Mechanism and Impact of Left Atrial Dyssynchrony on Long-Term Clinical Outcome During Cardiac Resynchronization Therapy.

Background: Left bundle branch block (LBBB) causes left atrial (LA) dyssynchrony. It is unknown if LA dyssynchrony impacts long-term prognosis.

Objectives: The purpose of this study was to determine mechanisms of LA dyssynchrony in LBBB and if LA dyssynchrony impacts long-term prognosis.

Prehospital computed tomography in a rural district for rapid diagnosis and treatment of stroke.

Background: Early diagnosis and triage of patients with ischemic stroke is essential for rapid reperfusion therapy. The prehospital delay may be substantial and patients from rural districts often arrive at their local hospital too late for disability-preventing thrombolytic therapy due to prolonged transport times.

Methods: Hallingdal District Medical Centre (HDMC) is located in a rural area of Norway and is equipped with a computed tomography (CT) scanner.

Pulse arrival time variation as a non-invasive marker of acute response to cardiac resynchronization therapy.

Aims: Successful cardiac resynchronization therapy (CRT) shortens the pre-ejection period (PEP) which is prolonged in the left bundle branch block (LBBB). In a combined animal and patient study, we investigated if changes in the pulse arrival time (PAT) could be used to measure acute changes in PEP during CRT implantation and hence be used to evaluate acute CRT response non-invasively and in real time.

Methods And Results: In six canines, a pulse transducer was attached to a lower limb and PAT was measured together with left ventricular (LV) pressure by micromanometer at baseline, after induction of LBBB and during biventricular pacing.

Determinants of left atrial reservoir and pump strain and use of atrial strain for evaluation of left ventricular filling pressure.

Aims: The aim of this study is to investigate determinants of left atrial (LA) reservoir and pump strain and if these parameters may serve as non-invasive markers of left ventricular (LV) filling pressure.

Methods And Results: In a multicentre study of 322 patients with cardiovascular disease of different aetiologies, LA strain and other echocardiographic parameters were compared with invasively measured LV filling pressure. The strongest determinants of LA reservoir and pump strain were LV global longitudinal strain (GLS) (r-values 0.

Noninvasive assessment of intraventricular pressure difference in left ventricular dyssynchrony using vector flow mapping.

Diastolic intraventricular pressure difference (IVPD) reflects left ventricular (LV) diastolic function. The relative pressure imaging (RPI) enables the noninvasive quantification of IVPD based on vector flow mapping (VFM) and visualization of regional pressure distribution. LV dyssynchrony causes deterioration of cardiac performance.

Clinical Significance of Late Enhancement and Regional Wall Remodeling Assessed by 3T Magnetic Resonance Imaging.

Background: Clinical follow-up studies comparing left ventricular (LV) function and late gadolinium enhancement (LGE) by high-field 3T cardiac magnetic resonance (CMR) are of general interest due to the increased use of 3T scanners. In this study, the occurrence of LGE and LV regional wall remodeling (RWR) was assessed by 3T CMR in patients undergoing coronary angiography for suspected stable coronary artery disease (CAD).

Materials And Methods: Analysis of myocardial viability by LGE was performed at the segmental level.

Increased LV apical untwist during preload reduction in healthy humans: an echocardiographic speckle tracking study during lower body negative pressure.

We sought to investigate the effect of reduced preload on left ventricle (LV) untwist and early diastolic filling in healthy individuals. Twelve healthy men, 22 (22, 23) years of age, were examined at rest and during applied lower body negative pressure (LBNP) of -20 mmHg and -40 mmHg, respectively. Regional untwist and untwist rate during IVRT were calculated at LV basal, papillary, subpapillary, and apical short axis levels by two dimensional speckle tracking echocardiography.

Energy loss in the left ventricle obtained by vector flow mapping as a new quantitative measure of severity of aortic regurgitation: a combined experimental and clinical study.

Aims: In aortic regurgitation (AR), energy loss (EL) produced by inefficient turbulent flow may be a burden to the heart predicting decompensation. We attempted to quantify EL in AR induced in an acute dog model and in patients with chronic AR using novel echocardiographic method vector flow mapping (VFM).

Methods And Results: In 11 anaesthetized open-chest dogs, AR was induced by distorting the aortic valve with a pigtail catheter, in totally 20 cases.

Regional LV deformation in healthy individuals during isovolumetric contraction and ejection phases assessed by 2D speckle tracking echocardiography.

Purpose: The main purpose of the this human study was by speckle tracking imaging to characterize the regional and temporal distribution of normal left ventricular (LV) deformation and the LV geometry during isovolumetric contraction (IVC) and the ejection phase.

