Prolongation of the QT-corrected interval during dobutamine stress echocardiography: a marker for ischemia

T, Vora; Pendyala, Prashant; López‐Candales, Angel

doi:10.1097/01.mca.0000063502.13456.44

Cited by 3 publications

(5 citation statements)

References 17 publications

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“…1G). Overall, these results demonstrate the ability to induce cardiovascular stress and acute myocardial ischemia, with observed physiological feature changes similar to human myocardial ischemia ( 4 , 8 , 10 , 11 , 31 , 32 , 41 , 42 ).…”

Section: Resultssupporting

confidence: 55%

“…1C) ( 40 ), and corrected QT (QTc) prolongation (using Bazett’s formula; an electrophysiological abnormality occurring during acute myocardial ischemia, related to proarrhythmic states; Fig. 1D) ( 41 , 42 ). The combined D + NE infusion tended to have the largest effect.…”

Section: Resultsmentioning

confidence: 99%

“…2) Related to Fig. 1D: QTc across time was not a component of the overall 13-element feature vector but was calculated offline using the emka ecgAUTO software and Bazett’s formula [similar to previous studies ( 41 , 42 )]: QTc = (QT interval; milliseconds)/√ (RR interval; milliseconds).…”

Section: Methodsmentioning

confidence: 99%

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Dynamic detection and reversal of myocardial ischemia using an artificially intelligent bioelectronic medicine

et al. 2022

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Myocardial ischemia is spontaneous, frequently asymptomatic, and contributes to fatal cardiovascular consequences. Importantly, myocardial sensory networks cannot reliably detect and correct myocardial ischemia on their own. Here, we demonstrate an artificially intelligent and responsive bioelectronic medicine, where an artificial neural network (ANN) supplements myocardial sensory networks, enabling reliable detection and correction of myocardial ischemia. ANNs were first trained to decode spontaneous cardiovascular stress and myocardial ischemia with an overall accuracy of ~92%. ANN-controlled vagus nerve stimulation (VNS) significantly mitigated major physiological features of myocardial ischemia, including ST depression and arrhythmias. In contrast, open-loop VNS or ANN-controlled VNS following a caudal vagotomy essentially failed to reverse cardiovascular pathophysiology. Last, variants of ANNs were used to meet clinically relevant needs, including interpretable visualizations and unsupervised detection of emerging cardiovascular stress. Overall, these preclinical results suggest that ANNs can potentially supplement deficient myocardial sensory networks via an artificially intelligent bioelectronic medicine system.

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Section: Resultssupporting

confidence: 55%

Section: Resultsmentioning

confidence: 99%

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Dynamic detection and reversal of myocardial ischemia using an artificially intelligent bioelectronic medicine

et al. 2022

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“…Local QTc prolongation indicates the presence of viable myocardium in the affected areas ( Ieva et al, 2016 ). Furthermore, QTc prolongation has been shown to be an early marker of myocardial ischemia at admission ( Kenigsberg et al, 2007 ; Jiménez-Candil et al, 2008 ) or in stress-tests ( Guideri et al, 1995 ; Arab et al, 2000 ; Vora et al, 2003 ).…”

Section: Discussionmentioning

confidence: 99%

Prolonged repolarization in the early phase of ischemia is associated with ventricular fibrillation development in a porcine model

et al. 2023

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Background: Repolarization prolongation can be the earliest electrophysiological change in ischemia, but its role in arrhythmogenesis is unclear. The aim of the present study was to evaluate the early ischemic action potential duration (APD) prolongation concerning its causes, expression in ECG and association with early ischemic ventricular fibrillation (phase 1A VF).Methods: Coronary occlusion was induced in 18 anesthetized pigs, and standard 12 lead ECG along with epicardial electrograms were recorded. Local activation time (AT), end of repolarization time (RT), and activation-repolarization interval (ARIc) were determined as dV/dt minimum during QRS-complex, dV/dt maximum during T-wave, and rate-corrected RT–AT differences, respectively. Patch-clamp studies were done in enzymatically isolated porcine cardiomyocytes. IK(ATP) activation and Ito1 inhibition were tested as possible causes of the APD change.Results: During the initial period of ischemia, a total of 11 pigs demonstrated maximal ARIc prolongation >10 ms at 1 and/or 2.5 min of occlusion (8 and 6 cases at 1 and 2.5 min, respectively) followed by typical ischemic ARIc shortening. The maximal ARIc across all leads was associated with VF development (OR 1.024 95% CI 1.003–1.046, p = 0.025) and maximal rate-corrected QT interval (QTc) (B 0.562 95% CI 0.346–0.775, p < 0.001) in logistic and linear regression analyses, respectively. Phase 1A VF incidence was associated with maximal QTc at the 2.5 min of occlusion in ROC curve analysis (AUC 0.867, p = 0.028) with optimal cut-off 456 ms (sensitivity 1.00, specificity 0.778). The pigs having maximal QTc at 2.5 min more and less than 450 ms significantly differed in phase 1A VF incidence in Kaplan-Meier analysis (log-rank p = 0.007). In the patch-clamp experiments, 4-aminopyridine did not produce any effects on the APD; however, pinacidil activated IK(ATP) and caused a biphasic change in the APD with initial prolongation and subsequent shortening.Conclusion: The transiently prolonged repolarization during the initial period of acute ischemia was expressed in the prolongation of the maximal QTc interval in the body surface ECG and was associated with phase 1A VF. IK(ATP) activation in the isolated cardiomyocytes reproduced the biphasic repolarization dynamics observed in vivo, which suggests the probable role of IK(ATP) in early ischemic arrhythmogenesis.

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“…Like isoproterenol, dobutamine infusion could potentially promote torsade de pointes in susceptible patients as previously reported [1]. Both QT interval and QTc interval have been shown to normally shorten during dobutamine stress echocardiography [7]; however, in our patients, dobutamine infusion provoked a moderate shortening of the QT interval by 54 ms and a significant prolongation of the QTc interval by 80 ms, a behavior similar to that shown during exercise in patients with long QT syndrome [2,5]; this may suggest the presence of a form bfrusteQ of inherited long QT syndrome with torsade de pointes as a possible cause for syncope. It is therefore possible that some forms of latent long QT syndrome as other electrical disorders (i.e.…”

mentioning

confidence: 85%

Form “fruste” of long QT syndrome as a possible cause for unexplained syncope revealed by dobutamine infusion

Schläpfer¹,

Gollut²,

Pruvot³

2006

International Journal of Cardiology

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Prolongation of the QT-corrected interval during dobutamine stress echocardiography: a marker for ischemia

Cited by 3 publications

References 17 publications

Dynamic detection and reversal of myocardial ischemia using an artificially intelligent bioelectronic medicine

Dynamic detection and reversal of myocardial ischemia using an artificially intelligent bioelectronic medicine

Prolonged repolarization in the early phase of ischemia is associated with ventricular fibrillation development in a porcine model

Form “fruste” of long QT syndrome as a possible cause for unexplained syncope revealed by dobutamine infusion

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