interstudy reproducibility of left ventricular (LV) and right ventricular (RV) mass quantification with cardiac CT.

Methods: Thirty-eight patients who underwent cardiac CT twice within 365 days were included in this analysis.

Cost-effectiveness of substituting dual-energy CT for SPECT in the assessment of myocardial perfusion for the workup of coronary artery disease.

Purpose: We compared cost-effectiveness and potential lifetime benefits of using dual-energy computed tomography (DECT) for myocardial perfusion assessment instead of single photon emission computed tomography (SPECT) for the workup of coronary artery disease (CAD).

Materials And Methods: A decision and simulation model was developed to estimate cost and health effects of using DECT myocardial perfusion imaging instead of SPECT for identifying patients in need of invasive imaging and possible revascularization. The model was based on the performance indices of stress/rest DECT compared with stress/rest SPECT for detecting myocardial perfusion deficits in 50 patients (mean age 61±10 years) with CAD.

Adenosine-stress dynamic myocardial volume perfusion imaging with second generation dual-source computed tomography: Concepts and first experiences.

Recent research suggests that multidetector-row CT may have potential as a standalone modality for integrative imaging of coronary heart disease, including the assessment of the myocardial blood supply. However, the technical prerequisites for volumetric, time-resolved imaging of the passage of a contrast medium bolus through the myocardium have only been met with latest generation wide-detector CT scanners. Second-generation dual-source CT enables performing electrocardiographic (ECG)-synchronized dynamic myocardial perfusion imaging by a dedicated "shuttle" mode.

Role of transesophageal echocardiography among patients with atrial fibrillation undergoing electrophysiology testing.

External or internal shocks administered to terminate ventricular arrhythmias as a part of electrophysiology or implantable cardioverter-defibrillator testing, can inadvertently cardiovert atrial fibrillation (AF). Moreover, anticoagulation therapy is often withheld in these patients in anticipation of an invasive procedure. The risk of embolic events during these procedures has not been well described.

Noncalcified atherosclerotic plaque burden at coronary CT angiography: a better predictor of ischemia at stress myocardial perfusion imaging than calcium score and stenosis severity.

Objective: The purpose of this study was to examine the relation between the coronary CT angiographic findings of calcified and noncalcified plaque burden and stenosis severity and the myocardial perfusion imaging finding of ischemia.

Materials And Methods: Seventy-two patients (41 men, 31 women; mean age, 56 years) underwent coronary CT angiography and stress-rest SPECT myocardial perfusion imaging. Calcium scoring was performed.

Comparison of dual-energy computed tomography of the heart with single photon emission computed tomography for assessment of coronary artery stenosis and of the myocardial blood supply.

To evaluate the performance of dual-energy computed tomography (CT) for integrative imaging of the coronary artery morphology and the myocardial blood supply, 36 patients (15 women, mean age 57 +/- 11 years) with equivocal or incongruous single photon emission CT (SPECT) results were investigated by a single-contrast medium-enhanced, retrospectively electrocardiographic-gated dual-energy CT (DECT) scan with simultaneous acquisition of high and low x-ray spectra. Thirteen patients subsequently underwent invasive coronary angiography (ICA). The DECT data were used to reconstruct anatomic coronary CT angiographic images and to map the myocardial iodine distribution within the left ventricular myocardium.

Dual-energy CT of the heart--principles and protocols.

The introduction of coronary CT angiography (cCTA) has reinvigorated the debate whether management of patients with suspected coronary artery disease (CAD) should be primarily based on physiological versus anatomical testing. Anatomical testing (i.e.

Integrated assessment of coronary anatomy and myocardial perfusion using a retractable SPECT camera combined with 64-slice CT: initial experience.

We evaluated a prototype SPECT system integrated with multidetector row CT (MDCT) for obtaining complementary information on coronary anatomy and hemodynamic lesion significance. Twenty-five consecutive patients with known or suspected coronary artery disease (CAD) underwent routine SPECT myocardial perfusion imaging (MPI). All patients also underwent repeat MPI with a mobile SPECT unit which could be attached to a 64-slice MDCT system.

