Ventricular arrhythmia ablation in the presence of mechanical valve utilization and complications of catheter ablation for ventricular arrhythmia in patients with mechanical prosthetic valves.

BACKGROUND: Catheter ablation (CA) for ventricular arrhythmias (VAs) is increasingly utilized in recent years. We aimed to investigate the nationwide trends in utilization and procedural complications of CA for VAs in patients with mechanical valve (MV) prosthesis. METHODS: We drew data from the US National Inpatient Sample database to identify cases of VA ablations, including premature ventricular contraction and ventricular tachycardia, in patients with MVs, between 2003 and 2015. Sociodemographic and clinical data were collected and the incidence of catheter ablation complications, mortality, and length of stay were analyzed. We compared the outcomes to a propensity-matched cohort of patients without prior valve surgery. RESULTS: The study population included a weighted total of 647 CA cases in patients with prior MVs. The annual number of ablations almost doubled, from 34 ablations on average during the "early years" (2003-2008) to 64 on average during the "late years" (2009-2015) of the study (p = .001). Length of stay at the hospital did not differ significantly between patients with MVs and 649 matched patients without prior MVs (5.4 ± 0.4, 4.7 ± 0.3 days, respectively, p = .12). The data revealed a trend toward a higher incidence of complications (12.6% vs. 7.5% respectively, p = .14) and mortality (3.7% vs. 0.7%, respectively, p = .087) among patients with MVs compared to the matched control group, not reaching statistical significance. CONCLUSION: The data show increased utilization of VA ablations in patients with MVs and a trend toward a higher incidence of in-hospital mortality and complications compared to the propensity-matched control group without MVs.

Isolated very low QRS voltage predicts response to tilt-table testing in patients with neurally mediated syncope.

BACKGROUND: A number of patients with neurally mediated syncope (NMS) have isolated QRS complexes of very low voltage (≤0.3 mV) in the frontal plane leads on the 12-lead electrocardiogram (ECG). HYPOTHESIS: The aim of this study was to assess the importance of QRS voltage in predicting response to tilt-table testing (TTT) in patients with suspected NMS. METHODS: We included 216 patients (age: 49 ± 20 years, 103 men) with suspected NMS who had either a positive or negative response to TTT (n = 91 TTT+, and n = 125 TTT-). The QRS voltage was measured in mV on 12-lead ECGs performed within 3 days of the TTT. The lowest QRS voltage (QRSmin), as well as the voltage in each of the 12 leads was also determined. RESULTS: Very low voltage (QRSmin  ≤ 0.3 mV) in the frontal leads was significantly more prevalent in the TTT+ group than in the TTT- group (74 vs 22%, respectively; P  < .001). Patients in the TTT+ group had significantly lower QRSmin when compared to patients in the TTT- group. QRSmin predicted a positive tilt-table test in a multivariate model that also included patient gender, height, history of presyncope, QRS duration, and left ventricular end-diastolic diameter indexed to height. ROC analysis showed that QRSmin of ≥0.3 mV discriminated between TTT+ and TTT- patients with a sensitivity of 78% and specificity of 68%. CONCLUSION: Isolated very low QRS voltage in the frontal leads predicts a positive response to TTT in patients with suspected NMS.

Isolated very low QRS voltage in the frontal leads predicts recurrence of neurally mediated syncope.

BACKGROUND: The study was prompted by our observation that some patients with neurally mediated syncope (NMS) have an isolated QRS complex, of very low voltage (≤0.3 mV cutoff), in 1 of the frontal leads on the 12-lead electrocardiogram. OBJECTIVE: To prospectively evaluate whether the presence of isolated very low voltage (VLV) predicts recurrence of NMS. METHODS: We included 205 patients (aged 50 ± 17 years) with a median of 3 syncopal episodes. Tilt testing was performed in all patients and was positive in 87 (42%). The patients were followed for a median of 14 months. RESULTS: VLV in frontal leads was present in 92 patients (45%). During the follow-up period 60 patients experienced recurrence of syncope. The actuarial total syncope recurrence rate at 1 year was 32% (95% confidence interval [CI 23%-44%) in patients with isolated VLV in frontal plane leads, and 14% (95% CI 8%-24%) in patients without VLV (log-rank test P < .0001). The significant relationship between the presence of isolated VLV in the frontal leads and syncope recurrence was retained in Cox multivariate analysis that included the history of presyncope and syncope as well as the left ventricular end-diastolic diameter. The presence of isolated VLV in frontal leads was associated with a 3-fold increase of the risk of recurrent syncope. CONCLUSIONS: Isolated very low QRS voltage in the frontal leads predicts recurrence of NMS independent of clinical factors that predict recurrence of syncope in such patients. This phenomenon may help generate new diagnostic tools and insights into the pathogenesis of NMS.

