Perfect Pace Mapping Research Articles

Ventricular arrhythmias ablated successfully in the subvalvular interleaflet triangle between the right and left coronary cusps: Electrophysiological characteristics and catheter ablation.

Ventricular arrhythmias (VAs) ablated successfully at the right-left subvalvular interleaflet triangle (R-L ILT) between right and left coronary cusps have not been fully characterized. The purpose of this study was to investigate the electrophysiological characteristics of these VAs and their relationships with the left ventricular (LV) summit. Twenty-eight VAs ablated successfully at the R-L ILT were studied. Ninety-six percent of VAs had an early precordial electrocardiographic transition. R-wave amplitude in lead V1 was relatively high (RS morphology, R-wave amplitude 0.35 ± 0.09 mV; R/S ratio 0.35 ± 0.27), whereas the morphology of lead I was R-shaped in 71% and M-shaped in 50% of VAs. Earliest potential was recorded at the R-L ILT in 13 of 28 patients and the left pulmonary sinus cusp (LC) in 6 of 28 patients. Mapping the summit communicating vein (summit-CV) failed because of anatomic or instrumental limitations in these 19 patients. In the other 9 patients, earliest potential was successfully recorded at the summit-CV, while perfect pacemapping was achieved. Poor pace mapping was achieved at the R-L ILT or LC in most patients (27/28). Target site was located at the top of the R-L ILT in all cases. A presystolic potential was present at the target site in 18 of 28 patients. A U-curve via the retrograde method was conventionally used to reach the top of the R-L ILT. VAs ablated successfully at the R-L ILT have unique electrophysiological characteristics, and R-L ILT may be an endocardial anatomic ablation target for VAs originating from the base of the LV summit.

Perfect pace-mapping with different latencies from adjacent sites in bilateral outflow tract leading to successful sequential unipolar ablation

A 77-year-old man with frequent monomorphic ventricular premature contractions (VPCs) was referred for catheter ablation. Detailed mapping just above the pulmonary valve (PV) revealed tiny fragmented potentials earlier than the VPC onset. Perfect pace-mapping was obtained using high voltage pacing just above the PV and the left aortic sinus of Valsalva, whose stimulus-to-VPC latencies differed by 20 ms. While the ablation at the pulmonary valve could not completely eliminate the VPCs, unipolar sequential ablation on both sides of the outflow tracts led to their successful abolition that was guided by perfect pace-mapping.

Successful ablation for premature ventricular contraction originating from moderator band of morphologic right ventricle in congenitally corrected transposition of great arteries

A 54-year-old man with congenitally corrected transposition of great arteries (CCTGA) was referred to our hospital for palpitation. 24-hour Holter ECG showed frequent premature ventricular contraction (PVC) and we performed catheter ablation for this PVC. Pace-mapping was performed in morphologic right ventricle (RV) by transaortic approach. Perfect pace-map was achieved in morphologic RV midpart lateral and ablation at this site could eliminate the clinical PVC. After the ablation, by integrating ablation site and 3D mapping, we diagnosed that the clinical PVC was originated from the moderator band (MB) of morphologic RV.

Eliminating the trigger for polymorphic ventricular tachycardia

A 60-year-old female patient was referred to our hospital because of recurrent syncope. The resting 12-lead ECG showed sinus rhythm with left bundle branch block and a high burden of monomorphic single premature ventricular beats (PVCs). Imaging studies confirmed a structurally normal heart and ischaemic heart disease was ruled out by coronary angiography. Telemetry revealed repeated episodes of polymorphic ventricular tachycardia (VT) triggered by monomorphic PVCs causing syncope. Therefore, an ICD was implanted and the patient was discharged on bisoprolol 10 mg/day. A few weeks later, she was referred to our hospital owing to repeated ICD shocks triggered by monomorphic PVCs with long-short sequences. Radio­frequency catheter ablation targeting the monomorphic PVC causing polymorphic VT was performed. With an almost perfect pace map within the distal coronary sinus, ablation in this region did not abolish the PVC. Therefore, we antegradely mapped the LV via transseptal access. Endocardial mapping at the anterior mitral anulus using the reverse S-curve technique revealed the earliest bipolar activation in close proximity to the ablated region within the coronary sinus. Ablation at this site abolished the clinical PVC. ECG monitoring at 3, 6 and 12 months did not reveal any PVC, and no ICD discharges have occurred since ablation.

