How to recognize, manage, and prevent complications during atrial fibrillation ablation.
Explore the source record for details and available documents.
Atrial Fibrillation↗
Biomedical subjects
Sanjay Dixit
Publications and source records attributed to Sanjay Dixit.
Case report: Placement of a coronary sinus lead in a patient with dextrocardia and situs inversus.
Situs inversus with dextrocardia is a congenital condition in which the heart is a mirror image of the anatomically normal heart on the right side. Patients with this condition are increasingly surviving into adulthood and may present with heart failure. Several of such patients may benefit from atriobiventricular pacing which may be technically challenging. This case report describes techniques and equipment used to successfully place a coronary sinus lead in a patient with this congenital condition.
Dextrocardia↗
Incidence and predictors of very late recurrence of atrial fibrillation after ablation.
INTRODUCTION: Radiofrequency catheter ablation can effectively treat patients with refractory atrial fibrillation (AF). Very late AF recurrence (> or = 12 months post-ablation) is uncommon and may represent a unique patient cohort. METHODS AND RESULTS: A nested case-control study was performed in the cohort who underwent AF ablation at the University of Pennsylvania to characterize patients who develop very late AF recurrence after ablation. The procedure consisted of isolation of pulmonary veins (PVs) demonstrating triggers and elimination of non-PV triggers initiating AF. Twenty-seven (7.9%) patients with very late recurrence were compared to 219 patients without recurrence and > or = 12 months of follow-up. The mean age was 54.6 +/- 11.3 years and 79% were men. Very late recurrence patients more likely weighed >200 lbs (70% vs 55%, P = 0.01); during initial ablation had fewer PVs isolated (2.8 +/- 1.1 vs 3.3 +/- 1.0, P = 0.03); and were less likely to have right inferior PV isolation (37% vs 61%, P = 0.02), less likely to have isolation of all PVs (30% vs 56%, P = 0.01), and more likely to have non-PV triggers (30% vs 11% OR 3.4(95% CI, 1.3-8.7), P = 0.01). PV reconnectivity and new triggers were found in the majority of patients with very late recurrence of AF who underwent repeat ablation. CONCLUSION: Very late recurrence of AF more likely occurred in patients >200 lbs who demonstrated non-PV triggers and did not undergo right inferior PV isolation. The majority of patients undergoing repeat ablation for very late recurrence demonstrated PV reconnectivity and new non-PV and PV triggers not observed during the initial ablation.
Adolescent↗
Reversal of left ventricular dysfunction following ablation of atrial fibrillation.
BACKGROUND: Evaluation of ventricular rate control in atrial fibrillation (AF) can be difficult, and the presence of an AF-induced ventricular cardiomyopathy due to intermittent poor rate control or other causes may be underestimated. The outcome with AF ablation in patients with a decreased left ventricular ejection fraction (LVEF) may provide insight into this important clinical issue. OBJECTIVE: To determine the effect of pulmonary vein isolation on LVEF in patients with AF and decreased LVEF (< or = 50%). METHODS: Ablation consisted of proximal isolation of arrhythmogenic pulmonary veins (PVs) and elimination of non-PV triggers. LVEF was determined within 24 hours after ablation and again at up to 6 months follow-up. Transtelephonic monitoring was performed routinely for 2-3 weeks prior to ablation, at 6 weeks, and 6 months post and with symptoms following ablation. AF control was defined as freedom from AF or marked (>90%) reduction in AF burden on or off previously ineffective antiarrhythmic medication. RESULTS: AF ablation was performed in 366 patients and 67 (18%) patients had decreased LV function with a mean LVEF of 42 +/- 9%. An average of 3.4 +/- 0.9 PVs were isolated. AF control in the depressed LVEF group compared favorably with the normal EF group (86% vs. 87% P = NS), although more redo procedures were required (1.6 +/- 0.8 vs 1.3 +/- 0.6 procedures; P < or = 0.05). Only 15 of 67 patients (22%) with decreased LVEF had shown tachycardia (>100 bpm) on repeated preablation ECG recordings during AF. In the decreased LVEF group, the LVEF increased from 42 +/- 9% to 56 +/- 8% (P < 0.001) after ablation. CONCLUSIONS: Patients with AF and decreased LVEF undergoing AF ablation have similar success to patients with normal LVEF and have improvement in LVEF after ablation. These results suggest the presence of a reversible AF-induced ventricular cardiomyopathy in many patients with AF and depressed LV function. The presence of under-recognized and reversible cardiomyopathy even when tachycardia is not persistent is important to recognize.
