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Induced effects of transcranial magnetic stimulation on the autonomic nervous system and the cardiac rhythm.

Cabrerizo M, Cabrera A, Perez JO, de la Rua J, Rojas N, Zhou Q, Pinzon-Ardila A, Gonzalez-Arias SM, Adjouadi M - ScientificWorldJournal (2014)

Bottom Line: The rTMS activation resulted in a reduction of the RR intervals (cardioacceleration) in most cases.Most of these cases also showed significant changes in the Poincare plot descriptor SD2 (long-term variability), the area under the low frequency (LF) power spectrum density curve, and the low frequency to high frequency (LF/HF) ratio.The RR intervals changed significantly in specific instants of time during rTMS activation showing either heart rate acceleration or heart rate deceleration.

View Article: PubMed Central - PubMed

Affiliation: Center for Advanced Technology and Education, Department of Electrical and Computer Engineering, College of Engineering and Computing, Florida International University (FIU), USA.

ABSTRACT
Several standard protocols based on repetitive transcranial magnetic stimulation (rTMS) have been employed for treatment of a variety of neurological disorders. Despite their advantages in patients that are retractable to medication, there is a lack of knowledge about the effects of rTMS on the autonomic nervous system that controls the cardiovascular system. Current understanding suggests that the shape of the so-called QRS complex together with the size of the different segments and intervals between the PQRST deflections of the heart could predict the nature of the different arrhythmias and ailments affecting the heart. This preliminary study involving 10 normal subjects from 20 to 30 years of age demonstrated that rTMS can induce changes in the heart rhythm. The autonomic activity that controls the cardiac rhythm was indeed altered by an rTMS session targeting the motor cortex using intensity below the subject's motor threshold and lasting no more than 5 minutes. The rTMS activation resulted in a reduction of the RR intervals (cardioacceleration) in most cases. Most of these cases also showed significant changes in the Poincare plot descriptor SD2 (long-term variability), the area under the low frequency (LF) power spectrum density curve, and the low frequency to high frequency (LF/HF) ratio. The RR intervals changed significantly in specific instants of time during rTMS activation showing either heart rate acceleration or heart rate deceleration.

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Related in: MedlinePlus

PQRST waveforms from an electrocardiography device.
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Related In: Results  -  Collection


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fig1: PQRST waveforms from an electrocardiography device.

Mentions: The TMS technology was introduced in the 1980s, and since its introduction, it has been used in clinical care for several neurological disorders [1–4]. The initial intent of this technology was to improve the health of patients with depression as exemplified in studies [5–8]. Its application has now been extended to gauge the merits of magnetic stimulation to other neurological disorders such as epilepsy [9–11], Huntington's disease [12], Parkinson's disease [13], different effects of schizophrenia [14–16], Alzheimer's disease, and effects of aging [17, 18], in patients who have had a stroke [19–21], autism [22], and attention deficit and hyperactivity disorders [23, 24]. These are by no means an exhaustive listing of such noteworthy references, but these are examples of studies that highlight the extensive use of TMS technology. It should be noted that the use of TMS can be performed under two modes of operation, namely, single pulse [25] or repetitive mode of stimulation [26, 27]. Safety measures and ethical considerations in the use of TMS technology are well described in [28, 29]. In many of these disorders, the autonomic symptoms are peculiar and may represent the clinical onset of the disorder. For instance, motor activity and some brain abnormalities are associated with changes in the heart rate rhythm and blood pressure; among those abnormal conditions are epilepsy, stroke, and intense emotional stress. External stimulations with TMS are accompanied with diverse effects depending on the site of stimulation [28, 29]. When applied to the motor cortex, which is accompanied by the contraction of muscles, TMS can alter the heart rate variability (HRV) due to connections between the brain cortex and the autonomic centers [30, 31]. Generally, central nervous system (CNS) activation of motor areas is accompanied by diverse scales of cardiac acceleration mediated by the autonomic nervous system (ANS). The ANS is in turn modified by the reflex activity triggered by feedback of the cardiovascular system and articulation sensors which are stimulated by movement [32]. The brain cortex, the brain stem, and the autonomic nerves can alter the heart function and potentially trigger arrhythmias [33]. Such clinical manifestations in some patients suggest that there is a link between cortical structures and autonomic centers. However, not too many studies refer to this problem; only very few research groups have investigated this phenomenon [29]. For example, it is known that epilepsy alters significantly the heart rhythm [10] and produces prolonged QT intervals, T wave alternans, and ventricular late potentials. During seizures, bradycardia and asystole states can occur in some patients. Stroke can also alter the heart rhythm [34] and intense emotions can disrupt significantly the heart rate and blood pressure of a given patient [35]. An illustration of the PQRST deflections of the heart is given in Figure 1.


Induced effects of transcranial magnetic stimulation on the autonomic nervous system and the cardiac rhythm.

