scholarly journals Intraventricular Pressure Gradients in Heart Failure

2013 ◽  
pp. 479-487 ◽  
Author(s):  
M. GUERRA ◽  
C. BRÁS-SILVA ◽  
M. J. AMORIM ◽  
C. MOURA ◽  
P. BASTOS ◽  
...  
Keyword(s):  
Heart Failure ◽  
Minimal Length ◽  
Saline Control ◽  
Control Group ◽  
Intraventricular Pressure ◽  
Pressure Gradients ◽  
Saline Control Group ◽  
Failure Group ◽  
Intraventricular Pressure Gradients ◽  
Ventricular Filling

The aim of the present study was to characterize intraventricular pressure gradients (IVPGs) in an animal model of chronic heart failure. New Zealand rabbits were treated with doxorubicin (heart failure group, n=5) or saline (control group, n=5) and instrumented with pressure catheters placed in the apex and outflow-tract of left ventricle (LV) and with sonomicrometer crystals placed in the apex and base of the LV free wall. In heart failure animals, ventricular filling was delayed and slower when compared with control animals. Moreover, the physiological nonuniformity observed between apical and basal segments in normal hearts was abolished in failing hearts. Simultaneously, physiological IVPGs observed during normal ventricular filling were entirely lost in heart failure animals. During ventricular emptying physiological nonuniformity between apical and basal segments observed in control animals was also abolished in heart failure animals. In failing hearts minimal length occurred later and almost at same time both in apical and in basal myocardial segments. Simultaneously, the characteristic IVPG pattern observed in healthy hearts during systole, which promotes ventricular emptying, was not observed in failing hearts. The present study showed that diastolic IVPGs, a marker of normal ventricular filling, and systolic IVPGs, a marker of normal ventricular emptying, are abolished in heart failure.

Relationship of diastolic intraventricular pressure gradients and aerobic capacity in patients with diastolic heart failure

2005 ◽  
Vol 289 (5) ◽  
pp. H2081-H2088 ◽  
Author(s):  
Aleksandr Rovner ◽  
Neil L. Greenberg ◽  
James D. Thomas ◽  
Mario J. Garcia
Keyword(s):  
Heart Failure ◽  
Diastolic Function ◽  
Aerobic Capacity ◽  
Normal Subjects ◽  
Intraventricular Pressure ◽  
Pressure Gradients ◽  
Suction Force ◽  
Myocardial Relaxation ◽  
Patients With Heart Failure ◽  
Intraventricular Pressure Gradients

We sought to elucidate the relationship between diastolic intraventricular pressure gradients (IVPG) and exercise tolerance in patients with heart failure using color M-mode Doppler. Diastolic dysfunction has been implicated as a cause of low aerobic potential in patients with heart failure. We previously validated a novel method to evaluate diastolic function that involves noninvasive measurement of IVPG using color M-mode Doppler data. Thirty-one patients with heart failure and 15 normal subjects were recruited. Echocardiograms were performed before and after metabolic treadmill stress testing. Color M-mode Doppler was used to determine the diastolic propagation velocity ( Vp) and IVPG off-line. Resting diastolic function indexes including myocardial relaxation velocity, Vp, and E/ Vp correlated well with V̇o2 max ( r = 0.8, 0.5, and −0.5, respectively, P < 0.001 for all). There was a statistically significant increase in Vp and IVPG in both groups after exercise, but the change in IVPG was higher in normal subjects compared with patients with heart failure (2.6 ± 0.8 vs. 1.1 ± 0.8 mmHg, P < 0.05). Increase in IVPG correlated with peak V̇o2 max ( r = 0.8, P < 0.001) and was the strongest predictor of exercise capacity. Myocardial relaxation is an important determinant of exercise aerobic capacity. In heart failure patients, impaired myocardial relaxation is associated with reduced diastolic suction force during exercise.

MRI Assessment of Diastolic and Systolic Intraventricular Pressure Gradients in Heart Failure

2016 ◽  
Vol 13 (1) ◽  
pp. 37-46 ◽  
Author(s):  
Snigdha Jain ◽  
Francisco J. Londono ◽  
Patrick Segers ◽  
Thierry C. Gillebert ◽  
Marc De Buyzere ◽  
...  
Keyword(s):  
Heart Failure ◽  
Intraventricular Pressure ◽  
Pressure Gradients ◽  
Intraventricular Pressure Gradients

Abstract 20360: MRI Assessment of Diastolic and Systolic Intraventricular Pressure Gradients in Heart Failure

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Francisco J Londoño ◽  
Patrick Segers ◽  
Prithvi Shiva kumar ◽  
Prasad Konda ◽  
Payman Zamani ◽  
...  
Keyword(s):  
Heart Failure ◽  
Ejection Fraction ◽  
Pressure Gradient ◽  
Diastolic Function ◽  
Diastolic Filling ◽  
Intraventricular Pressure ◽  
Pressure Gradients ◽  
Intraventricular Pressure Gradients ◽  
Intraventricular Pressure Gradient ◽  
Early Filling

