149 resultados para LEFT-VENTRICULAR VOLUMES


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Objective: Previous studies reported on the association of left ventricular mass index (LVMI) with urinary sodium or with circulating or urinary aldosterone.We investigated the independent associations of LVMI with the urinary excretion of both sodium and aldosterone. Design and method: We randomly recruited 317 untreated subjects from a White population (45.1%women; mean age 48.2 years).Measurements included echocardiographic left ventricular (LV) properties, the 24 h urinary excretion of sodium and aldosterone, plasma renin activity (PRA), and proximal (RNaprox) and distal (RNadist) renal sodium reabsorption, assessed fromthe endogenous lithium clearance. Inmultivariable-adjusted models,we expressed changes in LVMI per 1 SD increase in the explanatory variables, while accounting for sex, age, systolic blood pressure and the waist-to-hip ratio. Results: LVMI increased independentlywith the urinary excretion of both sodium (+2.48 g/m2; P=0.005) and aldosterone (+2.63 g/m2; P=0.004). Higher sodium excretion was associated with increased mean wall thickness (MWT: +0.126 mm, P=0.054), but with no change in LV end-diastolic diameter (LVID: +0.12mm, P=0.64). In contrast, higher aldosterone excretion was associated with higher LVID (+0.54 mm; P=0.017), but with no change in MWT (+0.070mm; P=0.28).Higher RNadistwas associatedwith lower relativewall thickness (−0.81×10−2, P=0.017), because of opposite trends in LVID(+0.33 mm; P=0.13) and MWT (−0.130mm; P=0.040). LVMI was not associated with PRA or RNaprox. Conclusions: LVMI independently increased with both urinary sodium and aldosterone excretion. IncreasedMWT explained the association of LVMI with urinary sodium and increased LVID the association of LVMI with urinary aldosterone.

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BACKGROUND: Determining a specific death cause may facilitate individualized therapy in patients with heart failure (HF). Cardiac resynchronization therapy (CRT) decreased mortality in the Cardiac Resynchronization in Heart Failure trial by reducing pump failure and sudden cardiac death (SCD). This study analyzes predictors of specific causes of death. METHODS AND RESULTS: Univariate and multivariate analyses used 8 baseline and 3-month post-randomization variables to predict pump failure and SCD (categorized as "definite," "probable," and "possible"). Of 255 deaths, 197 were cardiovascular. There were 71 SCDs with a risk reduction by CRT of 0.47 (95% confidence interval 0.29-0.76; P = .002) with similar reductions in SCD classified as definite, probable, and possible. Univariate SCD predictors were 3-month HF status (mitral regurgitation [MR] severity, plasma brain natriuretic peptide [BNP], end-diastolic volume, and systolic blood pressure), whereas randomization to CRT decreased risk. Multivariate SCD predictors were randomization to CRT 0.56 (0.53-0.96, P = .035) and 3-month MR severity 1.82 (1.77-2.60, P = .0012). Univariate pump failure death predictors related to baseline HF state (quality of life score, interventricular mechanical delay, end-diastolic volume, plasma BNP, MR severity, and systolic pressure), whereas randomization to CRT and nonischemic cardiomyopathy decreased risk; multivariate predictors of pump failure death were baseline plasma BNP and systolic pressure and randomization to CRT. CONCLUSION: CRT decreased SCD in patients with systolic HF and ventricular dyssynchrony. SCD risk was increased with increased severity of MR (including the 3-month value for MR as a time-dependent covariate) and reduced by randomization to CRT. HF death was increased related to the level of systolic blood pressure, log BNP, and randomization to CRT. These results emphasize the importance and interdependence of HF severity to mortality from pump failure and SCD.

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Heart transplantation (HTx) is the treatment of choice for end-stage heart failure but the limited availability of heart's donors still represents a major issue. So long-term mechanical circulatory support (MCS) has been proposed as an alternative treatment option to assist patients scheduled on HTx waiting list bridging them for a variable time period to cardiac transplantation-the so-called bridge-to-transplantation (BTT) strategy. Nowadays approximately 90% of patients being considered for MCS receive a left ventricular assist device (LVAD). In fact, LVAD experienced several improvements in the last decade and the predominance of continuous-flow over pulsatile-flow technology has been evident since 2008. The aim of the present report is to give an overview of continuous-flow LVAD utilization in the specific setting of the BTT strategy taking into consideration the most representative articles of the scientific literature and focusing the attention on the evolution, clinical outcomes, relevant implications on the HTx strategy and future perspectives of the continuous-flow LVAD technology.

