scholarly journals Study of the time-relationship of the mechano-electrical interaction in an animal model of tetralogy of Fallot: implications for the risk assessment of ventricular arrhythmias

2020 ◽  
Vol 31 (1) ◽  
pp. 129-137
Author(s):  
Thierry Bove ◽  
Rahi Alipour Symakani ◽  
Jonas Verbeke ◽  
Anne Vral ◽  
Milad El Haddad ◽  
...  
Keyword(s):  
Tetralogy Of Fallot ◽  
Ventricular Arrhythmias ◽  
Pulmonary Regurgitation ◽  
Left Ventricular ◽  
Monophasic Action Potential ◽  
Control Group ◽  
Stroke Work ◽  
Long Term Outcome ◽  
Intraventricular Conduction ◽  
Qrs Prolongation

Abstract OBJECTIVES The long-term outcome of tetralogy of Fallot (TOF) is determined by progressive right ventricular (RV) dysfunction through pulmonary regurgitation (PR) and the risk of malignant arrhythmia. Although mechano-electrical coupling in TOF is well-known, its time effect on the inducibility of arrhythmia remains ill-defined. The goal of this study was to investigate the mechano-electrical properties at different times in animals with chronic PR. METHODS PR was induced by a transannular patch with limited RV scarring in infant pigs. Haemodynamic assessment included biventricular pressure–volume loops after 3 (n = 8) and 6 months (n = 7) compared to controls (n = 5). The electrophysiological study included endocardial monophasic action potential registration, intraventricular conduction velocity and induction of ventricular arrhythmia by burst pacing. RESULTS Progressive RV dilation was achieved at 6 months (RV end-diastolic volume 143 ± 13 ml/m2—RV end-systolic volume 96 ± 7 ml/m2; P < 0.001), in association with depressed RV contractility (preload recruitable stroke work-slope: 19 ± 1 and 11 ± 3 Mw.ml−1.s−1 for control and 6 m; P < 0.001) and left ventricular contractility (preload recruitable stroke work-slope: 60 ± 13 and 40 ± 11 Mw.ml−1.s−1 for control and 6 m; P = 0.005). Concomitant to QRS prolongation, monophasic action potential90-duration and dispersion at the RV and left ventricle were increased at 6 months. Intraventricular conduction was delayed only in the RV at 6 months (1.8 ± 0.2 and 2.4 ± 0.6 m/s for group 6M and the control group; P = 0.035). Sustained ventricular arrhythmias were not inducible. CONCLUSIONS In animals yielding the sequelae of a contemporary operation for TOF, mechano-electrical alterations are progressive and affect predominantly the RV after midterm exposure of PR. Because ventricular arrhythmias were not inducible despite significant RV dilation, the data suggest that the haemodynamic RV deterioration effectively precedes the risk of inducing sustained arrhythmia after TOF repair and opens a window for renewed stratification of contemporary risk factors of ventricular arrhythmias in patients operated on with currently used pulmonary valve- and RV-related techniques.

Assessment of Right Ventricular Inefficiency Using Energy Transfer Ratio in Repaired Tetralogy of Fallot

2011 ◽  
Author(s):  
Namheon Lee ◽  
Ashish Das ◽  
William M. Gottliebson ◽  
Rupak K. Banerjee
Keyword(s):  
Energy Transfer ◽  
Right Ventricular ◽  
Tetralogy Of Fallot ◽  
Main Pulmonary Artery ◽  
Pulmonary Regurgitation ◽  
Pulmonary Insufficiency ◽  
Control Group ◽  
Stroke Work ◽  
Transfer Ratio ◽  
Repaired Tetralogy Of Fallot

Pulmonary insufficiency (PI) induces pulmonary regurgitation and often leads to right ventricular (RV) enlargement and RV pressure overloading in repaired Tetralogy of Fallot (rTOF) patients. The appropriate timing of surgical treatments to renormalize RV function remains uncertain due to lack of suitable clinical diagnostic parameters. An energy transfer ratio (eMPA) between the net energy (Enet) transferred at main pulmonary artery (MPA) from RV and stroke work (SW) by RV was calculated using RV volume and pressure data for subjects in two study groups: the rTOF patient group (n = 7) and the control group (n = 7). Statistical analysis was performed to determine the difference of eMPA between the two groups. The mean eMPA for rTOF patients (0.64) was significantly lower (60.2%, p<0.05) than that of controls (1.61).

