Samuel J. Asirvatham

The Heart Rhythm Society (HRS)/American Society of Anesthesiologists (ASA) Expert Consensus Statement on the Perioperative Management of Patients with Implantable Defibrillators, Pacemakers and Arrhythmia Monitors: Facilities and Patient Management: Executive Summary: This document was developed as a joint project with the American Society of Anesthesiologists (ASA), and in collaboration with the American Heart Association (AHA), and the Society of Thoracic Surgeons (STS)

a t C r a t a R The Heart Rhythm Society (HRS)/American Society of Anesthesiologists (ASA) Expert Consensus Statement on the Perioperative Management of Patients with Implantable Defibrillators, Pacemakers and Arrhythmia Monitors: Facilities and Patient Management This document was developed as a joint project with the American Society of Anesthesiologists (ASA), and in collaboration with the American Heart Association (AHA), and the Society of Thoracic Surgeons (STS)

Long-Term Quality of Life After Ablation of Atrial Fibrillation The Impact of Recurrence, Symptom Relief, and Placebo Effect

OBJECTIVES We sought to determine the relationship between atrial fibrillation (AF) ablation efficacy, quality of life (QoL), and AF-specific symptoms at 2 years. BACKGROUND Although the primary goal of AF ablation is QoL improvement, this effect has yet to be demonstrated in the long term. METHODS A total of 502 symptomatic AF ablation recipients were prospectively followed for recurrence, QoL, and AF symptoms. RESULTS In 323 patients with 2 years of follow-up, 72% achieved AF elimination off antiarrhythmic drugs (AADs), 15% achieved AF control with AADs, and 13% had recurrent AF. The physical component summary scores of the Medical Outcomes Study Short Form 36 increased from 58.8 +/- 20.1 to 76.2 +/- 19.2 (p < 0.001) and the mental component summary scores of the Short Form 36 increased from 65.3 +/- 18.6 to 79.8 +/- 15.8 (p < 0.001). Post-ablation QoL improvements were noted across ablation outcomes, including recurrent AF (change in physical component summary: 12.1 +/- 19.7 and change in mental component summary: 9.7 +/- 17.9), with no significant differences in QoL improvement across 3 ablative efficacy outcomes. However, in 103 patients who completed additional assessment with Mayo AF Symptom Inventories (on a scale of 0 to 48), those with AF elimination off AADs had a change in AF symptom frequency score of -9.5 +/- 6.3, which was significantly higher than those with AF controlled with AADs (-5.6 +/- 3.8, p = 0.03) or those with recurrent AF (-3.4 +/- 8.4, p = 0.02). Independent predictors of limited QoL improvement included higher baseline QoL, obesity, and warfarin use at follow-up. CONCLUSIONS AF ablation produces sustained QoL improvement at 2 years in patients with and without recurrence. AF-specific symptom assessment more accurately reflects ablative efficacy.

KATP channel mutation confers risk for vein of Marshall adrenergic atrial fibrillation

Background A 53-year-old female presented with a 10-year history of paroxysmal atrial fibrillation (AF), precipitated by activity and refractory to medical therapy. In the absence of traditional risk factors for disease, a genetic defect in electrical homeostasis underlying stress-induced AF was explored.Investigations Echocardiography, cardiac perfusion stress imaging, invasive electrophysiology with isoproterenol provocation, genomic DNA sequencing of KATP channel genes, exclusion of mutation in 2,000 individuals free of AF, reconstitution of channel defect with molecular phenotyping, and verification of pathogenic link in targeted knockout.Diagnosis KATP channelopathy caused by missense mutation (Thr1547Ile) of the ABCC9 gene conferring predisposition to adrenergic AF originating from the vein of Marshall.Management Disruption of arrhythmogenic gene–environment substrate at the vein of Marshall by radiofrequency ablation.

Clinical correlates and prognostic significance of electrocardiographic abnormalities in apical ballooning syndrome (Takotsubo/stress-induced cardiomyopathy)

BACKGROUND Apical ballooning syndrome (ABS) is a unique transient cardiomyopathy that mimics an acute myocardial infarction. The relative frequency of ST-segment elevation on the 12-lead electrocardiogram (ECG) and its prognostic significance is unknown. The aims of this study were to evaluate the frequency and the clinical correlates of ST- and T-wave abnormalities on the admission ECG in patients with ABS. METHODS Patients were retrospectively identified from the cardiac catheterization database--those who underwent coronary and left ventricular angiography and fulfilled the Mayo criteria for ABS during the period January 1988 to November 2006. They were divided into 3 groups according to the presence of (1) ST-segment elevation (>1 mm in 2 contiguous lead) or new left bundle branch block, (2) T-wave inversion (>3 mm in 3 contiguous leads) but no ST shift, and (3) nonspecific ST-T abnormalities or normal ECG at the time of admission. Clinical and echocardiographic findings were compared between groups. RESULTS Among the 105 patients, 36 (34.2%), 32 (30.4%), and 37 (35.2%) patients were in the three respective groups. There were no differences in the clinical characteristics, ejection fraction, and outcomes between the 3 groups. Over a median follow-up of 2.5 years, there was no difference in the 5-year recurrence rate of ABS between the 3 groups (13%, 5%, 17% patients, respectively, P = .25). The 5-year mortality was similar in the 3 groups (24%, 7.3%, 10.8%, P = .58). CONCLUSIONS ST-segment elevation is absent in two thirds of patients with ABS. Thus, the cardiomyopathy may mimic either ST-elevation or non-ST-elevation myocardial infarction. The ECG abnormalities at presentation do not correlate with the magnitude of ventricular dysfunction or outcomes.

