Incidence of atrial arrhythmias detected by permanent pacemakers (PPM) post-pulmonary vein antrum isolation (PVAI) for atrial fibrillation (AF): correlation with symptomatic recurrence.

BACKGROUND: Studies examining AF recurrences post-PVAI base recurrence on patient reporting of symptoms. However, whether asymptomatic recurrences are common is not well known. OBJECTIVE: To assess the incidence of atrial tachycardia/fibrillation post-PVAI as detected by a PPM and whether these recurrences correlate to symptomatic recurrence. METHODS: Eighty-six consecutive patients with symptomatic AF and PPMs with programmable mode-switch capability underwent PVAI. Mode switching was programmed post-PVAI to occur at an atrial-sensed rate of >170 bpm. Patients were followed with clinic visits, ECG, and PPM interrogation at 1, 3, 6, and 9 months post-PVAI. The number and duration of mode-switching episodes (MSEs) were recorded at each visit and is presented as median (interquartile range). RESULTS: The patients (age 57 +/- 8 years, EF 54 +/- 10%) had paroxysmal (65%) and persistent (35%) AF pre-PVAI. Sensing, pacing, and lead function were normal for all PPMs at follow-up. Of the 86 patients, 20 (23%) had AF recurrence based on symptoms. All 20 of these patients had appropriate MSEs detected. Of the 66 patients without symptomatic recurrence, 21 (32%) had MSEs detected. In 19 of these patients, MSEs were few in number, compared with patients with symptomatic recurrence (16 [4-256] vs 401 [151-2,470], P < 0.01). The durations were all <60 seconds. All of these nonsustained MSEs occurred within the first 3 months post-PVAI, gradually decreasing over time. The other 2 of 21 remaining patients had numerous (1,343 [857-1,390]) and sustained (18 +/- 12 minutes) MSEs that also persisted beyond 3 months (1 beyond 6 months). Therefore, the incidence of numerous, sustained MSEs in asymptomatic patients post-PVAI was 2 of 66 (3%). CONCLUSIONS: Detection of atrial tachyarrhythmias by a PPM occurred in 30% of patients without symptomatic AF recurrence. Most of these episodes were <60 seconds and waned within 3 months. Sustained, asymptomatic episodes were uncommon.

Extensive ablation during pulmonary vein antrum isolation has no adverse impact on left atrial function: an echocardiography and cine computed tomography analysis.

BACKGROUND: Although pulmonary vein antrum isolation (PVAI) may cure atrial fibrillation (AF) and improve left atrial (LA) function, the effect of extensive LA ablation on LA function is not well known. OBJECTIVE: To assess the impact of PVAI on LA function remotely postablation. METHODS: Consecutive patients undergoing PVAI had either transthoracic (TTE) and transesophageal (TEE) echocardiography (n = 41) or cine EBCT (n = 26) performed preablation and 6 months postablation. Only patients with paroxysmal and persistent, but not permanent, AF were included. Imaging was done in sinus rhythm for all patients. LA diameter (LAD), LA systolic and diastolic areas, and left atrial fractional area change (LFAC) were assessed by TTE. Transmitral (TMF), left atrial appendage (LAA), and pulmonary venous (PVF) Doppler flows were measured by TEE. Peak A on TMF, LAA peak emptying velocity (LAAF), and peak A reversal (AR) on PVF were used as surrogates of LA contractile function. Peak S on PV flow was used as a surrogate of reservoir function. LA areas, volumes, and LA ejection fraction (LAEF) were measured from cine EBCT. RESULTS: Mean radiofrequency ablation time was 45 +/- 21 minutes. All four PVs were isolated for all patients; there were no cases of PV stenosis. Echocardiography revealed a significant reduction in LAD and LA areas post-PVAI. Both peak A and peak AR were also higher post, while other variables showed strong trends toward improvement. In the subset of patients with persistent AF, post-PVAI improvements were seen in LA size, peak A, and even peak S (P = 0.04). Cine EBCT showed a significant decrease in both LA areas and volumes post-PVAI. There was also a significant improvement in LAEF post-PVAI from 17 +/- 6% to 22 +/- 5% (P = 0.01). CONCLUSION: Extensive ablation during PVAI does not cause deterioration in LA function, and may cause long-term improvement, especially in patients with higher AF burden.

