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M Takahito D Sone - One of the best experts on this subject based on the ideXlab platform.
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negative participation of the left posterior fascicle in the reentry circuit of verapamil sensitive idiopathic left ventricular tachycardia
Journal of Cardiovascular Electrophysiology, 2012Co-Authors: M Itsuro D Morishima, M Akihiko D Nogami, M Hideyuki D Tsuboi, M Takahito D SoneAbstract:Left posterior fascicle and idiopathic Left VT. The left posterior fascicle may be a bystander of the circuit of verapamil-sensitive idiopathic left ventricular tachycardia. During ventricular tachycardia (VT), 3 sequences of potentials were seen at the left posterior septum: diastolic Purkinje potentials propagating from base to apex and presystolic left posterior fascicular potentials and systolic left ventricular (LV) myocardial potentials propagating in the reverse direction. Selective capture of the left posterior fascicle by the Sinus Beat did not affect the VT cycle length. Entrainment pacing revealed that the retrograde limb of the circuit was not the left posterior fascicle, but the LV myocardium.
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negative participation of the left posterior fascicle in the reentry circuit of verapamil sensitive idiopathic left ventricular tachycardia
Journal of Cardiovascular Electrophysiology, 2012Co-Authors: M Itsuro D Morishima, M Akihiko D Nogami, M Hideyuki D Tsuboi, M Takahito D SoneAbstract:Left Posterior Fascicle and Idiopathic Left VT. The left posterior fascicle may be a bystander of the circuit of verapamil-sensitive idiopathic left ventricular tachycardia. During ventricular tachycardia (VT), 3 sequences of potentials were seen at the left posterior septum: diastolic Purkinje potentials propagating from base to apex and presystolic left posterior fascicular potentials and systolic left ventricular (LV) myocardial potentials propagating in the reverse direction. Selective capture of the left posterior fascicle by the Sinus Beat did not affect the VT cycle length. Entrainment pacing revealed that the retrograde limb of the circuit was not the left posterior fascicle, but the LV myocardium. (J Cardiovasc Electrophysiol, Vol. 23, pp. 556-559, May 2012)
M Itsuro D Morishima - One of the best experts on this subject based on the ideXlab platform.
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negative participation of the left posterior fascicle in the reentry circuit of verapamil sensitive idiopathic left ventricular tachycardia
Journal of Cardiovascular Electrophysiology, 2012Co-Authors: M Itsuro D Morishima, M Akihiko D Nogami, M Hideyuki D Tsuboi, M Takahito D SoneAbstract:Left posterior fascicle and idiopathic Left VT. The left posterior fascicle may be a bystander of the circuit of verapamil-sensitive idiopathic left ventricular tachycardia. During ventricular tachycardia (VT), 3 sequences of potentials were seen at the left posterior septum: diastolic Purkinje potentials propagating from base to apex and presystolic left posterior fascicular potentials and systolic left ventricular (LV) myocardial potentials propagating in the reverse direction. Selective capture of the left posterior fascicle by the Sinus Beat did not affect the VT cycle length. Entrainment pacing revealed that the retrograde limb of the circuit was not the left posterior fascicle, but the LV myocardium.
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negative participation of the left posterior fascicle in the reentry circuit of verapamil sensitive idiopathic left ventricular tachycardia
Journal of Cardiovascular Electrophysiology, 2012Co-Authors: M Itsuro D Morishima, M Akihiko D Nogami, M Hideyuki D Tsuboi, M Takahito D SoneAbstract:Left Posterior Fascicle and Idiopathic Left VT. The left posterior fascicle may be a bystander of the circuit of verapamil-sensitive idiopathic left ventricular tachycardia. During ventricular tachycardia (VT), 3 sequences of potentials were seen at the left posterior septum: diastolic Purkinje potentials propagating from base to apex and presystolic left posterior fascicular potentials and systolic left ventricular (LV) myocardial potentials propagating in the reverse direction. Selective capture of the left posterior fascicle by the Sinus Beat did not affect the VT cycle length. Entrainment pacing revealed that the retrograde limb of the circuit was not the left posterior fascicle, but the LV myocardium. (J Cardiovasc Electrophysiol, Vol. 23, pp. 556-559, May 2012)
Kyoungmin Park - One of the best experts on this subject based on the ideXlab platform.