Isolated Left Ventricular Noncompaction Syndrome

Isolated left ventricular noncompaction (ILVNC) is a rare congenital cardiomyopathy characterized by prominent trabeculae, deep intertrabecular recesses, and thickened myocardium with 2 distinct layers (compacted and noncompacted). Clinical characteristics, outcomes, and appropriate therapies remain poorly defined. Data were collected on patients diagnosed with ILVNC by echocardiographic criteria at the Mayo Clinic from 2001 through 2006. These data were entered prospectively into a clinical database and retrospectively analyzed. All-cause mortality, stroke, and development of atrial fibrillation (AF) were compared to community and nonischemic dilated cardiomyopathic (DC) controls. Implantable cardioverter-defibrillator (ICD) therapies were examined. Thirty patients with confirmed ILVNC were included in analyses (mean age at diagnosis 39 +/- 19.5 years, 60% men). Three patients with ILVNC died during follow-up (mean 2.5 +/- 1.2 years) compared to 5 DC and 1 community controls. No mortality difference was observed among these groups (p = 0.42 and 0.054, respectively). No ILVNC deaths were observed in patients with normal LV ejection fraction. New-onset AF was diagnosed in 2 patients with ILVNC, and none was observed in DC controls. Stroke occurred in 2 DC controls and none was observed in patients with ILVNC. ICDs were implanted in 11 patients with ILVNC. No appropriate therapies were identified during follow-up, but 2 patients underwent inappropriate therapies related to AF. In conclusion, mortality in patients with ILVNC is similar to that in DC patients. Deaths were observed only in patients with decreased LV ejection fraction, suggesting that ICD therapy may be reserved for this subgroup. New-onset AF may lead to inappropriate ICD discharges.

Characteristics of premature ventricular complexes as correlates of reduced left ventricular systolic function: study of the burden, duration, coupling interval, morphology and site of origin of PVCs.

PVCs and Left Ventricular Dysfunction. Background: Frequent premature ventricular complexes (PVCs) can cause a decline in left ventricular ejection fraction (LVEF). We investigated whether the site of origin and other PVC characteristics are associated with LVEF.

Noncontact mapping to guide ablation of right ventricular outflow tract arrhythmias

BACKGROUND There is limited data on outcomes after noncontact mapping (NCM)-guided right ventricular outflow tract (RVOT) ventricular arrhythmia (VA) ablation. OBJECTIVES To assess outcomes of NCM-guided RVOT VA ablation in a large cohort with extended follow-up, to determine optimal ablation site, and to analyze limitations of conventional mapping techniques. METHODS In consecutive patients undergoing RVOT VA ablation, 2 sites of early activation--earliest activation (EA) and breakout (BO) sites--were identified on NCM maps. Pace mapping and activation mapping were performed at both sites. The area of depolarized myocardium during the first 10 ms of spontaneous VA and pacing was measured. The initial site of ablation was randomized to either EA or BO sites, with crossover to the alternate site if ablation was not successful. RESULTS In 136 patients, prematurity of local activation and pace maps were similar at EA and BO sites. More myocardium was depolarized 10 ms after pacing than during spontaneous VA (12.9 ± 7.8 cm(2) vs 5.3 ± 3.9 cm(2); P < .01). Clinical success was more likely achieved when initial ablation was directed toward the EA site (P < .05). A wider EA-BO separation was associated with acute procedural failure (P < .01). With a follow-up of 36.2 ± 17.5 months, the success rate after a single procedure without antiarrhythmic agents was 86.8%. CONCLUSIONS NCM-guided RVOT VA ablation is highly effective, and clinical success is best achieved by ablating the EA site. Broad regions of early activation are associated with worsened clinical outcomes. Spatial resolution of activation and pace mapping is limited by rapid electrical propagation in the RVOT.