Atrial Fibrillation↗
Characteristics of patients undergoing atrial fibrillation ablation: trends over a seven-year period 1999-2005.
BACKGROUND: Catheter ablation procedures for treating atrial fibrillation (AF) have dramatically increased since triggers of AF were first described in 1998. OBJECTIVE: We explored changes in patient characteristics in patients referred for catheter ablation of AF over a seven-year period from 1999 through 2005. METHODS: Patient characteristics were examined for all patients undergoing AF ablation from 1999 through 2005 at the University of Pennsylvania Health System (UPHS). The gender of patients undergoing ablation was also compared with outpatients seen at UPHS with a primary diagnosis of AF. RESULTS: From 1999 to 2005 the number of patients undergoing ablation has increased steadily, from 29 patients in 1999 to 265 patients in 2005 (P < 0.01). Patients have become older (47 to 56 years; P < 0.01), with more persistent or permanent AF (17% to 45%; P < 0.01), larger left atrial size (4.0 to 4.4 cm; P < 0.01), and fewer antiarrhythmic drugs used prior to ablation (3.9 to 2.0 drugs; P < 0.01). Patients undergoing ablation have been predominantly male, with a significantly higher male prevalence than patients seen in the UPHS outpatient primary care clinic with AF (77% vs 59% male; P < 0.001). CONCLUSIONS: Patients undergoing AF ablation from 1999 to 2005 are older, with larger left atrial size, more persistent/permanent AF, and fewer prior antiarrhythmic agents used. Compared with the gender-specific rates of AF in the population, the majority of patients referred for ablation are men, suggesting a referral bias against this invasive procedure for women. These findings are important for interpreting the outcome of ablation in the current era, and for designing prospective randomized trials.
Aged↗
Comparison of cool tip versus 8-mm tip catheter in achieving electrical isolation of pulmonary veins for long-term control of atrial fibrillation: a prospective randomized pilot study.
OBJECTIVE: To compare safety and efficacy of 8-mm versus cooled tip catheter in achieving electrical isolation (EI) of pulmonary veins (PV) for long-term control of atrial fibrillation (AF). BACKGROUND: There is paucity of studies comparing safety/efficacy of 8-mm and cooled tip catheters in patients undergoing AF ablation. METHODS AND RESULTS: This was a randomized and patient-blinded study. Subjects were followed by clinic visits (at 6 weeks and 6 months) and transtelephonic monitoring (3-week duration) done around each visit. Primary endpoints were: (1) long-term AF control (complete freedom and/or >90% reduction in AF burden on or off antiarrhythmic drugs at 6 months after a single ablation), and (2) occurrence of serious adverse events (cardiac tamponade, stroke, LA-esophageal fistula, and/or death). Eighty-two patients (age 56 +/- 9 years, 60 males, paroxysmal AF = 59) were randomized (42 patients to 8-mm tip and 40 patients to cooled tip). EI of PVs was achieved in shorter time by the 8-mm tip as compared with cooled tip catheter (40 +/- 23 minutes vs 50 +/- 30 minutes; P < 0.05) but long-term AF control was not different between the two (32 patients [78%] vs 28 patients [70%], respectively; P = NS). One serious adverse event occurred in each group (LA-esophageal fistula and stroke, respectively) and no significant PV stenosis was observed in either. CONCLUSION: EI of PVs using either 8-mm or cooled tip catheter results in long-term AF control in the majority after a single ablation procedure, with comparable efficacy and safety.
Atrial Fibrillation↗
Atrioventricular nodal reentrant tachycardia in patients referred for atrial fibrillation ablation: response to ablation that incorporates slow-pathway modification.
