BACKGROUND—Reduced electrogram amplitude has been shown to correlate with diseased myocardium. We describe a novel individualized approach for catheter ablation of atrial fibrillation (AF) based on ...low-voltage areas (LVAs) in the left atrium (LA). We sought to assess (1) the incidence of LVAs in patients undergoing AF catheter ablation, (2) the distribution of LVAs within the LA, and (3) the effect of an individualized ablation strategy on long-term rhythm outcomes.
METHODS AND RESULTS—In 178 patients with paroxysmal or persistent AF, LA voltage maps were created during sinus rhythm after circumferential pulmonary vein isolation. Subsequent substrate modification was confined to the presence of LVA (<0.5 mV) and inducible regular atrial tachycardias. LVAs were identified in 35% and 10% of patients with persistent and paroxysmal AF, respectively. The LA roof and the anterior, septal, and posterior wall LA were most often affected. The 12-month atrial tachycardias/AF-free survival was 62% for patients without LVAs and 70% for patients with LVAs and tailored substrate modification (P=0.3). Success rate in a comparison group of 26 LVA patients without further substrate modification was 27%.
CONCLUSIONS—LVAs can be found at preferred sites in 10% of patients with paroxysmal AF and in 35% of patients with persistent AF. This is the first clinical report describing a consistent voltage-based approach for substrate modification in addition to circumferential pulmonary vein isolation irrespective of AF type. Application of this limited individualized approach may have the potential to compensate for the impaired 12-month outcome of patients with endocardial structural defects.
This randomized single-centre study sought to compare the efficacy and safety of pulmonary vein isolation (PVI) plus voltage-guided ablation vs. PVI with or without linear ablation depending on the ...type of atrial fibrillation (AF).
Overall, 124 ablation-naive patients with paroxysmal or persistent AF were randomized to PVI with (persistent AF) or without (paroxysmal AF) additional linear ablation (control group) vs. PVI plus ablation of low-voltage areas (LVAs) irrespective of AF type. Bipolar voltage mapping was performed during stable sinus rhythm. An LVA consisted of ≥ 3 adjacent mapping points that each had a peak-to-peak amplitude ≤0.5 mV. After a mean follow-up of 12 ± 3 months, significantly more patients in the LVA ablation group were free from atrial arrhythmia recurrence >30 s off antiarrhythmic drugs (AADs) after a single procedure (primary endpoint) compared with control group patients 40/59 (68%) vs. 25/59 (42%), log-rank P = 0.003. Arrhythmia-free survival on or off AADs was found in 33/59 control group patients (56%) and in 41/59 LVA ablation group patients (70%) (adjusted log-rank P = 0.10). During the 7 day Holter monitoring period at 12 months, significantly more patients in the LVA ablation group were free from arrhythmia recurrence on or off AADs 45/50 (90%) vs. 33/46 (72%), P = 0.04. No between-group differences were observed regarding procedure duration, fluoroscopy time, and major complications.
In this single-centre study, individually tailored substrate modification guided by voltage mapping was associated with a significantly higher arrhythmia-free survival rate compared with a conventional approach applying linear ablation according to AF type.
Cryoballoon ablation has emerged as a novel treatment strategy for patients with atrial fibrillation (AF).
The purpose of this study was to compare pulmonary vein isolation (PVI) using cryoballoon ...ablation versus RF ablation with regard to myocardial injury, pulmonary vein (PV) reconnection patterns, and outcome.
Fifty patients (age 59 ± 9 years, ejection fraction 0.59 ± 0.06, left atrial size 41 ± 5 mm) with paroxysmal AF were studied. Twenty-five patients underwent PVI using a 28-mm cryoballoon. A control group of 25 patients underwent PVI using an open-irrigation RF ablation catheter. Myocardial injury was determined by measuring troponin T (TnT). PV reconnection patterns were studied in case of repeat procedures.
