Speckle tracking echocardiography (STE) is an emerging tool to characterize and quantify myocardial segmental and rotational mechanics. This literature review is aimed at clinical and academic cardiologists to provide: (1) a conceptual framework of STE to initiate understanding of myocardial mechanics; (2) evidence that three-dimensional (3D) STE overcomes the problems of time-consuming data acquisition and postprocessing seen with two-dimensional STE; and (3) illustrative clinical cases with analysis of myocardial mechanics via 3D STE to show the incremental value of strain in clinical decision making.
IMPORTANCE Malignant arrhythmic mitral valve prolapse (MVP) phenotype poses a substantial risk of sudden cardiac death (SCD), and an estimated 26 000 individuals in the United States are at risk of SCD per year. Thus, identifying risk-stratification strategies for SCD is imperative.OBSERVATIONS Patients with MVP have a heterogenous clinical spectrum, ranging from a benign course to a devastating complication such as SCD. Some of the high-risk markers of MVP, which are identified electrocardiographically, include inverted or biphasic T waves, QT dispersion, QT prolongation, and premature ventricular contractions originating from the left ventricular outflow tract and papillary muscles. Morphofunctional characteristics of SCD are leaflet thickness of 5 mm or greater, mitral annulus disjunction, paradoxical systolic increase of the mitral annulus diameter, increased tissue Doppler velocity of the mitral annulus, and higher mechanical dispersion on echocardiography and fibrosis identified by late gadolinium enhancement on cardiac magnetic resonance imaging.CONCLUSIONS AND RELEVANCE Findings from this review suggest that SCD can occur earlier in the course of MVP from complex arrhythmias that are triggered by the repeated tugging and traction of the chordopapillary muscle unit and basal mid-myocardium, even before macrofibrosis can be identified in these regions by late gadolinium enhancement on cardiac magnetic resonance imaging. Some of the newer markers identified by speckle-tracking Doppler, such as mechanical dispersion, myocardial work index, and postsystolic shortening, need further validation in a larger population.
Echocardiography is an important imaging modality used to determine the indication of left ventricular assist device (LVAD) implantation for patients with advanced heart failure (HF) and for serial follow-up to make management decisions in patient care post-implant. Continuous axial-flow LVAD therapy provides effective haemodynamic support for the failing left ventricle, improving both the clinical functional status and quality of life. Echocardiographers must develop a systematic approach to echocardiographic assessment of LVAD implantation and post-LVAD implant cardiac morphology and physiology. This approach must include the evaluation of left and right heart chamber morphology and physiology and the anatomy and physiology of the inflow and outflow cannulas and the rotor pump, and the determination of the degree of tricuspid regurgitation and the presence of interatrial shunts and aortic regurgitation. Collaboration among the echocardiography and HF/transplant teams is essential to obtain this comprehensive evaluation. We outline a systematic approach to evaluating patients with HF who have failed conventional therapy and require LVAD therapy as a bridge to cardiac transplantation or destination therapy.
Endovascular aneurysm repair (EVAR) has developed as a less invasive alternative to open surgery for patients with abdominal aortic aneurysms. However, patients with very short infrarenal necks require complex surgical open repair, which is associated with increased mortality and morbidity. The risk of complex open repair may be prohibitive in high-risk patients. Thus, modifying the technique of EVAR may be required in such patients to successfully exclude aneurysms. An alternative that can be used in these patients is the so-called "chimney graft" technique. We report two cases where the chimney graft technique was used with good immediate results.
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