Andrew P. Kramer

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OBJECTIVES We assessed the clinical efficacy of single-site left ventricular (LV) pacing and determined the impact of baseline conduction delay severity on the magnitude of benefit. BACKGROUND Multisite biventricular pacing can improve heart failure (HF) symptoms in patients with an intraventricular conduction delay by resynchronizing abnormal ventricular(More)
OBJECTIVES We sought to determine whether radial left ventricular (LV) asynchrony in patients with heart failure predicts systolic function improvement with cardiac resynchronization therapy (CRT). BACKGROUND We quantified LV wall motion by echocardiography to correlate the effects of CRT on LV systolic function with wall motion synchrony. METHODS(More)
Synaptic pathways linking sensory neurons, interneurons and motoneurons participating in local bending and whole-body shortening reflexes inHaementeria ghilianii were found to be generally similar in both connectivity pattern and physiology to those ofHirudo medicinalis, although some difference in detail was observed. In both species the local bending(More)
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(More)
This study explores the use of interventricular asynchrony (interVA) for optimizing cardiac resynchronization therapy (CRT), an idea emerging from a simple pathway model of conduction in the ventricles. Measurements were performed in six dogs with chronic left bundle branch block (LBBB) and in 29 patients of the Pacing Therapies for Congestive Heart Failure(More)
We tested whether biventricular resynchronization explains contractile function changes with univentricular and biventricular pacing in heart failure patients with varying magnitudes of baseline biventricular asynchrony. Thirty patients (New York Hospital Association class > or = III, QRS duration > or =120 ms) were tested. Contractile function was measured(More)
BACKGROUND Single-site ventricular pacing in patients with heart failure, atrial fibrillation, and severe atrioventricular (AV) nodal block risks the generation of discoordinate contraction. Whether altering the site of stimulation can offset this detrimental effect and what role sequential right ventricular-left ventricular (RV-LV) stimulation might play(More)
AIMS Atrial fibrillation (AFib) with a rapid ventricular response may adversely impact cardiac performance, especially in patients with heart failure. However, it remains uncertain whether rhythm irregularity per se has unfavourable effects apart from tachycardia, and whether rate regularization alone can improve heart function. METHODS AND RESULTS Nine(More)
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