BACKGROUND: Although the most common sites of atrial ectopy that trigger atrial fibrillation (AF) are in or around the pulmonary veins (PVs), atrioventricular nodal reentrant tachycardia (AVNRT) can also cause or coexist with AF. We sought to characterize patients with AF and AVNRT and assess clinical outcomes after ablation. METHODS AND RESULTS: To determine the prevalence of concomitant AVNRT and AF, 629 consecutive patients referred for catheter ablation between November 1998 and March 2005 were studied. Electrophysiological studies with programmed stimulation during isoproterenol infusion identified atrial ectopy that initiated AF and the presence of inducible AVNRT. AF ablation consisted of proximal isolation of PVs and elimination of any non-PV trigger of AF, including AVNRT. There were 27 patients (4.3%) who had inducible AVNRT at the time of AF ablation. Of these, 13 underwent AVNRT ablation without PV isolation. Compared with the rest of the cohort, patients with AVNRT and AF were younger at the time of symptom onset (age 36.8+/-13.8 versus 48.2+/-11.7 years; P<0.01). Freedom from AF with or without previously ineffective antiarrhythmic medication was similar in both groups (96.3% versus 90.7%; mean follow-up 21.4+/-9.4 months); however, patients with AVNRT targeted for ablation were more likely to be AF free while not taking any antiarrhythmic medication after a single procedure during the follow-up period (87.5% versus 54.7%; P<0.01) and had fewer complications (0% versus 2.5%; P=0.30). Twelve of the 13 patients who underwent slow-pathway ablation without left atrial ablation remained AF free without the need for antiarrhythmic medication after a single procedure. CONCLUSIONS: AVNRT is an uncommon AF trigger seen more frequently in younger patients. Ablation of AVNRT in patients with AF was associated with improved outcomes compared with those with other triggers of AF.
Adult↗
Twelve-lead ECG features to identify ventricular tachycardia arising from the epicardial right ventricle.
BACKGROUND: Usefulness of 12-lead ECG for predicting an epicardial origin for ventricular tachycardia (VT) arising from the right ventricle (RV) has not been assessed. An epicardial approach is sometimes warranted to eliminate RV VT. OBJECTIVES: The purpose of this study was investigate the hypothesis that specific ECG features identify an epicardial origin for RV VT. METHODS: To mimic an endocardial or epicardial origin, we paced representative sites in 13 patients undergoing RV endocardial/epicardial mapping (134/180 pace map sites). RESULTS: QRS duration from epicardial vs endocardial sites was not different (183 +/- 27 ms vs 185 +/- 28 ms, P = .3). Reported cut-off values for identifying epicardial left ventricular origin, pseudo-delta wave (> or =34 ms), intrinsicoid deflection time (> or =85 ms), and RS complex (> or =121 ms) did not apply to the RV. A Q wave in lead II, III, or aVF was more likely noted from inferior epicardial vs endocardial sites (53/73 vs 16/43, P <.01). A Q wave in lead I was more frequently present from epicardial vs endocardial anterior RV sites (30/82 vs 5/52, P <.001). QS in lead V(2) was noted from anatomically matched epicardial anterior RV sites (22/33 vs 13/33, P <.05). In the RV outflow tract, no ECG feature distinguishing epicardial/endocardial origin reached statistical significance. CONCLUSION: A Q wave or QS in leads that best reflect local activation suggest an epicardial origin for RV depolarization and may help in identifying a probable epicardial site of origin for RV VT. QRS duration and reported criteria for epicardial origin of VT in the left ventricle do not identify a probable epicardial origin in the RV.
Catheter Ablation↗
Elevated defibrillation thresholds in patients undergoing biventricular defibrillator implantation: incidence and predictors.
