Responses of chronically hypoxic rat hearts to ischemia: KATP channel blockade does not abolish increased RV tolerance to ischemia

2004 ◽  
Vol 286 (2) ◽  
pp. H545-H551 ◽  
Author(s):  
Joerg Forkel ◽  
Xiaochao Chen ◽  
Susanne Wandinger ◽  
Florian Keser ◽  
Alexey Duschin ◽  
...  
Keyword(s):  
Protein Expression ◽  
Left Ventricular Function ◽  
Right Ventricular ◽  
Ventricular Function ◽  
Right Ventricular Function ◽  
Chronic Hypoxia ◽  
Ischemia Reperfusion ◽  
Left Ventricular ◽  
Rat Hearts ◽  
Left And Right

Chronic hypoxia may precondition the myocardium and protect from ischemia-reperfusion damage. We therefore examined the recovery of left and right ventricular function after ischemia and reperfusion (15 min each) in isolated blood-perfused working hearts from normoxic (Norm) and hypoxic (Hypo; 14 days, 10.5% O2) adult rats. In addition, the mRNA expression of hypoxia-inducible factor (HIF)-1α and the protein expression of endothelial nitric oxide synthase (eNOS) were measured. Postischemic left ventricular function recovered to 66 ± 6% and 67 ± 5% of baseline in Norm and Hypo, respectively. In contrast, postischemic right ventricular function was 93 ± 2% of baseline in Hypo vs. 67 ± 3% in Norm ( P < 0.05). Improved postischemic right ventricular function in Hypo (93 ± 2% and 96 ± 2% of baseline) was observed with 95% O2 or 21% O2 in the perfusate, and it was not attenuated by glibenclamide (5 and 10 μmol/l) (86 ± 4% and 106 ± 6% recovery). HIF-1α mRNA and eNOS protein expression were increased in both left and right hypoxic ventricles. In conclusion, postischemic right, but not left, ventricular function was improved by preceding chronic hypoxia. ATP-sensitive K+ channels are not responsible for the increased right ventricular tolerance to ischemia after chronic hypoxia in adult rat hearts.

scholarly journals Limb remote ischemia per-conditioning protects the heart against ischemia–reperfusion injury through the opioid system in rats

2018 ◽  
Vol 96 (1) ◽  
pp. 68-75 ◽  
Author(s):  
Li Zhang ◽  
Hui Guo ◽  
Fang Yuan ◽  
Zeng-chao Hong ◽  
Yan-ming Tian ◽  
...  
Keyword(s):  
Protein Expression ◽  
Left Ventricular Function ◽  
Ventricular Function ◽  
Ischemia Reperfusion Injury ◽  
Ischemia Reperfusion ◽  
Left Ventricular ◽  
Cardiac Ischemia ◽  
Cardiac Protection ◽  
Expression Levels ◽  
Infarct Area

Remote ischemia per-conditioning (RPerC) has been demonstrated to have cardiac protection, but the underlying mechanism remains unclear. This study aimed to investigate the mechanism underlying cardiac protection of RPerC. Adult male Sprague–Dawley rats were used in this study. Cardiac ischemia/reperfusion (I/R) was induced by 30 min of occlusion and 3 h of reperfusion of the left anterior descending coronary artery. RPerC were performed by 5 min of occlusion of the right femoral artery followed by 5 min of reperfusion for three times during cardiac ischemia. The hemodynamics, left ventricular function, arrhythmia, and infarct area were measured. Protein expression levels of endothelial nitric oxide synthase (eNOS), inducible NOS (iNOS), protein kinase C-ε (PKCε), and PKCδ in the myocardium were assayed. During I/R, systolic artery pressure and left ventricular function were decreased, infarct area was increased, and arrhythmia score was increased (P < 0.05). However, changes of the above parameters were significantly attenuated in RPerC-treated rats compared with control rats (P < 0.05). The cardiac protective effects of RPerC were prevented by naloxone or glibenclamide. Also, RPerC increased the protein expression levels of eNOS, iNOS, PKCε, and PKCδ in the myocardium compared with control rats. These effects were blocked by naloxone, an opioid receptor antagonist, and glibenclamide, an ATP-sensitive K+ channel blocker (KATP). In summary, this study suggests that RPerC protects the heart against I/R injury through activation of opioid receptors and the NO–PKC–KATP channel signaling pathways.