Cabrerizo M, Cabrera A, Perez JO, de la Rua J, Rojas N, Zhou Q, Pinzon-Ardila A, Gonzalez-Arias SM, Adjouadi M - ScientificWorldJournal (2014)

PQRST waveforms from an electrocardiography device.
© Copyright Policy - open-access
Related In: Results  -  Collection

Show All Figures
getmorefigures.php?uid=PMC4127210&req=5

fig1: PQRST waveforms from an electrocardiography device.
Mentions: The TMS technology was introduced in the 1980s, and since its introduction, it has been used in clinical care for several neurological disorders [1–4]. The initial intent of this technology was to improve the health of patients with depression as exemplified in studies [5–8]. Its application has now been extended to gauge the merits of magnetic stimulation to other neurological disorders such as epilepsy [9–11], Huntington's disease [12], Parkinson's disease [13], different effects of schizophrenia [14–16], Alzheimer's disease, and effects of aging [17, 18], in patients who have had a stroke [19–21], autism [22], and attention deficit and hyperactivity disorders [23, 24]. These are by no means an exhaustive listing of such noteworthy references, but these are examples of studies that highlight the extensive use of TMS technology. It should be noted that the use of TMS can be performed under two modes of operation, namely, single pulse [25] or repetitive mode of stimulation [26, 27]. Safety measures and ethical considerations in the use of TMS technology are well described in [28, 29]. In many of these disorders, the autonomic symptoms are peculiar and may represent the clinical onset of the disorder. For instance, motor activity and some brain abnormalities are associated with changes in the heart rate rhythm and blood pressure; among those abnormal conditions are epilepsy, stroke, and intense emotional stress. External stimulations with TMS are accompanied with diverse effects depending on the site of stimulation [28, 29]. When applied to the motor cortex, which is accompanied by the contraction of muscles, TMS can alter the heart rate variability (HRV) due to connections between the brain cortex and the autonomic centers [30, 31]. Generally, central nervous system (CNS) activation of motor areas is accompanied by diverse scales of cardiac acceleration mediated by the autonomic nervous system (ANS). The ANS is in turn modified by the reflex activity triggered by feedback of the cardiovascular system and articulation sensors which are stimulated by movement [32]. The brain cortex, the brain stem, and the autonomic nerves can alter the heart function and potentially trigger arrhythmias [33]. Such clinical manifestations in some patients suggest that there is a link between cortical structures and autonomic centers. However, not too many studies refer to this problem; only very few research groups have investigated this phenomenon [29]. For example, it is known that epilepsy alters significantly the heart rhythm [10] and produces prolonged QT intervals, T wave alternans, and ventricular late potentials. During seizures, bradycardia and asystole states can occur in some patients. Stroke can also alter the heart rhythm [34] and intense emotions can disrupt significantly the heart rate and blood pressure of a given patient [35]. An illustration of the PQRST deflections of the heart is given in Figure 1.

Bottom Line: The rTMS activation resulted in a reduction of the RR intervals (cardioacceleration) in most cases.Most of these cases also showed significant changes in the Poincare plot descriptor SD2 (long-term variability), the area under the low frequency (LF) power spectrum density curve, and the low frequency to high frequency (LF/HF) ratio.The RR intervals changed significantly in specific instants of time during rTMS activation showing either heart rate acceleration or heart rate deceleration.

View Article: PubMed Central - PubMed

Affiliation: Center for Advanced Technology and Education, Department of Electrical and Computer Engineering, College of Engineering and Computing, Florida International University (FIU), USA.

ABSTRACT
Several standard protocols based on repetitive transcranial magnetic stimulation (rTMS) have been employed for treatment of a variety of neurological disorders. Despite their advantages in patients that are retractable to medication, there is a lack of knowledge about the effects of rTMS on the autonomic nervous system that controls the cardiovascular system. Current understanding suggests that the shape of the so-called QRS complex together with the size of the different segments and intervals between the PQRST deflections of the heart could predict the nature of the different arrhythmias and ailments affecting the heart. This preliminary study involving 10 normal subjects from 20 to 30 years of age demonstrated that rTMS can induce changes in the heart rhythm. The autonomic activity that controls the cardiac rhythm was indeed altered by an rTMS session targeting the motor cortex using intensity below the subject's motor threshold and lasting no more than 5 minutes. The rTMS activation resulted in a reduction of the RR intervals (cardioacceleration) in most cases. Most of these cases also showed significant changes in the Poincare plot descriptor SD2 (long-term variability), the area under the low frequency (LF) power spectrum density curve, and the low frequency to high frequency (LF/HF) ratio. The RR intervals changed significantly in specific instants of time during rTMS activation showing either heart rate acceleration or heart rate deceleration.

Show MeSH
Related in: MedlinePlus