Rupa Bala

Electroanatomic Substrate and Ablation Outcome for Suspected Epicardial Ventricular Tachycardia in Left Ventricular Nonischemic Cardiomyopathy

OBJECTIVES The aim of the study was to define the epicardial substrate and ablation outcome in patients with left ventricular nonischemic cardiomyopathy (NICM) and suspected epicardial ventricular tachycardia (VT). BACKGROUND Ventricular tachycardia in NICM often originates from the epicardium. METHODS Twenty-two patients with NICM underwent detailed endocardial and epicardial bipolar voltage maps and VT ablation for suspected epicardial VT. Eight patients with normal hearts and idiopathic VT served to define normal epicardial electrograms. Low-voltage regions were also assessed for wide (>80 ms), split, or late electrograms. RESULTS Normal epicardial bipolar voltage was identified as >1.0 mV on the basis of the reference population. Confluent low-voltage areas were present in 18 epicardial (82%) and 12 endocardial (54%) maps and were typically over basal lateral LV. In the 18 patients with epicardial VT on the basis of activation/pacemapping, the mean epicardial area was greater than the endocardial low-voltage area (55.3 +/- 33.5 cm(2) vs. 22.9 +/- 32.4 cm(2), p < 0.01). Epicardial low-voltage areas showed 49.7% wide (>80 ms), split, and/or late electrograms rarely seen in the reference patients (2.3%). During follow-up of 18 +/- 7 months, ablation resulted in VT elimination in 15 of 21 patients (71%) including 14 of 18 patients (78%) with epicardial VT. CONCLUSIONS In patients with NICM and VT of epicardial origin, the substrate is characterized by areas of basal LV epicardial > endocardial bipolar low voltage. The electrograms in these areas are not only small (<1.0 mV) but wide (>80 ms), split, and/or late, and help identify the substrate targeted for successful ablation.

Endocardial unipolar voltage mapping to detect epicardial ventricular tachycardia substrate in patients with nonischemic left ventricular cardiomyopathy

Background—Patients with nonischemic left ventricular cardiomyopathy (LVCM) and ventricular tachycardia (VT) have complex 3-dimensional substrate with variable involvement of the endocardium (ENDO) and epicardium (EPI). The purpose of this study was to determine whether ENDO unipolar (UNI) mapping with a larger electric field of view could identify EPI low bipolar (BIP) voltage regions in patients with LVCM undergoing VT ablation. Methods and Results—The reference value for normal ENDO unipolar voltage was determined from 6 patients without structural heart disease. Consecutive patients undergoing VT ablation over an 8-year period with detailed (>100 points) LV ENDO and EPI mapping and normal LV ENDO BIP voltage were identified. From this cohort, we compared patients with structurally normal hearts and normal EPI BIP voltage (EPI−, group 1) with patients with LVCM and low LV EPI BIP voltage regions present (EPI+, group 2). Confluent regions of ENDO UNI and EPI BIP low voltage (>2 cm2) were measured. The normal signal amplitude was >8.27 mV for LV ENDO UNI electrograms. Detailed LV ENDO-EPI maps in 5 EPI− patients were compared with 11 EPI+ patients. Confluent ENDO UNI low-voltage regions were seen in 9 of 11 (82%) of the EPI+ (group 2) patients compared with none of 5 EPI− (group 1) patients (P<0.001). In all 9 patients with ENDO UNI low voltage, the ENDO UNI low-voltage regions were directly opposite to an area of EPI BIP low voltage (61% ENDO UNI-EPI BIP low-voltage area overlap). Conclusions—EPI arrhythmia substrate can be reliably identified in most patients with LVCM using ENDO UNI voltage mapping in the absence of ENDO BIP abnormalities.

Long-Term Outcome After Successful Catheter Ablation of Atrial Fibrillation

Background—Pulmonary vein isolation (PVI) is increasingly used for treatment of atrial fibrillation (AF), but few reports exist regarding long-term success. We determined 5-year outcomes of PVI among patients with freedom from AF off antiarrhythmic drugs (AAD) for 1 year after PVI. Methods and Results—Consecutive patients with paroxysmal or persistent AF who underwent PVI at the University of Pennsylvania from 2000 to 2003 and were free from AF 1 year after ablation were included. Proximal isolation of PVs and non-PV triggers of AF was performed. Long-term ablation success, defined as freedom from AF off AAD after a single ablation procedure, was determined. All patients had transtelephonic monitoring at 3 to 6 months and 12 months and at least yearly contact thereafter. One hundred twenty-three patients were free of AF without AAD at 1 year. AF freedom off AAD was 85% at 3 years and 71% at 5 years, with an approximate 7% per year late recurrence rate after the first year. Patients with recurrent AF ≥5 years after index PVI were older, had larger left atrial size, more AF triggers and more likely had persistent AF. In multivariate analysis, persistent AF (odds ratio, 2.8; 95% confidence interval, 1.4 to 5.7, P=0.005) and age (odds ratio, 1.1; 95% confidence interval, 1.0 to 1.1, P=0.036) independently predicted long-term AF recurrence. Conclusions—Among patients with paroxysmal or persistent AF and AF freedom 1 year after segmental PVI, the majority (71%) remained free of AF for up to 5 years, with an approximate late recurrence rate of 7% per year. Continued vigilance for recurrent AF after PV isolation is warranted, particularly in patients with persistent AF.