Patient-Specific Bioinks for 3D Bioprinting of Tissue Engineering Scaffolds.

Bioprinting has emerged as a promising tool in tissue engineering and regenerative medicine. Various 3D printing strategies have been developed to enable bioprinting of various biopolymers and hydrogels. However, the incorporation of biological factors has not been well explored. As the importance of personalized medicine is becoming more clear, the need for the development of bioinks containing autologous/patient-specific biological factors for tissue engineering applications becomes more evident. Platelet-rich plasma (PRP) is used as a patient-specific source of autologous growth factors that can be easily incorporated to hydrogels and printed into 3D constructs. PRP contains a cocktail of growth factors enhancing angiogenesis, stem cell recruitment, and tissue regeneration. Here, the development of an alginate-based bioink that can be printed and crosslinked upon implantation through exposure to native calcium ions is reported. This platform can be used for the controlled release of PRP-associated growth factors which may ultimately enhance vascularization and stem cell migration.

Rapid computation of single PET scan rest-stress myocardial blood flow parametric images by table look up.

PURPOSE: We have recently reported a method for measuring rest-stress myocardial blood flow (MBF) using a single, relatively short, PET scan session. The method requires two IV tracer injections, one to initiate rest imaging and one at peak stress. We previously validated absolute flow quantitation in ml/min/cc for standard bull's eye, segmental analysis. In this work, we extend the method for fast computation of rest-stress MBF parametric images. METHODS: We provide an analytic solution to the single-scan rest-stress flow model which is then solved using a two-dimensional table lookup method (LM). Simulations were performed to compare the accuracy and precision of the lookup method with the original nonlinear method (NLM). Then the method was applied to 16 single scan rest/stress measurements made in 12 pigs: seven studied after infarction of the left anterior descending artery (LAD) territory, and nine imaged in the native state. Parametric maps of rest and stress MBF as well as maps of left (fLV ) and right (fRV ) ventricular spill-over fractions were generated. Regions of interest (ROIs) for 17 myocardial segments were defined in bull's eye fashion on the parametric maps. The mean of each ROI was then compared to the rest (K1r ) and stress (K1s ) MBF estimates obtained from fitting the 17 regional TACs with the NLM. RESULTS: In simulation, the LM performed as well as the NLM in terms of precision and accuracy. The simulation did not show that bias was introduced by the use of a predefined two-dimensional lookup table. In experimental data, parametric maps demonstrated good statistical quality and the LM was computationally much more efficient than the original NLM. Very good agreement was obtained between the mean MBF calculated on the parametric maps for each of the 17 ROIs and the regional MBF values estimated by the NLM (K1mapLM  = 1.019 × K1ROINLM  + 0.019, R2  = 0.986; mean difference = 0.034 ± 0.036 mL/min/cc). CONCLUSIONS: We developed a table lookup method for fast computation of parametric imaging of rest and stress MBF. Our results show the feasibility of obtaining good quality MBF maps using modest computational resources, thus demonstrating that the method can be applied in a clinical environment to obtain full quantitative MBF information.

The Impact of First Procedure Success Rate on the Economics of Atrial Fibrillation Ablation.