Short- and long-term success of substrate-based mapping and ablation of ventricular tachycardia in arrhythmogenic right ventricular dysplasia.

BACKGROUND: Multiple morphologies, hemodynamic instability, or noninducibility may limit ventricular tachycardia (VT) ablation in patients with arrhythmogenic right ventricular dysplasia (ARVD). Substrate-based mapping and ablation may overcome these limitations. We report the results and success of substrate-based VT ablation in ARVD. METHODS AND RESULTS: Twenty-two patients with ARVD were studied. Traditional mapping for VT was limited because of multiple/changing VT morphologies (n=14), nonsustained VT (n=10), or hemodynamic intolerance (n=5). Sinus rhythm CARTO mapping was performed to define areas of "scar" (<0.5 mV) and "abnormal" myocardium (0.5 to 1.5 mV). Ablation was performed in "abnormal" regions, targeting sites with good pace maps compared with the induced VT(s). Linear lesions were created in these areas to (1) connect the scar/abnormal region to a valve continuity or other scar or (2) encircle the scar/abnormal region. Eighteen patients had implanted cardioverter defibrillators, 15 had implanted cardioverter defibrillator therapies, and 7 had sustained VT (6 with syncope). VTs (3+/-2 per patient) were induced (cycle length, 339+/-94 ms), and scar was identified in all patients. Scar areas were related to the tricuspid annulus, proximal right ventricular outflow tract, and anterior/inferior-apical walls. Lesions connected abnormal regions to the annulus (n=12) or other scars (n=4) and/or encircled abnormal regions (n=13). Per patient, a mean of 38+/-22 radiofrequency lesions was applied. Short-term success was achieved in 18 patients (82%). VT recurred in 23%, 27%, and 47% of patients after 1, 2, and 3 years' follow-up, respectively. CONCLUSIONS: Substrate-based ablation of VT in ARVD can achieve a good short-term success rate. However, recurrences become increasingly common during long-term follow-up.

The need for atrial flutter ablation following pulmonary vein antrum isolation in patients with and without previous cardiac surgery.

OBJECTIVES: The aim of this study was to assess the incidence of atrial flutter (AFL) after pulmonary vein antrum isolation (PVAI) in patients with previous cardiac surgery (PCS) in comparison to patients without PCS and to assess the need for AFL ablation in both groups. BACKGROUND: Atrial fibrillation (AF) and AFL often co-exist. Pulmonary vein antrum isolation may be sufficient to control both arrhythmias. However, in patients with PCS, atrial incisions, cannulations, and scar areas may cause AFL recurrence despite elimination of pulmonary vein triggers. METHODS: Data from 1,345 patients who had PVAI were analyzed. Patients with a history of AFL ablation and patients who had concomitant AFL ablation during PVAI were excluded from analysis. Sixty-three patients constituted the PCS group (Group 1, age 57 +/- 13 years, 12 female) and 1,062 patients constituted the non-PCS group (Group 2, age 55 +/- 12 years, 212 female). Patients in Group 1 had larger left atria, higher incidence of AFL pre-PVAI, and lower ejection fraction. RESULTS: There was no significant difference in post-PVAI AF recurrence between Groups 1 and 2, but AFL incidence after PVAI was higher in Group 1 (33% vs. 4%, p < 0.0001). Ablation of AFL in Group 1 patients resulted in an 86% acute success rate and 11% recurrence over a mean follow-up of 357 +/- 201 days. CONCLUSIONS: In patients with PCS, post-PVAI AF recurrence is similar to patients without PCS. However, history of PCS is associated with a higher recurrence of AFL after PVAI. In a significant number of patients with PCS, AFL ablation is required to achieve a cure.

Pre-existent left atrial scarring in patients undergoing pulmonary vein antrum isolation: an independent predictor of procedural failure.