A novel steerable Foley balloon catheter for preventing phrenic nerve injury during epicardial catheter ablation

A 69-year-old man with a history of dilated cardiomyopathy underwent epicardial catheter ablation of repetitive ventricular tachycardia through a subxiphoid pericardial window. A perfect pace map was obtained at the lateral aspect of the left ventricular epicardium, but it was accompanied by phrenic nerve capture. We combined a 14-French Foley balloon catheter with a 5French steerable mapping catheter, (Fig. 1). The Foley balloon was then advanced into the pericardial space and navigated into position near the site of perfect pace map using the steerable mapping catheter. During the high-output pacing from the ablation catheter, the Foley balloon was inflated and resulted in the absence of phrenic nerve capture (Fig. 2). With the balloon inflated, irrigated radiofrequency current was delivered at that site. After the ablation, normal function of the left diaphragm was verified by fluoroscopy.

A case of premature ventricular contractions originating from the papillary muscle in the right ventricle

A 45-year-old man with premature ventricular contractions (PVCs) underwent electrophysiological studies. Activation mapping using a noncontact electroanatomical mapping system indicated that the septal mid-apical region in the right ventricle was activated earliest. However, pace mapping did not match the activation mapping. Although the PVCs were successfully eliminated by applying radiofrequency current to the prepotential site preceding their QRS onset, a recurrence of PVCs with the same QRS morphology was observed at the 2-month follow-up examination, necessitating a second procedure. During the second procedure, echocardiography-guided electroanatomic mapping revealed centrifugal activation from the right ventricular mid-apical region on the septal portion of the anterior papillary muscle, but perfect pace mapping was not obtained at that site. With intracardiac echocardiography confirming good contact between the ablation catheter and papillary muscle, an irrigated radiofrequency current successfully eliminated the PVCs. This case indicates that the use of a guidance system may be feasible and useful for catheter ablation of PVCs originating from the right ventricular papillary muscle when there are discrepancies between activation mapping and pace mapping.

Catheter ablation of ventricular tachycardia originating from the diverticulum of the right ventricular outflow tract

Ventricular tachyarrhythmias from the right ventricular outflow tract (RVOT) are well recognized.1 In most cases, such arrhythmias are idiopathic because of the presence of a structurally normal heart. However, this ‘normal heart’ can sometimes be due to the early stage of heart disease or minor abnormalities that cannot be detected by routine examination. We report one case with ventricular tachycardia (VT) originating from the diverticulum of the RVOT. The electrocardiographic and electrophysiological characteristics, mapping and ablation strategies, and detailed images are described in this report. A 62-year-old man with a repetitive monomorphic VT with a typical RVOT origin morphology for 19 years was referred for catheter ablation. The echocardiogram did not suggest any evidence of structural heart disease and revealed a normal left ventricular ejection fraction. The oral administration of amiodarone was initially effective, but the patient was referred for an electrophysiological assessment and catheter ablation because of the side effects of amiodarone and reoccurrence of syncope. Ambulatory monitoring did not reveal any large burden of premature ventricular contractions. The 12-lead electrocardiogram (ECG) during the VT demonstrated a left bundle branch block (LBBB) and inferior axis morphology with a late QRS transition in the precordial lead, V4. The QRS complexes had a tall positive component without a notch in the inferior leads and a Qr pattern in lead I ( Figure 1A ). Figure 1 ( A ) Left panel: the 12-lead electrocardiogram of clinical ventricular tachycardia. Right panel: perfect pace mapping was obtained with an almost 11/12 match to clinical ventricular tachycardia morphology from the target site in the diverticulum. ( B ) The local fragmented, low-voltage electrograms at the earliest site which preceded the onset of QRS during ventricular tachycardia by 23 ms was recorded at the same site. ECG, electrocardiogram; VT, ventricular tachycardia. An electrophysiological study was performed under a fasting state …

Catheter Ablation on Papillary Muscle in the Patient with Arrhythmogenic Right Ventricular Cardiomyopathy