OBJECTIVES: The purpose of this study was to compare health care costs associated with repeat ablation of atrial fibrillation (AF) with health care costs associated with a successful first procedure. BACKGROUND: Catheter ablation has become established as a rhythm control strategy for symptomatic paroxysmal and persistent AF. The economic impact of ablation is not completely understood, and it may be affected by repeat procedures performed for recurrent AF. METHODS: The source of data was the MarketScan (Truven Health, Ann Arbor, Michigan) administrative claims dataset from April 2008 to March 2013, including U.S. patients with private and Medicare supplemental insurance. Patients who underwent an outpatient atrial ablation procedure and a diagnosis of AF were identified. Total health care cost was calculated for 1 year before and after the ablation. Patients were categorized as having undergone a repeat ablation if an additional ablation was performed in the following year. RESULTS: Of 12,027 patients included in the study, repeat ablation was performed in 2,066 (17.2%) within 1 year. Patients with repeat ablation had higher rates of emergency department visits (43.4% vs. 32.2%; < 0.001) and subsequent hospitalization (35.6% vs. 21.5%; p < 0.001), after excluding hospitalizations for the repeat procedure. Total medical cost was higher for patients with repeat ablation ($52,821 vs. $13,412; p < 0.001), and it remained 46% higher even after excluding the cost associated with additional ablations ($19,621 vs. $13,412; p < 0.001). CONCLUSIONS: Health care costs are significantly higher for patients with a repeat ablation for AF than for patients with only a single ablation procedure, even though both groups have similar baseline characteristics. The increased costs persist even after excluding the cost of the repeat ablation itself. These results emphasize the economic benefit of procedural success in AF ablation.

Pulmonary Vein Isolation Using the Visually Guided Laser Balloon: Results of the U.S. Feasibility Study.

INTRODUCTION: Visually guided laser balloon (VGLB) ablation is unique in that the operator delivers ablative energy under direct visual guidance. In this multicenter study, we sought to determine the feasibility, efficacy, and safety of performing pulmonary vein isolation (PVI) using this VGLB. METHODS: Patients with symptomatic, drug-refractory paroxysmal atrial fibrillation (AF) underwent PVI using the VGLB with the majority of operators conducting their first-ever clinical VGLB cases. The primary effectiveness endpoint was defined as freedom from treatment failure that included: Occurrence of symptomatic AF episodes ≥1 minutes beyond the 90-day blanking, the inability to isolate 1 superior and 2 total PVs, occurrence of left atrial flutter or atrial tachycardia, or left atrial ablation/surgery during follow-up. RESULTS: A total of 86 patients (mean age 56 ± 10 years, 67% male) were treated with the VGLB at 10 US centers. Mean fluoroscopy, ablation, and procedure times were 39.8 ± 24.3 minutes, 205.2 ± 61.7 minutes, and 253.5 ± 71.3 minutes, respectively. Acute PVI was achieved in 314/323 (97.2%) of targeted PVs. Of 84 patients completing follow-up, the primary effectiveness endpoint was achieved in 50 (60%) patients. Freedom from symptomatic or asymptomatic AF was 61%. The primary adverse event rate was 16.3% (8.1% pericarditis, phrenic nerve injury 5.8%, and cardiac tamponade 3.5%). There were no cerebrovascular events, atrioesophageal fistulas, or significant PV stenosis. CONCLUSIONS: This multicenter study of operators in the early stage of the learning curve demonstrates that PVI can be achieved with the VGLB with a reasonable safety profile and an efficacy similar to radiofrequency ablation.

Pulmonary vein isolation for atrial fibrillation in the postpneumonectomy population: a feasibility, safety, and outcomes study.

BACKGROUND: Pulmonary vein isolation (PVI) of the remnant pulmonary vein (PV) stumps in pneumonectomy patients has not been well characterized. METHODS: This is a multicenter observational study of patients with a remnant PV stump after pneumonectomy. Consecutive patients with a history of pneumonectomy and who had undergone RF ablation for drug refractory AF were identified from the AF database at the participating institutions. RESULTS: There were 15 patients in whom pneumonectomy was performed, for resection of tumors in 10, infection in 4, and bullae in 1 patient and who underwent RF ablation for AF. The mean age was 63 ± 7 years. The stumps were from the right lower PV in 5, left upper PV in 5, left lower PV in 3, and right upper PV in 2 patients. All the PV stumps were electrically active with PV potentials and 9 (60%) of them had triggered activity. PVI was performed in 14 and focal isolation in 1 patient. At 1-year follow-up, 80% were free of AF, off of antiarrhythmic medications. CONCLUSION: PV stumps in AF patients with previous pneumonectomy are electrically active and are frequently the sites of active firing. Isolation of these PV stumps can be accomplished safely and effectively using catheter ablation with no practical concern for PV stenosis or compromising PV stump integrity.

