Relationship Between QT Interval and Outcome in Low‐Flow Low‐Gradient Aortic Stenosis With Low Left Ventricular Ejection Fraction

Dahou, Abdellaziz; Toubal, Oumhani; Clavel, Marie‐Annick; Beaudoin, Jonathan; Magné, Julien; Mathieu, Patrick; Philippon, François; Dumesnil, Jean G.; Puri, Rishi; Ribeiro, Henrique Barbosa; Larose, Éric; Rodés‐Cabau, Josep

doi:10.1161/jaha.116.003980

Cited by 10 publications

(7 citation statements)

References 29 publications

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“…This was further supported by a prolonged QTc interval in SPF animals (Table 1). A prolonged QTc in animal models and humans have been associated with lower stroke volume, compromised left ventricular function and increased mortality 16,17 . Our interpretation of a failing cardiovascular system in SPF animals was further supported by the presence of ventricular arrhythmias (Table 1, Fig.…”

Section: Discussionmentioning

confidence: 99%

Conventional and Specific-Pathogen Free Rats Respond Differently to Anesthesia and Surgical Trauma

Letson

Morris

Biroš

et al. 2019

Sci Rep

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Specific-pathogen free (SPF) animals were introduced in the 1960s to minimize disease and infection as variables in biomedical research. Our aim was to examine differences in physiological response in rat colonies bred and housed in a conventional versus SPF facility, and implications for research. Sprague-Dawley rats were anesthetized and catheterized for blood and pressure monitoring, and electrocardiogram (ECG) leads implanted. Hematology was assessed, and coagulation profile using rotational thromboelastometry. Health screening was outsourced to Cerberus Sciences. SPF rats had significantly lower pulse pressure (38% decrease), arrhythmias and prolonged QTc (27% increase) compared to conventional rats. No arrhythmias were found in conventional rats. SPF rats had significantly higher white cell, monocyte, neutrophil and lymphocyte counts, and were hyperfibrinolytic, indicated by EXTEM maximum lysis >15%. Independent assessment revealed similar pathogen exclusion between colonies, with the exception of Proteus in SPF animals. Returning to a conventional facility restored normal host physiology. We conclude that SPF animals displayed an abnormal hemodynamic, hematological and hemostatic phenotype in response to anesthesia and surgery, and provide a number of recommendations to help standardize research outcomes and translation.

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Section: Discussionmentioning

confidence: 99%

Conventional and Specific-Pathogen Free Rats Respond Differently to Anesthesia and Surgical Trauma

Letson

Morris

Biroš

et al. 2019

Sci Rep

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“…Left ventricular systolic dysfunction has been linked to a prolonged QT interval (Baumgartner et al, 2007; Dahou et al, 2016; Davey, 2000; Davey et al, 2000; Lu et al, 2017). The degree of prolongation of the QT interval is also associated with the development of new left ventricular systolic dysfunction in patients with preserved left ventricular systolic function after permanent pacemaker implantation (Cho et al, 2016).…”

Section: Discussionmentioning

confidence: 99%

“…The degree of prolongation of the QT interval is also associated with the development of new left ventricular systolic dysfunction in patients with preserved left ventricular systolic function after permanent pacemaker implantation (Cho et al, 2016). Coexistence of moderate to severe left ventricular systolic dysfunction and prolonged QT interval is associated with higher mortality (Dahou et al, 2016; Padmanabhan et al, 2003). Also, our results revealed that the changes in the LVSP obtained in isolated hearts are accompanied by a prolonged QT interval in α7 −/− mice.…”

