Progress in cardiovascular diseases
-
Prog Cardiovasc Dis · Sep 2012
ReviewRight ventricular assist device in end-stage pulmonary arterial hypertension: insights from a computational model of the cardiovascular system.
The high mortality rate of pulmonary arterial hypertension (PAH) mainly relates to progressive right ventricular (RV) failure. With limited efficacy of medical therapies, mechanical circulatory support for the RV has been considered. However, there is lack of understanding of the hemodynamic effects of mechanical support in this setting. ⋯ The results of this theoretical analysis suggest that RVAD support can effectively increase cardiac output and decreases RA pressure with the consequence of increasing pulmonary artery and capillary pressures. Especially in advanced PAH, low RVAD flow rates may mitigate these potentially detrimental effects while effectively increasing systemic hemodynamics.
-
Anesthesia and surgery are associated with significantly increased morbidity and mortality in patients with pulmonary hypertension due mainly to right ventricular failure, arrhythmias, postoperative hypoxemia, and myocardial ischemia. Preoperative risk assessment and successful management of patients with pulmonary hypertension undergoing cardiac surgery involve an understanding of the pathophysiology of the disease, screening of patients at-risk for pulmonary arterial hypertension, analysis of preoperative and operative risk factors, thorough multidisciplinary planning, careful intraoperative management, and early recognition and treatment of postoperative complications. This article will cover each of these aspects with particular focus on the anesthetic approach for non-cardiothoracic surgeries.
-
Pulmonary hypertension, a condition that can lead to right ventricular failure and hemodynamic collapse, can be very challenging to manage in critically ill patients who require the intensive care unit. Because of the underlying structure of the right ventricle, significant increases in right ventricular afterload initiate a vicious cycle of degenerating right ventricular function, giving rise to right ventricular failure and cardiogenic shock. ⋯ Important management principles include close monitoring of hemodynamics with both noninvasive and invasive modalities, optimization of right ventricular preload, maintenance of systemic blood pressure, enhancement of right ventricular contractility, reduction of right ventricular afterload, and reversal of identifiable inciting factors. The goal of this review is to discuss these key concepts in managing this difficult patient population.
-
The lungs are the only organ that receives the entire cardiac output with every stroke. The pulmonary circulation is normally a high-flow, low-resistance, low-pressure system that carries blood into the pulmonary microcirculation. ⋯ The functional status of the pulmonary circulation and the levels of PVR and PAP ultimately determine the outcome of patients with PAH. Study of the pressure-flow relationships in the pulmonary vascular bed will provide an improved appreciation of the pathophysiology of pulmonary hypertension.
-
Prog Cardiovasc Dis · May 2012
ReviewDiversity of mitral valve abnormalities in obstructive hypertrophic cardiomyopathy.
Hypertrophic cardiomyopathy (HCM) is a complex and common genetic disease. The left ventricular outflow tract obstruction is an important determinant of symptoms and outcomes. Its pathophysiology is determined by the complex interaction of the mitral valve, papillary muscles, chordae tendinea, and interventricular septum. ⋯ Several abnormalities of the mitral apparatus have been described in patients with HCM including abnormal papillary muscles, leaflets' lengths, and mitral regurgitation. Ignoring these variables can lead to unnecessary or incomplete surgical treatments and worse outcomes. This review discusses the role of the mitral apparatus in HCM with a focus on a multimodality imaging approach and the clinical importance of each abnormality.