Effects of hypoproteinemia-induced myocardial edema on left ventricular function

1998 ◽  
Vol 274 (3) ◽  
pp. H937-H944 ◽  
Author(s):  
M. Miyamoto ◽  
D. E. McClure ◽  
E. R. Schertel ◽  
P. J. Andrews ◽  
G. A. Jones ◽  
...  
Keyword(s):  
Plasma Protein ◽  
Protein Concentration ◽  
Systolic Dysfunction ◽  
Myocardial Edema ◽  
Left Ventricular ◽  
Control Group ◽  
Lv Function ◽  
Stroke Work ◽  
Plasma Protein Concentration ◽  
Total Plasma Protein

In previous studies, we observed left ventricular (LV) systolic and diastolic dysfunction in association with interstitial myocardial edema (IME) induced by either coronary venous hypertension (CVH) or lymphatic obstruction. In the present study, we examined the effects of myocardial edema induced by acute hypoproteinemia (HP) on LV systolic and diastolic function. We also combined the methods of HP and CVH (HP-CVH) to determine their combined effects on LV function and myocardial water content (MWC). We used a cell-saving device to lower plasma protein concentration in HP and HP-CVH groups. CVH was induced by inflating the balloon in the coronary sinus. Six control dogs were treated to sham HP. Conductance and micromanometer catheters were used to assess LV function. Contractility, as measured by preload recruitable stroke work, did not change in control or HP groups but declined significantly (14.5%) in the HP-CVH group. The time constant of isovolumic LV pressure decline (τ) increased significantly from baseline by 3 h in the HP (24.8%) and HP-CVH (27.1%) groups. The end-diastolic pressure-volume relationship (stiffness) also increased significantly from baseline by 3 h in the HP (78.6%) and HP-CVH (42.6%) groups. Total plasma protein concentration decreased from 5.2 ± 0.2 g/dl at baseline to 2.5 ± 0.0 g/dl by 3 h in the HP and HP-CVH groups. MWC of the HP (79.8 ± 0.25%) and HP-CVH groups (79.8 ±0.2%) were significantly greater than that of the control group (77.8 ± 0.3%) but not different from one another. In conclusion, hypoproteinemia-induced myocardial edema was associated with diastolic LV dysfunction but not systolic dysfunction. The edema caused by hypoproteinemia was more than twice that produced by our previous models, yet it was not associated with systolic dysfunction. CVH had a negative inotropic effect and no significant influence on MWC. IME may not have the inverse causal relationship with LV contractility that has been previously postulated but appears to have a direct causal association with diastolic stiffness as has been previously demonstrated.

scholarly journals Altered biventricular hemodynamic forces in patients with repaired tetralogy of Fallot and right ventricular volume overload because of pulmonary regurgitation

2018 ◽  
Vol 315 (6) ◽  
pp. H1691-H1702 ◽  
Author(s):  
Pia Sjöberg ◽  
Johannes Töger ◽  
Erik Hedström ◽  
Per Arvidsson ◽  
Einar Heiberg ◽  
...  
Keyword(s):  
Blood Flow ◽  
Right Ventricular ◽  
Tetralogy Of Fallot ◽  
Flow Direction ◽  
Pulmonary Regurgitation ◽  
Ventricular Volume ◽  
Left Ventricular ◽  
Hemodynamic Forces ◽  
Control Subjects ◽  
Repaired Tetralogy Of Fallot