Aims: Ventricular tachycardia (VT) originating from left ventricular papillary muscle has been reported. However, VT originating from right ventricular papillary muscle was rare. Results: A 74-year-old male underwent implantable cardioverter defibrillator (ICD) implantation for VT with arrhythmogenic right ventricular cardiomyopathy (ARVC) in 2008. However, he referred to our hospital with palpitation attack in 2010. VT of 105 bpm with its morphology of left bundle branch block pattern, superior axis, was documented in 12-lead electrocardiogram during attack, and we performed electrophysiological study. Clinical VT was induced by programmed stimuli from right ventricle (RV). Diastolic potential preceded by 65 ms from surface QRS onset was recorded by mapping catheter located in RV base during VT. We confirmed concealed entrainment by burst pacing and perfect pace mapping was acquired at this region. Delivery of radiofrequency energy from this region could eliminate VT. After catheter ablation, any VT was not induced by programmed stimulation with or without isoproterenol infusion. Ablation success site was confirmed as RV papillary muscle by electro-anatomical mapping system and intra-cardiac echocardiography. Conclusion: In the patient with ARVC, VT may originate from RV papillary muscle. The VT mapping is difficult because of the complex anatomy of RV papillary muscles. Several imaging technologies are useful for identify the site of VT origin.

A Case of Epicardial RV-VT Eliminated by Endocardial Ablation

A 66-year-old female had ECG similar to type 1-Brugada and VT showing LBBB+LAD. EPS and radiofrequency (RF) ablation were performed with NavX system. A 3D-electroanatomic voltage map on an endocardial RV geometry indicated that low amplitude potentials (less than 0.5 mV) existed in infero-basal and apical walls. Activation mapping during a VT induced by programmed RV stimulation was achieved using an irrigated 4-mm-tip ablation catheter, so that the VT was confirmed a focal pattern originating from within the infero-basal low voltage area. This earliest activation site during the VT had a QS pattern on a unipolar intracardiac electrogram of the catheter and preceded about 10 ms from onset of QRS wave. Initial irrigated catheter ablation was performed here on the condition of a 20-watt power or 40C temperature limit and a flow rate of 13 ml/min, only resulting in transient termination of the VT. However, the shift of the earliest site to mid-inferior area, showing a normal amplitude (more than 1.5 mV), was clarified by further activation mapping. Additionally, perfect pace-mapping was obtained from the site. Although the potential on a unipolar electrogram of this site depicted no QS pattern during the VT, ablation could terminate the VT and render its inducibility impossible. These findings may suggest that endocardial RF ablation could eliminate focal VT originating from epicardial RV.

Ventricular Tachycardia on Previous Myocardial Infarction: Effective by Nifekalant, Bepridil and Two Sessions of Catheter Ablation

A 74-year-old man with previous myocardial infarction and CABG was admitted our hospital because of sustained VT. VT’s cycle length (CL) was 460 ms and QRS morphology was RBBB+LAD (VT1). As he had intestinal pneumonia, amiodarone was contraindicated. Thus we started nifekalant and d-sotalol. VT was controlled by nifekalant, but relapsed and became uncontrollable after discontinuation of nifekalant, even with increased dosage of d-sotalol. Temporary pacing from RVA wasn’t effective, and QT interval became be more prolonged after increased dosage of nifekalant and d-sotalol. Thus catheter ablation was performed. Clinical VT couldn’t induced by programmed stimulations at RVA and RVOT. Perfect pacemap site was existed at inferoseptal wall. At this site, purkinje potential preceded ventricular potential. Radiofrequency (RF) energy was delivered around this site. Next evening, altenated VT was appeared. QRS morphologies were LBBB+LAD (VT2, CL: 440 ms) and RBBB+superior axis (VT3, CL: 520 ms). After we administration of nifekalant, VT was supressed. After ICD implantation, we stopped d-sotalol and started bepridil. VT duration became shorter, but its frequency showed no change. We performed catheter ablation again because of repetitive VT. VT couldn’t induced on this session, either. RF energy was delivered at perfect (VT2, midseptal) and good (VT3, inferoseptal, slightly anterior of VT1) pacemap site. Linear lesion was made in low voltage zone between two pacemap sites and between septal and anterior wall. After ablation, VT dissappeared with low dose bepridil. Conclusion: Alterated VT modified by focal ablation was effective linear ablation at low voltage zone and pottasium channel blocker.