Long‐Term Clinical Efficacy and Risk of Catheter Ablation for Atrial Fibrillation in the Elderly

Introduction: The number of elderly patients with atrial fibrillation (AF) is increasing rapidly, and the safety and efficacy of catheter ablation in this demographic group has not been established.

The V2 Transition Ratio: A New Electrocardiographic Criterion for Distinguishing Left From Right Ventricular Outflow Tract Tachycardia Origin

2011;57;2255-2262 J. Am. Coll. Cardiol. David Lin, Michael P. Riley, and Edward P. Gerstenfeld Fermin C. Garcia, Sanjay Dixit, David J. Callans, Joshua M. Cooper, Rupa Bala, Brian P. Betensky, Robert E. Park, Francis E. Marchlinski, Matthew D. Hutchinson, Origin Distinguishing Left From Right Ventricular Outflow Tract Tachycardia Transition Ratio: A New Electrocardiographic Criterion for 2 The V This information is current as of May 29, 2011 http://content.onlinejacc.org/cgi/content/full/57/22/2255 located on the World Wide Web at: The online version of this article, along with updated information and services, isOBJECTIVES We sought to develop electrocardiography (ECG) criteria for distinguishing left ventricular outflow tract (LVOT) from right ventricular outflow tract (RVOT) origin in patients with idiopathic outflow tract ventricular tachycardia (OTVT) and lead V(3) R/S transition. BACKGROUND Several ECG criteria have been proposed for differentiating left from right OTVT origin; ventricular tachycardias (VTs) with left bundle branch block and V(3) transition remain a challenge. METHODS We analyzed the surface ECG pattern of patients with OTVT with a precordial transition in lead V(3) who underwent successful catheter ablation. Sinus and VT QRS morphologies were measured in limb and precordial leads with electronic calipers. The V(2) and V(3) transition ratios were calculated by computing the percentage R-wave during VT (R/R+S)(VT) divided by the percentage R-wave in sinus rhythm (R/R+S)(SR). RESULTS We retrospectively analyzed ECGs from 40 patients (mean age 44 ± 14 years, 21 female) with outflow tract premature ventricular contractions (PVCs)/VT. Patients with structural heart disease, paced rhythms, and bundle branch block during sinus rhythm were excluded. The V(2) transition ratio was significantly greater for LVOT PVCs compared with RVOT PVCs (1.27 ± 0.60 vs. 0.23 ± 0.16; p < 0.001) and was the only independent predictor of LVOT origin. In 21 prospective cases, a V(2) transition ratio ≥0.60 predicted an LVOT origin with 91% accuracy. A PVC precordial transition occurring later than the sinus rhythm transition excluded an LVOT origin with 100% accuracy. CONCLUSIONS The V(2) transition ratio is a novel electrocardiographic measure that reliably distinguishes LVOT from RVOT origin in patients with lead V(3) precordial transition. This measure might be useful for counseling patients and planning an ablation strategy.

Clinical ResearchHeart Rhythm DisorderThe V2 Transition Ratio: A New Electrocardiographic Criterion for Distinguishing Left From Right Ventricular Outflow Tract Tachycardia Origin

