Abnormalities of the corrected QT interval in familial dysautonomia: An indicator of autonomic dysfunction

Glickstein, Julie S.; Schwartzman, David; Friedman, Deborah; Rutkowski, Monika; Axelrod, Felicia B.

doi:10.1016/s0022-3476(09)90022-1

Cited by 43 publications

(32 citation statements)

References 8 publications

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“…Children with orthostatic positive neurocardiogenic syncope showed a significantly larger QT interval increment than the negative group after bolus injection of isoproterenol (1,4). This supports the theory that altered beta-adrenergic sensitivity exists in children with neurocardiogenic syncope.…”

Section: Discussionsupporting

confidence: 72%

“…It has been reported that children with orthostatic positive neurocardiogenic syncope showed a different QT response to beta-adrenergic stimulation of isoproterenol (1). Autonomic dysfunction has been postulated as a possible underlying mechanism for syncopal episodes; cardiac and peripheral vascular autonomic control appeared to play a role (2)(3)(4).…”

Section: Introductionmentioning

confidence: 99%

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The Effect of beta Adrenergic Stimulation on QT and QTc Interval in Syncope Children with or without Coexisting Ventricular Arrhythmias

et al. 2003

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We investigated the effect of beta-adrenergic stimulation on the heart rate and QT interval in syncope children with or without coexisting ventricular arrhythmias (VA). Of the 24 children who presented with syncope or presyncope and showed negative tilt test, 13 were classified into a group with VA and the remaining 11 without VA. The provocative test was performed in bolus infusion and continuous infusion. RR, QT, and QTc intervals on routine 12-lead surface electrocardiogram were obtained during each stage of isoproterenol infusion. In all cases, malignant ventricular arrhythmia and syncope were not induced by isoproterenol provocative test. RR and QT intervals were shortened and QTc intervals were prolonged as the isoproterenol dose was increased in both groups and methods. The QTc interval reached its peak level after the bolus injection of 1.0 g and during the continuous infusion of 0.03 g/kg/min. The two groups showed no significant difference in the QTc interval change according to the infusion methods. This study indicates that changes in the heart rate and QT interval by beta-adrenergic stimulation were not different according to the coexisting ventricular arrhythmias in syncope children with negative head-up tilt test.

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Section: Discussionsupporting

confidence: 72%

Section: Introductionmentioning

confidence: 99%

The Effect of beta Adrenergic Stimulation on QT and QTc Interval in Syncope Children with or without Coexisting Ventricular Arrhythmias

et al. 2003

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“…Patients exhibit sympathovagal imbalance which is clinically manifested as abnormal blood pressure (BP) and heart rate (HR) response to pos tural change and stress [2][3][4], Abnormalities in cardiovas cular regulation cause pervasive effects on overall func-tion and intrinsic abnormalities of heart rate control may be one of the major factors affecting survival [5][6][7], Retro spective analysis of cause of death in 48 patients with FD [6] revealed 23% of the total group had unexplained "sleep death' and 17% had sudden daytime cardiorespiratory arrest. Individuals in the latter group frequently had a his tory of the terminal episode being precipitated by an event that could result in vagal stimulation such as postu ral change, morning micturition, and nasogastric tube placement.…”

Section: Introductionmentioning

confidence: 99%

Electrocardiographic Measures and Heart Rate Variability in Patients with Familial Dysautonomia