BACKGROUND: The biventricular implantable cardioverter-defibrillator (ICD) is an important therapy for select patients with severe heart failure. Given reported risk factors for elevated defibrillation thresholds (DFTs), patients undergoing biventricular ICD placement would be suspected of having a higher incidence of elevated DFT. OBJECTIVES: The purpose of this study was to examine the clinical predictors and mortality risk of elevated DFTs in patients receiving a biventricular ICD. METHODS: Characteristics of patients undergoing biventricular ICD placement with an elevated DFT were compared to those without an elevated DFT. RESULTS: An elevated DFT was found in 14 (12%) of 121 patients. Mean QRS duration was 210 +/- 50 ms in the elevated DFT group and 171 +/- 36 ms in the normal DFT group (P = .01). Patients with a QRS duration >or=200 ms were more likely to have an elevated DFT than those with a duration <200 ms (odds ratio 13.4, 95% confidence interval 3.1-66.7, P <.01). No other clinical characteristics were associated with an elevated DFT. More than 90% of patients with an elevated DFT achieved an adequate safety margin through system modification or manipulation of their drug regimen. An elevated DFT did not have an impact on 2-year mortality. CONCLUSION: Patients with a biventricular ICD had a 12% incidence of elevated DFT in our sequential patient cohort. QRS duration prior to biventricular ICD placement is the most powerful predictor of patients at risk for an elevated DFT. An elevated DFT does not have an impact on mortality, perhaps because of successful implementation of system modifications to ensure an adequate defibrillation safety margin.
Adult↗
Proper management of pericardial tamponade as a late complication of implantable cardiac device placement.
Cardiac tamponade as a late complication of device placement is exceedingly rare, with only several case reports previously published. We sought to characterize our institution's experience with cardiac tamponade occurring >30 days after permanent pacemaker or implantable cardioverter-defibrillator placement. From January 2000 to June 2003, 2,535 patients received an implantable cardiac device at our institution. Four patients (0.17%) presented with cardiac tamponade>30 days after the procedure. A fifth patient who had undergone implantation at another institution but was referred to our group with tamponade was also included in the analysis. The baseline characteristics varied widely with respect to age, gender, device type, and anticoagulation status. Lead parameters were altered in 2 of 5 patients. Two patients were treated with pericardiocentesis, 1 patient had pericardiocentesis followed by lead extraction, and 2 patients required cardiac surgical intervention. Pericardial fluid culture and cytologic findings were negative in all patients. All patients had normal recovery and were well at a mean follow-up of 31 months. In conclusion, cardiac tamponade is a rare, but serious late complication of permanent pacemaker and implantable cardioverter-defibrillator placement. The patient characteristics and mode of presentation vary widely. Once tamponade is recognized and treated, these patients appear well at long-term follow-up, with no other device-related problems. A role for lead manipulation does not appear to exist in the standard treatment of these patients.
Adult↗
Effect of pulmonary vein isolation on the left-to-right atrial dominant frequency gradient in human atrial fibrillation.
BACKGROUND: We previously demonstrated the existence of a left-to-right atrial dominant frequency gradient during paroxysmal but not persistent atrial fibrillation (AF) in humans. One possible mechanism of the left-to-right dominant frequency gradient involves the role of the pulmonary veins (PVs) in AF maintenance. OBJECTIVES: The purpose of this study was to examine the effect of PV isolation on the dominant frequency gradient and outcome after PV isolation. METHODS: Patients with either paroxysmal or persistent AF were studied. Recordings were made from catheters in the coronary sinus (CS), posterior right atrium (RA), and posterior left atrium (LA) during AF before and after PV isolation. Mean left-to-right dominant frequency gradient was measured before and after segmental PV isolation. Patients were followed for AF recurrence after PV isolation. RESULTS: Twenty-seven patients with paroxysmal (n = 15) or persistent (n = 12) AF were studied. In the paroxysmal group, baseline dominant frequency was greatest in the posterior LA with a significant left-to-right atrial dominant frequency gradient (posterior LA = 6.2 +/- 0.9 Hz, CS = 5.8 +/- 0.8 Hz, posterior RA = 5.4 +/- 0.9 Hz; P <.001). After PV isolation, there was no regional difference in dominant frequency (5.9 +/- 0.7 Hz vs 5.7 +/- 0.6 Hz vs 5.7 +/- 0.7 Hz, respectively; P = NS). In the persistent AF group, there was no overall difference in dominant frequency among sites before or after PV isolation (P = NS); however, patients with long-term freedom from AF after PV isolation had a higher left-to-right dominant frequency gradient compared with patients with recurrent AF (0.4 vs 0.1 Hz; P <.05). CONCLUSION: PV isolation results in a loss in the left-to-right dominant frequency gradient in patients with paroxysmal AF. This finding supports the critical role of PVs in the maintenance of ongoing paroxysmal AF. Patients with persistent AF and a baseline left-to-right dominant frequency gradient have a better success rate with PV isolation alone compared with patients without a dominant frequency gradient.