Intracardiac hemodynamic forces have been proposed to influence remodeling and be a marker of ventricular dysfunction. We aimed to quantify the hemodynamic forces in patients with repaired tetralogy of Fallot (rToF) to further understand the pathophysiological mechanisms as this could be a potential marker for pulmonary valve replacement (PVR) in these patients. Patients with rToF and pulmonary regurgitation (PR) > 20% ( n = 18) and healthy control subjects ( n = 15) underwent MRI, including four-dimensional flow. A subset of patients ( n = 8) underwent PVR and MRI after surgery. Time-resolved hemodynamic forces were quantified using 4D-flow data and indexed to ventricular volume. Patients had higher systolic and diastolic left ventricular (LV) hemodynamic forces compared with control subjects in the lateral-septal/LV outflow tract ( P = 0.011 and P = 0.0031) and inferior-anterior ( P < 0.0001 and P < 0.0001) directions, which are forces not aligned with blood flow. Forces did not change after PVR. Patients had higher RV diastolic forces compared with control subjects in the diaphragm-right ventricular (RV) outflow tract (RVOT; P < 0.001) and apical-basal ( P = 0.0017) directions. After PVR, RV systolic forces in the diaphragm-RVOT direction decreased ( P = 0.039) to lower levels than in control subjects ( P = 0.0064). RV diastolic forces decreased in all directions ( P = 0.0078, P = 0.0078, and P = 0.039) but were still higher than in control subjects in the diaphragm-RVOT direction ( P = 0.046). In conclusion, patients with rToF and PR had LV hemodynamic forces less aligned with intraventricular blood flow compared with control subjects and higher diastolic RV forces along the regurgitant flow direction in the RVOT and that of tricuspid inflow. Remaining force differences in the LV and RV after PVR suggest that biventricular pumping does not normalize after surgery. NEW & NOTEWORTHY Biventricular hemodynamic forces in patients with repaired tetralogy of Fallot and pulmonary regurgitation were quantified for the first time. Left ventricular hemodynamic forces were less aligned to the main blood flow direction in patients compared with control subjects. Higher right ventricular forces were seen along the pulmonary regurgitant and tricuspid inflow directions. Differences in forces versus control subjects remain after pulmonary valve replacement, suggesting that altered biventricular pumping does not normalize after surgery.

Tetralogy of Fallot

Circulation ◽  
2000 ◽  
Vol 102 (suppl_3) ◽  
Author(s):  
Y. d’Udekem ◽  
C. Ovaert ◽  
F. Grandjean ◽  
V. Gerin ◽  
M. Cailteux ◽  
...  
Keyword(s):  
Right Ventricular ◽  
Tetralogy Of Fallot ◽  
Left Ventricular ◽  
Ventricular Dilatation ◽  
Pulmonary Insufficiency ◽  
Direct Closure ◽  
Long Term Outcome ◽  
Cox Regression Analysis ◽  
Right Ventricular Dilatation

Background —In tetralogy of Fallot, transannular patching is suspected to be responsible for late right ventricular dilatation. Methods and Results —In our institution, 191 patients survived a tetralogy of Fallot repair between 1964 and 1984. Transannular patching was used in 99 patients (52%), patch closure of a right ventriculotomy in 35, and direct closure of a right ventriculotomy in 55. Two had a transatrial-transpulmonary approach. To identify predictive factors of adverse long-term outcome related to right ventricular dilatation, the following events were investigated: cardiac death, reoperation for symptomatic right ventricular dilatation, and NYHA class II or III by Cox regression analysis. Mean follow-up reached 22±5 years. The 30-year survival was 86±5%. Right ventricular patching, whether transannular or not, was the most significant independent predictor of late adverse event (improvement χ 2 =16.6, P <0.001). In patients who had direct closure, the ratio between end-diastolic right and left ventricular dimensions on echocardiography was smaller (0.61±0.017 versus 0.75±0.23, P =0.007), with a smaller proportion presenting severe pulmonary insufficiency (9% versus 40%, P =0.005). There was no difference between right ventricular and transannular patching concerning late outcome (log rank P value=0.6), right ventricular size (0.70±0.28 versus 0.76±0.26, P =0.4), or incidence of severe pulmonary insufficiency (30% versus 43%, P =0.3). Conclusions —In tetralogy of Fallot, transannular patching does not result in a worse late functional outcome than patching of an incision limited to the right ventricle. Both are responsible for a similar degree of long-term pulmonary insufficiency and right ventricular dilatation.

