Cycle Length Dynamics and Spatial Stability at the Onset of Postinfarction Monomorphic Ventricular Tachycardias Induced in Patients and Canine Preparations

Circulation ◽  
1996 ◽  
Vol 93 (10) ◽  
pp. 1845-1859 ◽  
Author(s):  
Alain Vinet ◽  
René Cardinal ◽  
Pierre LeFranc ◽  
François Hélie ◽  
Pierre Rocque ◽  
...  
Keyword(s):  
Cycle Length ◽  
Spatial Stability ◽  
Ventricular Tachycardias

scholarly journals Cycle length of nonsustanied ventricular tachycardias among ICD patients: implications on subsequent appropriate therapies

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Javier Jiménez-Candil ◽  
Olga Duran ◽  
Armando Oterino ◽  
Jendri Pérez ◽  
Juan Carlos Castro ◽  
...  
Keyword(s):  
At Risk ◽  
Secondary Prevention ◽  
Beta Blocker ◽  
Cycle Length ◽  
Close Relationship ◽  
Appropriate Therapy ◽  
The Mean ◽  
Ventricular Tachycardias ◽  
The Relationship

Abstract Background ICD patients with episodes of nonsustained ventricular tachycardias (NSVT) are at risk of appropriate therapies. However, the relationship between the cycle length (CL) of such NSVTs and the subsequent incidence of appropriate interventions is unknown. Methods 416 ICD patients with LVEF < 45% were studied. ICD programming was standardized. NSVT was defined as any VT of 5 or more beats at ≥ 150 bpm occurred in the first 6 months after implantation that terminated spontaneously and was not preceded by any appropriate therapy. The mean follow-up was 41 ± 27 months. Results We analyzed 2201 NSVTs (mean CL = 323 ms) that occurred in 250 patients; 111 of such episodes were fast (CL ≤ 300 ms). Secondary prevention (HR = 1.7; p < 0.001), number of NSVT episodes (HR = 1.05; 95% CI 1.04–1.07; p < 0.001) and beta-blocker treatment (HR = 0.7; p = 0.04) were independent predictors of appropriate interventions; however, the mean CL of NSVTs was not (p = 0.6). There was a correlation between the mean CL of NSVTs and the CL of the first monomorphic VT: r = 0.88; p < 0.001. This correlation was especially robust in individuals with > 5 NSVTs (r = 0.97; p < 0.001), with an agreement between both values greater than 95%. Patients with any fast NSVT experienced a higher incidence of VF episodes (26%) compared to those without NVSTs (3%) or with only slow NSVTs (7%); p < 0.001. Conclusions Unlike the burden, the CL of NSVTs is not a predictor of subsequent appropriate interventions. However, there is a close relationship between the CL of NSVTs and that of arrhythmias that will later lead to appropriate therapies.

915ATP efficacy on terminating ventricular tachycardia by device type, indication, and ventricular median cycle length

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
M Brown ◽  
T Kurita ◽  
L D Sterns ◽  
E J Schloss ◽  
A Auricchio ◽  
...  
Keyword(s):  
Primary Prevention ◽  
Secondary Prevention ◽  
Success Rate ◽  
Cycle Length ◽  
P Value ◽  
Success Rates ◽  
Device Type ◽  
The Difference ◽  
Ventricular Tachycardias ◽  
Rate Of Success