Background: Non-invasive assessment of left ventricular (LV) diastolic function is an important goal to better understand physiologic abnormalities in heart failure. The spatiotemporal pattern of LV blood flow velocities during early filling can be used to estimate intraventricular pressure gradients driving early filling. MRI can provide accurate flow velocity information in the LV, but this method has not been exploited to assess diastolic function in heart failure (HF). Aim: To assess differences in intraventricular pressure gradients in heart failure and preserved ejection fraction (HFPEF) and heart failure with reduced ejection fraction (HFREF), compared to subjects without HF. Methods: We studied 23 subjects without HF, 13 subjects with HFREF and 14 subjects with HFPEF. Intraventricular flow during diastole was measured using 2D in-plane phase-contrast MRI. We solved the Eulier equations to compute intraventricular pressure gradients during LV early filling (figure) and during ejection. Results: Whereas the initial velocity of wave propagation (was not significantly different between the groups, the terminal diastolic propagation velocity during early diastolic filling was significantly slower (P=0.004) in HFREF (5.2 m/s; 95%CI=3.9-6.8) than in patients with HFPEF (9.5; 95%CI=6.6-13.6) or subjects without HF (8.9; 95%CI=7.3-10.7). In contrast, HFPEF was associated with a greater amplitude of the reversal of the base-to-apex intraventricular pressure gradient during early filling (β=-0.34; P=0.04), which was driven by the inertial component. Conclusions: HFPEF and HFREF are associated with distinct patterns of intraventricular pressure gradient abnormalities during early diastolic filling. Our findings support fundamental differences in the nature of diastolic dysfunction in these 2 conditions.

Addition of Epinephrine to Intrathecal Bupivacaine and Sufentanil for Ambulatory Labor Analgesia

1997 ◽  
Vol 86 (3) ◽  
pp. 525-531 ◽  
Author(s):  
David C. Campbell ◽  
Robert Banner ◽  
Lesley-Ann Crone ◽  
Wendy Gore-Hickman ◽  
Ray W. Yip
Keyword(s):  
Labor Analgesia ◽  
Saline Control ◽  
Control Group ◽  
Double Blind Study ◽  
Saline Control Group ◽  
Double Blind ◽  
Prolonged Labor ◽  
Intrathecal Analgesia ◽  
Limited Duration ◽  
Effective Analgesia

Background The intrathecal combination of sufentanil and bupivacaine provides rapid, effective analgesia for labor with a limited duration. Many anesthesiologists have concerns that the use of intrathecal local anesthetics precludes maternal ambulation. This prospective, randomized, double-blind study was designed to determine whether the addition of epinephrine to the combination of sufentanil and bupivacaine would prolong intrathecal analgesia for labor. Patients' ability to ambulate was also assessed. Methods Thirty-nine patients received either an intrathecal control dose of 10 micrograms sufentanil plus 2.5 mg bupivacaine plus 0.2 ml normal saline (control group); or 10 micrograms sufentanil plus 2.5 mg bupivacaine plus 0.2 ml (0.2 mg) of epinephrine (EPI group). Results Seven patients (3 control, 4 EPI) delivered vaginally and two (1 control, 1 EPI) required cesarean delivery before requesting epidural analgesia. The duration (mean +/- SD) of intrathecal labor analgesia was prolonged significantly by the addition of epinephrine: control (n = 15): 145 +/- 23 min; EPI (n = 15): 188 +/- 25 min (P &lt; 0.0001). Maternal ambulation was demonstrated in 100% (19 of 19) of the control group and in 80% (16 of 20) of the EPI group (P = NS). Conclusions The addition of 0.2 mg epinephrine to the intrathecal combination of sufentanil and bupivacaine significantly prolonged labor analgesia without causing adverse effects to the mother or fetus. The intrathecal combination of sufentanil and bupivacaine, with or without epinephrine, provided rapid, profound labor analgesia and allowed most patients to ambulate.

Arrhythmogenic effects of catecholamines are decreased in heart failure induced by rapid pacing in dogs

1993 ◽  
Vol 265 (5) ◽  
pp. H1654-H1662 ◽  
Author(s):  
H. G. Li ◽  
D. L. Jones ◽  
R. Yee ◽  
G. J. Klein
Keyword(s):  
Heart Failure ◽  
Ventricular Arrhythmias ◽  
Control Group ◽  
Purkinje Fibers ◽  
Failure Group ◽  
Failing Heart ◽  
Minimal Dose ◽  
Arrhythmogenic Effect ◽  
Rapid Pacing ◽  
Arrhythmogenic Effects