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OBJECTIVES: The purpose of this study was to compare a novel compressed sensing (CS)-based single-breath-hold multislice magnetic resonance cine technique with the standard multi-breath-hold technique for the assessment of left ventricular (LV) volumes and function. BACKGROUND: Cardiac magnetic resonance is generally accepted as the gold standard for LV volume and function assessment. LV function is 1 of the most important cardiac parameters for diagnosis and the monitoring of treatment effects. Recently, CS techniques have emerged as a means to accelerate data acquisition. METHODS: The prototype CS cine sequence acquires 3 long-axis and 4 short-axis cine loops in 1 single breath-hold (temporal/spatial resolution: 30 ms/1.5 × 1.5 mm(2); acceleration factor 11.0) to measure left ventricular ejection fraction (LVEFCS) as well as LV volumes and LV mass using LV model-based 4D software. For comparison, a conventional stack of multi-breath-hold cine images was acquired (temporal/spatial resolution 40 ms/1.2 × 1.6 mm(2)). As a reference for the left ventricular stroke volume (LVSV), aortic flow was measured by phase-contrast acquisition. RESULTS: In 94% of the 33 participants (12 volunteers: mean age 33 ± 7 years; 21 patients: mean age 63 ± 13 years with different LV pathologies), the image quality of the CS acquisitions was excellent. LVEFCS and LVEFstandard were similar (48.5 ± 15.9% vs. 49.8 ± 15.8%; p = 0.11; r = 0.96; slope 0.97; p < 0.00001). Agreement of LVSVCS with aortic flow was superior to that of LVSVstandard (overestimation vs. aortic flow: 5.6 ± 6.5 ml vs. 16.2 ± 11.7 ml, respectively; p = 0.012) with less variability (r = 0.91; p < 0.00001 for the CS technique vs. r = 0.71; p < 0.01 for the standard technique). The intraobserver and interobserver agreement for all CS parameters was good (slopes 0.93 to 1.06; r = 0.90 to 0.99). CONCLUSIONS: The results demonstrated the feasibility of applying the CS strategy to evaluate LV function and volumes with high accuracy in patients. The single-breath-hold CS strategy has the potential to replace the multi-breath-hold standard cardiac magnetic resonance technique.

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AIMS: Estimates of the left ventricular ejection fraction (LVEF) in patients with life-threatening ventricular arrhythmias related to coronary artery disease (CAD) have rarely been reported despite it has become the basis for determining patient's eligibility for prophylactic defibrillator. We aimed to determine the extent and distribution of reduced LVEF in patients with sustained ventricular tachycardia or ventricular fibrillation. METHODS AND RESULTS: 252 patients admitted for ventricular arrhythmia related to CAD were included: 149 had acute myocardial infarction (MI) (Group I, 59%), 54 had significant chronic obstructive CAD suggestive of an ischaemic arrhythmic trigger (Group II, 21%) and 49 patients had an old MI without residual ischaemia (Group III, 19%). 34% of the patients with scar-related arrhythmias had an LVEF > or =40%. Based on pre-event LVEF evaluation, it can be estimated that less than one quarter of the whole study population had a known chronic MI with severely reduced LVEF. In Group III, the proportion of inferior MI was significantly higher than anterior MI (81 vs. 19%; absolute difference, -62; 95% confidence interval, -45 to -79; P < or = 0.0001), though median LVEF was higher in inferior MI (0.37 +/- 10 vs. 0.29 +/- 10; P = 0.0499). CONCLUSION: Patients included in defibrillator trials represent only a minority of the patients at risk of sudden cardiac death. By applying the current risk stratification strategy based on LVEF, more than one third of the patients with old MI would not have qualified for a prophylactic defibrillator. Our study also suggests that inferior scars may be more prone to ventricular arrhythmia compared to anterior scars.

