Intracardiac electrical bioimpedance as a basis for controlling of pacing rate limits.

Intracardiac impedance can provide real-time hemodynamic information to automatically control the lower and upper rate limits of a rate-adaptive pacemaker. It is necessary to overcome a number of technical challenges to accomplish this within the constraints of an implantable device.

Ventricular preexcitation modulates strain and attenuates cardiac remodeling in a swine model of myocardial infarction.

Background: Myocardial infarction modifies the distribution of stress within the heart, increasing wall stress in ischemic and surrounding tissue, which often leads to adverse left ventricular remodeling. Electrical preexcitation pacing with appropriate timing of high-stress regions can reduce local strain and may attenuate global remodeling.

Methods And Results: Myocardial infarction was induced in 24 swine to study the short-term (n=12) and long-term (n=12) effects of therapy.

Feasibility of biventricular pacing in patients with recent myocardial infarction: impact on ventricular remodeling.

To test the hypothesis that biventricular pacing after a myocardial infarction with reduced ejection fraction can attenuate left ventricular (LV) remodeling, the authors studied 18 patients (myocardial infarction within 30-45 days, ejection fraction View Article and Find Full Text PDF

Cardiac resynchronization therapy restores optimal atrioventricular mechanical timing in heart failure patients with ventricular conduction delay.

We characterized the relationship between systolic ventricular function and left ventricular (LV) end-diastolic pressure (LVEDP) in patients with heart failure (HF) and baseline asynchrony during ventricular stimulation. The role of preload in the systolic performance improvement that can be obtained in HF patients with LV stimulation is uncertain.We measured the maximum rate of increase of LV pressure, LVEDP, aortic pulse pressure (PP) and the atrioventricular mechanical latency (AVL) between left atrial systole and LV pressure onset in 39 patients with HF.