Progressive ventricular dysfunction among nonresponders to cardiac resynchronization therapy: baseline predictors and associated clinical outcomes.

BACKGROUND: Cardiac resynchronization therapy (CRT) nonresponders have poor outcomes. The significance of progressive ventricular dysfunction among nonresponders remains unclear. OBJECTIVE: We sought to define predictors of and clinical outcomes associated with progressive ventricular dysfunction despite CRT. METHODS: We conducted an analysis of 328 patients undergoing CRT with defibrillator for standard indications. On the basis of 6-month echocardiograms, we classified patients as responders (those with a ≥5% increase in ejection fraction) and progressors (those with a ≥5% decrease in ejection fraction), and all others were defined as nonprogressors. Coprimary end points were 3-year (1) heart failure, left ventricular assist device (LVAD), transplantation, or death and (2) ventricular tachycardia (VT) or ventricular fibrillation (VF). RESULTS: Multivariable predictors of progressive ventricular dysfunction were aldosterone antagonist use (hazard ratio [HR] 0.23; P = .008), prior valve surgery (HR 3.3; P = .005), and QRS duration (HR 0.98; P = .02). More favorable changes in ventricular function were associated with lower incidences of heart failure, LVAD, transplantation, or death (70% vs 54% vs 33%; P < .0001) and VT or VF (66% vs 38% vs 28%; P = .001) for progressors, nonprogressors, and responders, respectively. After multivariable adjustment, progressors remained at increased risk of heart failure, LVAD, transplantation, or death (HR 2.14; P = .0029) and VT or VF (HR 2.03; P = .046) as compared with nonprogressors. Responders were at decreased risk of heart failure, LVAD, transplantation, or death (HR 0.44; P < .0001) and VT or VF (0.51; P = .015) as compared with nonprogressors. CONCLUSION: Patients with progressive deterioration in ventricular function despite CRT represent a high-risk group of nonresponders at increased risk of worsened clinical outcomes.

Effects of sex on the incidence of cardiac tamponade after catheter ablation of atrial fibrillation: results from a worldwide survey in 34 943 atrial fibrillation ablation procedures.

BACKGROUND: Cardiac tamponade is the most dramatic complication observed during atrial fibrillation (AF) ablation and the leading cause of procedure-related mortality. Female sex is a known risk factor for complications during AF ablation; however, it is unknown whether women have a higher risk of tamponade. METHODS AND RESULTS: A systematic Medline search was used to locate academic electrophysiological centers that reported cases of tamponade occurring during AF ablation. Centers were asked to provide information on cases of acute tamponade according to sex and their mode of management including any case of related mortality. Nineteen electrophysiological centers provided information on 34 943 ablation procedures involving 25 261 (72%) men. Overall, 289 (0.9%) cases of tamponade were reported: 120 (1.24%) in women and 169 (0.67%) in men (odds ratio, 1.83; P<0.001). There was a reciprocal association between center volume and the occurrence of tamponade with substantially lower risk in high-volume centers. Most cases of tamponade occurred during catheter manipulation or ablation; women tended to develop more tamponades during transseptal catheterization. No sex difference in the mode of management was observed. However, 16% cases of tamponade required surgery with lower rates in high-volume centers. Three cases of tamponade (1%) culminated in death. CONCLUSIONS: Tamponade during AF ablation procedures is relatively rare. Women have an ≈2-fold higher risk for developing this complication. The risk of tamponade among women decreases substantially in high-volume centers. Surgical backup and acute management skills for treating tamponade are important in centers performing AF ablation.

Incidence and significance of early recurrences of atrial fibrillation after cryoballoon ablation: insights from the multicenter Sustained Treatment of Paroxysmal Atrial Fibrillation (STOP AF) Trial.