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OBJECTIVE: The aim of this investigation was to improve the hemodynamics during venoarterial bypass by remote decompression of the left ventricle (LV). METHODS: Venoarterial bypass was established in 5 bovine experiments (69+/-10 kg) by the transjugular insertion of a self-expanding cannula (smartcanula) with return through a carotid artery. Cardiogenic shock was simulated with ventricular fibrillation induced by an external stimulator. Left ventricular decompression was achieved by switching to transfemoral drainage of the pulmonary artery (PA) with a long self-expanding cannula. RESULTS: Initial pump flow was 4.7+/-0.9 l/min and the aortic pressure accounted for 75+/-21 mmHg. After induction of ventricular fibrillation, the pump flow dropped after 11+/-8 min to 2.5+/-0.1 l/min. Transfemoral decompression increased the pump flow to 5.6+/-0.7 l/min, while the RV pressure decreased from 27+/-9 to 3+/-5 mmHg, the PA pressure decreased from 29+/-7 to 5+/-4 mmHg, the LV pressure decreased from 29+/-6 to 7+/-2 mmHg, and the aortic pressure increased from 31+/-3 to 47+/-11 mmHg. CONCLUSIONS: Remote drainage of the pulmonary artery during venoarterial bypass allows for effective decompression of the left ventricle and provides superior hemodynamics.

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Idiopathic premature ventricular complexes originating from the ventricular outflow tract: evaluation, prognosis and management The prognosis of ventricular premature complexes (VPC) in the absence of heart disease is considered benign. VPC usually originate from the right or, less commonly, left ventricular outflow tract. QRS complexes therefore usually assume a left bundle branch block and inferior axis morphology. These VPC, particularly if very frequent (> 20,000 per day), may adversely affect left ventricular function and their suppression can restore normal function. Moreover, there is a clinical overlap with arrhythmogenic right ventricular dysplasia and this diagnosis should be considered when facing a left bundle branch block shaped VPC. However, the prognosis of outflow tract VPC is good for appropriately selected patients with normal left ventricular function, absence of syncope or ventricular tachycardia, and no evidence of cardiac disease.

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Background: Chronic mountain sickness (CMS) is characterized by exaggerated exercise-induced pulmonary hypertension. Evidences suggests that exercise may cause lung fluid accumulation at high altitude. We hypothesized that, in patients with CMS, exercise causes lung fluid accumulation.Methods: In 21 male CMS patients and 20 matched healthy controls born and permanently living in La Paz (Bolivia, 3600m) we assessed with echocardiogram, pulmonary artery pressure (PASP), right and left ventricular function and ultrasoundlung comets (ULCs, a marker of lung fluid accumulation) at rest and during mild bicycle exercise (10 min at 50W).Results: CMS patients presented a more than 2-fold greater exercise-induced increase in pulmonary artery pressure than controls (17.1±8.3 vs 7.2±7.9 mmHg, P=0.003). This exaggerated PASP response to exercise was associated with a roughly 3-fold greater increase in UCLs in patients with CMS than in controls (6.3±5.1 vs. 2.1±5.3, p<0.05), and there existed a significant relationship between PASP and UCLs (r=0.44, p<0.001). Finally, TDI on lateral tricuspid annulus decreased during exercise in patients with CMS (from 13.2±3.2 to 11.5±2.1 cm s-1, p=0.03), but increased in controls (from 13.1±2.9 to 14.9±2.6 cm s-1 , p=0.04). Left ventricular function remained unaltered in the 2 groups.Conclusions: we provide the first direct evidence in CMS patients that exaggerated exercise-induced pulmonary hypertension causes rapid lung fluid accumulation and right ventricular dysfunction. We speculate that in patients with CMS these two phenomena contribute to reduced exercise performances and Figure 1 increased cardiovascular morbidity and mortality that characterise these subjects.