scholarly journals Tirilazad mesylate (U-74006F) inhibits effects of endotoxin in dogs

1995 ◽  
Vol 268 (5) ◽  
pp. H1847-H1855 ◽  
Author(s):  
H. Zhang ◽  
H. Spapen ◽  
P. Manikis ◽  
P. Rogiers ◽  
G. Metz ◽  
...  
Keyword(s):  
Endotoxic Shock ◽  
Left Ventricular ◽  
Oxygen Extraction ◽  
Volume Index ◽  
Whole Body ◽  
Control Group ◽  
Stroke Work ◽  
Critical Oxygen ◽  
Group 3 ◽  
Group 2

The present study explored the effects of a potent antioxidant, the 21-aminosteroid U-74006F, on the systemic and regional hemodynamics and the oxygen extraction capabilities during endotoxic shock. Twenty-four anesthetized dogs were randomized into three groups. Group 1 (n = 8) served as control. Group 2 (n = 8) and group 3 (n = 8) received 2 mg/kg iv of Escherichia coli endotoxin, followed 30 min later by saline infusion. Group 3 was given U-74006F as an intravenous bolus of 80 micrograms/kg followed by an infusion of 10 micrograms.kg-1.min-1, and group 2 received an equivalent volume of vehicle. Tamponade was induced 30 min later to study the oxygen extraction capabilities of the animals. Compared with the endotoxin-alone group, the U-74006F-treated dogs maintained higher mean arterial pressure, cardiac index, stroke volume index, and left ventricular stroke work index and lower pulmonary vascular resistance. They also showed a higher fractional blood flow to mesenteric and renal beds. Endotoxin administration increased whole body critical oxygen delivery (DO2crit) from 7.7 +/- 2.4 to 12.0 +/- 1.9 ml.kg-1.min-1 (P < 0.05), but U-74006F decreased DO2crit to 7.8 +/- 2.0 ml.kg-1.min-1 (P < 0.05 vs. endotoxin alone). Endotoxin decreased critical oxygen extraction ratio (O2ERcrit) from 75.0 +/- 12.7 to 44.3 +/- 8.7% (P < 0.05), but U-74006F increased O2ERcrit to 64.1 +/- 11.2% (P < 0.05 vs. endotoxin alone). U-74006F also decreased endotoxin-induced elevation of mesenteric and renal DO2crit and markedly increased regional O2ERcrit. Systemic and regional blood lactate concentrations were lower in the U-74006F-treated animals.(ABSTRACT TRUNCATED AT 250 WORDS)

scholarly journals Right ventricular systolic dysfunction but not dilatation correlates with prognostically significant reductions in exercise capacity in repaired Tetralogy of Fallot

2019 ◽  
Vol 21 (8) ◽  
pp. 906-913 ◽  
Author(s):  
Imran Rashid ◽  
Adil Mahmood ◽  
Tevfik F Ismail ◽  
Shamus O’Meagher ◽  
Shelby Kutty ◽  
...  
Keyword(s):  
Right Ventricular ◽  
Tetralogy Of Fallot ◽  
Exercise Capacity ◽  
Multivariable Analysis ◽  
Cardiopulmonary Exercise Testing ◽  
Pulmonary Regurgitation ◽  
Left Ventricular ◽  
Left Ventricular Ejection ◽  
Peak Vo2 ◽  
Repaired Tetralogy Of Fallot