Abstract Funding Acknowledgements Medtronic OnBehalf PainFree SST Background Anti-tachycardia Pacing (ATP) is an established therapy that terminates VT without the need for painful ICD shocks. Here we use the data from PainFree SST clinical trial to evaluate the ATP success rate by device type, indication and MCL.  Methods Spontaneous episodes that were detected by ICD or CRT-D devices in the VT, fast VT and VF zones were included in the analysis. Episodes successfully terminated by ATP were deemed as having ATP success. Using the GEE method, ATP success rate and its 95% CI were calculated for device types, indications and ventricular MCL.  Results Of the 2770 enrolled patients (79% male, average age 65 years), 1699 (61%) were implanted with an ICD and 1071 (39%) with a CRT-D system; 1917 (69%) were reported as primary prevention and 847 (31%) were secondary prevention patients. For all MVT episodes, the ATP success rate was similar between ICD and CRT-D devices (82.3% vs 80.3%, p = 0.74). Patients with secondary prevention had a higher ATP success rate compared to those with primary prevention but the difference was not statistically significant (84.4% vs 76.8%, p = 0.16). Regardless of device type and indication, ATP success rate was significantly higher in the slower VTs (MCL ≥ 320 ms) compared to the faster VTs (MCL ≥ 240 to &lt; 320 ms) (89.2% vs 73.7%, p &lt; 0.0001).  Conclusion We found that ATP had a greater than 80% rate of success for terminating ventricular tachycardias overall. Slower VTs was significantly associated with a higher ATP success rate regardless of device type and indication compared to faster VTs. For faster VTs with a MCL ≥ 240 to &lt; 320 ms, the ATP success rate was still successful at terminating VT more than 70% of the time. Table 1. ATP Success Rates - No. of Enrolled Subjects (% of total) No. of Episodes Analyzed for ATP Success (No. of Subjects) GEE-estimated ATP Success Rate (95% CI) P-value* Overall 2770 (100%) 2277 (376) 81.5% (78.4%, 84.2%) - Device Type - - - 0.7440 ICD 1699 (61.3%) 1484 (229) 82.3% (78.3%, 85.6%) - CRT-D 1071 (38.7%) 793 (147) 80.3% (75.0%, 84.6%) - Indication - - - 0.1609 Primary Prevention 1917 (69.2%) 631 (160) 76.8% (71.2%, 81.6%) - Secondary Prevention 847 (30.6%) 1615 (212) 84.4% (80.7%, 87.6%) - Median Cycle Length - - - &lt;0.0001 (&gt;/=) 240 ms and &lt; 320 ms - 861 (257) 73.7% (69.2%, 77.7%) - (&gt;/=) 320 ms - 1416 (209) 89.2% (85.7%, 91.9%) - * Per a GEE main effect model for all episodes where device type, indication and median cycle length were considered.

Cycle Length Dynamics at the Onset of Postinfarction Ventricular Tachycardias Induced in Canines:.

2000 ◽  
Vol 11 (5) ◽  
pp. 531-544 ◽  
Author(s):  
V FRANÇOIS HÉLIE ◽  
ALAIN VINET ◽  
RENÉ CARDINAL
Keyword(s):  
Cycle Length ◽  
Ventricular Tachycardias

Abstract 2132: Beta-Blocker Therapy and Effectiveness of Antitachycardia Pacing among ICD Patients: A Dose-Dependent Effect

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Javier Jimenez-Candil ◽  
Jose Morinigo ◽  
Maria Ruiz Olgado ◽  
Claudio Ledesma ◽  
Cándido Martín-Luengo
Keyword(s):  
Cycle Length ◽  
Beta Blockers ◽  
Antitachycardia Pacing ◽  
Blocker Therapy ◽  
Dependent Effect ◽  
Ventricular Tachycardias ◽  
The Relationship ◽  
Dose Dependent ◽  
Dose Dependent Effect

