The influence of myocardial scar and dyssynchrony on reverse remodeling in cardiac resynchronization therapy.

Aim: The influence of location and extent of transmural scar and its relation with dyssynchrony in cardiac resynchronization therapy (CRT) was investigated as posterolateral scar tissue has been invoked as a cause of non-response to CRT.

Methods And Results: Fifty-seven patients eligible for CRT were assessed for transmural scar with gadolinium-enhanced MRI and for left ventricular (LV) dyssynchrony with tissue Doppler. After implant, both atrioventricular and interventricular pacing intervals were optimized.

Improvement in diastolic function and left ventricular filling pressure induced by cardiac resynchronization therapy.

Background: Variable results of cardiac resynchronization therapy (CRT) on diastolic function have been described. We investigated 3 and 12 months' effect of CRT on diastolic function and left ventricular (LV) filling pressures and their relation to LV reverse remodeling.

Methods: Fifty-two patients' (36 male, 69 +/- 8 years, QRS duration 170 +/- 29 milliseconds) echo-Doppler was performed before and 3 and 12 months after CRT.

Qualitative observation of left ventricular multiphasic septal motion and septal-to-lateral apical shuffle predicts left ventricular reverse remodeling after cardiac resynchronization therapy.

A multiphasic septal motion and typical septal-to-lateral apical shuffle of the left ventricle can be observed echocardiographically in some patients with left branch bundle block. The relation of both with left ventricular (LV) dyssynchrony according to tissue Doppler and LV reverse remodeling after cardiac resynchronization therapy was investigated. Fifty-three patients (37 men; age 68+/-8 years) with ischemic (n=26) or idiopathic (n=27) cardiomyopathy, baseline QRS duration 171+/-30 ms, LV ejection fraction 21+/-7%, and LV end-diastolic volume 257+/-91 ml were studied.

Identification of cardiovascular dilution systems by contrast ultrasound.

Indicator dilution techniques permit accurate measurements of important cardiovascular parameters, such as pulmonary blood volume (PBV) and ejection fraction (EF). However, their use is limited by the need for central catheterization. Contrast ultrasonography allows overcoming this problem.

Relation of isovolumic times after cardiac resynchronization therapy to improvement in exercise capacity.

Isovolumic times (IVTs) comprise a determinant of exercise capacity in cardiomyopathy. We postulated that an increase in exercise capacity after cardiac resynchronization therapy (CRT) might be related to a more efficient cardiac cycle due to decreasing IVTs and increased filling times. According to standard selection criteria, a CRT device was implanted in 52 patients (37 men; 69 +/- 8 years) with a QRS duration of 174 +/- 30 ms.

Correlation of echo-Doppler optimization of atrioventricular delay in cardiac resynchronization therapy with invasive hemodynamics in patients with heart failure secondary to ischemic or idiopathic dilated cardiomyopathy.

This study investigated the optimal echocardiographic indexes to determine the most hemodynamically appropriate atrioventricular (AV) delay in cardiac resynchronization therapy (CRT) for heart failure. Doppler echocardiographic optimization of AV delay in CRT has not been correlated with invasive hemodynamic indexes. In 30 patients who underwent CRT, invasive left ventricular (LV) pressure measurements with a sensor-tipped pressure guidewire and Doppler echocardiographic examination were performed <24 hours after pacemaker implantation.

Optimization of pulsed wave tissue Doppler to predict left ventricular reverse remodeling after cardiac resynchronization therapy.

Objective: The optimal use of pulsed wave Doppler tissue imaging (DTI) in predicting left ventricular (LV) reverse remodeling after cardiac resynchronization therapy (CRT) was investigated.

Methods: DTI was performed in 69 patients before and 3 months after CRT. Echocardiographic reverse remodeling was observed in 38 patients.

Identification of ultrasound contrast agent dilution systems for ejection fraction measurements.

Left ventricular ejection fraction is an important cardiac-efficiency measure. Standard estimations are based on geometric analysis and modeling; they require time and experienced cardiologists. Alternative methods make use of indicator dilutions, but they are invasive due to the need for catheterization.