[Hemodynamics and physical capacity in patients with left ventricular assist devices : An overview]. / Hämodynamik und körperliche Belastbarkeit bei Patienten mit Linksherzunterstützungssystem : Ein Überblick.

In the course of time implantation of left ventricular assist devices (LVAD) has become an alternative to heart transplantation due to the enormous technical developments and miniaturization of these systems. Following implantation most patients show a significant improvement in their clinical condition and exercise capacity as measured by the New York Heart Association (NYHA) classification; nevertheless, exercise tolerance remains clearly limited even after LVAD implantation. The complex physiological and hemodynamic changes in LVAD patients both at rest and during exercise are ultimately not completely understood. The aim of this article is to describe the current state of scientific knowledge with respect to the physical capacity of patients with terminal heart failure after LVAD implantation at rest and during exercise. The influence of increasing the pump speed and continuous physical exercise training on the physical capacity in the long-term course is reviewed. The significance of new diagnostic tools, such as the non-invasive inert gas rebreathing method for measurement of cardiac output and arteriovenous oxygen difference (AVDO2) in assessment of the performance of LVAD patients is discussed.

Comparative coronary anatomy in six twin pairs with coronary artery disease.

OBJECTIVE: To compare the coronary anatomy and the location of coronary lesions in monozygotic and dizygotic twin pairs affected with coronary artery disease. DESIGN: Coronary angiographic findings were compared with respect to the distribution of coronary blood supply and the location of coronary lesions. MAIN OUTCOME MEASURES: Distribution of coronary blood supply, diameters and length of proximal coronary arteries. RESULTS: The lumen diameters of the left main coronary artery, the left anterior descending coronary artery, the circumflex artery, and the right coronary artery, as well as the lengths of the left main coronary artery, showed similar variability within monozygotic and dizygotic twin pairs. With respect to the dominance pattern of coronary blood supply, two of three monozygotic twin pairs differed, while all dizygotic twin pairs were concordant. Concordant and discordant locations of stenoses were found with similar frequency in monozygotic and dizygotic twin pairs. CONCLUSIONS: The dominance pattern of coronary blood supply and the location of coronary lesions are not strictly hereditary. The high concordance of premature coronary artery disease found in monozygotic twin pairs may largely be related to factors that are independent of the macroanatomic distribution of the coronary blood supply.