Percutaneous Mitral Valve Repair in Cardiac Amyloidosis and Severe Mitral Regurgitation.

Amyloidosis is an infiltrative disease with severe impact on the cardiac anatomy resulting in structural changes1. Mitral valve insult from the infiltrative process, although rare, has been known to cause severe mitral regurgitation4. Due to underlying comorbidities these patients may not be surgical candidates.17,18,19,20 The role of percutaneous mitral valve repair in cardiac amyloidosis has been described in a few prior cases.4,15 We review the epidemiology, diagnosis, and treatment of cardiac amyloidosis. We also highlight prior cases described in the literature of cardiac amyloidosis and severe mitral regurgitation, while discussing the role of percutaneous mitral valve repair in these patients.

A case report of thoracic aneurysm with aortopulmonary artery fistula.

Rupture of an aortic aneurysm into the pulmonary artery is a rare and often a fatal event. This complication results in the development of an acute left to right shunt, volume overload, and rapid right heart deterioration. We describe a case of thoracic aortic aneurysm in whom the diagnosis of a communication with the pulmonary artery was made on the basis of transthoracic echocardiography.

Ultrasound at 27 kHz increases tissue expression and activity of nitric oxide synthases in acute limb ischemia in rabbits.

Transcutaneous low-frequency ultrasound (US) preserves myocardial and skeletal muscle viability by increasing tissue perfusion through an undefined nitric oxide (NO)-dependent mechanism. We have examined whether US increases tissue expression and activity of the three nitric oxide synthase (NOS) isoforms: endothelial (eNOS), neuronal (nNOS) and inducible (iNOS). The two femoral arteries of four New Zealand rabbits were ligated for a total of 120 min. After 60 min of ligation, transcutaneous low-frequency US (27 kHz, 0.13 W/cm2) was applied for 60 min to one thigh, while the contra-lateral artery served as a control (total ischemia time=120 min). Calcium-dependent (cNOS) and -independent (ciNOS) NOS activity, and concentration of total eNOS, ser-1177 phosphorylated eNOS (P-eNOS), nNOS and iNOS were then determined in the gracilis muscle. Compared with the control, US application significantly increased cNOS activity [3.34+/-0.28 versus 3.87+/-0.10x1000 counts per minute (cpm), respectively, p=0.031] and ciNOS activity (1.99+/-0.09 versus 3.26+/-0.68 cpm, respectively, p<0.001). Western immunoblotting revealed a significant increase in protein content of both iNOS (184.5+/-1.08%; p<0.0001) and P-eNOS (381.5+/-2.47%; p<0.001), with only a small increase in total eNOS and nNOS expression. In conclusion, application of transcutaneous low-frequency US to ischemic muscular tissue significantly increases both cNOS and ciNOS activity by increasing eNOS phosphorylation and iNOS expression, respectively.

Systematic overview and clinical applications of pacing atrial stress echocardiography.

Pacing atrial stress echocardiography (PASE) has been studied over the past 3 decades for the evaluation of myocardial ischemia. Published studies suggest that PASE may be used as an alternative to exercise or pharmacologic stress imaging. The recent introduction of improved pacing electrodes, together with use of accelerated and shortened pacing protocols and improvements in transthoracic echocardiographic imaging techniques, makes PASE an appealing stress imaging method. A critical analysis of the diagnostic accuracy of PASE shows equivalence with other imaging stress modalities. PASE has been found to be highly feasible and accurate technique that may expedite the diagnosis and risk stratification of patients with coronary artery disease. This review addresses the history, hemodynamics, protocols, accuracy, clinical utility, and cost-effectiveness of PASE as well as elucidating its place among other stress modalities.