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Non-infarcted myocardium after coronary occlusion undergoes progressive morphological and functional changes. The purpose of this study was to determine whether non-infarcted myocardium exhibits (1) alteration of the substrate pattern of myocardial metabolism and (2) concomitant changes in the expression of regulatory proteins of glucose and fatty acid metabolism. Myocardial infarction was induced in rats by ligation of the left coronary artery. One day and eight weeks after coronary occlusion, glucose and palmitate oxidation were measured. Expression of selected proteins of metabolism were determined one day to 12 weeks after infarction. One day after coronary occlusion no difference of glucose and palmitate oxidation was detectable, whereas after eight weeks, glucose oxidation was increased (+84%, P<0.05) and palmitate oxidation did not change significantly (-19%, P=0.07) in infarct-containing hearts, compared with hearts from sham-operated rats. One day after coronary occlusion, myocardial mRNA expression of the glucose transporter GLUT-1 was increased (+86%, P<0.05) and the expression of GLUT-4 was decreased (-28%, P<0.05) in surviving myocardium of infarct-containing hearts. Protein level of GLUT-1 was increased (+81%, P<0.05) and that of GLUT-4 slightly, but not significantly, decreased (-16%, P=NS). mRNA expressions of heart fatty acid binding protein (H-FABP), and of medium chain acyl-CoA dehydrogenase (MCAD), were decreased by 36% (P<0.05) and 35% (P=0. 07), respectively. Eight weeks after acute infarction, the left ventricle was hypertrophied and, at this time-point, there was no difference in the expression of GLUT-1 and GLUT-4 between infarcted and sham-operated hearts. However, myocardial mRNA and protein content of MCAD were decreased by 30% (P<0.01) and 27% (P<0.05), respectively. In summary, in surviving myocardium, glucose oxidation was increased eight weeks after coronary occlusion. Concomitantly, mRNA and protein expression of MCAD were decreased, compatible with a role of altered expression of regulatory proteins of metabolism in post-infarction modification of myocardial metabolism.

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Isolated ventricular non-compaction (IVNC) is a rare, congenital, unclassified cardiomyopathy characterized by prominent trabecular meshwork and deep recesses. Major clinical manifestations of IVNC are heart failure, atrial and ventricular arrhythmias, and thrombo-embolic events. We describe a case of a 69-year-old woman in whom the diagnosis of IVNC was discovered late, whereas former echocardiographic examinations were considered normal. She was known for systolic left ventricular dysfunction for 3 years and then became symptomatic (NYHA III). In the past, she suffered from multiple episodes of deep vein thrombosis and pulmonary embolism. Electrocardiogram revealed a wide QRS complex, and transthoracic echocardiography showed typical apical thickening of the left and right ventricular myocardial wall with two distinct layers. The ratio of non-compacted to compacted myocardium was >2:1. Cardiac MRI confirmed the echocardiographic images. Cerebral MRI revealed multiple ischaemic sequellae. In view of the persistent refractory, heart failure in medical treatment of patients with classical criteria for cardiac re-synchronization therapy, as well as the ventricular arrhythmias, a biventricular automatic intracardiac defibrillator (biventricular ICD) was implanted. The 2-year follow-up period was characterized by improvement of NYHA functional class from III to I and increasing in left ventricular function. We hereby present a case of IVNC with favourable outcome after biventricular ICD implantation. Cardiac re-synchronization therapy could be considered in the management of this pathology.

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BACKGROUND: Obesity is a major health problem in the Western world. Among obese subjects cardiac pathology is common, but conventional noninvasive imaging modalities are often suboptimal for detailed evaluation of cardiac structure and function. We investigated whether cardiovascular magnetic resonance imaging (CMR) can better characterize possible cardiac abnormalities associated with obesity, in the absence of other confounding comorbidities. METHODS: In this prospective cross-sectional study, CMR was used to quantify left and right ventricular volumes, ejection fraction, mass, cardiac output, and apical left ventricular rotation in 25 clinically healthy obese men and 25 age-matched lean controls. RESULTS: Obese subjects had higher left ventricular mass (203 +/- 38 g vs. 163 +/- 22 g, p < 0.001), end-diastolic volume (176 +/- 29 mL vs. 156 +/- 25 mL, p < 0.05), and cardiac output (8.2 +/- 1.2 L/min vs. 6.4 +/- 1.3 L/min, p < 0.001). The obese also had increased right ventricular mass (105 +/- 25 g vs. 87 +/- 18 g, p < 0.005) and end-diastolic volume (179 +/- 36 mL vs. 155 +/- 28 mL, p < 0.05). When indexed for height, differences in left and right ventricular mass, and left ventricular end-diastolic volume remained significant. Apical left ventricular rotation and rotational velocity patterns were also different between obese and lean subjects. CONCLUSIONS: Obesity is independently associated with remodeling of the heart. Cardiovascular magnetic resonance imaging identifies subtle cardiac abnormalities and may be the preferred imaging technique to evaluate cardiac structure and function in the obese.