Adult↗
Predictors of success after selective pulmonary vein isolation of arrhythmogenic pulmonary veins for treatment of atrial fibrillation.
BACKGROUND: Atrial fibrillation (AF) ablation procedures typically involve isolation of all pulmonary veins (PVs) in addition to adjunctive linear lesions, yet the need for such an extensive ablation strategy in all patients is unclear. OBJECTIVES: The purpose of this study was to identify a subgroup of patients undergoing AF ablation with good clinical success after limited PV isolation. METHODS: Patients (N = 450) underwent trigger-guided segmental isolation of only arrhythmogenic PVs. We compared clinical characteristics of patients who required isolation of only one or two PVs to those in whom AF ablation required isolating > or = 3 PVs. RESULTS: For the group of patients undergoing isolation of < or = 2 PVs, AF freedom without antiarrhythmic drug use was achieved in 56 (58%) of 97 patients, and AF control was achieved in 66 (68%) of 97 patients after a single procedure. After additional procedures, 77 (79%) of 97 patients achieved complete AF freedom without antiarrhythmic drugs, and 82 (85%) of 97 patients achieved AF control. Younger age (odds ratio [OR] 1.05; confidence interval [CI] 1.01,1.09) and lack of persistent AF (OR 3.27; CI 1.0, 10.7) were each independent predictors of freedom from AF. In patients younger than 50 years with paroxysmal AF undergoing isolation of < or = 2 PVs (n = 44), AF freedom without antiarrhythmic drugs was achieved in 32 (73%) of 44 after a single ablation procedure. CONCLUSION: Targeted PV isolation has a good long-term (18-month) success rate in patients younger than 50 years with paroxysmal AF and < or = 2 PVs triggering AF.
Atrial Fibrillation↗
Reentrant and nonreentrant forms of atrio-ventricular nodal tachycardia mimicking atrial fibrillation.
BACKGROUND: Atrial fibrillation (AF) manifests disorganized atrial activity and irregular R-R intervals on electrocardiogram (ECG). Variation in R-R intervals can also be seen with other supraventricular tachycardias that may mimic AF. OBJECTIVE: We report our observations on three patients who were referred to our center to undergo pulmonary vein (PV) isolation for erroneously diagnosed AF in the setting of dual atrio-ventricular (AV) nodal pathways manifesting as AV nodal reentrant tachycardia (AVNRT) and/or double response during sinus rhythm. METHODS AND RESULTS: These three subjects (two females) were derived from a group of 456 consecutive patients undergoing AF ablation at our center over a 3-year period. All three patients had been symptomatic for over 2 years, having failed two or more antiarrhythmic medications. In each case AF was initially diagnosed on ECG and/or recordings from ambulatory monitoring. However, in all three cases the correct diagnosis was established during the invasive electrophysiologic study. In one patient during the stimulation protocol, two narrow complex tachycardias were serially induced (cycle lengths: 305 and 360 msecs; VA time: 60 and 240 msecs). The latter was confirmed to be atypical AVNRT and during this tachycardia, block in upper pathway was observed. In the other two patients, sinus rhythm with repetitive runs of double response and isolated junctional beats were observed in the absence of retrograde conduction. Successful slow pathway modification was performed in each subject and all three patients have remained arrhythmia free over a mean follow-up of 31 +/- 16 months off antiarrhythmic medications. CONCLUSIONS: AF can be erroneously diagnosed in patients with dual AV nodal pathways manifesting double response and/or AVNRT. Incorporating a stimulation protocol as a part of the AF ablation procedure may help in diagnosing these rare clinical presentations that can be cured by slow pathway modification alone.
Adult↗
Defibrillation threshold testing: is it really necessary at the time of implantable cardioverter-defibrillator insertion?
