Evidence for Slow Conduction Areas during Pacing in Patients with Sinus Rhythm, and their Relation to the Site of VT Origin.

1994 ◽  
Vol 35 (1) ◽  
pp. 1-13 ◽  
Author(s):  
Masaomi CHINUSHI ◽  
Yoshifusa AIZAWA ◽  
Yoriko KUSANO ◽  
Takashi WASHIZUKA ◽  
Akira SHIBATA
Keyword(s):  
Sinus Rhythm ◽  
Slow Conduction

Action of Mephentermine on Arrhythmias Due to Pulsus Alternans, Rapidly Discharging Single Atrial Foci and Prolonged P-R Intervals

1957 ◽  
Vol 191 (3) ◽  
pp. 481-486 ◽  
Author(s):  
M. J. Oppenheimer ◽  
P. R. Lynch ◽  
G. Ascanio
Keyword(s):  
Sinus Rhythm ◽  
Refractory Period ◽  
Conduction Time ◽  
Digitalis Intoxication ◽  
Methyl Group ◽  
Slow Conduction ◽  
Normal Series ◽  
Pulsus Alternans ◽  
Conduction Velocities ◽  
Regular Rhythm

Slow conduction velocities play a role in pulsus alternans and digitalis intoxication and possibly in the arrhythmia due to a rapidly discharging atrial aconitine focus. In the ventricle mephentermine increases conduction velocity, shortens refractory period and A-V conduction time. The present study investigates the usefulness of mephentermine in these conditions. Pulsus alternans was reverted to a normal series of mechanical contractions by mephentermine. The same agent provided periods of regular rhythm during the presence of an atrial aconitine focus; in two cases a permanent sinus rhythm was established. The prolonged P-R interval due to intoxication with acetyl strophanthidin was restored to normal by mephentermine. The action of mephentermine is specific since compounds with addition or subtraction of one methyl group or the hydroxy-mephentermine were ineffective against a circus flutter.

scholarly journals A new approach to atrial flutter ablation using functional substrate mapping with wavefront discontinuity during sinus rhythm

EP Europace ◽  
2021 ◽  
Vol 23 (Supplement_3) ◽  
Author(s):  
D Valbom Mesquita ◽  
L Parreira ◽  
J Farinha ◽  
R Marinheiro ◽  
P Amador ◽  
...  
Keyword(s):  
Sinus Rhythm ◽  
Atrial Flutter ◽  
Small Area ◽  
Low Voltage ◽  
Categorical Variables ◽  
Accurate Identification ◽  
Funding Sources ◽  
Slow Conduction ◽  
Voltage Mapping ◽  
Conduction Zone

Abstract Funding Acknowledgements Type of funding sources: None. Background Ultra high-density (UHD) mapping allows accurate identification of local abnormal electrograms and low voltage within a small area range, allowing precise identification of reentry circuits. Areas with high isochronal density in a small area known as deceleration zones (DZ) are responsible for reentry. Purpose Identify the DZ and areas of low voltage in sinus rhythm (SR) and evaluate the feasibility of performing atrial flutter (AFL) ablation by targeting those zones. Methods We prospectively enrolled patients in SR referred for AFL ablation (either typical or atypical). An isochronal late activation mapping (ILAM) during SR with UHD catheter was performed, annotating latest deflection of local electrograms. DZ were defined as areas with >3 isochrones within 1cm radius, prioritizing zones with maximal density. Atrial flutter was then induced and ILAM during flutter was performed for comparison. Voltage mapping was also assessed (0.1-0.5mV). Ablation targeted DZ in SR that displayed the higher voltage. DZ in SR were compared to DZ in AFL. Number of radiofrequency (RF) applications needed to terminate AFL were assessed. After AFL termination, complete line of the slow conduction zone was completed, and pulmonary vein isolation (PVI) was done in case of left AFL. Categorical variables are presented in absolute and relative values and median and interquartile range were used for numerical variables, as well t-student test for correlation of numerical variables. Results We studied 6 AFL (4 atypical, 66.7%) in 5 patients, 2 male (40%), median age 70 (64- 72). UHD ILAM in SR with 2195 points (1212-2865) and 2197 points (1356-3102) in AFL (p = 0.62).  The UHD ILAM identified a median of (QR) DZ in SR, that colocalized with AFL isthmus and DZ in AFL in 100%. DZ were not always located in low voltage areas. Aiming at the higher voltage in the DZ terminated the AFL in all cases, with a median RF time of 38 (25-58) seconds and AFL was no longer inducible. However, according to protocol, the complete line of slow conduction zone was done, with a median RF time of 1049.5 (274-1194) seconds (p = 0,009). Conclusions Isochronal mapping in sinus rhythm with UHD catheters can display the functional substrate for reentry in AFL, allowing a substrate guided ablation in case of non-inducible AFL. Targeting the areas of high isochronal density, is effective in terminating AFL, obviating the need for extensive ablation. Abstract Figure.

scholarly journals P3629Rotational and Focal AF Sources Localize to Low Voltage Areas Displaying Slow Conduction in Sinus Rhythm

2017 ◽  
Vol 38 (suppl_1) ◽  
Author(s):  
A.S. Jadidi ◽  
J. Chen ◽  
H. Lehrmann ◽  
B. Mueller-Edenborn ◽  
J. Allgeier ◽  
...  
Keyword(s):  
Sinus Rhythm ◽  
Low Voltage ◽  
Slow Conduction

Abstract 18662: Ablation of Regions of Very Slow Conduction Within a Myocardial Scar and Recurrence of Ventricular Tachycardia After Catheter Ablation

