Background Temporal changes in systemic arterial compliance and wave propagation properties (pulsatile arterial load) and their role in ventricular–systemic arterial coupling during gestation have not been explored. Noninvasive methods combined with recently developed mathematical modeling techniques were used to characterize vascular and left ventricular (LV) mechanical adaptations during normal gestation. Methods and Results Fourteen healthy women were studied at each trimester of pregnancy and again postpartum. Experimental measurements included instantaneous aortic pressure (subclavian pulse tracings) and flow (aortic Doppler velocities) and echocardiographic imaging of the LV. A small increase in LV muscle mass and end-diastolic chamber dimension occurred by late gestation, with no significant alterations in myocardial contractility. Cardiac output increased and the steady component of arterial load (total vascular resistance) decreased during pregnancy. Several changes in pulsatile arterial load were noted: Global arterial compliance increased (≈30%) during the first trimester and remained elevated thereafter. The magnitude of peripheral wave reflections at the aorta was reduced. The mathematical model-based analysis revealed that peripheral wave reflections at the aorta were delayed and that both conduit and peripheral vessels contributed to the increased arterial compliance. Finally, coordinated changes in the pulsatile arterial load and LV properties were responsible for maintaining the efficiency of LV-to–arterial system energy transfer. Conclusions The rapid time course of compliance changes and the involvement of both conduit and peripheral vessels are consistent with reduced vascular tone as being the main underlying mechanism. The pulsatile arterial load alterations during normal pregnancy are adaptive in that they help to accommodate the increased intravascular volume while maintaining the efficiency of ventricular-arterial coupling and diastolic perfusion pressure.

Idiopathic-dilated cardiomyopathy (IDC) is a common primary myocardial disease of unknown etiology characterized by progressive biventricular failure, cardiac dilatation, and premature mortality. Here we show that transgenic mice expressing a dominant-negative form of the CREB transcription factor (CREBA133) under the control of the cardiac myocyte-specific alpha-MHC promoter develop dilated cardiomyopathy that closely resembles many of the anatomical, physiological, and clinical features of human IDC. Between 2 and 20 wk of age, these mice develop four chamber cardiac dilatation, decreased systolic and diastolic left ventricular function, and attenuated contractile responses to the beta-adrenergic agonist, isoproterenol. Histologically, the CREBA133 hearts demonstrated both atrophic and hypertrophied fibers as well as significant interstitial fibrosis. These anatomical and hemodynamic changes were associated with hepatic congestion and peripheral edema, intracardiac thrombi, and premature mortality. Taken together, these results implicate CREB as an important regulator of cardiac myocyte function and provide a genetic model of dilated cardiomyopathy which should facilitate studies of both the pathogenesis and therapy of this clinically important disorder.

Objectives—: To identify and characterize an association between persistent asthma and cardiovascular disease (CVD) risk in the Multi-Ethnic Study of Atherosclerosis (MESA). Approach and Results—: MESA is a longitudinal prospective study of an ethnically diverse cohort of individuals free of known CVD at its inception. The presence and severity of asthma were assessed in the MESA at examination 1. Persistent asthma was defined as asthmatics using controller medications (inhaled corticosteroids, leukotriene inhibitors, and oral corticosteroids) and intermittent asthma as asthmatics not using controller medications. Participants were followed up for a mean (SD) of 9.1 (2.8) years for development of incident CVD (coronary death, myocardial infarction, angina, stroke, and CVD death). Multivariable Cox regression models were used to assess associations of asthma and CVD. The 6792 participants were 62.2 (SD, 10.2) years old: 47% men (28% black, 22% Hispanic, and 12% Chinese). Persistent asthmatics (n=156), compared with intermittent (n=511) and nonasthmatics (n=6125), respectively, had higher C-reactive protein (1.2 [1.2] versus 0.9 [1.2] versus 0.6 [1.2] mg/L) and fibrinogen (379 [88] versus 356 [80] versus 345 [73] mg/dL) levels. Persistent asthmatics had the lowest unadjusted CVD-free survival rate of 84.1%, 95% confidence interval (78.9%–90.3%) compared with intermittent asthmatics 91.1% (88.5%–93.8%) and nonasthmatics 90.2% (89.4%–91%). Persistent asthmatics had greater risk of CVD events than nonasthmatics (hazard ratio [95% confidence interval], 1.6 [1.01–2.5]; P =0.040]), even after adjustment for age, sex, race, CVD risk factors, and antihypertensive and lipid medication use. Conclusions—: In this large multiethnic cohort, persistent asthmatics had a higher CVD event rate than nonasthmatics.