Premature Ventricular Contraction Originating from Posteroseptum

Introduction: Idiopathic premature ventricular contractions (PVCs) mainly have an outflow tract origin. The PVC originating from posteroseptum (PS) is very uncommon. Results: We describe the case of a 64-year-old woman with a 6-month history of palpitation and dizziness with premature ventricular contraction (PVC) was refractory to treatment with beta-blockers and calcium channel blockers drugs. Transthoracic echocardiography showed mild left ventricular hypertrophy. The PVC beat had morphology of left bundle branch block with superior axis. The duration of the QRS complex PVC was 120 msec. The QRS complex had QS pattern in lead V1, R pattern in lead I and aVL, and an early precordial R/S transition between V1 and V2. Mapping at the site between tricuspid annulus (TV) and coronary sinus ostium (CSo) showed an early local activation at −22 msec and a QS pattern on unipolar lead. Pace mapping at this site showed perfect pace mapping. Radiofrequency (RF) catheter ablation was performed at this site during sinus rhythm. RF energy was delivered with maximum power of 30 W and maximum temperature of 55 degrees. PVC disappeared by a single RF application for a few seconds. PVC was not inducible with ventricular burst pacing and isoproterenol infusion. During 10-month follow-up, PVC was not documented. Conclusions: We report a case with PVC arising from PS and were successfully treated with RF.

Successful Radiofrequency Catheter Ablation of Monomorphic Ventricular Tachycardia in a Patient of Hypertrophic Obstructive Cardiomyopathy with an Apical Aneurysm: A Case Report

A 56-year-old man suffered from hypertrophic obstructive cardiomyopathy (HOCM) associated with an apical aneurysm and monomorphic ventricular tachycardia (VT). The patient was transferred to our hospital for the purpose of the electrophysiologic study (EPS) and radiofrequency catheter ablation. In the EPS, clinical VT could be induced only during isoproterenol infusion but it lasted only for a few seconds. Because the activation map using the contact mapping system (Ensite NavXTN) was considered to be difficult, the substrate map underwent. The electrical potential could hardly be recorded inside the apical aneurysm. Because of plural slow conductions around the aneurysm, the earliest activation site was difficult to be identified by the activation map. The pace mapping conducted in the boundary area between the intact cardiac muscle and the aneurysm exhibited a perfect pace map at postero-lateral edge of the aneurysm. The point radiofrequency catheter ablation was performed at this site, and additional circumferential ablation was performed to isolate the scar area within apical aneurysm from the intact ventricular muscles. After these ablation procedures, the VT became un-inducible even during isoproterenol infusion and no recurrence was observed for 18 months.

Premature Ventricular Contractions Arising from the Intramural Ventricular Septum

A 68-year-old man with symptomatic idiopathic premature ventricular contractions (PVCs) underwent electrophysiological testing. Radiofrequency catheter ablation was unsuccessful at the earliest endocardial ventricular activation site in the left coronary cusp. Epicardial mapping via the cardiac veins was then performed. Balloon-occluded coronary sinus venography revealed the small branches of the anterior interventricular vein. Mapping with a microcatheter revealed the earliest ventricular activation and perfect pace map at the distal portion of the septal perforating branch, suggesting an intramural ventricular septal PVC origin. Catheter ablation was abandoned because of the inaccessibility of the ablation catheter to that site via the venous system.

Left Ventricular Outflow Tract Tachycardia With Preferential Conduction and Multiple Exits

A 50-year-old man with idiopathic premature ventricular contractions (PVCs; PVC 1, Figure 1A) and ventricular tachycardias (VTs) was referred for catheter ablation. Activation and pace mapping were performed at multiple sites in the right and left ventricular outflow tracts (RVOT and LVOT) (Figure 1). Nonirrigated radiofrequency (RF) applications delivered in the left coronary cusp where pacing reproduced a perfect pace map failed to suppress PVCs but gave a slight change in the QRS morphology of the PVCs characterized by S waves in lead V6 (PVC 2, Figure 1B). VT with this altered QRS morphology was induced by programmed stimulation (VT 1, Figure 1B). Pacing in the distal great cardiac vein (GCV) reproduced a different QRS morphology (Figure 1D). During PVC 2, the earliest ventricular activation was observed at the aorto-mitral continuity (AMC) where pacing reproduced a perfect pace map (Figure 1B). However, nonirrigated RF applications at this site did not …