2011;57;2255-2262 J. Am. Coll. Cardiol. David Lin, Michael P. Riley, and Edward P. Gerstenfeld Fermin C. Garcia, Sanjay Dixit, David J. Callans, Joshua M. Cooper, Rupa Bala, Brian P. Betensky, Robert E. Park, Francis E. Marchlinski, Matthew D. Hutchinson, Origin Distinguishing Left From Right Ventricular Outflow Tract Tachycardia Transition Ratio: A New Electrocardiographic Criterion for 2 The V This information is current as of May 29, 2011 http://content.onlinejacc.org/cgi/content/full/57/22/2255 located on the World Wide Web at: The online version of this article, along with updated information and services, isOBJECTIVES We sought to develop electrocardiography (ECG) criteria for distinguishing left ventricular outflow tract (LVOT) from right ventricular outflow tract (RVOT) origin in patients with idiopathic outflow tract ventricular tachycardia (OTVT) and lead V(3) R/S transition. BACKGROUND Several ECG criteria have been proposed for differentiating left from right OTVT origin; ventricular tachycardias (VTs) with left bundle branch block and V(3) transition remain a challenge. METHODS We analyzed the surface ECG pattern of patients with OTVT with a precordial transition in lead V(3) who underwent successful catheter ablation. Sinus and VT QRS morphologies were measured in limb and precordial leads with electronic calipers. The V(2) and V(3) transition ratios were calculated by computing the percentage R-wave during VT (R/R+S)(VT) divided by the percentage R-wave in sinus rhythm (R/R+S)(SR). RESULTS We retrospectively analyzed ECGs from 40 patients (mean age 44 ± 14 years, 21 female) with outflow tract premature ventricular contractions (PVCs)/VT. Patients with structural heart disease, paced rhythms, and bundle branch block during sinus rhythm were excluded. The V(2) transition ratio was significantly greater for LVOT PVCs compared with RVOT PVCs (1.27 ± 0.60 vs. 0.23 ± 0.16; p < 0.001) and was the only independent predictor of LVOT origin. In 21 prospective cases, a V(2) transition ratio ≥0.60 predicted an LVOT origin with 91% accuracy. A PVC precordial transition occurring later than the sinus rhythm transition excluded an LVOT origin with 100% accuracy. CONCLUSIONS The V(2) transition ratio is a novel electrocardiographic measure that reliably distinguishes LVOT from RVOT origin in patients with lead V(3) precordial transition. This measure might be useful for counseling patients and planning an ablation strategy.

Reversal of outflow tract ventricular premature depolarization–induced cardiomyopathy with ablation: Effect of residual arrhythmia burden and preexisting cardiomyopathy on outcome

BACKGROUND Outflow tract ventricular premature depolarizations (VPDs) can be associated with reversible left ventricular cardiomyopathy (LVCM). Limited data exist regarding the outcome after ablation of outflow tract VPDs from the LV and the impact of residual VPDs or preexisting LVCM prior to the diagnosis of VPDs on recovery of LV function. OBJECTIVE To examine the safety, efficacy, and long-term effect of radiofrequency ablation on LV function in patients with LVCM and frequent outflow tract VPDs and examine the effect of ablation in patients with LVCM known to precede the onset of VPDs and the impact of residual VPD frequency on recovery of LV function. METHODS Sixty-nine patients (43 men; age 51 ± 16 years) with nonischemic LVCM (left ventricular ejection fraction [LVEF] 35% ± 9%, left ventricular diastolic diameter [LVDD] 5.8 ± 0.7 cm) were referred for ablation of frequent outflow tract VPDs (29% ± 13%). RESULTS VPDs originated in the right ventricular outflow tract in 27 (39%) patients and the left ventricular outflow tract in 42 (61%) patients. After follow-up of 11 ± 6 months, 44 (66%) patients had rare (<2%) VPDs, 15 (22%) had decreased VPD burden (>80% reduction and always <5000 VPDs), and 8 (12%) had no clinical improvement with persistent (5 patients) or recurrent (3 patients) VPDs. Only patients with either rare or decreased VPD burden had a significant improvement in LVEF (ΔLVEF 14% ± 9% vs 13% ± 7% vs -3% ± 6%, respectively, P <.001) and LVDD (ΔLVDD -4 ± 5 vs -2 ± 4 vs 0 ± 4, respectively, P = .038), regardless of chamber of origin. The magnitude of LVEF improvement correlated with the decline in residual VPD burden (r = 0.475, P = .007). Patients with preexisting LVCM had a more modest but still significant improvement in LV function compared to patients without preexisting LVCM (ΔLVEF 8% vs 13%, P = .046). Multivariate analysis revealed ablation outcome, higher LVEF, and absence of preexisting LVCM were independently associated with LVEF improvement. CONCLUSION Frequent outflow tract VPDs are associated with LVCM regardless of ventricle of origin. Significant (>80%) reduction in VPD burden has comparable improvement in LV function to complete VPD elimination. Successful VPD ablation may be beneficial even in patients with preexisting LVCM.