OBJECTIVES: The purpose of this study was to (1) determine how often implantable cardioverter-defibrillator (ICD) system modifications were needed to obtain an adequate safety margin for defibrillation, (2) identify how often and for what indications defibrillation threshold (DFT) testing was not performed, and (3) identify factors predicting the need for modification. BACKGROUND: Ventricular fibrillation (VF) typically is induced at the time of ICD insertion. Although DFT testing often is minimized, a safety margin of 10 J has been utilized as a standard of care. However, current devices offer technology such as biphasic waveforms and high outputs, and the need for testing has been questioned. METHODS: We reviewed the records of the last 1,139 patients undergoing initial ICD placement, generator replacement, or revision. RESULTS: Seventy-one patients (6.2%) were identified as having an unacceptably high DFT (<10 J safety margin) requiring intervention, and some required >1 modification. Use of a high-output device alone was not enough to obtain an adequate DFT in 48% (34/71) of patients who required modifications (3% of the total population). No arrhythmia inductions were performed in 54 patients (4.7%) because of well-defined clinical conditions. Patients who required system modification had a lower ejection fraction, were younger, were less likely to have coronary artery disease, were more likely to be undergoing upgrade/generator replacement, and were more likely to be taking amiodarone. Long-term mortality was not different between the group of patients who required modification compared with those who did not (17% vs 20%, P = NS). CONCLUSIONS: Routine VF induction and documentation of effective defibrillation still remains a reasonable part of ICD placement because an inadequate safety margin may occur in >6% of patients. The incidence of patients who were inappropriate for testing based on well-defined clinical conditions is small (<5%) in this unselected large series. Although some clinical features may predict the need for system modification, additional studies are needed to better define "acceptable efficacy" of ICDs in preventing sudden death prior to altering these standards in selected patients.
Aged↗
Identification of distinct electrocardiographic patterns from the basal left ventricle: distinguishing medial and lateral sites of origin in patients with idiopathic ventricular tachycardia.
BACKGROUND: Idiopathic ventricular tachycardias (IVTs) can originate from the basal left ventricle (LV). OBJECTIVE: To determine if using magnetic electroanatomic mapping (MEAM) for accurate localization (1) unique ECG morphologies on pace maps from medial and lateral sites in basal LV could be identified and (2) this ECG information would facilitate VT localization. METHODS: In 12 patients with structurally normal hearts undergoing ablation for IVT, detailed MEAM of LV was constructed in sinus rhythm and pace-mapping was done from the septal-parahisian (S-P) region, aortomitral continuity (AMC), and superior, superolateral, and lateral mitral annular (MA) locations. Pace maps were analyzed for ECG morphologies in limb leads and transition patterns in precordial leads. RESULTS: Medial pacing sites (S-P and AMC) compared with lateral sites (superolateral and lateral MA) demonstrated narrower QRS complexes (134 +/- 24 msec vs. 182 +/- 18 msec; P < .05) with initial negative forces in lead V1 and predominantly positive forces in lead I (amplitude 0.59 +/- 0.27 mV vs. 0.16 +/- 0.34 mV; P < .05). The ratio of QRS complexes in leads II and III was >1 for all (12 of 12) S-P pace maps and 11 of 12 lateral MA pace maps but remained < or =1 for pace maps from 10 of 12 AMC locations, 11 of 12 superior MA locations, and 10 of 11 superolateral MA locations. Using these ECG criteria, a blinded reviewer was able to accurately localize the site of origin (SOO) of clinical arrhythmia (successful ablation site on MEAM) in 10 of 12 cases (83%) of IVT originating from basal LV. CONCLUSION: Pace maps from basal LV endocardium manifest site-dependent ECG morphologies that can help differentiate medial from lateral locations and can predict the SOO of clinical arrhythmias from this region.
Adult↗
Idiopathic fascicular left ventricular tachycardia: linear ablation lesion strategy for noninducible or nonsustained tachycardia.