Reentrant Ventricular Tachycardia Originating in the Right Ventricular Outflow Tract Slow Conduction Identified by Right Coronary Artery Ostium Pacing

A case of reentrant ventricular tachycardia (VT) originating from the right ventricular outflow tract (RVOT) is described. An electrophysiological study revealed that programmed stimulation from the right ventricle apex induced 2 types of VT with similar left bundle branch block configuration and inferior axis. Yet, VT cycle length (CL) was different; one was stable, sustained VT with a CL of 360 ms and the other was hemodynamically intolerable VT with a CL of 330 ms. Similarly for both VTs, perfect pace mapping was obtained at the anterior septum beneath the pulmonary valve in the RVOT, and exits of both VTs were very close. Entrainment mapping during stable VT was performed and the anterior septum RVOT was designated as the exit for the stable VT. Intriguingly, entrainment pacing from the ostium of the right coronary artery showed that the post-pacing interval was identical to VTCL. The stimulus to QRS interval was very long (340 ms) during entrainment with concealed fusion, and the right coronary artery ostium was therefore consistent with the VT reentry circuit inner loop or the upper portion of the VT reentry circuit exit. These findings suggest that the stable VT reentry circuit had a slow conduction zone from the ostium of the right coronary artery to the exit in the anterior septum RVOT. When radiofrequency catheter ablation was performed at the 2 exits of the anterior septum RVOT, both VTs then could not be induced.

Preferential Conduction Across the Ventricular Outflow Septum in Ventricular Arrhythmias Originating From the Aortic Sinus Cusp

The purpose of this study was to examine the relationship between the origin and breakout site of idiopathic ventricular tachycardia (VT) or premature ventricular contractions (PVCs) originating from the myocardium around the ventricular outflow tract. The myocardial network around the ventricular outflow tract is not well known. We studied 70 patients with idiopathic VT (n = 23) or PVCs (n = 47) with a left bundle branch block and inferior QRS axis morphology. Electroanatomical mapping was performed in both the right ventricular outflow tract (RVOT) and aortic sinus cusp (ASC) during VT or PVCs. The earliest ventricular activation (EVA) was recorded in the RVOT in 55 patients (group R) and in the ASC in 15 (group A). In all group R patients, the closest pace map and successful ablation were achieved at the EVA site. Although a successful ablation was achieved at the EVA site in all group A patients, the closest pace map was obtained at the EVA site in 8 and RVOT in 7 (with an excellent pace map in 4). The stimulus to QRS interval was 0 ms during pacing from the RVOT and 36 +/- 8 ms from the ASC. The distance between the EVA and perfect pace map sites in those 4 patients was 11.9 +/- 3.0 mm. Ventricular arrhythmias originating from the ASC often show preferential conduction to the RVOT, which may render pace mapping or some algorithms using the electrocardiographic characteristics less reliable. In some of those cases, an insulated myocardial fiber across the ventricular outflow septum may exist.

Idiopathic Ventricular Tachycardia Originating from the Posteroseptal Mitral Annulus: A Case Report

Idiopathic VT originating from posteroseptal mitral annulus. We describe a 71-year-old man with a ventricular tachycardia (VT) originating from the mitral annulus. A sustained VT was induced by exercise or an isoproterenol administration, but not by pacing. Frequent premature ventricular contractions(PVCs) with the same QRS as the VT were transiently suppressed by an adenosine triphosphate injection,suggesting that it was due to cyclic-AMP mediated triggered activity. The PVCs and VT were all abolished by radiofrequency catheter ablation guided by the earliest activation and a perfect pace map, which was located at the posteroseptal mitral annulus. The patient has been free from any symptoms for 2 years.(J Cardiovasc Electrophysiol, Vol. 17, pp. 1375-1377, December 2006)

Isolated Potentials During Sinus Rhythm and Pace-Mapping Within Scars as Guides for Ablation of Post-Infarction Ventricular Tachycardia

