Effect of left ventricular pacing mode and site on hemodynamic, torsional and strain indices.

Introduction: Several reports have indicated that left ventricular (LV) lead placement at an optimal pacing site is an important determinant of short- and long-term outcome. This study investigated the effect of pacing mode (atrioventricular [AV] or ventricular) and site (LV apical or lateral) outside the ischemic region on the LV hemodynamic, torsional and strain indices in the ischemic myocardium.

Methods: Experiments were conducted in anesthetized open-chest pigs (n = 15) 30 min after LAD ligation to investigate the hemodynamic effects of temporary epicardial AV and ventricular LV pacing at the LV apical (outside the ischemic region) or lateral wall.

Effect of pacing mode and pacing site on torsional and strain parameters and on coronary flow.

Background: Right ventricular apical pacing may induce detrimental effects on left ventricular function and coronary flow. In this study, the effects of pacing site and mode on cardiac mechanics and coronary blood flow were evaluated.

Methods: This prospective study included 25 patients who received dual-chamber pacemakers with the ventricular lead placed in the right ventricular apex and presented in sinus rhythm (SR) at their regularly scheduled visits at the pacemaker clinic.

Value of apical circumferential strain in the early post-myocardial infarction period for prediction of left ventricular remodeling.

Background: Left ventricular (LV) remodeling after acute myocardial infarction (AMI) is related to increased morbidity and mortality. The aim of the present study was to examine whether LV deformational and torsional parameters can predict LV remodeling in patients with AMI.

Methods: Forty-two patients (age 57 ± 14 years) presenting with an anterior ST-elevation AMI and treated with primary percutaneous transluminal coronary angioplasty (PTCA) were included in the study.

Atrioventricular left ventricular apical pacing improves haemodynamic, rotational, and deformation variables in comparison to pacing at the lateral wall in intact myocardium: experimental study.

Aim. To assess the effect on left ventricular (LV) function of atrioventricular (AV) and ventricular pacing at the LV apical or lateral wall and to compare the normal torsional and deformation pattern of the intact LV myocardium with those created by the aforementioned LV pacing modes and sites. Methods.

Factors Influencing the twisting and untwisting properties of the left ventricle during normal pregnancy.

Aims: During pregnancy, important hemodynamic changes occur, consistent with an increase in preload and decrease in afterload and systemic vascular resistance. The aim of the present study was to investigate the changes in left ventricular (LV) strain and rotational properties during the 3 trimesters of normal pregnancy and to examine the factors that drive these changes.

Methods And Results: Twenty-seven pregnant women (29.

Apical rotation as an early indicator of left ventricular systolic dysfunction in acute anterior myocardial infarction: experimental study.

Introduction: The aim of this study was to determine whether left ventricular (LV) apical rotation assessed by speckle tracking echocardiography (STE) can predict global LV systolic dysfunction after acute anterior myocardial infarction (AMI).

Methods: STE analysis was applied to LV short-axis images at the basal and apical levels in 21 open-chest pigs, before and after left anterior descending coronary artery ligation. LV radial and circumferential strain and strain rate, apical and basal rotation, and LV torsion were recorded.

The impact of ultrasound contrast medium administration on the right ventricle in patients with heart failure.

Background: The purpose of the present study was to examine the effect of SonoVue™ on right ventricular (RV) dimensions and contractility in patients with heart failure.

Patients And Methods: Twenty-four patients were divided into two groups. Group A consisted of 15 patients with heart failure and group B (control) of nine patients without heart disease.

Effect of dobutamine combined with intra-aortic balloon counterpulsation on left ventricular function early after acute myocardial infarction: experimental study.

Acute myocardial infarction (AMI) causes left ventricular (LV) remodeling, which forms the substrate for its early and late complications. The purpose of this study was to compare the acute effect of dobutamine or intra-aortic balloon pumping (IABP), alone or in combination, on LV function in the early phase of an experimental AMI. In 18 pigs, AMI was induced by ligation of the left anterior descending artery (LAD).

Effect of early changes in functional geometry of left ventricular contraction on the development of ventricular fibrillation during acute myocardial ischaemia. An experimental study.

Objective: The early appearance of ventricular fibrillation (VF) following acute myocardial infarction (MI) is associated with adrenergic effects and electrical interactions although some early "mechanical" changes may also occur. The aim of the present experimental study was to examine whether early changes in the functional geometry of left ventricular (LV) contraction may be associated with ventricular arrhythmias occurring during the first 120min of MI.

Methods: In 11 swine left anterior descending (LAD) coronary artery ligation was performed.

Pacing within the ischemic area significantly decreases the left ventricular ejection fraction during experimental acute myocardial infarction.

Background: The aim of this study was to examine the effects on left ventricular (LV) function of LV apical or/and lateral wall pacing during an experimental acute myocardial infarction.

Methods: In 12 anesthetized pigs, epicardial LV pacing at the apex or lateral wall, or at both sites simultaneously, was performed before and after left anterior descending (LAD) ligation. Data concerning LV function were obtained by two-dimensional echo during spontaneous sinus rhythm (SR) and during pacing before and 15, 45, 60, and 90 minutes after LAD ligation.