BACKGROUND: Early recurrence of atrial fibrillation (ERAF) is common after radiofrequency catheter ablation for AF. We sought to determine the incidence and prognostic significance of ERAF after cryoballoon ablation. Moreover, the benefit of early reablation for ERAF after cryoballoon ablation is undetermined. METHODS AND RESULTS: The Sustained Treatment of Paroxysmal Atrial Fibrillation (STOP AF) trial randomized 245 patients with paroxysmal AF to medical therapy versus cryoballoon-based pulmonary vein ablation. Patients were followed for 12 months. ERAF was defined as any recurrence of AF >30 seconds during the first 3 months of follow-up. Late recurrence (LR) was defined as any recurrence of AF >30 seconds between 3 and 12 months. Of the 163 patients randomized to cryoablation, 84 patients experienced ERAF (51.5%). The only significant factor associated with ERAF was male sex (hazard ratio [HR], 2.18; 95% confidence interval [CI], 1.03-4.61; P=0.041). LR was observed in 41 patients (25.1%), and was significantly related to ERAF (55.6% LR with ERAF versus 12.7% without ERAF; P<0.001). Among patients with ERAF, only current tobacco use (HR, 3.84; 95% CI, 1.82-8.11; P<0.001) was associated with LR. Conversely, early reablation was associated with greater freedom from LR (3.3% LR with early reablation versus 55.6% without; HR, 0.04; 95% CI, 0.01-0.32; P=0.002). CONCLUSIONS: ERAF after cryoballoon ablation occurs in ≈50% of patients and is strongly associated with LR. Early reablation for ERAF is associated with excellent long-term freedom from recurrent AF.

Cryoballoon ablation of pulmonary veins for paroxysmal atrial fibrillation: first results of the North American Arctic Front (STOP AF) pivotal trial.

OBJECTIVES: This study sought to assess the safety and effectiveness of a novel cryoballoon ablation technology designed to achieve single-delivery pulmonary vein (PV) isolation. BACKGROUND: Standard radiofrequency ablation is effective in eliminating atrial fibrillation (AF) but requires multiple lesion delivery at the risk of significant complications. METHODS: Patients with documented symptomatic paroxysmal AF and previously failed therapy with ≥ 1 membrane active antiarrhythmic drug underwent 2:1 randomization to either cryoballoon ablation (n = 163) or drug therapy (n = 82). A 90-day blanking period allowed for optimization of antiarrhythmic drug therapy and reablation if necessary. Effectiveness of the cryoablation procedure versus drug therapy was determined at 12 months. RESULTS: Patients had highly symptomatic AF (78% paroxysmal, 22% early persistent) and experienced failure of at least one antiarrhythmic drug. Cryoablation produced acute isolation of three or more PVs in 98.2% and all four PVs in 97.6% of patients. PVs isolation was achieved with the balloon catheter alone in 83%. At 12 months, treatment success was 69.9% (114 of 163) of cryoblation patients compared with 7.3% of antiarrhythmic drug patients (absolute difference, 62.6% [p < 0.001]). Sixty-five (79%) drug-treated patients crossed over to cryoablation during 12 months of study follow-up due to recurrent, symptomatic AF, constituting drug treatment failure. There were 7 of the resulting 228 cryoablated patients (3.1%) with a >75% reduction in PV area during 12 months of follow-up. Twenty-nine of 259 procedures (11.2%) were associated with phrenic nerve palsy as determined by radiographic screening; 25 of these had resolved by 12 months. Cryoablation patients had significantly improved symptoms at 12 months. CONCLUSIONS: The STOP AF trial demonstrated that cryoballoon ablation is a safe and effective alternative to antiarrhythmic medication for the treatment of patients with symptomatic paroxysmal AF, for whom at least one antiarrhythmic drug has failed, with risks within accepted standards for ablation therapy. (A Clinical Study of the Arctic Front Cryoablation Balloon for the Treatment of Paroxysmal Atrial Fibrillation [Stop AF]; NCT00523978).

Towards regenerative therapy for cardiac disease.

Development of regenerative therapeutic strategies to reverse the progression of advanced heart failure is one of the most urgent clinical needs of this century. Insights gained from clinical trials of adult stem cells, together with fundamental scientific advances in cardiac stem cell and regenerative biology, are beginning to yield potential new targets and strategies for regenerative therapies. Of particular importance are new scientific discoveries related to intrinsic cardiac regeneration, renewal factors that can trigger regeneration, and tissue-engineering technology, which are beginning to change the way investigators view the scientific and clinical position of cardiovascular regenerative therapy.

Severity of esophageal injury predicts time to healing after radiofrequency catheter ablation for atrial fibrillation.

