Fractionated endocardial electrograms are associated with slow conduction in humans: Evidence from pace-mapping

Stevenson, William G.; Weiss, James N.; Wiener, Isaac; Rivitz, S. Mitchell; Nademanee, Koonlawee; Klitzner, Thomas S.; Yeatman, Lawrence A.; Josephson, Martin A.; Wohlgelernter, Daniel

doi:10.1016/0735-1097(89)90514-7

Cited by 108 publications

(25 citation statements)

References 38 publications

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“…Sites showing abnormal local electrograms may be involved in the arrhythmogenic substrate of ventricular tachyarrhythmia, 16 but in such sites the late diastolic threshold of pacing is usually high (>5 V) and is able to capture a large amount of the myocardium surrounding the unipolar electrogram recording site. Thus, as the first step, we studied the relationship between the ERP and the ARI at the sites where the local electrogram showed normal configuration 8 and its late diastolic threshold was less than 1.5 V. Because previous experimental studies have shown that the ARIs derived from unipolar electrograms are reasonably approximate to local ERPs regardless of the T wave morphology, 5,9,17 we consistently measured the ARI as the interval between the time of minimum derivative of the intrinsic deflection and the maximum derivative of the T wave of the unipolar electrogram, and confirmed a reasonable correlation between the ERP and the ARI in the sites showing normal bipolar electrocardiograms.…”

Section: Study Limitationsmentioning

confidence: 99%

Correlation Between the Effective Refractory Period and Activation-Recovery Interval Calculated From the Intracardiac Unipolar Electrogram of Humans With and Without dl-Sotalol Treatment

Chinushi

Tagawa²,

Kasai³

et al. 2001

Jpn Circ J

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eterogeneous distribution of ventricular repolarization can contribute to the construction of the arrhythmogenic substrate of ventricular tachyarrhythmia, and this has been well documentted in experimental studies of optical mapping and/or tridimensional repolarization analysis. 1-3 However, in clinical electrophysiologic studies (EPS), the beat-to-beat change in the distribution of intraventricular repolarization is difficult to analyze.Previous experimental studies reported that the activation -recovery interval (ARI) calculated from the unipolar electrogram was approximate to the local effective refractory period (ERP) under various conditions. 4,5 Thus, analysis of ARIs from intracardiac multipolar electrode catheters may be helpful in assessing the distribution of ventricular refractoriness from a clinical viewpoint. Because it has not been well clarified whether the ARI calculated from human intracardiac electrograms reasonably corresponds to local refractoriness, we examined the relationship between ERP and ARI during clinical EPS. The analysis was performed in patients treated with dl-sotalol, as well as in the control state, because dl-sotalol is commonly used in the treatment of sustained ventricular tachyarrhythmia, and its antiarrhythmic effect is considered to be mediated by prolongation of the refractoriness and homogenization of the dispersion of refractoriness of the heart. 6,7 Therefore, if the ARI calculated from the intracardiac unipolar electrogram was reasonably approximate to the local ERP under treatment with dlsotalol, the therapeutic effect of dl-sotalol could be evaluated by measuring the ARI in EPS. Methods SubjectsNineteen patients were enrolled and of these, an EPS was performed without any medication, except for diuretics In experimental studies and/or human body surface mapping, the activation -recovery interval (ARI) is used as a parameter to estimate local repolarization. However, it has not been clarified whether the ARI calculated from the intracardiac unipolar electrogram of humans reasonably represents the local effective refractory period (ERP). Measurement of ARIs at multiple ventricular sites can be helpful in assessing the dispersion of ventricular refractoriness of humans, so we examined the relationship between ERP and ARI in the control state and under treatment with dl-sotalol during clinical electrophysiologic studies (EPS). Of 19 patients, an EPS was performed in the control state in 12 and during treatment with dl-sotalol in the other 7. Quadripolar electrode catheters with an interelectrode distance of 5 mm were placed at the right atrium and in the right ventricle. Using atrial pacing, the heart rate was increased incrementally by 10 beats/min, and ERP and ARI were measured for each pacing rate. The ERP at the right ventricle was measured by single extrastimulation between the first and third distal electrodes of the catheter in the right ventricle, and the ARI was calculated from the second distal unipolar electrode of the same catheter as the interval between t...