BACKGROUND: Idiopathic "fascicular" left ventricular tachycardia (IFLVT) is frequently not inducible or nonsustained at the time of planned catheter ablation. The mechanism of the arrhythmia has been suggested to be reentry involving a sizable area of the LV inferior septum extending from base toward the apex. OBJECTIVE: We tested the ability of a series of radiofrequency lesions delivered in a linear fashion to the inferior-mid septum to control ventricular tachycardia not amenable to standard mapping ablation strategies. METHODS: Programmed stimulation both at baseline state and with isoproterenol after heart rate was increased by at least 25% was performed in all patients. The patients included in the study were either non-inducible or only had brief nonsustained VT not amenable to "traditional" mapping. A detailed electroanatomic map of the LV was performed in sinus rhythm. The location of the linear lesion along the inferior septum was guided by the presence of Purkinje potentials, with pacemapping as an additional guide. A linear lesion was placed perpendicular to the long axis of the ventricle approximately midway from the base to the apex in the region of the mid to mid-inferior septum. Radiofrequency lesions were delivered using a 4mm tip catheter at 50 Watts and 52 degrees for 60-90 seconds. RESULTS: Of 122 consecutive patients who underwent ablation of idiopathic VT from 1999 to 2003, 15 had IFLVT based on standard diagnostic criteria. Six of the 15 patients (40%) had nonsustained or no inducible VT in the EP lab. The number of RF lesions ranged from 7 to 15 (mean 9). The length of the effective linear lesion ranged from 1.2 to 2.2 cm (mean 1.7 cm). Development of left posterior fascicular block was noted in two of the six patients. However, despite the absence of development of left posterior fascicular block in the other four patients, no VT or premature ventricular beats could be induced after ablation using the same provocation maneuvers as performed in the baseline state. No spontaneous arrhythmias occurred during follow-up to 16 +/- 8 months (range 6 to 30 months). CONCLUSION: In patients with difficult to induce or nonsustained VT with the typical right bundle branch block pattern and a superiorly directed axis on 12-lead ECG, RF energy ablation delivered in a linear fashion approximately midway to two thirds toward the apex along the mid to inferior septum and perpendicular to the plane of the septum is safe and effective for VT control.
Adolescent↗
Increased intensity of anticoagulation may reduce risk of thrombus during atrial fibrillation ablation procedures in patients with spontaneous echo contrast.
INTRODUCTION: A 10% incidence of left atrial (LA) thrombus formation has been detected using intracardiac echocardiography (ICE) imaging monitoring during LA ablation for atrial fibrillation (AF). The aim of this study was to determine if the intensity of anticoagulation reduces LA thrombus formation during pulmonary vein isolation procedure in patients with AF and spontaneous echo contrast (SEC). METHODS AND RESULTS: We studied 511 patients (age 56 +/- 10 years) undergoing pulmonary vein ostial isolation/ablation using radiofrequency energy. SEC was detected in 179 of 511 patients with ICE imaging before dual transseptal catheterization. All patients were anticoagulated with heparin to achieve activated clotting time (ACT) 250-300 seconds (group I) or >300 seconds (group II) confirmed at 30-minute intervals. SEC was detected in 49/294 (16.7%) patients in group I versus 130/217 (59.9%) in group II (P < 0.0001). LA thrombus was observed in 33/294 (11.2%) patients in group I versus 6/217 (2.8%) in group II (P < 0.05). For those patients with SEC, LA thrombus was observed in 22/49 (44.9%) in group I versus 2/61 (4.6%) in group II (P < 0.0001). There were no significant differences in age, number of unsuccessful drugs, persistent AF, left ventricular ejection fraction, and LA diameter between the two groups. No clinical embolic event was observed with withdrawal of LA thrombus to the RA. CONCLUSION: ICE-diagnosed SEC before transseptal catheterization identifies an increased risk of LA thrombus. Increased intensity of heparin anticoagulation (ACT >300 seconds) during LA ablation for AF may prevent LA thrombus formation especially in patients with SEC.
Anticoagulants↗
Ventricular tachycardia/ventricular fibrillation ablation in the setting of ischemic heart disease.
Recurrent ventricular tachycardia (VT) in the setting of coronary artery disease is frequently a life-threatening electrophysiologic emergency. Even in patients with an implantable defibrillator, recurrent VT is frequently accompanied by repeated and disabling shock therapy. Catheter ablative therapy offers the ability to provide immediate control of recurrent VT. Long-term elimination of VT should be anticipated in most patients. This article reviews the strategies, tools, techniques, and expected outcome for catheter ablation of stable and unstable ventricular arrhythmias in the setting ischemic heart disease.
Catheter Ablation↗