Procedure duration was 166 ± 32 minutes in the cryoballoon group versus 197 ± 52 minutes in the RF group (P = .014), with similar ablation times (cryoballoon: 45 minutes interquartile range 40-52.5 minutes; RF: 47 minutes interquartile range 44-65 minutes, P = .17). Postprocedural TnT in the RF group was 1.29 ± 0.41 μg/L versus 0.76 ± 0.55 μg/L in the cryoballoon group (P = .002). In 12 patients who underwent repeat ablation, 74% of PV reconnection sites were inferiorly located in the cryoballoon group compared to 17% in the RF group (P = .0004). With 1.2 ± 0.4 and 1.3 ± 0.6 procedures per patient, 88% of patients in the cryoballoon group and 92% in the RF group were in stable sinus rhythm after follow-up of 12 ± 3 months (P = NS).
Differences in the extent of myocardial injury and patterns of PV reconnection were observed between cryoballoon ablation and RF ablation of paroxysmal AF.
Elevated cardiac troponin I (cTnI) is frequently observed in patients with severe sepsis and septic shock. However, the mechanisms underlying cTnI release in these patients are still unknown. To date ...no data regarding coagulation disturbances as a possible mechanism for cTnI release during sepsis are available.
Consecutive patients with systemic inflammatory response syndrome (SIRS), sepsis or septic shock without evidence of an acute coronary syndrome were analyzed. Coagulation parameters (clotting time (CT), clot formation time (CFT), maximum clot firmness (MCF), alpha-angle) were assessed in native whole blood samples, and using specific activators to evaluate the extrinsic and intrinsic as well as the fibrin component of the coagulation pathway with the use of rotational thrombelastometry (ROTEM). Thirty-eight patients were included and 22 (58%) were cTnI-positive. Baseline characteristics between TnI-positive and -negative patients were similar. The CT, CFT, MCF and the alpha-angle were similar between the groups with trends towards shorter CT in the extrinsic and fibrin activation.
We found no differences in coagulation parameters analyzed with rotational thrombelastometry between cTnI-positive and -negative patients with SIRS, severe sepsis, and septic shock. These findings suggest that pathophysiological mechanisms other than thrombus-associated myocardial damage might play a major role, including reversible myocardial membrane leakage and/or cytokine mediated apoptosis in these patients.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Anatomical Predictors for Acute and Mid‐Term Success of Cryoballoon Ablation. Introduction: Cryoballoon (CB) pulmonary vein isolation (CB‐PVI) for the treatment of paroxysmal atrial fibrillation (AF) ...has been demonstrated to be safe and reliable. Preprocedural patient selection to address the high variability in pulmonary vein (PV) anatomy may improve the acute and chronic success of CB‐PVI. The purpose of this study was to identify anatomical predictors for CB‐PVI failure using the 28 mm balloon.
Methods and Results
: We included 47 patients with paroxysmal AF undergoing CB‐PVI with the 28 mm CB. Anatomical global left atrial and PV selective parameters were quantified from 3‐dimensional reconstructed preprocedural computed tomography or magnetic resonance imaging data. The mean follow‐up was 26 ± 9 months (range: 12–32 months). Multivariate logistic regression analysis revealed that a continuous sharp left lateral ridge between the left PVs and the left lateral appendage (OR, 7.09; 95% CI, 1.17–43.47) and a sharp carina between the left superior and left inferior PV (OR, 5.99; 95% CI, 1.33–27.03) predict acute and mid‐term failure. For the right inferior PVs, a non‐perpendicular angle between the axis of the PV and the ostial plane (OR, 6.33; 95% CI, 1.20–33.33) and an early branching PV with change in the axis angle (OR, 7.41; 95% CI, 1.44–38.46) were predictors of acute and mid‐term failure.
Conclusion:
Anatomical variables preventing maximal heat transfer from the tissue to the CB could be identified as predictors for CB‐PVI failure with the 28 mm balloon. These findings may be a step toward a more tailored ablation strategy based on individual anatomical variations. (J Cardiovasc Electrophysiol, Vol. 24, pp. 132‐138, February 2013)
The Achieve mapping catheter allows real-time recordings from the pulmonary veins (PVs) during cryoballoon (CB) ablation of atrial fibrillation (AF).