et al. 1997

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Cardiovascular abnormalities are prominent in the genetic disorder, familial dysautonomia (FD). To determine if autonomic dysfunction involves cardiac, as well as peripheral vascular integrity, noninvasive tests were performed in 10 FD patients and 8 healthy control subjects while supine and at 90° tilt. Simultaneous blood pressure (BP) and heart rate (HR) and QTc were obtained, while performing signal-averaged electrocardiography (SAECG) and heart rate variability (HRV). FD subjects were tested on 2 separate days, before and 1 h after oral fludrocortisone or midodrine; controls were tested once without medication. With tilt, all FD subjects decreased mean BP > 24 mm Hg by 5 min. On SAECG, 70% of supine FD subjects had a prolonged tQRS; only 2 FD subjects shortened tQRS with tilt. The QTc interval was prolonged ( > 440 ms) in 2 supine FD subjects; with tilt, the QTc prolonged in a third. Frequency domain analysis of HRV revealed that mid (MF) and high frequency band areas were significantly decreased when supine, but not when upright. On time domain analysis, the pNN50 was significantly decreased in FD subjects (8.9 ± 1.7 vs. 17.7 ± 3.6%, p < 0.01). Fiudrocortisone lowered supine BP and HR and increased supine MF area. Midodrine raised supine and erect BP, lowered erect HR, and shortened erect QTc. Although all FD subjects have abnormal orthostatic BP and HR responses, cardiac tone, as assessed by electrocardiographic and HRV responses, varies. Prolongation of the tQRS appears to be a sensitive but not specific indicator of autonomic dysfunction. QTc prolongation may indicate more extensive sympathetic dysfunction. HRV data suggest some FD patients have abnormalities in parasympathetic, as well as sympathetic, cardiac tone.

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“…QTc is prolonged in patients with diabetic autonomic neuropathy 6 and in patients with familial dysautonomia. 7 Similarly, QTc is increased in patients with primary autonomic failure due to pure autonomic failure (PAF) or multiple system atrophy (MSA). 8 However, studies using pharmacological blockade of ␤-adrenoreceptors alone or in combination with atropine have not consistently shown a similar increase in QT interval length.…”

mentioning

confidence: 99%

Modulation of QT Interval During Autonomic Nervous System Blockade in Humans

Diedrich¹,

Jordan²,

Shannon³

et al. 2002

Circulation

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Background-It is thought that the autonomic nervous system modulates QT interval, but traditional autonomic blockade combining propranolol and atropine has produced conflicting results. We used the alternative approach of interrupting neurotransmission at the level of autonomic ganglia to determine its effect on the QT interval. Methods and Results-We infused trimethaphan at increasing doses (0.5 to 10 mg/min IV) while monitoring heart rate, heart rate variability spectra, QT interval, and blood pressure in 10 normal volunteers, 9 patients with multiple system atrophy (MSA), and 8 patients with pure autonomic failure (PAF). The QT interval was corrected for heart rate using Bazett's formula (QTc). Patients with PAF had very low heart rate variability and a prolonged QTc at baseline (465Ϯ8 ms) compared with patients with MSA (448Ϯ6 ms) and normal subjects (432Ϯ6 ms). In normal subjects, trimethaphan dose-dependently prolonged QTc (to 469Ϯ7 ms), decreased RR interval (995Ϯ45 to 670Ϯ35 ms), and abolished heart rate variability. In MSA patients, trimethaphan also prolonged QTc (to 463Ϯ7 ms) and reduced heart rate variability but did not significantly change RR interval (from 813Ϯ38 to 801Ϯ39). Conclusions-Autonomic blockade prolongs QT interval in normal subjects to a similar duration as in PAF patients.Furthermore, blocking residual autonomic tone in PAF patients is associated with a further increase in QT interval length. Patients with MSA have greater residual sympathetic tone and greater prolongation of the QT interval during ganglionic blockade than PAF patients.

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Abnormalities of the corrected QT interval in familial dysautonomia: An indicator of autonomic dysfunction

Cited by 43 publications

References 8 publications

The Effect of beta Adrenergic Stimulation on QT and QTc Interval in Syncope Children with or without Coexisting Ventricular Arrhythmias

The Effect of beta Adrenergic Stimulation on QT and QTc Interval in Syncope Children with or without Coexisting Ventricular Arrhythmias

Electrocardiographic Measures and Heart Rate Variability in Patients with Familial Dysautonomia

Modulation of QT Interval During Autonomic Nervous System Blockade in Humans

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