The purpose of this study was to identify ventricular tachycardia (VT) isthmus sites by pace-mapping within scar tissue and to identify electrogram characteristics that are helpful in identifying VT isthmus sites during sinus rhythm (SR). Pace-mapping has been used in the scar border zone to identify the exit site of post-infarction VT. In 19 consecutive patients (18 men, mean age 66 +/- 9 years, mean ejection fraction 0.24 +/- 0.12) with post-infarction VT, a left ventricular voltage map was generated during SR. Pace-mapping was performed at sites with abnormal electrograms or isolated potentials. Radiofrequency ablation was performed at isthmus sites as defined by pace-mapping (perfect pace-map = 12/12 matching electrocardiogram leads; good pace-map = 10/12 to 11/12 matching electrocardiogram leads) and/or entrainment mapping. A total of 81 VTs (mean cycle length 396 +/- 124 ms) were inducible. In 16 of the 19 patients, a total of 41 distinct isthmus areas of 41 distinct VTs were identified and successfully ablated. All but one displayed isolated potentials during SR. Furthermore, 22 of the 81 VTs (27%) for which no isthmus was identified became noninducible after ablation of a targeted VT. The 16 patients in whom > or =1 isthmus was identified and ablated were free of arrhythmic events during a mean follow-up of 10 months. During SR, excellent or good pace-maps at sites of isolated potentials within areas of scar identify areas of fixed block that are protected and part of the critical isthmus of post-infarction VT. Shared common pathways might explain why non-targeted VTs might become noninducible after ablation of other VTs.

Remote magnetic navigation for mapping and ablating right ventricular outflow tract tachycardia

Navigation, mapping, and ablation in the right ventricular outflow tract (RVOT) can be difficult. Catheter navigation using external magnetic fields may allow more accurate mapping and ablation. The purpose of this study was to assess the feasibility of RVOT tachycardia ablation using remote magnetic navigation. Mapping and ablation were performed in eight patients with outflow tract ventricular arrhythmias. Tachycardia mapping was undertaken with a 64-polar basket catheter, followed by remote activation and pace-mapping using a magnetically enabled catheter. The area of interest was localized on the basket catheter in seven patients in whom an RVOT arrhythmia was identified. Remote navigation of the magnetic catheter to this area was followed by pace-mapping. Ablation was performed at the site of perfect pace-mapping, with earliest activation if possible. Acute success was achieved in all patients (median four applications). Median procedural time was 144 minutes, with 13.4 minutes of patient fluoroscopy time and 3.8 minutes of physician fluoroscopy time. No complications occurred. One recurrence occurred during follow-up (mean 366 days). RVOT tachycardias can be mapped and ablated using remote magnetic navigation, initially guided by a basket catheter. Precise activation and pace-mapping are possible. Remote magnetic navigation permitted low fluoroscopy exposure for the physician. Long-term results are promising.

Prevalence of a shared isthmus in postinfarction patients with pleiomorphic, hemodynamically tolerated ventricular tachycardias.

Multiple forms of ventricular tachycardia (VT) after myocardial infarction may result from multiple reentrant circuits that share an isthmus or from separate reentrant circuits. The prevalence of a shared isthmus in patients with multiple hemodynamically tolerated VTs has not been determined. Criteria for a shared isthmus consisted of (1) concealed entrainment of >1 VT at a single pacing site; (2) concealed entrainment during VT and a perfect pace map of another VT at the same pacing site; or (3) concealed entrainment of VT of a given morphology that had at least two cycle lengths that varied by at least 100 msec. In a series of 19 patients (16 men and 3 women; age 65+/-14 years, ejection fraction 0.25+/-0.09) with 54 VTs (mean cycle length 494+/-98 msec), there was evidence of a shared isthmus in 23 VTs (43%) at 11 sites in 9 patients. Concealed entrainment of two different VTs was observed at 4 of 11 sites. At 5 of 11 sites there was concealed entrainment of one VT and a perfect pace map of another VT. At the remaining 2 of 11 sites, there was concealed entrainment of a VT that had two different cycle lengths. Nineteen of the 23 VTs were ablated successfully with radiofrequency energy applications at 11 sites. In postinfarction patients with pleiomorphic, hemodynamically stable VT, a shared isthmus may be present in approximately 40% of VTs.