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.

Disintegration with right ventricular and pulmonary embolization of a SMART stent: a case report and review of literature.

As composition and design have improved the integrity and durability of peripheral stents, vascular stent fracture and embolization have become less frequent complications of endovascular intervention. However, this phenomenon still remains a possibility with potentially catastrophic consequences, either from damage to cardiac structures or from disruption of vessel integrity, infarction, and thrombosis. Advancements in the tools for foreign body retrieval have allowed the skilled interventionalist to intercede without the need for surgical intervention. We report the case of retrieval of a self-expandable SMART (Cordis, Florida) stent that was deployed for relief of superior vena cava syndrome but fractured and embolized to the right ventricle.

Sheath hemorrhage after percutaneous ventricular assist device implantation.

Technical advances in temporary ventricular assist devices (VADs) continue to progress, allowing for percutaneous implantation during times of hemodynamic instability. However, device delivery systems, i.e., sheaths, lag in their ability to sustain the mechanical demands of these VADs for extended periods. We propose both a novel technique and the implementation of an emergency preparedness plan to be enacted specifically during those times when delivery systems fail thereby leading to potentially catastrophic bleeding complications.

How do you treat patients with myalgia who take statins?

3-Hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) are safe and effective in lowering low-density lipoprotein cholesterol. As a result, they confer an all-cause mortality benefit across a wide range of patient groups. The utility of statins is limited by their adverse effects, including myalgias and rhabdomyolysis. These clinical events, plus other symptoms, constitute what is termed statin myopathy. This review summarizes current concepts of statin myopathy and presents strategies to minimize statin-associated myopathic complaints.

Improvement in arterial stiffness following cardiac rehabilitation.

BACKGROUND: Exercise has been shown to beneficially alter arterial stiffness in selected clinical settings. However, the effects of a standardized exercise protocol--"cardiac rehabilitation (CR)"--on measures of arterial stiffness in patients with established coronary heart disease (CHD) has not been well studied. METHODS: Using applanation tonometry, we studied arterial vascular properties in 26 men and 22 women (mean age 60.5 ± 10.8 years) with established CHD over a 20 week CR program. All patients continued to receive their anti-anginal and vasoactive medications. In addition to standard hemodynamics we estimated central aortic pressure, central arterial pulsatility, augmentation index and arterial pulse wave velocity (PWV). RESULTS: After 20 weeks of CR, there were no significant changes in resting heart rate or peripheral blood pressure. In 33 patients with at least two follow-up visits, central aortic systolic pressure was consistently lower than peripheral arterial blood pressure and decreased over the CR program time (baseline, 109 ± 16 mmHg; final, 105 ± 14 mmHg. p=0.01). Both carotid-radial (n=12) and carotid-femoral (n=21) - derived PWV decreased over the CR program (carotid-radial: baseline, 7.3 ± 1.2m/s; final, 6.6 ± 1.2m/s, p=0.028. carotid-femoral: baseline, 7.2 ± 1.4m/s; final, 6.5 ± 1.3m/s, p=0.02). CONCLUSIONS: In this group of patients with established CHD, arterial PWV was noted to significantly decrease over a 20 week CR program. This change occurred in the absence of detectable changes in peripheral blood pressure or heart rate. Decreases in PWV may serve as a sensitive indicator of improved arterial stiffness in patients with atherosclerotic arterial disease notwithstanding ongoing medical therapy.

Gated myocardial perfusion SPECT asynchrony measurements in patients with left bundle branch block.

PURPOSE: This investigation sought to determine which newly available asynchrony parameter derived from gated myocardial perfusion SPECT (GMPS) systolic wall thickening data best distinguishes patients with left bundle branch block (LBBB) from normal subjects. METHODS AND MATERIALS: Emory Cardiac Toolbox (ECTb) algorithms were used to compute left ventricular (LV) global and regional function and perfusion indices with regional contraction phases for 20 patients with LBBB, and in 9 control (CTL) subjects who had no function or perfusion abnormalities. Histogram plots of phase frequencies versus R-R interval times included phase standard deviation (SD), bandwidth (BW), skewness and kurtosis. Z-score asynchrony measures were derived for phases sampled using the conventional 17-segment model. RESULTS: In CTLs contraction occurred nearly simultaneously in all segments, while LBBBs exhibited a wide variety of heterogeneous contraction patterns. Global parameters that differed between LBBBs versus CTLs included EF, end-systolic volume and end-diastolic volume, and asynchrony measures that were different included BW, phase SD and z-scores. Z-scores most strongly discriminated LBBBs from CTLs (93% of cases correctly predicted, logistic regression chi(2) = 29.7, P < 0.0001). Z-scores, phase SD and lateral-septal wall timing were highly reproducible (r = 0.99, 0.99 and r = 0.87, respectively), with no significant inter-observer differences. CONCLUSION: While traditional global function parameters were different in LBBBs and CTLs, asynchrony parameters characterized LBBB most strongly.