Search results for "Ventricular function"
showing 10 items of 237 documents
Left Ventricle Biomechanics of Low-Flow, Low-Gradient Aortic Stenosis: A Patient-Specific Computational Model
2022
This study aimed to create an imaging-derived patient-specific computational model of low-flow, low-gradient (LFLG) aortic stenosis (AS) to obtain biomechanics data about the left ventricle. LFLG AS is now a commonly recognized sub-type of aortic stenosis. There remains much controversy over its management, and investigation into ventricular biomechanics may elucidate pathophysiology and better identify patients for valve replacement. ECG-gated cardiac computed tomography images from a patient with LFLG AS were obtained to provide patient-specific geometry for the computational model. Surfaces of the left atrium, left ventricle (LV), and outflow track were segmented. A previously validated …
QT interval heterogeneities induced through local epicardial warming/cooling. An experimental study
2014
[EN] ntroduction and objectives Abnormal QT interval durations and dispersions have been associated with increased risk of ventricular arrhythmias. The present study examines the possible arrhythmogenic effect of inducing QT interval variations through local epicardial cooling and warming. Methods In 10 isolated rabbit hearts, the temperatures of epicardial regions of the left ventricle were modified in a stepwise manner (from 22 °C to 42 °C) with simultaneous electrogram recording in these regions and in others of the same ventricle. QT and activation-recovery intervals were determined during sinus rhythm, whereas conduction velocity and ventricular arrhythmia induction were determined dur…
Outcome after mitral valve operations with depressed left ventricular function.
2012
We retrospectively investigated 42 patients (27 men, 15 women; mean age, 67 years) with severe mitral valve incompetence and endstage cardiomyopathy (ejection fraction <30%) who were operated on between January 2002 and March 2009. Of these, 14 were in New York Heart Association class IV, and 27 were in class III. The etiology was ischemic in 18 patients and idiopathic dilated in 24. Mitral valve repair was performed in 25 patients, and 17 had mitral valve replacement. The mean logistic EuroSCORE was 33.41. The mean follow-up was 44.52 months. There were no perioperative deaths. Three patients died within 30 days postoperatively. Thirty-day mortality was lower than predicted by EuroSCOR…
Papillary muscle relocation and mitral annuloplasty in ischemic mitral valve regurgitation: midterm results.
2014
Objectives The surgical approach for ischemic mitral regurgitation remains unclear. Many studies are in favor of adding the subvalvular procedure to mitral annuloplasty to reduce recurrent mitral regurgitation. This study reports the clinical and echocardiographic outcomes of papillary muscle relocation combined with mitral annuloplasty.Methods From 2003, 115 patients with severe ischemic mitral regurgitation who underwent papillary muscle relocation plus nonrestrictive mitral annuloplasty and coronary artery bypass grafting were retrospective analyzed. Patients' mean age was 52 ± 12.8 years, New York Heart Association class III or IV was 71%, and preoperative left ventricular ejection frac…
Mid-term results of bicuspid aortic valve repair guided by morphology and function assessment.
2016
Bicuspid aortic valve (BAV) is frequently associated with aortic insufficiency (AI) due to cusp disease and/or aortic root dilatation. Based on functional classification and morphology, a systematic surgical approach was used for aortic valve repair (AVr).From 2004 to 2014, 152 consecutive patients (mean age 55 ± 7 years) with BAV underwent AVr with or without concomitant aortic root surgery. Cusp pathology was treated with central plication in 60 (39.5%) patients, free edge reinforcement in 45 (29.6%), triangular resection in 28 (18.4%) and pericardial patch in 19 (12.5%). Aortic root dilatation was corrected with valve sparing reimplantation in 65 patients. Mean follow-up was 68 ± 36 mont…
Assessment of cardiac performance using Tei indices in patients undergoing pulmonary thromboendarterectomy.
2002
This study was designed to evaluate left and right ventricular performance using Tei indices in patients with severe chronic thromboembolic pulmonary hypertension undergoing pulmonary thromboendarterectomy (PTE). The Doppler-derived indices are easily measurable indicators of ventricular function based on nongeometric assessment, which helps overcome some of the difficulties entailed in the geometric assessment of left ventricular (LV) and right ventricular (RV) function in pulmonary hypertension.The indices were derived for 24 patients (aged 54+/-14 years) before and after PTE. Calculation of these indices was based on the duration of two time intervals using the formula (A - B)/B, where A…
Regulation of endothelial nitric oxide synthase (eNOS) in myocardium subjected to cardioplegic arrest.
2009
BACKGROUND: Nitric oxide (NO) production by both coronary endothelial cells and cardiomyocytes is thought to play a significant role in myocardial pathophysiology following ischemia/reperfusion (I/R). METHODS: In thirteen pigs subjected to 1 hour cardioplegic arrest (CA) on CPB, left ventricular (LV) biopsies were collected prior to CPB (baseline), at 60 min CPA, at 15 and 30 min reperfusion on CPB, and at 120 min post CPB. LV specimens were immunocytochemically stained against phospho-eNOS Ser1177 , phospho-eNOS Thr495 , phosphorylated ERK1/2, and AKT/PKB. Four additional pigs without CA served as controls. Cardiomyocytes were quantitatively investigated using TV densitometry (gray units: …
Importance of noninvasively measured respiratory muscle overload among the causes of hospital readmission of COPD patients.
2008
To evaluate the influence of respiratory muscle overload and right cardiac overload among the possible risk factors of hospital readmission in a 1-year follow-up of a cohort of patients with moderate-to-severe COPD.A total of 112 COPD patients who were admitted consecutively to the hospital for acute exacerbation. At hospital discharge, we evaluated the conventional clinical and functional determinations in addition to the pressure-time index (PTI), which is obtained using the equation PTI = (Pawo/Pimax) x (Ti/Ttot) x 100, where Pawo represents the mean airway pressure measured at the mouth during spontaneous breathing, Pimax is the maximal inspiratory pressure, Ti is the inspiratory time, …
Endoventricular patch plasty improves results of LV aneurysmectomy.
1993
From May 1985 to December 1991 52 patients were operated upon for postischemic left ventricular aneurysm (LV-A). Between May 1985 and July 1989 25 patients (group I) with a mean age of 59 (46-72) years underwent conventional aneurysmectomy with direct closure of the left ventricle (LV) and a mean of 1.9 (0-3) additional bypass grafts (54% triple-vessel disease). The hospital mortality was 8% (2/25) and the late mortality during a median follow-up time of 34 months was 28% (7/25) with a 4-year survival of 66%. Improvement in the quality of life (NYHA from 2.6 to 2.1, P = 0.078) and global left ventricular ejection fraction (EF) (from 35 to 38%) proved to be unsatisfactory in conjunction with…
Postoperative non-invasive assessment of pulmonary vascular resistance using Doppler echocardiography.
2011
Non-invasive monitoring of pulmonary vascular resistance (PVR) in postoperative cardiac surgery patients might be useful, particularly for management of pulmonary hypertension. For this purpose, we sought to assess Doppler echocardiography in the intensive care setting. In 73 patients, hemodynamics was measured using both, invasive gold standard (pulmonary artery catheter), and non-invasively by Doppler echocardiography. Four Doppler parameters: (1) tricuspid regurgitant velocity/time-velocity-integral of right ventricular outflow tract (TRV/VTI(RVOT)), (2) tricuspid annular systolic velocity (S'), (3) tricuspid annular strain, and (4) tricuspid annular strain rate, were compared with invas…