scholarly journals Anterior Chordal Transection Impairs Not Only Regional Left Ventricular Function But Also Regional Right Ventricular Function in Mitral Regurgitation

Circulation ◽  
2001 ◽  
Vol 104 (suppl 1) ◽  
pp. I-41-I-46 ◽  
Author(s):  
Thierry Le Tourneau ◽  
Daniel Grandmougin ◽  
Claude Foucher ◽  
Eugene P. McFadden ◽  
Pascal de Groote ◽  
...  
Keyword(s):  
Mitral Regurgitation ◽  
Left Ventricular Function ◽  
Right Ventricular ◽  
Ventricular Function ◽  
Right Ventricular Function ◽  
Left Ventricular ◽  
Regional Left Ventricular Function

P356Effect of catheter ablation on left and right ventricular function in patients with frequent premature ventricular contractions and preserved ejection fraction

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
J Stassen ◽  
D Dilling ◽  
J Vijgen ◽  
M Scherrenberg ◽  
J Schurmans ◽  
...  
Keyword(s):  
Right Ventricular ◽  
Ventricular Function ◽  
Right Ventricular Function ◽  
Left Ventricular ◽  
Premature Ventricular Contractions ◽  
Significant Difference ◽  
Significant Amelioration ◽  
2D Speckle Tracking ◽  
Left And Right

Abstract INTRODUCTION Improvement of left ventricular ejection fraction (LVEF) after catheter ablation (CA) in patients with left ventricular (LV) dysfunction and frequent premature ventricular contractions (PVCs) of the outflow tract (OT) has been reported. However, many patients with PVCs of the OT have a normal LVEF. The effect of CA on the left and right ventricular function in these patients is not well established.   PURPOSE  This study aims to evaluate the effect of CA on improvement of left and right ventricular function in patients with a preserved LVEF (EF &gt; 50%) and frequent PVCs originating from the OT.  METHODS  We retrospectively examined clinical, electrophysiological and echocardiographic measurements in 95 patients with a preserved LVEF and frequent PVCs from the OT who underwent CA, dating from January 2014 till December 2018. Two dimensional TTE was performed at baseline and follow up. LV volumes and LVEF were calculated using the Simpson’s method. LV global longitudinal strain (GLS) and RV free wall longitudinal strain were calculated by 2D speckle tracking.  The Shapiro-Wilk test was used to determine the normal distribution of all variables. The Wilcoxon Signed Rank test was used to compare the evolution of the categorical and continuous variables between the TTE at baseline and follow-up.  RESULTS  Mean age of our study population was 52.8 ± 16.6 years, 49% was female. Mean burden of PVC before ablation was 18423 (2496-54000)/24h; 23.2% had a burden of less than 10.000 PVCs/24h. Mean burden of PVC after ablation was 1403 (0-27349)/24h. Median time between ablation and follow-up TTE was 117,8 days. There was a significant amelioration of LVEF (54.0 ± 4.0 vs 58.0 ± 3.8%, p &lt;0.001) and LV GLS (18.4 ± 2.2 vs 20.4 ± 2.0 %, p &lt; 0.001) as well as TAPSE (24.8 ± 3.5 vs 25.2 ± 3.1mm, p 0.013) and RV strain (25.4 ± 3.9 vs 27.6 ± 3.7%, p &lt;0.001). There was no significant difference in LV end diastolic diameter (50.1 ± 5.6 vs 49.6 ± 5.3mm, p 0.06) or LV end diastolic volume (109.7 ± 27.8 vs 107.2 ± 24.9mm, p 0.25), but there was a significant reduction in LV end systolic volume  (50.7 ± 13.9 vs 44.7 ± 11.1mm, p &lt; 0.001). RV basal diameter was not different (33.8 ± 4.5mm vs 33.6 ± 4.2mm, p 0.30).In the patient group with VES &lt;10000/24h, there was no significant difference in LVEF (55,2 ± 4,6 vs 55,9 ± 4,6%, p 0,12), but there was a significant amelioration of GLS (18.4 ± 2.2 vs 19.9 ± 2.1%, p &lt; 0.001) and RV strain (24.1 ± 4.3 vs 25.9 ±3.3%, p0.003). In the patient group with VES &gt;10000/24h, beneficial effects were noticed in LVEF (53.6 ± 3.8 vs 58.7 ±3.2%, p &lt; 0.001), GLS (18.4 ± 2.2 vs 20.5 ± 2.0%, p &lt; 0.001) and RV strain (25.8 ± 3.7 vs 28.1 ± 3.7%, p &lt; 0.001). CONCLUSION Frequent PVCs from the OT can induce subtle cardiac dysfunction in patients without apparent cardiomyopathy. CA can improve left and right ventricular function in these patients, which can be detected by conventional TTE parameters but also in an earlier stage by 2D speckle tracking.