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Section: Study Limitationsmentioning

confidence: 99%

Correlation Between the Effective Refractory Period and Activation-Recovery Interval Calculated From the Intracardiac Unipolar Electrogram of Humans With and Without dl-Sotalol Treatment

Chinushi

Tagawa²,

Kasai³

et al. 2001

Jpn Circ J

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“…Of those with scar-related reentry, middiastolic potentials were identified in 6 cases (42.8%), and "fractionated" signals consistent with slowed conduction in the scar region were identified in 7 (50.0%). 9 Endocardial ablation (median 18 lesions per patient) abolished, at least in the short term, all inducible monomorphic VTs in all 14 patients with scar-related reentry. In those cases in which the isthmus approximated the valve annulus, a line of lesions was placed from the isthmus to the electrically unexcitable region of the annulus.…”

Section: Scar-related Reentrymentioning

confidence: 99%

Sustained Ventricular Tachycardia Associated With Corrective Valve Surgery

et al. 2007

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Background-The causes of sustained monomorphic ventricular tachycardia (VT) after cardiac valve surgeries have not been studied extensively, although bundle-branch reentry has been reported. Methods and Results-Records of 496 patients referred for electrophysiology study and catheter ablation of recurrent VT were reviewed. Twenty patients (4%) had VT after aortic or mitral valve surgery in the absence of known myocardial infarction. The median age was 53 years, and the median ejection fraction was 45%. In 4 patients, VT occurred early after surgery, and electrophysiology study was performed 3 to 10 days later. In the remaining patients, electrophysiology study was performed a median of 12 years (interquartile range 5 to 15 years) after surgery. Sustained VT was inducible in 17 patients. VT was attributed to scar-related reentry in 14 patients (70%) and to bundle-branch reentry in 2 (10%).Multiple VTs were present in 9 of 14 patients with scar-related reentry. A total of 42 induced VTs were targeted for ablation. Of the 14 patients with scar-related reentry, 9 (64%) had periannular scar, and 10 (71%) had an identifiable endocardial circuit isthmus. Ablation abolished 41 (98%) of the 42 targeted VTs. At a median follow-up of 2.1 years, 3 deaths occurred 8 to 14 months after ablation. One patient with incessant VT early after valve surgery suffered a stroke with residual hemianopsia. Of the 20 patients, 3 required repeat ablation after recurrence, and 2 of these who were not inducible during electrophysiology study had clinical recurrence that necessitated ablation. Conclusions-Sustained VT after valve surgery appears to be bimodal in presentation, occurring either early after surgery or years later. In this referral population, reentry in a region of scar is more common than bundle-branch reentry. Catheter ablation can be successful.

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“…Other approaches based on fragmented low-amplitude potential or late activation during sinus rhythm have been used for the ablation of unstable VTs. 20,21 These characteristics have been shown to be present at successful ablation sites. They can, however, also be demonstrated at sites not involved in the reentry circuit and are therefore not specific for a distinct VT.…”

Section: Ablation Strategymentioning

confidence: 99%

Catheter Ablation of Multiple Ventricular Tachycardias After Myocardial Infarction Guided by Combined Contact and Noncontact Mapping

Klemm¹,

Ventura²,

Steven³

et al. 2007

Circulation

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Background-Insights gained from noncontact mapping of ventricular tachycardia (VT) have not been systematically applied to contact maps. This study sought to unify both techniques for an individualized approach to the patient with multiple ischemic VTs irrespective of cycle length. Methods and Results-For 12 consecutive patients with chronic myocardial infarction and recurrent VT, bipolar contact maps were acquired during sinus or paced rhythm. Additional noncontact maps were obtained during 48 induced VTs (cycle length 192 to 579 ms). Endocardial exit sites were superimposed on contact maps and verified by pace-mapping. Radiofrequency lesions were extended for critical borders defined by multiple neighboring exits and followed the isovoltage contour line of contact maps. Nine critical borders were identified in 8 patients and constituted the substrate for 31 VTs. The voltage at exit sites was 0.8 mV (range 0.1 to 2.3). Noncontact maps revealed 23Ϯ18% of isthmus conduction. Thirty-seven (77%) of all and 83% of clinically documented VTs were rendered noninducible irrespective of cycle length by application of 27 radiofrequency lesions (range 18 to 56). Spontaneous transitions between distinct VTs along critical borders were demonstrated in 4 patients. Pace-mapping reproduced the QRS morphology of 81% of VTs and was associated with successful ablation (PϽ0.01). Noninducibility of any sustained VT was reached for 8 (67%) patients. During 15 months (range 5 to 28) of follow-up, 8 patients remained without recurrence, and VT episodes were reduced in the other 4 patients (PϽ0.01). VT cycle length was not predictive for acute or long-term success. Conclusion-The combined approach of contact and noncontact mapping effectively defines critical borders as the substrate of multiple VTs without limitation for unstable VTs.

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Fractionated endocardial electrograms are associated with slow conduction in humans: Evidence from pace-mapping

Cited by 108 publications

References 38 publications

Correlation Between the Effective Refractory Period and Activation-Recovery Interval Calculated From the Intracardiac Unipolar Electrogram of Humans With and Without dl-Sotalol Treatment

Correlation Between the Effective Refractory Period and Activation-Recovery Interval Calculated From the Intracardiac Unipolar Electrogram of Humans With and Without dl-Sotalol Treatment

Sustained Ventricular Tachycardia Associated With Corrective Valve Surgery

Catheter Ablation of Multiple Ventricular Tachycardias After Myocardial Infarction Guided by Combined Contact and Noncontact Mapping

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