BACKGROUND: The delivery of radiofrequency (RF) energy to the posterior left atrium creates a risk of injury to the adjacent esophagus. Esophageal endoscopy (EGD) is used to screen patients at risk for esophageal thermal injury after RF ablation. OBJECTIVE: The purpose of this study was to analyze the macroscopic features of the severity of esophageal injuries induced by RF ablation to the left atrium as seen by EGD and evaluate the association of these descriptions with the time elapsed until complete healing. METHODS: This study analyzed 219 patients undergoing RF ablation for atrial fibrillation. Esophageal temperature probes were used during each ablation, and EGD was performed in cases with intraesophageal temperature ≥39°C. Repeat EGD was obtained at 10 days to evaluate for healing in all cases demonstrating esophageal injury. Serial endoscopies were repeated every 2 weeks until complete healing was documented. Lesions were classified according to severity as superficial or deep ulceration; size and shape were also noted. RESULTS: We found 37.4% of patients (82 of 219) with esophageal intraluminal temperatures ≥39°C. Of these, 22 patients (27%) were identified with esophageal injury, with 68% being superficial ulcerations and 32% deep. On repeat EGD at 10 days, only 29% of deep ulcerations were healed, as compared with 87% of the superficial injuries (P = .0136). No difference in healing was found when analyzed for size or shape. CONCLUSIONS: The macroscopic severity of esophageal lesions detected on endoscopy the day after RF ablation can predict the time to resolution, with severe, deep ulcerations requiring a longer time to heal.

Mapping and ablation of atypical AVNRT from the morphologic left atrium in a patient with dextrocardia and situs inversus.

A 75-year-old woman with dextrocardia, situs inversus, and subpulmonic outflow obstruction presented with recurrent supraventricular tachycardia (SVT). This SVT was easily inducible during electrophysiology study, and pacing maneuvers during SVT were consistent with atypical, slow-slow atrioventricular nodal reentrant tachycardia (AVNRT). The His bundle was identified in the low postero-septal morphologic right atrium, at the typical anatomic site for slow pathway ablation of AVNRT. Mapping of the retrograde earliest atrial electrogram during AVNRT localized this site to the mid-septal morphologic left atrium, and cryoablation at this site terminated the AVNRT and rendered it noninducible.

Impact of tricuspid regurgitation and prior coronary bypass surgery on the geometry of the coronary sinus: a rotational coronary angiography study.

INTRODUCTION: The coronary sinus (CS) is often distorted in patients with advanced cardiomyopathy, making CS cannulation difficult. The objective of this study was to examine the impact of the underlying cardiac pathology on the variability of the CS anatomy, using rotational coronary venous angiography (RCVA). METHODS AND RESULTS: Seventy-nine patients undergoing RCVA for cardiac resynchronization therapy (CRT) were evaluated: age 63 +/- 15 years, 43% with prior coronary artery bypass grafting (CABG). Aspects of the CS anatomy which could impact cannulation were examined: the CS ostial angle, the posterior displacement of the CS away from the atrioventricular groove, a measure of CS curvature, and the presence of stenoses and aneurysmal dilatations. The CS ostial angle was variable (65-151 degrees, mean 119 +/- 19 degrees, <90 degrees in 8 patients) and decreased significantly (P = 0.0022) with increasing severity of tricuspid regurgitation (TR), reaching 94 +/- 18 degrees in patients with severe TR. The posterior displacement of the CS was significantly more accentuated in patients with prior CABG when compared with the patients without CABG (7.1 +/- 3.7 vs 4.5 +/- 2.8 mm; P = 0.0246). The decrease in luminal diameter at the CS-great cardiac vein (GCV) junction was 2.0 +/- 1.0 mm, being more pronounced in patients with prior CABG versus nonCABG (26 vs 20%; P = 0.042). Stenoses and aneurysmal dilatations of the CS-GCV were encountered in 4 (5%) and 6 (8%) of patients, respectively, all of them with prior CABG, representing 12% and 18% of the CABG group. CONCLUSION: The CS anatomy in patients undergoing CRT is variable, and is impacted by the severity of the underlying TR and history of a prior CABG.

Ability of terminal QRS notching to distinguish benign from malignant electrocardiographic forms of early repolarization.