Increased circulating catecholamines are considered to be arrhythmogenic in heart failure. It is unclear whether increased circulating catecholamines contribute directly to ventricular arrhythmias or are only markers of the severity of heart failure. The present study determined the sensitivity of the failing heart to the arrhythmogenic effect of exogenous norepinephrine in a rapid pacing-induced model of heart failure in dogs (240 beats for 4 wk, n = 14). A similarly operated, non-paced group served as controls (n = 9). Cardiac sensitivity to the arrhythmogenic effect of catecholamines was determined by measuring the minimal dose of exogenous norepinephrine that induced ventricular tachycardia (arrhythmogenic threshold dose, ATD). ATD significantly increased after development of heart failure in heart-failure group (1.62 +/- 0.32 microgram/kg at baseline vs. 16.65 +/- 3.48 micrograms/kg at restudy, P < 0.01), whereas no significant change was noted in the control group (1.08 +/- 0.36 microgram/kg at baseline vs. 2.53 +/- 0.36 micrograms/kg at restudy, P > 0.10). Action potential duration was unchanged by superfusion with 10(-7) M isoproterenol in both ventricular muscles (230.2 +/- 6.1 vs. 229.7 +/- 5.3 ms, P = NS) and Purkinje fibers (273.2 +/- 6.5 vs. 283.8 +/- 4.2 ms, P = NS) from the failing hearts, although isoproterenol induced a shortening in the control group (204.8 +/- 0.9 vs. 181.3 +/- 1.6 ms in ventricular muscles, P < 0.01; 313.8 +/- 6.5 vs. 279.5 +/- 5.7 ms in Purkinje fibers, P < 0.01). We conclude that the failing heart has a decreased sensitivity to the arrhythmogenic effect of catecholamines.

scholarly journals Interspecific Mating Effects on Locomotor Activity Rhythms and Refractoriness of Aedes albopictus (Diptera: Culicidae) Females

Insects ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 874
Author(s):  
Thais de Souza Feitoza ◽  
Victor Henrique Ferreira-de-Lima ◽  
Daniel Cardoso Portela Câmara ◽  
Nildimar Alves Honório ◽  
L. Philip Lounibos ◽  
...  
Keyword(s):  
Locomotor Activity ◽  
Aedes Albopictus ◽  
Accessory Gland ◽  
Saline Control ◽  
Sexual Receptivity ◽  
Control Group ◽  
Interspecific Mating ◽  
Saline Control Group ◽  
Activity Rhythms ◽  
Locomotor Activities

This study tests the hypotheses that the locomotor activity of Ae. albopictus females is not significantly altered by the presence of accessory gland (AG) extracts from conspecific and heterospecific males, and that Ae. albopictus females remain receptive to mating with conspecific males even after receiving AG of Ae. aegypti males. Virgin Ae. albopictus females were injected with saline (control group), AG extracts of Ae. aegypti males (aegMAG) or AG extracts of Ae. albopictus males (albMAG). Locomotor activity was evaluated under 12 h of light and 12 h of darkness at 25 °C. All live Ae. albopictus females were subsequently exposed to conspecific males for 48 h, and their spermathecae were dissected for the presence of sperm. Females injected with aegMAG and albMAG showed significant decreases in total, diurnal and diurnal without lights-on Period activities. Females injected with aegMAG showed significant decreases in nocturnal and nocturnal without lights-off period activities. Females injected with albMAG showed significant decreases in lights-off activity. A total of 83% of Ae. albopictus females injected with aegMAG and 10% of females injected with albMAG were inseminated by conspecific males. These results, coupled with our previous paper on MAG and interspecific mating effects on female Ae. aegypti, demonstrate contrasting outcomes on locomotor activities and loss of sexual receptivity, both conspecific and heterospecific MAGs capable of sterilizing virgin Ae. aegypti, but only conspecific MAGs sterilizing Ae. albopictus, whereas locomotor activities were depressed in females of both species after heterospecific and conspecific injections or treatments.

scholarly journals EFFECT OF MITRAL INFLOW PATTERN ON INTRAVENTRICULAR PRESSURE GRADIENTS IN HYPERTENSION RATS

2019 ◽  
Vol 37 ◽  
pp. e157-e158
Author(s):  
D. Ma ◽  
K. Matsuura ◽  
K. Takahashi ◽  
K. Shimada ◽  
T. Yoshida ◽  
...  
Keyword(s):  
Intraventricular Pressure ◽  
Pressure Gradients ◽  
Mitral Inflow ◽  
Intraventricular Pressure Gradients

scholarly journals Intraventricular pressure gradients throughout the cardiac cycle: effects of ischaemia and modulation by afterload

2012 ◽  
Vol 98 (1) ◽  
pp. 149-160 ◽  
Author(s):  
Miguel Guerra ◽  
Mário Jorge Amorim ◽  
Cármen Brás-Silva ◽  
Adelino F. Leite-Moreira
Keyword(s):  
Cardiac Cycle ◽  
Intraventricular Pressure ◽  
Pressure Gradients ◽  
Intraventricular Pressure Gradients
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