Contractile and Ca2+-handling properties of the right ventricular papillary muscle in the late-gestation sheep fetus

2006 ◽  
Vol 101 (3) ◽  
pp. 728-733 ◽  
Author(s):  
T. N. Spencer ◽  
K. J. Botting ◽  
J. L. Morrison ◽  
G. S. Posterino
Keyword(s):  
Right Ventricular ◽  
Papillary Muscle ◽  
Late Gestation ◽  
Postnatal Life ◽  
Excitation Contraction Coupling ◽  
Contraction Coupling ◽  
Force Development ◽  
Uptake Rates ◽  
Significant Difference ◽  
The Right

The force-generating capacity of cardiomyocytes rapidly changes during gestation and early postnatal life coinciding with a transition in cardiomyocyte nucleation in both mice and rats. Changes in nucleation, in turn, appear to coincide with important changes in the excitation-contraction coupling architecture. However, it is not clear whether similar changes are observed in other mammals in which this transition occurs prenatally, such as sheep. Using small (70–300 μM diameter) chemically skinned cardiomyocyte bundles from the right ventricular papillary muscle of sheep fetuses at 126–132 and 137–140 days (d) gestational age (GA), we aimed to examine whether changes in cardiomyocyte nucleation during late gestation coincided with developmental changes in excitation-contraction coupling parameters (e.g., Ca2+ uptake, Ca2+ release, and force development). All experiments were conducted at room temperature (23 ± 1°C). We found that the proportion of mononucleate cardiomyocytes decreased significantly with GA (126–132d, 45.7 ± 4.7%, n = 7; 137–140d, 32.8 ± 1.6%, n = 6; P < 0.05). When we then examined force development between the two groups, there was no significant difference in either the maximal Ca2+-activated force (6.73 ± 1.54 mN/mm2, n = 14 vs. 6.55 ± 1.25 mN/mm2, n = 7, respectively) or the Ca2+ sensitivity of the contractile apparatus (pCa at 50% maximum Ca2+-activated force: 126–132d, 6.17 ± 0.06, n = 14; 137–140d, 6.24 ± 0.08, n = 7). However, sarcoplasmic reticulum (SR) Ca2+ uptake rates (but not Ca2+ release) increased with GA ( P < 0.05). These data reveal that during late gestation in sheep when there is a major transition in cardiomyocyte nucleation, SR Ca2+ uptake rates increase, which would influence total SR Ca2+ content and force production.

DeVega versus ring annuloplasty in severe functional tricuspid insufficiency and their impact on the right ventricle

2019 ◽  
Vol 1 (4) ◽  
pp. 133-139
Author(s):  
Yasser Hamdy ◽  
Mohammed Mahmoud Mostafa ◽  
Ahmed Elminshawy
Keyword(s):  
Right Ventricular ◽  
Tricuspid Valve ◽  
Tricuspid Regurgitation ◽  
Early Postoperative Period ◽  
Tricuspid Valve Repair ◽  
Ring Annuloplasty ◽  
Significant Difference ◽  
Group A ◽  
Group B ◽  
The Right

Background: Functional tricuspid valve regurgitation secondary to left-sided valve disease is common. DeVega repair is simple, but residual regurgitation with subsequent impairment of the right ventricular function is a concern. This study aims to compare tricuspid valve repair using DeVega vs. ring annuloplasty and their impact on the right ventricle in the early postoperative period and after six months. Methods: This is a prospective cohort study of 51 patients with rheumatic heart disease who underwent tricuspid valve repair for secondary severe tricuspid regurgitation. Patients were divided into two groups: group A; DeVega repair (n=34) and group B; ring annuloplasty repair (n=17). Patients were assessed clinically and by echocardiography before discharge and after six months for the degree of tricuspid regurgitation, right ventricular diameter and tricuspid annular plane systolic excursion (TAPSE). Results: Preoperative echocardiographic assessment showed no difference in left ventricular end-systolic diameter, end-diastolic diameter, ejection fraction and right ventricular diameter, however; group A had significantly better preoperative right ventricular function measured by TAPSE (1.96 ± 0.27 vs1.75 ± 0.31 cm; p=0.02). Group B had significantly longer cardiopulmonary bypass time (127.65 ± 13.56 vs. 111.74 ± 18.74 minutes; p= 0.003) and ischemic time (99.06 ± 11.80 vs. 87.15 ± 16.01 minutes; p= 0.009). Pre-discharge, there was no statistically significant difference in the degree of tricuspid regurgitation, but the right ventricular diameter was significantly lower in group B (2.66 ± 0.41 and 2.40 ± 0.48 cm; p=0.049). After six months of follow up, the degree of tricuspid regurgitation (p= 0.029) and the right ventricular diameter were significantly lower in the ring annuloplasty group (2.56 ± 0.39 and 2.29 ± 0.44 cm; p=0.029). Although there was a statistically significant difference in preoperative TAPSE, this difference disappeared after six months. Conclusion: Both DeVega and ring annuloplasty techniques were effective in the early postoperative period, ring annuloplasty was associated with lesser residual regurgitation and better right ventricular remodeling in severe functional tricuspid regurgitation than DeVega procedure after 6-months of follow up.