Success of Ablation for Atrial Fibrillation in Isolated Left Ventricular Diastolic Dysfunction: A Comparison to Systolic Dysfunction and Normal Ventricular Function

Background— The efficacy of radiofrequency ablation for atrial fibrillation (AF) in patients with left ventricular (LV) systolic dysfunction and isolated diastolic dysfunction is uncertain. Methods and Results— A prospective cohort of patients with normal and abnormal LV function underwent ablation for antiarrhythmic drug (AAD)-refractory AF. Three groups were compared: 111 patients with systolic dysfunction, defined as LV ejection fraction (LVEF) ≤40%; 157 patients with isolated diastolic dysfunction but preserved LVEF ≥50%; and 100 patients with normal LV function. The primary end point was AAD-free AF elimination at 1 year after ablation. This end point was achieved in 62% of patients with systolic dysfunction, 75% of those with diastolic dysfunction, and 84% of controls ( P =0.007). AF control on or off AADs was achieved in 76% of patients with systolic dysfunction, 85% of those with diastolic dysfunction, and 89% of controls ( P =0.08). In the systolic dysfunction group, 49% experienced an increase in LVEF by ≥5% after ablation, of which 64% achieved normal LVEF. In the diastolic dysfunction group, 30% of patients demonstrated at least 1 grade improvement in diastolic dysfunction. Multivariable analysis demonstrated an increased relative risk of arrhythmia recurrence of 1.8 (95% CI, 1.1 to 3.1; P =0.02) in systolic dysfunction and 1.7 (1.0 to 2.7; P =0.04) in isolated diastolic dysfunction compared with normal function. Conclusions— Although an ablative approach for AF in patients with systolic or diastolic dysfunction is associated with an increased long-term recurrence risk, there is potential for substantial quality-of-life improvement and LV functional benefit.Background— The efficacy of radiofrequency ablation for atrial fibrillation (AF) in patients with left ventricular (LV) systolic dysfunction and isolated diastolic dysfunction is uncertain. Methods and Results— A prospective cohort of patients with normal and abnormal LV function underwent ablation for antiarrhythmic drug (AAD)-refractory AF. Three groups were compared: 111 patients with systolic dysfunction, defined as LV ejection fraction (LVEF) ⩽40%; 157 patients with isolated diastolic dysfunction but preserved LVEF ≥50%; and 100 patients with normal LV function. The primary end point was AAD-free AF elimination at 1 year after ablation. This end point was achieved in 62% of patients with systolic dysfunction, 75% of those with diastolic dysfunction, and 84% of controls (P=0.007). AF control on or off AADs was achieved in 76% of patients with systolic dysfunction, 85% of those with diastolic dysfunction, and 89% of controls (P=0.08). In the systolic dysfunction group, 49% experienced an increase in LVEF by ≥5% after ablation, of which 64% achieved normal LVEF. In the diastolic dysfunction group, 30% of patients demonstrated at least 1 grade improvement in diastolic dysfunction. Multivariable analysis demonstrated an increased relative risk of arrhythmia recurrence of 1.8 (95% CI, 1.1 to 3.1; P=0.02) in systolic dysfunction and 1.7 (1.0 to 2.7; P=0.04) in isolated diastolic dysfunction compared with normal function. Conclusions— Although an ablative approach for AF in patients with systolic or diastolic dysfunction is associated with an increased long-term recurrence risk, there is potential for substantial quality-of-life improvement and LV functional benefit.

Substrate and Procedural Predictors of Outcomes After Catheter Ablation for Atrial Fibrillation in Patients with Hypertrophic Cardiomyopathy

Background: Hypertrophic cardiomyopathy (HCM) is often accompanied by atrial fibrillation (AF) due to diastolic dysfunction, elevated left atrial pressure, and enlargement. Although catheter ablation for drug‐refractory AF is an effective treatment, the efficacy in HCM remains to be established.

Electrophysiological and hemodynamic characteristics associated with obesity in patients with atrial fibrillation.

OBJECTIVES The authors sought to characterize the left atrial (LA) and pulmonary vein (PV) electrophysiological and hemodynamic features in obese patients with atrial fibrillation (AF). BACKGROUND Obesity is associated with increased risk for AF. METHODS A total of 63 consecutive patients with AF who had normal left ventricular (LV) ejection fraction and who underwent catheter ablation were studied. Atrial and PV electrophysiological studies were performed at the time of ablation with hemodynamic assessment by cardiac catheterization, and LA/LV structure and function by echocardiography. Patients were compared on the basis of body mass index (BMI): <25 kg/m(2) (n = 19) and BMI ≥30 kg/m(2) (n = 44). RESULTS At a 600-ms pacing cycle length, obese patients had shorter effective refractory period (ERP) in the left atrium (251 ± 25 ms vs. 233 ± 32 ms, p = 0.04), and in the proximal (207 ± 33 ms vs. 248 ± 34 ms, p < 0.001) and distal (193 ± 33 ms vs. 248 ± 44 ms, p < 0.001) PV than normal BMI patients. Obese patients had higher mean LA pressure (15 ± 5 mm Hg vs. 10 ± 5 mm Hg, p < 0.001) and LA volume index (28 ± 12 ml/m(2) vs. 21 ± 14 ml/m(2), p = 0.006), and lower LA strain (5.5 ± 3.1% vs. 8.8 ± 2.8%; p < 0.001) than normal BMI patients. CONCLUSIONS Increased LA pressure and volume, and shortened ERP in the left atrium and PV are potential factors facilitating and perpetuating AF in obese patients with AF.