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LV Cavity (lv + cavity)
Selected AbstractsThe Effect of Hemodialysis on Left Ventricular Outflow Tract GradientECHOCARDIOGRAPHY, Issue 6 2010Pawel Petkow Dimitrow M.D. Background: The aim of the study was to assess the effect of hemodialysis (HD) on left ventricular outflow tract gradient (LVOTG) measured both in supine and upright position (provocative maneuver to unload LV cavity by rapid preload reduction). Supine/standing echocardiography was performed immediately before and immediately after HD. For additional verification of the hypothesis about preload-dependence of LVOTG, the echocardiograms after long (2-day delay HD due to weekend) versus short (usual 1-day) pause between HDs were compared. Methods: Forty-one patients on chronic HD (mean age 44 ± 11 years) were examined using a portable hand-carried echocardiograph. In accordance with the prestudy assumption the ultrafiltration volume was significantly greater during HD after a long pause in comparison to HD after a short pause (3707 ± 2826 mL vs. 2665 ± 1152 mL P < 0.05). Results: After a long pause, the mean value of LVOTG at the pre-HD was mildly increased in the supine position and remained at a similar level in the upright position (13.1 ± 6.1 vs. 13.6 ± 9.1 mmHg). Mean LVOTG at the post-HD in the supine position was similar to pre-HD, however the orthostatic stress test induced a significant increase of LVOTG (13.9 ± 15.2 vs. 18.2 ± 19.9 mmHg P < 0.05). After a short pause at the pre-HD the LVOTG in the supine position and after the orthostatic provocation was very similar to measurements after long pause (13.3 ± 9.1 vs. 13.3 ± 10.8 mmHg). At the post-HD the mean value of LVOTG increased during upright posture but the differences were of borderline significance (13.2 ± 6.6 vs. 17.9 ± 18.6 mmHg P = 0.052). Conclusions: HD predisposed to standing-provoked LVOTG especially when a long pause (2 days) between HDs induced a greater weight gain and subsequently a larger volume of ultrafiltration was needed to reduce hypervolemia. (Echocardiography 2010;27:603-607) [source] Left ventricular hypertrophy in rats with biliary cirrhosisHEPATOLOGY, Issue 3 2003Javier Inserte Portal hypertension induces neuroendocrine activation and a hyperkinetic circulation state. This study investigated the consequences of portal hypertension on heart structure and function. Intrahepatic portal hypertension was induced in male Sprague-Dawley rats by chronic bile duct ligation (CBDL). Six weeks later, CBDL rats showed higher plasma angiotensin-II and endothelin-1 (P < .01), 56% reduction in peripheral resistance and 73% reduction in pulmonary resistance (P < .01), 87% increase in cardiac index and 30% increase in heart weight (P < .01), and increased myocardial nitric oxide (NO) synthesis. In CBDL rats, macroscopic analysis demonstrated a 30% (P < .01) increase in cross-sectional area of the left ventricular (LV) wall without changes in the LV cavity or in the right ventricle (RV). Histomorphometric analysis revealed increased cell width (12%, P < .01) of cardiomyocytes from the LV of CBDL rats, but no differences in myocardial collagen content. Myocytes isolated from the LV were wider (12%) and longer (8%) than right ventricular myocytes (P < .01) in CBDL rats but not in controls. CBDL rats showed an increased expression of ANF and CK-B genes (P < .01). Isolated perfused CBDL hearts showed pressure/end-diastolic pressure curves and response to isoproterenol identical to sham hearts, although generated wall tension was reduced because of the increased wall thickness. Coronary resistance was markedly reduced. This reduction was abolished by inhibition of NO synthesis with N -nitro-L-arginine. Expression of eNOS was increased in CBDL hearts. In conclusion, portal hypertension associated to biliary cirrhosis induces marked LV hypertrophy and increased myocardial NO synthesis without detectable fibrosis or functional impairment. This observation could be relevant to patients with cirrhosis. [source] The Importance of Ventricular Septal Morphology in the Effectiveness of Dual Chamber Pacing in Hypertrophic Obstructive CardiomyopathyPACING AND CLINICAL ELECTROPHYSIOLOGY, Issue 9 2000PETKOW DIMITROW It has been reported that older patients with hypertrophic obstructive Cardiomyopathy (HOCM) benefited the most from dual chamber (DDD) pacing. Since in older patients the distribution of septal hypertrophy and left ventricular (LV) cavity shape differs from that in younger patients, we decided to study the efficacy of DDD pacing on the reduction of LV outflow tract (LVOT) gradient in different patterns of septal hypertrophy. We compared HOCM patients with nonreversed septal curvature, thus preserving the elliptical LV cavity contour (common in the elderly), (group I) versus patients with reversed septal curvature, deforming the LV cavity to a crescent shape (common in the young), (group II). Eighteen HOCM patients were studied (11 patients in group I and 7 patients in group II). After implantation of a DDD pacemaker, the LVOT gradient was measured using Doppler echocardiography at various programmed AV delay intervals to determine the maximal percentage decrease of LVOT gradient from baseline. The measurement was repeated after at least a 6-month follow-up (chronic DDD pacing). The baseline LVOT gradient was comparable between groups (79 ± 28 vs 81 ± 25 mmHg, P = 0.92). The LVOT gradient reduction at acute DDD pacing was significantly greater in group I than group II (61 ± 18% vs 23 ± 10%, P = 0.0001). This difference in favor of the patients from group I was maintained at midterm follow-up (69 ± 17% vs 40 ± 17% P = 0.0076). In conclusion, patients with normal septal curvature and preserved elliptical LV cavity shape had a greater reduction of LVOT gradient after DDD pacing than patients with reversed septal curvature deforming LV cavity. The proposed criterion assessing the septal curvature may be useful to predict the efficacy of DDD pacing in the reduction of LVOT gradient. [source] Left ventricular end-diastolic geometrical adjustments during exercise in endurance athletesCLINICAL PHYSIOLOGY AND FUNCTIONAL IMAGING, Issue 2 2008Egil Henriksen Summary The increase in left ventricular (LV) end-diastolic volume has recently been shown to explain more than 70% of the increase in stroke volume during upright exercise in endurance athletes. As the end-diastolic volume enhancement not could be explained by an increase in axial cavity length an augmentation in LV short-axis diameters is to be expected. To investigate LV end-diastolic geometrical alterations during exercise, 15 endurance athletes were examined using contrast exercise echocardiography. LV end-diastolic short-axis diameters were made from apical views at several LV cavity levels. From upright rest to upright exercise the LV end-diastolic internal cavity measurements increased significantly. During exercise, the LV cavity became geometrically more spherical with the largest increase in the LV end-diastolic short-axis cavity diameters in the mid and apical parts of the left ventricle. The LV internal long axis showed significant increase from rest to exercise but the absolute increase was small. [source] | ||||||||||