Section: Discussionmentioning

confidence: 99%

α7 nicotinic receptors play a role in regulation of cardiac hemodynamics

Targosova

Kučera

Fazekáš

et al. 2023

Journal of Neurochemistry

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The α7 nicotinic receptors (NR) have been confirmed in the heart but their role in cardiac functions has been contradictory. To address these contradictory findings, we analyzed cardiac functions in α7 NR knockout mice (α7−/−) in vivo and ex vivo in isolated hearts. A standard limb leads electrocardiogram was used, and the pressure curves were recorded in vivo, in Arteria carotis and in the left ventricle, or ex vivo, in the left ventricle of the spontaneously beating isolated hearts perfused following Langedorff's method. Experiments were performed under basic conditions, hypercholinergic conditions, and adrenergic stress. The relative expression levels of α and β NR subunits, muscarinic receptors, β1 adrenergic receptors, and acetylcholine life cycle markers were determined using RT‐qPCR. Our results revealed a prolonged QT interval in α7−/− mice. All in vivo hemodynamic parameters were preserved under all studied conditions. The only difference in ex vivo heart rate between genotypes was the loss of bradycardia in prolonged incubation of isoproterenol‐pretreated hearts with high doses of acetylcholine. In contrast, left ventricular systolic pressure was lower under basal conditions and showed a significantly higher increase during adrenergic stimulation. No changes in mRNA expression were observed. In conclusion, α7 NR has no major effect on heart rate, except when stressed hearts are exposed to a prolonged hypercholinergic state, suggesting a role in acetylcholine spillover control. In the absence of extracardiac regulatory mechanisms, left ventricular systolic impairment is revealed.image

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“… 34 – 39 In particular, a relationship was observed between outcome and QTc in severe AS with low flow, low gradient, reduced ejection fraction, and mortality. 40 Obviously, the QTc measurement does not make any sense in the presence of complete left bundle branch block and, in such a case, the use of the JTc interval is more appropriate. 20 , 21 , 41 The QRS duration, the transition QRS zone, the electrical left ventricular hypertrophy, and the frontal QRS-T angle are influenced by myocardial mass and fibrosis.…”

Section: Discussionmentioning

confidence: 99%

Possible predictive role of electrical risk score on transcatheter aortic valve replacement outcomes in older patients: preliminary data

Piccirillo¹,

Moscucci²,

Mastropietri³

et al. 2018

CIA

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ObjectivesTo evaluate the predicative power of the electrical risk score (ERS), a noninvasive and inexpensive test obtained by means of a standard 12-lead electrocardiogram (ECG), in a cohort of elderly patients who had undergone transcatheter aortic valve replacement (TAVR).MethodsSurvivors and non-survivors after TAVR at 1-year follow-up were compared in respect to the pre-procedural ERS as well as a number of other clinical and instrumental variables. ERS is composed of seven simple ECG markers: heart rate (>75 bpm); QRS duration (>110 ms); left ventricular hypertrophy (Sokolow–Lyon criteria); delayed QRS transition zone (≥ V4); frontal QRS-T angle (>90°); long QTBazett (>450 ms for men and >460 in women) or JTBazett (330 ms for men and >340 ms for women); and long Tpeak to Tend interval (Tp-e) (>89 ms). The trial was registered in ClinicalTrials.gov as NCT03145376.ResultsA total of 40 patients were evaluated. During the follow-up, the all-cause mortality rate was 25% (ten patients) with 15% of cardiovascular death (six patients). The ERS was the strongest predictor of all-cause (odds ratio 3.73, 95% CI: 1.44–9.66, P<0.05) or cardiovascular (odds ratio 3.95, 95% CI: 1.09–14.27, P<0.05) mortality. Receiver operating characteristic curves showed that ERS had the widest significant sensitivity-specificity area under the curve (AUC) predicting all-cause (AUC: 0.855, P<0.05) or cardiovascular mortality (AUC: 0.908, P<0.05).ConclusionERS seems to be a useful noninvasive tool able to stratify the risk of mortality in 1-year follow-up of TAVR patients. These findings, however, require larger trials to be confirmed.

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Relationship Between QT Interval and Outcome in Low‐Flow Low‐Gradient Aortic Stenosis With Low Left Ventricular Ejection Fraction

Cited by 10 publications

References 29 publications

Conventional and Specific-Pathogen Free Rats Respond Differently to Anesthesia and Surgical Trauma

Conventional and Specific-Pathogen Free Rats Respond Differently to Anesthesia and Surgical Trauma

α7 nicotinic receptors play a role in regulation of cardiac hemodynamics

Possible predictive role of electrical risk score on transcatheter aortic valve replacement outcomes in older patients: preliminary data

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