Talhat Azemi

Usefulness of stress gated technetium-99m single photon emission computed tomographic myocardial perfusion imaging for the prediction of cardiac death in patients with moderate to severe left ventricular systolic dysfunction and suspected coronary artery disease.

Although stress gated technetium-99m single-photon emission computed tomographic (SPECT) myocardial perfusion imaging (MPI) is useful in differentiating ischemic from nonischemic cardiomyopathy, its prognostic usefulness in this patient population is not well understood. Consecutive unique patients with suspected coronary artery disease who, for clinical indications, underwent technetium-99m rest and stress MPI demonstrating ejection fractions ≤40% by gated SPECT imaging were retrospectively identified. In addition to prescan variables, previously defined cutoffs for gated SPECT parameters using visual and standard 17-segment semiquantitative scoring were applied and related to the occurrence of cardiac death up to 5 years after MPI. Of the 475 patients fulfilling criteria for study inclusion, follow-up was complete in 444 (93%) over 3.7 ± 1.6 years. Of 393 patients without subsequent early (≤60 days) coronary revascularization, cardiac death occurred in 64 (16%). The summed stress score, an MPI measure of the extent and severity of coronary artery disease that also accounts for the ischemic burden, was the gated SPECT parameter most related to cardiac death with Kaplan-Meier 5-year cardiac death-free survival of 85.6% and 67.3% in patients with summed stress scores ≤8 and >8, respectively (p <0.001). In multivariate Cox regression analysis, a summed stress score >8 independently contributed to cardiac death (adjusted hazard ratio 2.20, 95% confidence interval 1.34 to 3.61), and its addition to the model significantly increased the global chi-square value over prescan variables (from 32.46 to 41.67, p = 0.002). In conclusion, stress MPI data from gated technetium-99m SPECT scans are useful for the prediction of cardiac death in patients with moderate to severe left ventricular systolic dysfunction in whom there is suspicion of underlying coronary artery disease.

Use of fractional flow reserve in the assessment of chronic mesenteric ischemia

Chronic mesenteric ischemia (CMI) is a rare condition that is usually the result of atherosclerotic obstructive disease affecting the mesenteric arteries. The classic triad of post-prandial pain, food aversion and weight loss is not always present, often leading to low clinical suspicion for CMI and underdiagnosis. Non-invasive evaluation for CMI usually starts with mesenteric arterial duplex scanning, followed by computed tomography angiography, magnetic resonance angiography or conventional angiography, the latter being the gold standard for establishing its diagnosis. However, angiography alone has been demonstrated in coronary and other vascular beds to be inaccurate in predicting the physiologic and hemodynamic significance of a certain subset of atherosclerotic stenoses. We present the case of a patient with risk factors and symptoms suggestive of CMI who underwent angiography. However, angiography was equivocal and invasive physiologic testing was required to confirm the diagnosis and guide revascularization.

Bailout antegrade coronary reentry with the stingray™ balloon and guidewire in the setting of an acute myocardial infarction and cardiogenic shock

Emergent coronary artery bypass surgery for failed percutaneous coronary intervention (PCI) during acute myocardial infarction (MI) is a bailout strategy that is associated with a high in‐hospital morbidity and mortality (7–10%). Innovative strategies to improve the probability of PCI success in this setting are needed. Antegrade coronary re‐entry with the Stingray™ balloon and guidewire has been shown to facilitate recanalization of chronic total occlusions in stable patients. We report a case where the Stingray™ device was successfully used as a bailout strategy in the setting of an acute MI complicated by cardiogenic shock.

Median arcuate ligament syndrome: Use of fractional flow reserve in documentation of chronic mesenteric ischemia.

Median arcuate ligament syndrome (MALS) is a rare clinical entity. This condition typically affects women between the ages of 20 and 40 years and causes symptoms of abdominal pain, primarily post-prandial, as well as nausea, vomiting and weight loss. MALS is considered a diagnosis of exclusion. Typically, mesenteric arterial duplex ultrasonography, computed tomography (CT), and magnetic resonance (MR) are highly suggestive, and conventional contrast angiography confirmatory. We explore the role of fractional flow reserve and intravascular ultrasound in the evaluation of MALS. In order to illustrate the utility of these tools, we present the case of a 47-year-old symptomatic woman who underwent angiography, complemented by assessment of fractional flow reserve and intravascular ultrasound. These data convincingly demonstrated the dynamic nature of the obstructive characteristic of MALS.

Cardiac Magnetic Resonance (CMR) Imaging

Although magnetic resonance imaging has been available for many years, the cardiac applications have grown and expanded in more recent times. The technology is widely available primarily through hospitals with no radiation exposure, giving physicians another important noninvasive imaging modality used for patients with cardiac disease. Cardiac magnetic resonance (CMR) imaging can include the assessment of myocardial structure, function, perfusion and viability. This chapter will examine the information provided by CMR training as well as the appropriateness criteria and guidelines for indications. Finally, the chapter will put in perspective CMR within the arena of other noninvasive diagnostic imaging procedures such as SPECT/PET myocardial perfusion imaging.

Cardiac Computed Tomography Imaging

Alternatives to nuclear cardiology procedures include the use of computed tomography (CT) for cardiac imaging. These procedures are widely available since the advent of the 64-slice CT instrumentation. Assessment of the location and severity of coronary artery calcium (CAC) as well as non-invasive imaging of coronary artery anatomy with coronary CT angiography (CTA) can provide useful information in patients with suspected CAD. This chapter will discuss CAC and coronary CTA imaging, their indications and relevance to nuclear cardiology procedures.

ASSESSMENT OF STROKE RISK USING LEFT ATRIAL VOLUME INDEX IN PATIENTS WITH LOW RISK CHADS2 SCORES

Left atrial volume index (LAVI) as a marker for discrimination of risk for stroke and transient ischemic attack (TIA) in patients with atrial fibrillation (AF) and low risk CHADS2 scores (≥1) has yet to be conclusively determined. Patients with AF, stroke or TIA, and CHADS2 scores ≥1 prior to

Acute inferior myocardial infarction complicated by a very large ventricular septal rupture and cardiogenic shock.

![Figure][1] [Online Video 1][2] Coronary angiogram of right coronary artery. ![Figure][1] [Online Video 2][3] Subcostal view of ventricular septal rupture (VSR) on 2-dimensional (2D) echocardiogram (ECG). ![Figure][1] [Online Video 3][4] Subcostal view with color