Quantitative assessment of pericardial effusion volume by two-dimensional echocardiography.

The clinical applicability of a method for quantifying pericardial effusion (PE) was studied. The pericardial and cardiac volumes were determined from border tracings of 2-dimensional echocardiograms fitted with 3-dimensional disk models. The PE volume was the difference between pericardial and cardiac volumes.

Does the serum cardiac troponin I level increase with stress test-induced myocardial ischemia?

To evaluate the sensitivity of the serum cardiac troponin I level in detecting stress test-induced myocardial ischemia, the authors conducted a prospective study including patients admitted for chest pain to the telemetry floor of Our Lady of Mercy Medical Center at Bronx, NY. Consecutive 134 telemetry patients that agreed to participate in this study were included. All of these patients had a nuclear stress test and were divided into various groups based on the prestress test probability of having coronary artery disease.

Comparison of echocardiography with technetium 99m-gated single photon emission computed tomography as diagnostic tools for left ventricular ejection fraction.

Left ventricular ejection fractions (LVEF) are routinely measured and result in critical decision-making algorithms in cardiology. This study was conducted to compare the accepted standard two-dimensional (2-D) echocardiogram ejection fraction (EF(ECHO)) with single photon emission computed tomography rest ejection fraction (EF(SPECT)). Data were acquired and analyzed from 51 inpatients.

Torsades de pointes in 3 patients with leukemia treated with arsenic trioxide.

Arsenic trioxide is used in clinical trials in the treatment of relapsed and resistant cases of acute promyelocytic leukemia. Adverse effects from arsenic in these studies have been multisystemic. Arsenic is known to cause corrected QT-interval prolongation and T-wave changes, but the potential for serious ventricular arrhythmias is less well understood.

Sensitivity and specificity of left ventricular ejection fraction by echocardiographic automated border detection: comparison with radionuclide ventriculography.

Background: Echocardiographic automated border detection (ABD) provides on-line, beat-to-beat estimation of left ventricular (LV) ejection fraction (EF). Sensitivity and specificity of using ABD-EF for diagnosing LV dysfunction in routine clinical situations have not been previously studied.

Hypothesis: Analysis of ABD-EF data based on receiver operating characteristic (ROC) should provide useful information about sensitivity and specificity for clinical diagnosis of LV function based on ABD-EF.

A comprehensive model for right-left heart interaction under the influence of pericardium and baroreflex.

A phenomenological model of the cardiopulmonary circulation is developed with a focus on the interaction between the right heart and the left heart. The model predicts the hemodynamic consequences of changing circulatory parameters in terms of a broad spectrum of pressure and flow waveforms. Hemodynamics are characterized by use of an electrical analog incorporating mechanisms for transseptal pressure coupling, pericardial volume coupling, intrathoracic pressure, and baroreflex control of heart rate.

Gaussian pulse decomposition: an intuitive model of electrocardiogram waveforms.

This study presents a novel approach to modeling the electrocardiogram (ECG): the Gaussian pulse decomposition. Constituent waves of the ECG are decomposed into and represented by Gaussian pulses using an iterative algorithm: the chip away decomposition (ChAD) algorithm. At each iteration, a nonlinear minimization method is used to fit a portion of the ECG waveform with a single Gaussian pulse, which is then subtracted from the ECG waveform.

Directional low-pass filtering for improved accuracy and reproducibility of stenosis quantification in coronary arteriograms.

Considers the quantification of percent diameter stenosis in digital coronary arteriograms of low spatial resolution. To improve accuracy and reproducibility an edge-preserving smoothing method, called the directional low-pass filter (DLF), was developed to suppress quantum noise by averaging image intensity in a direction parallel to the vessel border. Accuracy of stenosis quantification was assessed by using stenosis phantoms.