Methods: Twelve healthy young men [22 (2·3) years] were included. Longitudinal and circumferential strain and local twist angle were measured at four LV short-axis levels: basal, papillary, subpapillary and apical level during IVC and ejection phases.

Reduced preload elicits increased LV twist in healthy humans: an echocardiographic speckle-tracking study during lower body negative pressure.

Background: In normal left ventricles (LV), counterclockwise rotation (CCR) and net twist angle (NTA) have shown important roles during ejection. We investigated the effect of reduced preload by lower body negative pressure (LBNP) on CCR and NTA.

Methods And Results: Twelve healthy men were examined at rest, LBNP -20 and -40 mmHg.

Left ventricular systolic and diastolic function in asymptomatic patients with moderate aortic stenosis.

Tissue Doppler imaging (TDI) has improved the ability to detect subclinical changes in left ventricular (LV) function. The aim of this study was to investigate if asymptomatic patients with moderate aortic stenosis (AS) had impaired LV systolic and diastolic function. Fifty patients (mean age 65 +/- 12 years) recruited into the multicenter Simvastatin + Ezetimibe in Aortic Stenosis (SEAS) study with aortic peak velocities of 2.

LV systolic impairment in patients with asymptomatic coronary heart disease and type 1 diabetes is related to coronary atherosclerosis, glycaemic control and advanced glycation endproducts.

Aims: To evaluate whether heart failure in type 1 diabetes is linked to poor glycaemic control, coronary atherosclerosis or advanced glycation endproducts (AGEs).

Methods: Twenty six patients with type 1 diabetes (mean duration 32+/-5 years), and 16 age matched controls were recruited. Mean HbA(1c) through 18 years (HbA(1c)18), serum levels of AGEs and coronary atherosclerotic burden (CAB) were determined by IVUS.

Failure to prevent progressive dilation of ascending aorta by aortic valve replacement in patients with bicuspid aortic valve: comparison with tricuspid aortic valve.

Background: Patients with bicuspid aortic valve (BAV) have been frequently complicated with ascending aortic dilation possibly because of hemodynamic burdens by aortic stenosis (AS) or regurgitation (AR) or congenital fragility of the aortic wall.

Methods And Results: To clarify if the aortic dilation could be prevented by aortic valve replacement (AVR) in BAV patients, we studied 13 BAV (8 AR dominant, 5 AS dominant) and 14 tricuspid aortic valve (TAV) patients (7 AR, 7 AS) by echocardiography before and after AVR (9.7+/-4.

Quantitative assessment of short axis wall motion using myocardial strain rate imaging.

Although left ventricular wall motion has been usually assessed with four-point scale (1 = normal; 2 = hypokinesis; 3 = akinesis; 4 = dyskinesis) based on the visual assessment, this method is only qualitative and subjective. Recently, a new echocardiographic system that enables calculation of myocardial strain rate based on tissue Doppler information has been developed. We investigated whether myocardial strain rate could quantify regional myocardial contraction in 17 patients with and without wall motion abnormalities including 6 patients undergoing dobutamine stress echocardiography.

Distinction between well-differentiated liposarcoma and intramuscular lipoma by power Doppler ultrasonography.

Background: This study evaluates the feasibility of ultrasonography in the distinction between well-differentiated liposarcoma (WDLS) and intramuscular lipoma (IL).

Materials And Methods: Three WDLSs and 9 ILs were included. Gray scale images were assessed for echogenicity, textural pattern and margins.

Mechanisms of diastolic intraventricular regional pressure differences and flow in the inflow and outflow tracts.

Objectives: We sought to investigate the mechanisms of left ventricular (LV) intracavitary early diastolic flow during changes in contractility and loading.

Background: There is limited understanding of how intracavitary flow velocities relate to intraventricular driving pressures.

Methods: In 12 anesthetized dogs, we measured pressures in the left atrium (LA), LV at the mitral tip, apex, and subaortic region; intraventricular velocities by color M-mode Doppler echocardiography (CMD); and volume by sonomicrometry.

Postsystolic shortening in ischemic myocardium: active contraction or passive recoil?

Background: Postsystolic shortening in ischemic myocardium has been proposed as a marker of tissue viability. Our objectives were to determine if postsystolic shortening represents active fiber shortening or passive recoil and if postsystolic shortening may be quantified by strain Doppler echocardiography (SDE).

Methods And Results: In 15 anesthetized dogs, we measured left ventricular (LV) pressure, myocardial long-axis strains by SDE, and segment lengths by sonomicrometry before and during LAD stenosis and occlusion.