scholarly journals EVALUATION OF THE RELATIONSHIP BETWEEN PULMONARY ARTERY STIFFNESS AND RIGHT VENTRICULAR FUNCTION IN PATIENTS WITH BEHÇET’S DISEASE USING TRANSTHORACIC ECHOCARDIOGRAPHY

2021 ◽  
Author(s):  
Salim Yaşar ◽  
Murat Unlu ◽  
suat gormel ◽  
Emre Yalcinkaya ◽  
Baris BUGAN ◽  
...  
Keyword(s):  
Pulmonary Artery ◽  
Right Ventricular ◽  
Patient Group ◽  
Behcet’S Disease ◽  
Left Ventricular ◽  
Significant Difference ◽  
Artery Stiffness ◽  
The Right ◽  
The Relationship ◽  
Ventricular Functions

Background: Behçet’s disease is a systemic vasculitis that can affect all sizes of arteries and veins. Arterial stiffness is a term used to describe the visco-elastic properties of vessel wall. In this study, we aimed to evaluate the relationship between pulmonary artery stiffness (PAS) and the right ventricular (RV) functions in asymptomatic Behçet’s patients with no cardiovascular risk factors. Methods: We studied 40 patients who were diagnosed by the international diagnostic criteria of Behçet’s disease and 40 healthy individuals who were matching demographic properties with the patients. Two groups were matched by age, gender, clinical history and other clinical features. Substantial medical history concerning the factors that can affect right ventricle diastolic function (such as medications, smoking status, other comorbities, etc.) was taken and general physical examination was carried out. The right and left ventricular functions as well as valvular functions were evaluated by using echocardiography. Also Two-dimensional, M-mode, pulsed wave (PW) Doppler echocardiographic parameters were measured for right ventricular functions. PW Doppler flow trace was obtained from the pulmonary valve with regards to pulmonary artery stiffness. Results: There was no significant difference in terms of clinical and demographic properties. No statistically significant difference was found upon comparison of the left ventricular end of systole and diastole diameters, the diastolic and systolic thicknesses of the interventricular septum (IVS) and left ventricular posterior wall (LVPW), left atrium (LA) diameter and left ventricular ejection fraction (LVEF) values (p>0.05) of the two groups. Right ventricular myocardial performance index (MPI) value was found higher in Behçet’s patients and a statistically significant difference was detected between the groups (p<0.01). Tricuspid annular plane systolic excursion (TAPSE) values were found to be statistically significantly lower in the patient group as compared to the control group (p<0.01). In PW Doppler measurements, early passive filling (E) wave flow velocity and E/A ratio were found to be statistically significantly lower, deceleration time (DT) was higher in the patient group (p<0.01). In Behçet’s patients without clinical pulmonary involvement, the pulmonary artery systolic pressure (PASP) was found to be statistically significantly higher in the patient group (p<0.01). The values of pulmonary artery stiffness (PAS) were found to be significantly higher in the patient group (p<0.01). The relationship between the right ventricular function markers and PAS were evaluated in the patient group. There was no statistically significant relationship between PAS and MPI and TAPSE. But there was a significant correlation between PAS and PASP and duration of illness (p<0.001 and r=0.682 ; p=0.047 and r=0,316). Conclusion: Behçet’s patients without cardiac symptoms and signs, reduction in right ventricular functions and increase in PAS was detected. Although there is no correlation between right ventricular functions and PAS, increased PAS may be an early marker of reduction of the right ventricular functions. Consequently, routine cardiological examination and detailed evaluation of biventricular functions by using echocardiography should be greatly beneficial in Behcet’s patients, even though there are no signs or symptoms.

scholarly journals Target Characteristics and Voltage Mapping of the Matrix in Idiopathic Premature Ventricular Contractions Originating from the Right Ventricular Outflow Tract

2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Zhiyong Zhang ◽  
Xiaofeng Hou ◽  
Zhiyong Qian ◽  
Jianghong Guo ◽  
Jiangang Zou
Keyword(s):  
Right Ventricular ◽  
Right Ventricular Outflow Tract ◽  
Ventricular Outflow Tract ◽  
Outflow Tract ◽  
Premature Ventricular Contractions ◽  
Bipolar Voltage ◽  
Successful Ablation ◽  
Voltage Mapping ◽  
Significant Difference ◽  
The Right

Background. The study was aimed at exploring the electrophysiological characteristics (EPS) of the optimal ablation site and its relationship with electroanatomic voltage mapping (EVM) in idiopathic premature ventricular contractions (PVCs) originating from the right ventricular outflow tract (RVOT). Methods. A total of 28 patients with idiopathic RVOT PVCs underwent successful ablation and EVM using a 3D electroanatomical mapping (CARTO) system. Results. Both bipolar and unipolar EVM showed a similar band-like lower-voltage area (LVA) under the pulmonary valve in all the patients; 21.4% of the targets were located in the band-like LVA. 42.9% of the targets were at the border of the band-like LVA on the bipolar voltage map, but unipolar mapping showed that 53.6% of the targets were located in the band-like LVA, and 35.7% of the targets at the border of the band-like LVA. A significant difference was found in both unipolar and bipolar voltage values between the regions within 0-5 mm above the optimal ablation site and the other regions. A similar difference was observed only in unipolar voltage values below the optimal ablation site. At the ablation site, there were frequent occurrences of a fragmented wave and voltage reversion in the bipolar electrograms, frustrated falling limbs, W bottom, and a QS configuration width > 150  ms in the unipolar electrograms. Conclusions. EVM showed that the band-like LVA was an interesting area for the search of the optimal ablation sites of idiopathic RVOT-PVCs, especially the border area. There was focal microscarring around the ablation targets; some characteristics of EPS proved significant for successful ablation.