To assess the clinical applicability of the ...Achieve mapping catheter and the value of real-time recordings from the PVs during CB.
Patients with paroxysmal AF undergoing CB ablation were studied. Recordings from the PVs were analyzed during (real-time recordings) and after CB ablation and validated by using a variable circumferential mapping catheter (Achieve group; n = 20). A comparison was made by using a group of patients in whom CB ablation with a guidewire and a variable circumferential mapping catheter was performed (Guidewire group; n = 20).
Forty patients (age 58±11 years; ejection fraction 0.59±0.07; left atrial size 40±6 mm) with paroxysmal AF were included. In the Achieve group, real-time recordings from the PVs could be obtained in 40 of 80 (50%) PVs and could be seen more often at the left-sided PVs (25 of 39, 64%) than at the right-sided PVs (15 of 41, 37%; P = .02). Validation with a standard circumferential mapping catheter confirmed PV isolation in 75 of 80 (93%) PVs. After a single procedure and a follow-up of 14±4 months, 25 of 40 (63%) patients were in sinus rhythm with no significant difference between groups.
The Achieve catheter can be used as a substitute for a guidewire during CB ablation, but real-time recordings can be obtained only in half of the PVs and are not sufficient to accurately confirm isolation of all PVs.
Long‐Term Efficacy of Single Procedure Remote Magnetic Catheter Navigation.
Background:
Remote magnetic navigation (RMN) aims to reduce some inherent limitations of manual radiofrequency (RF) ...ablation. However, data comparing the effectiveness of both methods are scarce. This study evaluated the acute and long‐term success of RMN guided versus manual RF ablation in patients with ischemic sustained ventricular tachycardia (sVT).
Methods:
One hundred two consecutive patients (age 68 ± 10 years, LVEF 32 ± 12%, 88 men) with ischemic sVT were ablated with RMN (Stereotaxis; 49%) or manually (51%) using substrate and/or activation mapping (Carto) and open‐irrigated‐tip catheters. All received implantable defibrillators or loop recorders. Acute success was defined as noninducibility of any sVT at the end of the ablation procedure and long‐term success as freedom from VT upon follow‐up.
Results:
There was no difference in the baseline characteristics between the groups. Three patients died in hospital. Acute success rate was similar for RMN and manual ablation (82% vs 71%, P = 0.246). RMN was associated with significantly shorter fluoroscopy time (13 ± 12 minutes vs 32 ± 17 minutes, P = 0.0001) and RF time (2337.59 ± 1248.22 seconds vs 1589.95 ± 1047.42 seconds, P = 0.049), although total procedure time was similar (157 ± 40 minutes vs 148 ± 50 minutes, P = 0.42). There was a nonsignificant trend toward better long‐term success in RMN group: after a median of 13 (range 1–34) months, 63% in the RMN and 53% in the manual ablation group were free from VT recurrence (P = 0.206).
