Prognostic value of QT interval and QT dispersion in patients with left ventricular systolic dysfunction: Results from a cohort of 2265 patients with an ejection fraction of ≤40%

Padmanabhan, Sriram; Silvet, Helme; Amin, Jatin; Pai, Ramdas G.

doi:10.1067/mhj.2003.59

Cited by 63 publications

(46 citation statements)

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“…QT-interval measurements have been shown to be highly reproducible, 44 but the need for rate correction with suboptimal formulas limits the comparability of QT data in populations. QT prolongation has been associated with mortality in some observational studies in patients with depressed left ventricular function 45 but not in others. 46,47 Although a relation of QT interval to overall cardiovascular risk is demonstrable in large populations, 48,49 studies evaluating the QT interval for prediction of SCD risk in individuals who do not have long-QT syndrome have demonstrated mixed results but generally link prolonged QT intervals with increased risk.…”

Section: Qt Interval and Qt Dispersionmentioning

confidence: 99%

See 1 more Smart Citation

American Heart Association/American College of Cardiology Foundation/Heart Rhythm Society Scientific Statement on Noninvasive Risk Stratification Techniques for Identifying Patients at Risk for Sudden Cardiac Death

Goldberger¹,

Cain²,

Hohnloser³

et al. 2008

Circulation

780

361

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Section: Qt Interval and Qt Dispersionmentioning

confidence: 99%

“…It has been associated with increased mortality in some observational studies. 45,51,52 Several recent studies have found no relation between QT dispersion and outcome. 24,46,[53][54][55] Lack of a clear physiological correlate further clouds the utility of this parameter.…”

Section: Qt Interval and Qt Dispersionmentioning

confidence: 99%

American Heart Association/American College of Cardiology Foundation/Heart Rhythm Society Scientific Statement on Noninvasive Risk Stratification Techniques for Identifying Patients at Risk for Sudden Cardiac Death

Goldberger¹,

Cain²,

Hohnloser³

et al. 2008

Circulation

780

361

View full text Add to dashboard Cite

“…On the other hand, the homogeneous prolongation of the APD may act as an antiarrhythmic factor; however, clinical studies report that prolongation of repolarization is associated with an adverse prognosis in patients with organic heart disease. 31,32 Ample clinical evidence supports the usefulness of -blockade in preventing sudden cardiac death, [33][34][35] and we conjecture that the attenuation of both the transient prolongation and the steady-state shortening of the APD partially explains the effect of -blockade.…”

Section: Discussionmentioning

confidence: 99%

Biphasic Response of Action Potential Duration to Sudden Sympathetic Stimulation in Anesthetized Cats

Tatewaki

Inagaki

Kawada

et al. 2003

Circ J

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espite the tremendous progress in clinical cardiology, sudden cardiac death remains a major unsolved clinical issue. 1,2 As possible mechanisms of sudden cardiac death, certain roles of the sympathetic nervous system have been suggested because there is ample experimental, clinical and therapeutic evidence to support the hypothesis that sympathetic hyperactivity favors the onset of life-threatening arrhythmias. [3][4][5][6] A number of studies have examined how sympathetic nerve activation modulates the electrophysiological characteristics of the heart, especially ventricular repolarization. A shortening of the action potential duration (APD) 7 and refractory period 8,9 following sympathetic nerve stimulation have been reported.Sudden stress is known to immediately evoke life-threatening arrhythmias in subjects who have certain predisposing conditions, 3,10,11 suggesting that sudden sympathetic activation can abruptly render the heart vulnerable. Most previous studies, however, have focused on the steady-state electrophysiological response of the heart to sympathetic activation and the transient electrophysiological response to sympathetic activation remains unclear. In the present study, therefore, we investigated the dynamic response of APD to sudden sympathetic stimulation using monophasic action potential (MAP) recording. Methods Animal PreparationAnimal care was in accordance with the 'Guideline Principles for the Care and Use of Animals in the Field of Physiological Science' approved by Physiological Society of Japan. Experiments were performed on 10 cats of both sexes weighing 2.2-3.8 kg. The cats were anesthetized by intraperitoneal injection of pentobarbital sodium (30-35 mg/kg) and additional anesthetic (pentobarbital sodium 2.0 mg) was injected intravenously as needed to maintain the appropriate level of anesthesia. Cats were intubated using a cuffed endotracheal tube and mechanically ventilated with oxygenated air using a constant volume cycled respirator (Model SN-480-3, Shinano Inc, Tokyo, Japan). Polyethylene catheters were inserted into the femoral artery and vein for blood pressure (BP) recording and administration of fluids and drugs. Physiological saline was infused at a rate of 5 ml/h to replace spontaneous fluid loss. Each cat was placed on a heating pad. Throughout the experiment, body temperature, arterial blood gases and pH were maintained within their respective physiological ranges. A midline cervical incision was made and the bilateral vagal nerves were identified and were severed to eliminate the vagal effects on the heart. Right and left stellate ganglia were exposed by removing part of the second rib on either side and were carefully isolated from the surrounding tissue. The proximal and distal connections were cut to decentralize each ganglion. A pair of platinum electrodes was attached to each of the cardiac sympathetic nerves to provide electrical stimulation. To prevent drying and to provide insulation, the stimulation electrodes and nerves were soaked in a mixture of white petr...

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“…Although the reproducibility of the QT-interval is very high, the need for correction makes it difficult to compare values of this parameter for different patients. There are controversial studies where the QT-interval was related to higher mortality in patient with low EF, but with different results (Brendorp et al, 2001;Padmanabhan et al, 2003). The use of this parameter for risk stratification is not supported.…”

Section: Heterogeneous Ventricular Repolarization 221 Qt-intervalmentioning

confidence: 99%

ICDs and Risk Stratification in Magnetic Field Imaging

Paolo¹,

Toennis²,

Erné³

2011

Cardiac Defibrillation - Mechanisms, Challenges and Implications

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Prognostic value of QT interval and QT dispersion in patients with left ventricular systolic dysfunction: Results from a cohort of 2265 patients with an ejection fraction of ≤40%

Cited by 63 publications

References 0 publications

American Heart Association/American College of Cardiology Foundation/Heart Rhythm Society Scientific Statement on Noninvasive Risk Stratification Techniques for Identifying Patients at Risk for Sudden Cardiac Death

American Heart Association/American College of Cardiology Foundation/Heart Rhythm Society Scientific Statement on Noninvasive Risk Stratification Techniques for Identifying Patients at Risk for Sudden Cardiac Death

Biphasic Response of Action Potential Duration to Sudden Sympathetic Stimulation in Anesthetized Cats

ICDs and Risk Stratification in Magnetic Field Imaging

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