scholarly journals CYTOCHEMICAL LOCALIZATION OF CHOLINESTERASE ACTIVITY IN ADULT RABBIT HEART

1971 ◽  
Vol 19 (6) ◽  
pp. 376-381 ◽  
Author(s):  
MARTIN HAGOPIAN ◽  
VIRGINIA M. TENNYSON
Keyword(s):  
Sarcoplasmic Reticulum ◽  
Papillary Muscle ◽  
Cholinesterase Activity ◽  
Acetylcholinesterase Activity ◽  
Rabbit Heart ◽  
Adult Rabbit ◽  
Cytochemical Localization ◽  
Excitation Contraction Coupling ◽  
Contraction Coupling ◽  
T System

The papillary muscle of the adult rabbit heart was studied by a modification of the Koelle-Friedenwald copper thiocholine technique for the localization of cholinesterase activity. Butyrylcholinesterase (BuChE), identified by its substrate and inhibitor specificity, is found mainly in the terminal sacs of the sarcoplasmic reticulum adjacent to the T system. The localization of the reaction product in this particular site suggests that BuChE may play a role in excitation-contraction coupling in the adult rabbit heart. The present findings are also discussed in comparison with our previous work on the localization of acetylcholinesterase activity in the embryonic rabbit heart.

Right ventricular remodelling after endo-exclusion during pulmonary valve replacement: evaluation by cardiac magnetic resonance

2021 ◽  
Author(s):  
Marien Lenoir ◽  
Caroline Chenu ◽  
Amine Amrous ◽  
Anne-Claire Casalta ◽  
Catherine Guidon ◽  
...  
Keyword(s):  
Ejection Fraction ◽  
Right Ventricular ◽  
Right Ventricular Function ◽  
Pulmonary Valve ◽  
Right Ventricular Ejection Fraction ◽  
Pulmonary Valve Replacement ◽  
Ventricular Ejection Fraction ◽  
Significant Difference ◽  
The Right

Abstract OBJECTIVES Pulmonary valve replacement (PVR) performed for pulmonary valve regurgitation is the most common indication for reoperation during mid-to-long-term follow-up after tetralogy of Fallot repair. An aneurysmal dilation of the infundibulum is often associated secondary to the infundibulotomy performed in the first operation. The right ventricular outflow tract reconstruction with endo-exclusion aims to exclude the non-contractile segments of the dilated right ventricular. This study intends to assess the safety and efficiency of the endo-exclusion technique. METHODS Between January 2010 and December 2018, 86 patients underwent a PVR with (n = 46) or without (n = 40) endo-exclusion. The current study compares the outcomes in terms of survival, reintervention, structural valve deterioration, right ventricular function (volume and right ventricular ejection fraction) and pulmonary valve gradient. The median follow-up time was 4.45 years (1.9 months to 9.87 years). RESULTS There was no 30-day mortality. There was no difference in the freedom from reintervention at 7 years (without endo-exclusion, 97%, versus with endo-exclusion, 94%, log-rank = 0.68) or in the freedom from structural pulmonary valve deterioration at 7 years (without endo-exclusion, 94%, versus with endo-exclusion, 89%, log-rank = 0.94). No significant difference was observed in the indexed right ventricular end-diastolic volume (102.2 ± 34 ml/m2 in the PVR without endo-exclusion group and 93.3 ± 22 ml/m2 in the PVR with endo-exclusion group, P = 0.61). No significant difference was observed in the right ventricular function (right ventricular ejection fraction: 46 ± 11% in the PVR without endo-exclusion group and 46 ± 9% in the PVR with endo-exclusion group, P = 0.88). CONCLUSIONS PVR with or without endo-exclusion is a safe and effective procedure. PVR with endo-exclusion allows implantation without structural deformation of the valve and therefore excellent short- and medium-term results.

scholarly journals Impairment of Excitation-Contraction Coupling in Right Ventricular Hypertrophied Muscle with Fibrosis Induced by Pulmonary Artery Banding

PLoS ONE ◽  
2017 ◽  
Vol 12 (1) ◽  
pp. e0169564 ◽  
Author(s):  
Yoichiro Kusakari ◽  
Takashi Urashima ◽  
Daisuke Shimura ◽  
Erika Amemiya ◽  
Genki Miyasaka ◽  
...  
Keyword(s):  
Pulmonary Artery ◽  
Right Ventricular ◽  
Pulmonary Artery Banding ◽  
Excitation Contraction Coupling ◽  
Contraction Coupling
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