Abstract Aims The optimal timing for pulmonary valve replacement in asymptomatic patients with repaired Tetralogy of Fallot (rTOF) and pulmonary regurgitation remains uncertain but is often guided by increases in right ventricular (RV) end-diastolic volume. As cardiopulmonary exercise testing (CPET) performance is a strong prognostic indicator, we assessed which cardiovascular magnetic resonance (CMR) parameters correlate with reductions in exercise capacity to potentially improve identification of high-risk patients. Methods and results In all, 163 patients with rTOF (mean age 24.5 ± 10.2 years) who had previously undergone CMR and standardized CPET protocols were included. The indexed right and left ventricular end-diastolic volumes (RVEDVi, LVEDVi), right and left ventricular ejection fractions (RVEF, LVEF), indexed RV stroke volume (RVSVi), and pulmonary regurgitant fraction (PRF) were quantified by CMR and correlated with CPET-determined peak oxygen consumption (VO2) or peak work. On univariable analysis, there was no significant correlation between RVEDVi and PRF with peak VO2 or peak work (% Jones-predicted). In contrast, RVEF and RVSVi had significant correlations with both peak VO2 and peak work that remained significant on multivariable analysis. For a previously established prognostic peak VO2 threshold of &lt;27 mL/kg/min, receiver-operating characteristic curve analysis demonstrated a Harrell’s c of 0.70 for RVEF (95% confidence interval 0.61–0.79) with a sensitivity of 88% for RVEF &lt;40%. Conclusion In rTOF, CMR indices of RV systolic function are better predictors of CPET performance than RV size. An RVEF &lt;40% may be useful to identify prognostically significant reductions in exercise capacity in patients with varying degrees of RV dilatation.

scholarly journals Speckle tracking echocardiography before and after Surgical pulmonary valve replacement in Tetralogy of Fallot patients: Can STE elucidate early left ventricular dysfunction?

2020 ◽  
Author(s):  
Gholam Hossein Ajami ◽  
Fathi Alwasabi ◽  
Nima Mehdizadegan ◽  
Mohammad Reza Edraki ◽  
Hamid Mohammadi ◽  
...  
Keyword(s):  
Tetralogy Of Fallot ◽  
Speckle Tracking ◽  
Speckle Tracking Echocardiography ◽  
Pulmonary Valve ◽  
Pulmonary Valve Replacement ◽  
Left Ventricular ◽  
Control Group ◽  
Lv Function ◽  
Repaired Tetralogy Of Fallot ◽  
2D Echocardiography

Abstract Objectives: TOF is the most common cyanotic CHD. We investigated left ventricular (LV) function after surgical pulmonary valve replacement (sPVR) in patients with repaired Tetralogy of Fallot (rTOF) by Speckle Tracking Echocardiography (STE).Methods: 58 volunteers participated in this study who divided into 3 groups including 22 PVR patients (mean age 18.96±7 year), 16 repaired Tetralogy of Fallot and 20 healthy age match control. For all patients, we performed 2D echocardiography and STE.Results: 2D echocardiography in all groups showed normal LV ejection fraction without a significant statistical difference (64% sPVR, 60% in repaired Tetralogy of Fallot and 62.5% in the control group). However, the mean global longitudinal strains (GLS) of LV were significantly reduced in both sPVR (-17.5±2.5%) and repaired Tetralogy of Fallot (-17.1±4.7%) patients rather than control group (-20.2±0.7%) (P = 0.003). But GLS had no statistically significant difference between repaired Tetralogy of Fallot and sPVR patients (P=0.9). Segmental analysis of longitudinal strain (LS) showed a significant decrease in sPVR patients and repaired Tetralogy of Fallot group in basal anterior, basal septal, basal anterolateral segments, mid-anterior and anterolateral segments. Except for lower LS in the apical-anteroseptal segment, this level was mostly spared in both sPVR and repaired Tetralogy of Fallot patients.Conclusion: LVEF was within normal range after sPVR patients, but the pattern of impaired segmental LS and GLS did not change as compared with rTOF. Surgical PVR in patients with repaired TOF may not have a significant effect on the improvement of LV function assessed by STE. LV damage which happens during surgical correction of TOF may have a permanent deteriorating effect on LV function.

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