OBJECTIVES: The goal of this study was to assess the impact of left atrial scarring (LAS) on the outcome of patients undergoing pulmonary vein antrum isolation (PVAI) for atrial fibrillation (AF). BACKGROUND: Left atrial scarring may be responsible for both the perpetuation and genesis of AF. METHODS: A total of 700 consecutive patients undergoing first-time PVAI were studied. Before ablation, extensive voltage mapping of the left atrium (LA) was performed using a multipolar Lasso catheter guided by intracardiac echocardiography (ICE). Patients with LAS were defined by a complete absence of electrographic recording by a circular mapping catheter in multiple LA locations, and this was validated by electroanatomic mapping. All four pulmonary vein antra and the superior vena cava were isolated using an ICE-guided technique. Patients were followed at least nine months for late AF recurrence. Univariate and multivariate analyses were performed to assess the predictive value of LAS and other variables on outcome. RESULTS: Of 700 patients, 42 had LAS, which represented 21 +/- 11% of the LA surface area by electroanatomic mapping. Patients with LAS had a significantly higher AF recurrence (57%) compared with non-LAS patients (19%, p = 0.003). Also, LAS was associated with a significantly larger LA size, lower ejection fraction, and higher C-reactive protein levels. Univariate analysis revealed age, nonparoxysmal AF, and LAS as predictors of recurrence. Multivariate analysis showed LAS as the only independent predictor of recurrence (hazard ratio 3.4, 95% confidence interval 1.3 to 9.4; p = 0.01). CONCLUSIONS: Pre-existent LAS in patients undergoing PVAI for AF is a powerful, independent predictor of procedural failure. Left atrial scarring is associated with a lower EF, larger LA size, and increased inflammatory markers.

Prevalence, predictors, and mortality significance of the causative arrhythmia in patients with electrical storm.

INTRODUCTION: Electrical storm (ES) is characterized by either refractory ventricular tachycardia (VT) or ventricular fibrillation (VF). However, little is known about the prevalence, predictors, and mortality implications of the causative arrhythmia in ES. We sought to assess the prevalence, predictors, and survival significance of VT and VF as the causative arrhythmia of ES in implantable cardioverter defibrillator (ICD) patients. METHODS AND RESULTS: Consecutive patients from January 2000 to December 2002 who presented to the ICD clinic with > or = 2 separate ventricular arrhythmic episodes requiring shock within 24 hours were included in the study. ICD interrogation confirmed the number of shocks and provided electrograms for interpretation of the causative arrhythmia. Patients were grouped as VF or VT according to the causative arrhythmia. Their prevalence, predictors, and mortality rates were compared. Of 2,028 patients assessed in the ICD clinic, 208 (10%) presented with ES. VF was the cause of ES in 99 of 208 patients, for an overall prevalence of 48%. Original ICD indication, coronary artery disease, and amiodarone therapy were predictive for the causative arrhythmia. There was no mortality difference between the VT and VF groups; however, both groups had significantly increased mortality compared to a control ICD population without ES. CONCLUSION: VF is the causative arrhythmia for a sizable proportion of patients with ES. The initial ICD indication, coronary artery disease, and amiodarone therapy are predictors of the causative arrhythmias in ES. There does not appear to be any mortality difference between ES patients with VT and VF, but mortality is increased in patients with ES versus control ICD patients without ES.

Statins do not meet expectations for lowering low-density lipoprotein cholesterol levels when used in clinical practice.

BACKGROUND: Statins have become a mainstay in the treatment of hyperlipidemia, based on their potency and favorable side-effect profile. Drug choice is presumed to be guided by the estimated degree of low-density lipoprotein (LDL) cholesterol lowering required in a particular patient and the projected efficacy of any drug-dose combination, as contained in the package inserts for each medication. We investigated whether these expectations were met in a clinical practice. METHODS: Data were analyzed for 367 hyperlipidemic patients in a preventive cardiology practice who were not taking statins at entry, who were given a standard statin dose at their first visit, and who had at least one follow-up visit on the same drug/dose. Expected LDL cholesterol reductions were calculated for each patient based on guidelines in the package inserts for each drug. RESULTS: The mean (+/-SD) observed LDL cholesterol reduction of 26% +/- 20% was significantly less than expected (34% +/- 7%, P < 0.001). The ratio of observed to expected reduction was not different for the three statins used (atorvastatin, 0.79 +/- 0.48; simvastatin, 0.88 +/- 0.61; pravastatin, 0.75 +/- 0.69; P = 0.39). CONCLUSIONS: The use of statins in a clinical practice led to observed reductions in LDL cholesterol level that were significantly less than those projected by package insert guidelines. We believe this gap reflects the reduced patient compliance frequently observed in clinical practice settings, rather than any inherent difference in statin responsiveness of a practice versus a trial population. Physicians should be aware of this disparity when using statins in the clinical setting.