Circulation ◽  
2015 ◽  
Vol 132 (suppl_3) ◽  
Author(s):  
Asad A Aboud ◽  
M. Benjamin Shoemaker ◽  
Pablo Saavedra ◽  
Juan C Estrada ◽  
Sharon Shen ◽  
...  
Keyword(s):  
Logistic Regression ◽  
Ventricular Tachycardia ◽  
Sinus Rhythm ◽  
Structural Heart Disease ◽  
Myocardial Scar ◽  
Activation Time ◽  
Substrate Modification ◽  
Slow Conduction ◽  
Vt Ablation

Background: It has been established that areas of slow conduction within a myocardial scar identified by isochronal mapping during sinus rhythm harbor the functional substrate that is involved in sustaining ventricular tachycardia (VT). We sought to test the hypothesis that targeting the region of slowest conduction during sinus rhythm would reduce VT recurrence following ablation. Methods and Results: 32 subjects underwent ablation for sustained monomorphic VT associated with structural heart disease from 2013 to 2014. Sustained VT recurred in 12 patients (37.5%). Isochronal late activation maps were created to display activation during sinus rhythm in the region of bipolar scar. The scar was divided into three zones of equal activation time. The zone with the densest isochrones was designated as having the slowest conduction . We retrospectively analyzed isochronal maps and measured the proportion of the slowest zone that was ablated (median 14%, IQR 0-50). During a mean follow-up of 6 months, recurrence of ventricular arrhythmia was significantly associated with ablation of the slowest zone (OR 0.126, CI 0.024-0.68, p 0.016). Furthermore, univariate logistic regression demonstrated reduction of 30% in the 6-month VT recurrence rate for every 10% increase in percent of the slowest zone ablated (OR 0.7, 95% CI 0.5-1.0, p=0.05). Conclusions: Patients who had ablation in the region of slowest conduction were significantly less likely to have recurrence of ventricular tachycardia. Our data suggests a strategy to target the slowest region of conduction for substrate modification may hold promise for improving outcomes of scar-mediated VT ablation.

scholarly journals Slow conduction zone proved by the pacing during sinus rhythm and it's relation to the site of the origin of ventricular tachycardia.

1992 ◽  
Vol 12 (1) ◽  
pp. 108-116
Author(s):  
Masaomi Chinushi ◽  
Yoshifusa Aizawa ◽  
Yoriko Kusano ◽  
Takefumi Miyajima ◽  
Naoki Naitho ◽  
...  
Keyword(s):  
Ventricular Tachycardia ◽  
Sinus Rhythm ◽  
Slow Conduction ◽  
Conduction Zone

MAPping with fragmentation analysis in patients with atypical atrial FLUtter using the RHYthmia navigation system (MAP-FLURHY study)

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
E Franco ◽  
C Lozano Granero ◽  
R Matia ◽  
A Hernandez-Madrid ◽  
I Sanchez-Perez ◽  
...  
Keyword(s):  
Sinus Rhythm ◽  
Atrial Flutter ◽  
Cycle Length ◽  
Funding Source ◽  
Atrial Arrhythmias ◽  
Slow Conduction ◽  
Ablation Success ◽  
Focal Ablation ◽  
Procedural Success

Abstract Background Atypical atrial flutter (AAFL) circuits use areas of slow conduction which can be visualized as fragmented electrograms (fEGMs). Purpose To test an ablation strategy based on the identification and ablation of spots with fEGMs in AAFL. Methods The MAP-FLURHY study prospectively included all AAFL ablations with Rhythmia in our Center from June 2016 to June 2019. Patients with non-mappable AAFL, frequent conversion to atrial fibrillation, or cavotricuspid isthmus-dependent flutters were excluded from analysis. The IntellaMap ORION catheter was used to detect fragmentation areas, arbitrarily defined as fEGMs >70ms. Entrainment was used to check if these areas belonged to the AAFL circuit. Ablation targeted the longest fEGM within the circuit (return cycle <30ms): focal ablation for microreentries, and lines including the fEGMs for macroreentries. Ablation success was defined as conversion to sinus rhythm or another flutter. Procedural success was defined as successful ablation of all inducible flutters. Follow-up included visits with 24h Holter ECG at 3–6-12 months. Results 50 Patients received ablation (Figure). 27 Patients (70.6±13.1 years; 10 females; LVEF 57%±13%) with 44 mappable AAFLs were included in the analysis (Table). All AAFLs showed areas with fEGMs (106 areas; 2.4 areas per flutter). 42/44 AAFLs had fEGMs within the circuit, which were target of ablation. Ablation success: 34/36 AAFLs (94%); success could not be assessed in 6 circuits, due to mechanical conversion to sinus rhythm onto the target fEGM. Fragmented areas within the AAFL circuits (n=51) were longer (110±30 vs 90±15 ms, p<0.001) but had similar voltage (0.34±0.25 vs 0.36±0.26 mV) than areas outside the circuits (n=45). A fEGM duration >100ms/>40% of the cycle length predicted to be a successful site for ablation with 72.3%/73.8% specificity. Procedural success was achieved in 24/27 patients (89%). Excluding a 2-month blanking period, mean survival free from atrial arrhythmias was 19 (95% CI: 12.6–25.5) months. 57% of the patients were free from atrial arrhythmias at 1 year. Conclusions Most AAFLs had detectable fEGMs which could be target of ablation with high efficacy. Figure 1 Funding Acknowledgement Type of funding source: None

Sign in / Sign up

Export Citation Format

Share Document