Beta-blockers (BB) increase the efficacy of antitachycardia pacing (ATP) in terminating slow and monomorphic ventricular tachycardias (MVT) in ICD patients. Whether this effect occurs in fast MVT and whether it is dose-dependent it is unknown. Our aim is to determine the relationship between the indexed dose equivalents (IDE) of beta-blockers (BB-IDE) with the effectiveness of ATP in terminating MVT. In this prospective study we included 200 ICD patients (LVEF: 31±11). Detection and ATP therapies for VT were programmed as follows: Fast-VT zone (Cycle Length [CL]: 250 –320 ms; 1 burst of 5 pulses at 84% of CL); slow-VT zone (CL: 321–390 ms; 3 bursts of 15 pulses at 91%). In each patient we determined the BB-IDE at MVT presentation. Dose equivalents (DE) were defined with atenolol used as reference. IDE were calculated by dividing DE by body surface area (mg*m2/day). During a follow-up of 602±368 days, 546 MVT (CL: 329±35 ms; 41% fast-VT; 22 % no BB treatment; median of BB-IDE: 26 mg*m2/day) were recorded. Success rate of APT was 87%. BB-IDE was higher in the cases of successful ATP (S-ATP): 22±18 vs. 15±16 (p=0.001). Classifying the events into three groups according to the BB-IDE: no BB, low IDE (BB-IDE<median) and high IDE (BB-IDE≥median), the frequency of S-ATP increased with the BB-IDE: 78 vs. 84 vs. 94% (all MVTs; p<0.001 for the trend) and 47 vs. 84 vs. 97% (fast-MVTs; p<0.001, for the trend). In a multivariate analysis (logistic regression), BB-IDE (mg*m2/day) remained as a significant predictor of S-ATP: OR: 1.03 (95% CI: 1.01–1.05; p=0.001). The incidences of MVT-related symptoms and appropriate discharges were lower in higher values of BB-IDE. Table . Among ICD patients, BB therapy increases the likelihood of ATP terminating MVTs, especially in fast MVTs. This effect is dose-dependent: the higher the IDE, the more probable the S-ATP. Thus, BB improves MVT clinical tolerance. Frequencies of tachycardia-related symptoms and appropriate discharges with respect to BB-IDE

Spatiotemporal dynamics of reentrant ventricular tachycardias in canine myocardial infarction: pharmacological modulation

2003 ◽  
Vol 81 (5) ◽  
pp. 413-422 ◽  
Author(s):  
François Hélie ◽  
Alain Vinet ◽  
René Cardinal
Keyword(s):  
Myocardial Infarction ◽  
Cycle Length ◽  
Plasma Concentrations ◽  
Conduction Block ◽  
Pharmacological Modulation ◽  
Rate Dependent ◽  
Old Myocardial Infarction ◽  
Canine Myocardial Infarction ◽  
Activation Times ◽  
Ventricular Tachycardias

During the transition from a slow to rapid depolarization rhythm, rate-dependent sodium channel blockade develops progressively and increases from beat to beat under procainamide but more abruptly under lidocaine. We investigated the consequences of such differences on the dynamic course and stability of reentrant tachycardias at their onset. Procainamide and lidocaine were infused to equipotent plasma concentrations in canines with three-day-old myocardial infarction. We measured the activation times (ms) and maximum slopes of negative deflections in activation complexes (absolute value: |–dV/dtmax| in mV/ms) in 191 unipolar electrograms recorded from ischemically damaged subepicardial muscle during programmed stimulation inducing reentrant tachycardias. Procainamide caused a greater reduction in |–dV/dtmax| than did lidocaine in the responses to basic stimulation, and it favored the occurrence of cycle length prolongation at tachycardia onset as the |–dV/dtmax| decreased progressively in successive beats. This resulted in conduction block and tachycardia termination in three of eight preparations. In contrast, lidocaine caused a greater depression in |–dV/dtmax| in response to closely coupled extrastimuli, but |–dV/dtmax| remained constant or even improved thereafter, and none of the tachycardias terminated spontaneously under lidocaine (n = 9). However, the reentrant circuits remained spatially unstable, and lidocaine favored the occurrence of cycle length dynamics displaying constant or decreasing trends. This study supports the notion that cycle length dynamics at tachycardia onset are determined by the properties of the reentrant substrate and their pharmacological modulation. Key words: lidocaine, procainamide, reentry, ventricular tachycardia, cycle length dynamics.

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