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is the stroke volume during post ectopic Beat associated with ventricular premature complex related symptoms
Europace, 2018Co-Authors: Hye Bin Gwag, Eun Kyoung Kim, Jin Kyung Hwang, Seungjung Park, June Soo Kim, Kyoungmin ParkAbstract:Aims This study aimed to investigate if increased stroke volume (SV) after a ventricular premature complex (VPC) was related to VPC-related symptoms. Methods and results We selected patients having an isolated VPC during echocardiography from a prospective registry that included patients with a structurally normal heart and 24-h VPC >1%. Patients were divided into two groups according to the presence or absence of VPC-related symptoms (skipped Beat or palpitation) when VPC occurred. Left ventricular (LV) volumes and time-velocity integral (TVI) at the LV outflow tract were measured during the preceding Sinus Beat, VPC, and post-ectopic Sinus Beat. Percent LV SV of the VPC and post-ectopic Sinus Beat were calculated by dividing each SV by the SV of the preceding Sinus Beat. A total of 47 patients were eligible. Most patients had VPC with left bundle branch block morphology and inferior axis. Patients in the symptom (+) group had a significantly lower SV, %LV SV, and TVI during post-ectopic Sinus Beat than those in the symptom (-) group. The sum of SVs during VPC and post-ectopic Beat was significantly lower in symptomatic patients than non-symptomatic patients (103.4 mL vs. 125.1 mL, P = 0.02), while the sum of %LV SVs during VPC and post-ectopic Beat tended to be lower in patients with symptoms than those without symptoms (P = 0.08). The sum of %LV SVs during VPC and post-VPC was positively correlated with coupling interval (CI) and CI ratio. Conclusion Ventricular premature complex-related symptoms may not be associated with the amount of post-VPC SV.
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coupling interval ratio is associated with ventricular premature complex related symptoms
Korean Circulation Journal, 2015Co-Authors: Kyoungmin Park, Jin Kyung Hwang, Seungjung Park, Kwang Jin Chun, June Soo KimAbstract:BACKGROUND AND OBJECTIVES: Frequent ventricular premature complex (VPC) is one of the most common arrhythmia syndromes. Symptoms observed frequently with this arrhythmia syndrome remain limited. We sought to identify predictors of VPC-related symptoms by analyzing demographic information, VPC burden, and VPC surface electrocardiogram characteristics. SUBJECTS AND METHODS: We prospectively enrolled 109 patients with idiopathic outflow tract VPCs (63 males, 49±16 years old). They were divided into Group A (n=30, without VPC-related symptoms of palpitations or "dropped Beats") and Group B (n=79, with VPC-related symptoms). Measured parameters were Sinus and VPC QRS width, coupling interval (CI) between the previous Sinus Beat and VPC, CI ratio (%, CI/Sinus cycle length), post-VPC CI and CI ratio, and VPC amplitude. RESULTS: Both groups had similar age (p=0.22), daily VPC burden (p=0.15), and VPC site of origin (p=0.36). The VPC CI ratio was higher in Group B (60±15%) than in Group A (49±22%) (p=0.01). CONCLUSION: VPC-related symptoms are associated with a higher VPC CI ratio (>50%). The physiologic basis for these results deserves further study.
Bruce B Lerman - One of the best experts on this subject based on the ideXlab platform.
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heart rate changes preceding ventricular ectopy in patients with ventricular tachycardia caused by reentry triggered activity and automaticity
American Heart Journal, 1998Co-Authors: Kenneth M Stein, Labros A Karagounis, Jeffrey L Anderson, Steven M Markowitz, Bruce B LermanAbstract:Abstract Objectives Although enhanced sympathetic tone is thought to be proarrhythmic and β-blockade reduces the risk of sudden cardiac death in survivors of myocardial infarction, the role of the autonomic nervous system in triggering spontaneous ventricular ectopy and ventricular tachycardia (VT) has not been fully elucidated. The purpose of this study was to compare and contrast autonomic tone preceding spontaneous ventricular arrhythmias in patients with reentrant, triggered, and automatic forms of VT. Background The prevailing model of reentrant VT is based on a triggering Beat interacting with a fixed substrate. Within this model, cyclic fluctuations in autonomic tone comprise a "third factor" that may initiate the triggering extrasystoles as well as alter the substrate, facilitating perpetuation of tachycardia. Consistent with this model, adrenergic stimulation can facilitate the induction of reentrant arrhythmias as well as arrhythmias resulting from enhanced automaticity and those caused by triggered activity resulting from cyclic adenosine monophosphate–dependent delayed afterdepolarizations. Methods and Results On the basis of the results at electrophysiologic study, 26 patients with coronary artery disease were identified as having reentrant VT, 11 were identified as having idiopathic VT caused by triggered activity, and 4 were identified as having idiopathic VT caused by enhanced automaticity. Each patient underwent 24-hour electrocardiographic monitoring, and the mean Sinus R-R intervals immediately preceding each Sinus Beat as well as the 15 Beats preceding Sinus Beats, premature ventricular contractions (VPCs), and complex ventricular ectopy (couplet/nonsustained VT) were computed. In addition, high-frequency heart rate variability was determined. Heart rate accelerated before spontaneous ventricular ectopy for all three arrhythmia mechanisms. R-R intervals preceding episodes of complex ventricular ectopy were significantly shorter than the corresponding intervals preceding single VPCs in patients with triggered VT [ p = 0.006 and 0.01, R-R(-1) and R-R(-15), respectively] and in those with reentrant VT ( p = 0.007 and p = 0.05). There were no corresponding differences in high-frequency heart rate variability. R-R intervals preceding single VPCs were significantly shorter than the corresponding intervals preceding Sinus Beats in patients with automatic VT ( p = 0.0004 and 0.0001, respectively), which was accompanied by a small reduction in high-frequency heart rate variability ( p = 0.04). Conclusions Heart rate accelerates before spontaneous ventricular ectopy in patients with VT. The acceleration is disproportionate to parasympathetic withdrawal, implicating increased endogenous sympathetic tone in the genesis of spontaneous ventricular arrhythmias caused by all three electrophysiologic mechanisms: reentry, triggered activity, and automaticity. (Am Heart J 1998;136:425-34.)