Conclusion:
RMN guided RF ablation of ischemic sustained VT is equally efficient compared with manual ablation in terms of acute and long‐term success rate. These results are achieved with a significantly reduced fluoroscopy time and shorter RF time. (J Cardiovasc Electrophysiol Vol. 23, pp. 499‐505, May 2012)
Abstract Objective The aim of this study was to quantify daytime symptoms in atrial fibrillation (AF) patients with and without sleep related breathing disorders (SRBD). Background SRBD are common in ...patients with AF but little is known about daytime symptoms among those with SRBD. Methods Patients with AF admitted to clinics of two tertiary referral hospitals for a variety of different cardiovascular diseases were screened with a trans-nasal airflow measurement device allowing measurement of the apnea–hypopnea-index. Data on cardiac risk factors, left ventricular ejection fraction (LVEF) and cardiac medication were collected. Presence of SRBD was defined as an AHI ≥ 15/h. The Epworth sleepiness scale (ESS) was used to quantify daytime symptoms. Results Of 102 screened patients 8 were excluded due to device malfunction (n = 1), dislocation of nasal cannula (n = 6), or hyperthyroidism (n = 1). Among the remaining 94 patients, 40 (43%) were diagnosed with SRBD. Patients with and without SRBD had similar age, body mass index, LVEF and cardiac medication. The prevalence of coronary artery disease was higher in patients with SRBD than in those without (50 vs. 17%; p = 0.0007). ESS score was low and similar in both groups (no SRBD: median 4, interquartile range (IQR) 2–4 vs. SRBD: 5, IQR 3–8; p = 0.14). Only 6/40 (5%) of the patients underwent overnight polysomnography and 2 (5%) started CPAP ventilation during follow-up. Conclusions Even though SRBD are common in patients with AF, the prevalence of daytime symptoms is rare. Consequently, most patients will not initiate CPAP ventilation after positive SRBD screening.
Purpose
The purposes of this study were to determine whether predictors of phrenic nerve palsy (PNP) exist and to test whether a standardized ablation protocol may prevent PNP during cryoballoon (CB) ...ablation using the 28 mm CB.
Methods
Three-dimensional (3D) geometry of the pulmonary veins (PV) and their relationship to the superior vena cava (SVC) was analyzed. Phrenic nerve (PN) stimulation was performed during ablation of the right-sided PVs with a 28-mm CB. The freezing cycle was immediately terminated in case of loss of PN capture.
Results
Sixty-five patients (age, 58 ± 11 years; ejection fraction, 0.59 ± 0.06; left atrial size, 40 ± 5 mm) with paroxysmal atrial fibrillation were included. No persistent PNP was observed. Transient PNP occurred in 4 of 65 patients (6 %). PN function normalized within 24 h in all four patients. A short distance between the right superior PV and the SVC was significantly associated with PNP, but left atrial and 3D PV anatomy were not. Low temperature early during the freezing cycle (<−41 °C at 30 s) predicted PNP with a sensitivity and a specificity of 100 and 98 %, respectively.
Conclusion
The anatomical relationship between the right superior PV and the SVC is a preprocedural predictor for the development of transient PNP, and low temperature early during ablation at the right superior PV is a sensitive warning sign of impending PNP. Despite the use of the 28 mm CB, transient PNP occurred in 6 % of patients undergoing CB ablation.
Because the best possible device longevity is crucial (i.e., risk of infection with premature device exchange, current cost-effectiveness calculations depending on reasonable longevity, patient ...comfort), industry-independent real-life data are fundamental. However, only limited independent data on the longevity of implantable cardioverter-defibrillators (ICDs) are available.
The purpose of this study was to determine ICD device longevity and influencing factors.
From a prospective database, we studied overall device longevity and identified those devices with replacement for battery depletion or prolonged charge time. For every device, we determined factors that included averaged shocks, pacing percentage, pacing mode, device size, and time of implant. Survival probabilities at different time intervals were calculated, and Kaplan-Meier and Cox regression analyses were used. Observed longevity was compared to industry-projected longevity obtained from product performance reports.
A total of 644 ICDs (Medtronic 317, Guidant 189, St. Jude 118, Intermedics 20) were implanted in 499 patients. During follow-up, 163 (25.3%) ICDs were replaced. Manufacturer, time of implant, pacing mode, pacing percentage, and capacitor reformation interval influenced longevity, whereas device size and number of shocks did not. Median longevity was 7.6 years for Medtronic devices, 5.0 years for Guidant devices, and 3.8 years for St. Jude devices. After 5 years, only 70% of ICDs were still in service compared to the 80% projected by industry.
Marked differences in device longevity among manufacturers cannot be explained by pacing mode, number of shocks, or pacing percentage only. Overall, device performance requires further improvement for the sake of patient health and cost.
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