Doppler echocardiography in the ICU

2016 ◽  
Author(s):  
Julien Maizel ◽  
Michel Slama
Keyword(s):  
Right Ventricular ◽  
Ventricular Function ◽  
Right Ventricular Function ◽  
Left Ventricular ◽  
Ventricular Filling Pressure ◽  
Left And Right ◽  
Systolic And Diastolic Function ◽  
Icu Physicians ◽  
Ventricular Filling ◽  
Echocardiographic Findings

The capacity of echocardiography to non-invasively identify the major causes of circulatory failure has made it increasingly popular in the intensive care unit (ICU) setting. Assessing cardiac performance in shocked patients is a key point in therapeutic support decision-making. Analysing left and right ventricular function and morphology should be mandatory in the training curriculum of ICU physicians. Haemodynamic evaluation relies on several parameters examining left ventricular systolic and diastolic function, left ventricular filling pressure, fluid responsiveness, and right ventricular function. To correctly interpret the echocardiographic findings and adapt patient management appropriately, physicians must be aware of the limits of these parameters.

scholarly journals Prognostic Value of Echocardiographic Right Ventricular Function Parameters in the Presence of Severe Tricuspid Regurgitation

2021 ◽  
Vol 10 (11) ◽  
pp. 2266
Author(s):  
Matthias Schneider ◽  
Varius Dannenberg ◽  
Andreas König ◽  
Welf Geller ◽  
Thomas Binder ◽  
...  
Keyword(s):  
Right Ventricular ◽  
Ventricular Function ◽  
Tricuspid Regurgitation ◽  
Right Ventricular Function ◽  
Prognostic Value ◽  
Large Scale ◽  
Systolic Function ◽  
Left Ventricular ◽  
Severe Tricuspid Regurgitation ◽  
Vena Contracta

Background: Presence of severe tricuspid regurgitation (TR) has a significant impact on assessment of right ventricular function (RVF) in transthoracic echocardiography (TTE). High trans-valvular pendulous volume leads to backward-unloading of the right ventricle. Consequently, established cut-offs for normal systolic performance may overestimate true systolic RVF. Methods: A retrospective analysis was performed entailing all patients who underwent TTE at our institution between 1 January 2013 and 31 December 2016. Only patients with normal left ventricular systolic function and with no other valvular lesion were included. All recorded loops were re-read by one experienced examiner. Patients without severe TR (defined as vena contracta width ≥7 mm) were excluded. All-cause 2-year mortality was chosen as the end-point. The prognostic value of several RVF parameters was tested. Results: The final cohort consisted of 220 patients, 88/220 (40%) were male. Median age was 69 years (IQR 52–79), all-cause two-year mortality was 29%, median TAPSE was 19 mm (15–22) and median FAC was 42% (30–52). In multivariate analysis, TAPSE with the cutoff 17 mm and FAC with the cutoff 35% revealed non-significant hazard ratios (HR) of 0.75 (95%CI 0.396–1.421, p = 0.38) and 0.845 (95%CI 0.383–1.867, p = 0.68), respectively. TAPSE with the cutoff 19 mm and visual eyeballing significantly predicted survival with HRs of 0.512 (95%CI 0.296–0.886, p = 0.017) and 1.631 (95%CI 1.101–2.416, p = 0.015), respectively. Conclusions: This large-scale all-comer study confirms that RVF is one of the main drivers of mortality in patients with severe isolated TR. However, the current cut-offs for established echocardiographic parameters did not predict survival. Further studies should investigate the prognostic value of higher thresholds for RVF parameters in these patients.

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