Acute Aortic Regurgitation in the Current Era of Percutaneous Treatment: Pathophysiology and Hemodynamics.

Aortic regurgitation (AR) is characterized by the backflow of blood from the aorta to the left ventricle. Acute AR typically causes severe pulmonary edema and hypotension, and is a surgical emergency. In chronic AR, however, compensatory mechanisms can clinically compensate for years, with normal left ventricular function and no symptoms. While the hemodynamic mechanisms of chronic AR on the left ventricle are well described, the hemodynamic mechanisms of acute AR are not clear. Most of the literature on acute AR includes either small series or case reports. During the past decade the number of transcatheter aortic valve replacements (TAVRs) performed has increased dramatically, and TAVR is now an accepted treatment option for patients with severe aortic stenosis who are not surgical candidates or are at high risk for surgery. However, potential acute mild to severe AR occurring after TAVR seems a new and common cause of AR. Since more than mild AR increases the risk of mortality, the quantification of AR severity is a major challenge after TAVR. More accurate, reproducible and quantitative criteria need to be developed to assess and highlight the unknowns of acute AR. Information relating to the pathophysiology and hemodynamics of acute AR and TAVR-related acute AR, respectively, are collated in this review.

Migration of fully deployed stent after intracoronary glyceryl trinitrate administration: An unusual percutaneous coronary intervention complication.

Stent embolization is a rare complication of coronary stenting. If left untreated, it may lead to devastating consequences. Although there is much known about stent embolization, data about migration of stent after deployment is limited. We report an unusual case of a deployed stent migration into the distal part of right coronary artery after intracoronary glyceryl trinitrate administration during percutaneous coronary intervention.

Impaired aortic elastic properties in young patients with prehypertension.

OBJECTIVES: Although hypertension has been shown to be one of the most important predictors of reduced arterial elasticity, there is not enough data about aortic elastic properties in patients with prehypertension. Accordingly, the current study was designated to evaluate aortic elastic features in young patients with prehypertension. MATERIAL AND METHODS: The study population consisted of 25 newly diagnosed prehypertensive individuals (18 men, mean age=34+/-6 years) and 25 healthy controls (16 men, mean age=33+/-6 years) eligible for the current study. Aortic strain, distensibility index and stiffness index beta were calculated from aortic diameters measured by echocardiography and blood pressures simultaneously measured by sphygmomanometry. RESULTS: Prehypertensive patients were detected to have significantly lower aortic distensibility and strain indexes than the controls: (5.77+/-1.91 vs. 8.63+/-2.67 cm dynx10, respectively, P<0.001; strain index: 13.81+/-4.50 vs. 17.47+/-4.25%, respectively, P=0.005). Aortic stiffness index beta of the prehypertensive group, however, was significantly higher than that of the control group (3.73+/-1.41 vs. 2.97+/-0.82, P=0.02). CONCLUSION: Whatever the mechanism, young patients with prehypertension have impaired aortic elasticity compared with healthy controls. This finding has suggested that the development of overt hypertension may be prevented or delayed by using the agents that have the ability to reduce arterial stiffness by regressing and/or preventing functional and structural changes on the arterial wall.