Recent studies have suggested that early repolarization (ER) might be associated with up to 1/3 of idiopathic ventricular tachycardia/ventricular fibrillation (VT/VF) cases ("malignant" ER). We sought to identify electrocardiographic features to distinguish benign from malignant variants of ER. We reviewed the medical records for implantable-cardioverter defibrillators implanted at a single institution (1988 to 2008) to identify cases of idiopathic VT/VF. The electrocardiograms were scored for ER, defined as a >or=0.1-mV elevation of the QRS-ST junction manifesting as J-point slurring or notching in 2 contiguous leads. We also identified a cohort of 200 healthy age- and gender-matched controls with electrocardiographic findings previously identified as normal ER ("benign" ER cohort). Of 1,224 consecutive implantable-cardioverter defibrillator implants, we identified 39 cases of idiopathic VT/VF. Of the 39 cases, 9 (23%) demonstrated ER. During a mean follow-up of 7.2 +/- 4.6 years, the combined end point of appropriate implantable-cardioverter defibrillator shocks or all-cause mortality occurred less frequently in cases of idiopathic VT/VF with ER than in those without ER (11% vs 30%, odds ratio 0.29, 95% confidence interval 0.03 to 2.69, p = 0.40). A comparison of the electrocardiograms between those with malignant ER and controls demonstrated that QRS notching was significantly more prevalent among cases when present in leads V4 (44% vs 5%, p = 0.001) and V5 (44% vs 8%, p = 0.006), with a similar trend in lead V6 (33% vs 5%, p = 0.013). In conclusion, left precordial terminal QRS notching is more prevalent in malignant variants of ER than in benign cases. These findings could have important implications for risk stratification of patients with ER.

The esophageal effects of cryoenergy during cryoablation for atrial fibrillation.

BACKGROUND: Cryoenergy is being increasingly used for atrial fibrillation (AF) ablation, but the thermal effect of cryoenergy on the esophagus remains undefined. OBJECTIVE: This study examines the esophageal effects of cryoenergy used during AF ablation. METHODS: Catheter ablation was performed using a cryoballoon catheter in 67 AF patients (Cryoballoon group), and a spot cryocatheter to complete irrigated radiofrequency lesion sets at segments in close proximity to the esophagus in 7 AF patients (Cryo-Focal group). A temperature probe monitored the luminal esophageal temperature (LET) in all patients; LET changes did not guide therapy. Post-procedural endoscopy was performed on 35 of 67 (52%) Cryoballoon and all Cryo-Focal patients. RESULTS: Significant LET decreases (>1 degrees C) occurred in 62 of 67 (93%) Cryoballoon patients. LET continued to decrease after termination of cryoablation before recovering to normal. Temperature decreases were more pronounced during ablation at the inferior (3.1 degrees C) than superior pulmonary veins (1.5 degrees C); the lowest observed temperature was 0 degrees C. Post-procedural endoscopy showed esophageal ulcerations in 6 of 35 (17%) patients. There were no atrial-esophageal fistulas, and all ulcers had healed on follow-up endoscopy. Patients with and without ulceration differed with respect to mean LET nadir, cumulative LET decrease, and number of LETs <30 degrees C. In the Cryo-Focal group, 6 +/- 2 spot cryolesions per patient resulted in 1.3 +/- 1 LET decreases per patient, and an absolute nadir of 32.5 degrees C. CONCLUSION: Cryoballoon ablation can cause significant LET decreases, resulting in reversible esophageal ulcerations in 17% of patients. No ulcerations occurred with adjunctive spot cryoablation at regions near the esophagus during radiofrequency ablation procedures.

Nonpharmacologic strategies: the evolving story of ablation and hybrid therapy.

Technologic advancements have resulted in the more widespread use of catheter ablation to restore sinus rhythm in patients with atrial fibrillation (AF) and elicit improvement in symptoms, quality of life, and prognosis. However, the effectiveness of this procedure to prevent the occurrence of heart failure and stroke while reducing mortality has yet to be proved in major clinical trials. Factors influencing the results of ablation and possibly obfuscating the interpretation of data from early studies include variations in center experience and operator skill, the definition of procedural success, and follow-up interval and duration, as well as the complexity and heterogeneity of AF itself. Upcoming trials that will examine outcomes after catheter ablation and pharmacologic strategies from the end points of heart failure, stroke, and mortality are anticipated to yield more definitive conclusions about ablation efficacy.