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fractal clustering of ventricular ectopy correlates with sympathetic tone preceding ectopic Beats
Circulation, 1995Co-Authors: Kenneth M Stein, Labros A Karagounis, Jeffrey L Anderson, Paul Kligfield, Bruce B LermanAbstract:Background Fractal geometric analysis of ventricular ectopy yields a fractal dimension, which can range from zero to one and is inversely related to clustering of ventricular premature contractions (VPCs). Low values of this fractal dimension, which reflect significantly nonuniform distributions of ventricular ectopy, are found in patients with life-threatening ventricular arrhythmias and predict adverse outcomes in selected patients with congestive heart failure and with mitral regurgitation. However, the physiological mechanism and correlates of the fractal dimension are unknown. Methods and Results To explore the physiological correlates of clustered ventricular ectopy, we studied 30 patients with a history of sustained ventricular tachycardia or ventricular fibrillation who had inducible sustained monomorphic ventricular tachycardia during electrophysiological study and also underwent drug-free 24-hour ambulatory ECG. In addition to fractal dimension (determined by use of our previously described algorithm), we measured the mean RR interval (±SD) for all Sinus Beats preceding a Sinus Beat and for all Sinus Beats preceding a single VPC and the mean root-mean-square difference (RMSSD) of all windows of 15 successive RR intervals (excluding ectopic Beats) preceding a Sinus Beat and preceding a single VPC. Based on the directional changes of mean RR (a measure of both sympathetic and parasympathetic tone) and of RMSSD (a measure of parasympathetic tone), each patient’s inferred relative sympathetic tone preceding ventricular ectopy was classified as increased, unchanged, or decreased. If these values changed concordantly, relative sympathetic tone was indeterminate. Fractal dimension did not correlate with the mean RR interval, SD of the RR interval, or RMSSD preceding Sinus Beats or preceding VPCs (all P >.10). In 20 patients, fractal dimension was significantly lower among those with increased relative sympathetic tone (n=14) than those with unchanged or decreased sympathetic tone (n=6, P =.008). Ten patients had indeterminate relative sympathetic tone. Conclusions Clustering of ventricular ectopy, as measured by the fractal dimension, is observed in patients at increased risk of sudden cardiac death. A low fractal dimension (clustered ventricular ectopy) is related to changes in heart rate and heart rate variability that are consistent with transient increases in cardiac sympathetic tone.
M Akihiko D Nogami - One of the best experts on this subject based on the ideXlab platform.
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negative participation of the left posterior fascicle in the reentry circuit of verapamil sensitive idiopathic left ventricular tachycardia
Journal of Cardiovascular Electrophysiology, 2012Co-Authors: M Itsuro D Morishima, M Akihiko D Nogami, M Hideyuki D Tsuboi, M Takahito D SoneAbstract:Left posterior fascicle and idiopathic Left VT. The left posterior fascicle may be a bystander of the circuit of verapamil-sensitive idiopathic left ventricular tachycardia. During ventricular tachycardia (VT), 3 sequences of potentials were seen at the left posterior septum: diastolic Purkinje potentials propagating from base to apex and presystolic left posterior fascicular potentials and systolic left ventricular (LV) myocardial potentials propagating in the reverse direction. Selective capture of the left posterior fascicle by the Sinus Beat did not affect the VT cycle length. Entrainment pacing revealed that the retrograde limb of the circuit was not the left posterior fascicle, but the LV myocardium.
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negative participation of the left posterior fascicle in the reentry circuit of verapamil sensitive idiopathic left ventricular tachycardia
Journal of Cardiovascular Electrophysiology, 2012Co-Authors: M Itsuro D Morishima, M Akihiko D Nogami, M Hideyuki D Tsuboi, M Takahito D SoneAbstract:Left Posterior Fascicle and Idiopathic Left VT. The left posterior fascicle may be a bystander of the circuit of verapamil-sensitive idiopathic left ventricular tachycardia. During ventricular tachycardia (VT), 3 sequences of potentials were seen at the left posterior septum: diastolic Purkinje potentials propagating from base to apex and presystolic left posterior fascicular potentials and systolic left ventricular (LV) myocardial potentials propagating in the reverse direction. Selective capture of the left posterior fascicle by the Sinus Beat did not affect the VT cycle length. Entrainment pacing revealed that the retrograde limb of the circuit was not the left posterior fascicle, but the LV myocardium. (J Cardiovasc Electrophysiol, Vol. 23, pp. 556-559, May 2012)