Twelve-lead electrocardiographic characteristics of the aortic cusp region guided by intracardiac echocardiography and electroanatomic mapping

BACKGROUND The most common site of origin of idiopathic ventricular tachycardia (VT) is the right ventricular outflow tract. Idiopathic VT also can arise from the left ventricular outflow tract and the surrounding structures. Morphologic descriptions of 12-lead ECG characteristics of the aortic cusp region are limited. OBJECTIVE The purpose of this study was to define unique ECG characteristics of the aortic cusp region by performing a systematic analysis of pacemapping of this region in patients with structurally normal hearts. METHODS A combination of electroanatomic mapping, intracardiac echocardiography, and fluoroscopic guidance was used to study a total of 30 patients with structurally normal hearts undergoing left-sided ablation procedures. Each of the aortic valve cusps and the aortomitral continuity were paced at threshold and analyzed offline to determine unique ECG characteristics. RESULTS Pacing from the left coronary cusp typically produced a multiphasic QRS morphology consistent with an M or W pattern in lead V(1) with a precordial transition (R>S) no later than V(2). Pacing from the right coronary cusp typically resulted in a left bundle-type pattern with a broad small R wave in V(2) and a precordial transition generally at V(3). Pacing from the aortomitral continuity resulted in a qR pattern that was not observed anywhere else in the left ventricular outflow tract. When comparing the right coronary cusp and left coronary cusp, the precordial transition was earlier in the left coronary cusp than in the right coronary cusp. Pacing the noncoronary cusp uniformly resulted in atrial capture. CONCLUSION When considering ablation of idiopathic VT, the aortic cusps and aortomitral continuity must be considered as possible foci. The 12-lead ECG, a readily and easily obtainable source of information, has useful characteristics for differentiating VTs arising from the cusp region.

Antiarrhythmics After Ablation of Atrial Fibrillation (5A Study): Six-Month Follow-Up Study

Background—We previously demonstrated that treatment with antiarrhythmic drugs (AADs) during the first 6 weeks after atrial fibrillation (AF) ablation reduces the incidence of clinically significant atrial arrhythmias and need for cardioversion or hospitalization for arrhythmia management. Whether early rhythm suppression decreases longer-term arrhythmia recurrence is unknown. We now report the 6-month follow-up data from this study. Methods and Results—The Antiarrhythmics After Ablation of Atrial Fibrillation study prospectively randomized patients with paroxysmal AF undergoing ablation to either receive (AAD group) or not receive (no-AAD group) AAD treatment for the first 6 weeks after ablation; all patients received atrioventricular nodal blockers. Physicians were encouraged to stop the AADs after the 6-week treatment period. All patients underwent 4 weeks of transtelephonic monitoring to document asymptomatic AF and an evaluation at 6 weeks and 6 months. A total of 110 patients (71% men) aged 55±9 years were randomized, with 53 to AAD and 57 to no AAD. At 6 months, there was no difference in freedom from AF between the early AAD and no-AAD groups (38/53 [72%] versus 39/57 [68%]; P=0.84). Lack of early AF recurrence during the initial 6-week period was the only independent predictor of 6-month freedom from AF (64/76 [84%] without early recurrence versus 13/34 [38%] with early recurrence; P=0.0001). Conclusions—Although short-term use of AADs after AF ablation decreases early recurrence of atrial arrhythmias, early use of AADs does not prevent arrhythmia recurrence at 6 months. Early AF recurrence on or off AADs during the initial 6-week blanking period is a strong independent predictor of long-term AF recurrence. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT00408200.

Appropriateness of primary prevention implantable cardioverter- defibrillators at the time of generator replacement: Are indications still met?

OBJECTIVES This study sought to determine how often patients with primary prevention implantable cardioverter-defibrillators (ICDs) meet guideline-derived indications at the time of generator replacement. BACKGROUND Professional societies have developed guideline criteria for the appropriate implantation of an ICD for the primary prevention of sudden cardiac death. It is unknown whether patients continue to meet criteria when their devices need replacement for battery depletion. METHODS We performed a retrospective chart review of patients undergoing replacement of primary prevention ICDs at 2 tertiary Veterans Affairs Medical Centers. Indications for continued ICD therapy at the time of generator replacement included a left ventricular ejection fraction (LVEF) ≤35% or receipt of appropriate device therapy. RESULTS In our cohort of 231 patients, 59 (26%) no longer met guideline-driven indications for an ICD at the time of generator replacement. An additional 79 patients (34%) had not received any appropriate ICD therapies and had not undergone reassessment of their LVEF. Patients with an initial LVEF of 30% to 35% were less likely to meet indications for ICD therapy at the time of replacement (odds ratio: 0.52; 95% confidence interval: 0.30 to 0.88; p = 0.01). Patients without ICD indications subsequently received appropriate ICD therapies at a significantly lower rate than patients with indications (2.8% vs. 10.7% annually, p < 0.001). If ICD generator explantations were performed instead of replacements in the patients without ICD indications, the cost savings would be