Background
Atrial fibrillation is a common post‐operative complication of cardiac surgery and is associated with an increased risk of post‐operative stroke, increased length of intensive care unit ...and hospital stays, healthcare costs and mortality. Numerous trials have evaluated various pharmacological and non‐pharmacological prophylactic interventions for their efficacy in preventing post‐operative atrial fibrillation. We conducted an update to a 2004 Cochrane systematic review and meta‐analysis of the literature to gain a better understanding of the effectiveness of these interventions.
Objectives
The primary objective was to assess the effects of pharmacological and non‐pharmacological interventions for preventing post‐operative atrial fibrillation or supraventricular tachycardia after cardiac surgery. Secondary objectives were to determine the effects on post‐operative stroke or cerebrovascular accident, mortality, cardiovascular mortality, length of hospital stay and cost of treatment during the hospital stay.
Search methods
We searched the Cochrane Central Register of ControlLed Trials (CENTRAL) (Issue 8, 2011), MEDLINE (from 1946 to July 2011), EMBASE (from 1974 to July 2011) and CINAHL (from 1981 to July 2011).
Selection criteria
We selected randomized controlled trials (RCTs) that included adult patients undergoing cardiac surgery who were allocated to pharmacological or non‐pharmacological interventions for the prevention of post‐operative atrial fibrillation or supraventricular tachycardia, except digoxin, potassium (K+), or steroids.
Data collection and analysis
Two review authors independently ed study data and assessed trial quality.
Main results
One hundred and eighteen studies with 138 treatment groups and 17,364 participants were included in this review. Fifty‐seven of these studies were included in the original version of this review while 61 were added, including 27 on interventions that were not considered in the original version. Interventions included amiodarone, beta‐blockers, sotalol, magnesium, atrial pacing and posterior pericardiotomy. Each of the studied interventions significantly reduced the rate of post‐operative atrial fibrillation after cardiac surgery compared with a control. Beta‐blockers (odds ratio (OR) 0.33; 95% confidence interval) CI 0.26 to 0.43; I2 = 55%) and sotalol (OR 0.34; 95% CI 0.26 to 0.43; I2 = 3%) appear to have similar efficacy while magnesium's efficacy (OR 0.55; 95% CI 0.41 to 0.73; I2 = 51%) may be slightly less. Amiodarone (OR 0.43; 95% CI 0.34 to 0.54; I2 = 63%), atrial pacing (OR 0.47; 95% CI 0.36 to 0.61; I2 = 50%) and posterior pericardiotomy (OR 0.35; 95% CI 0.18 to 0.67; I2 = 66%) were all found to be effective. Prophylactic intervention decreased the hospital length of stay by approximately two‐thirds of a day and decreased the cost of hospital treatment by roughly $1250 US. Intervention was also found to reduce the odds of post‐operative stroke, though this reduction did not reach statistical significance (OR 0.69; 95% CI 0.47 to 1.01; I2 = 0%). No significant effect on all‐cause or cardiovascular mortality was demonstrated.
Authors' conclusions
Prophylaxis to prevent atrial fibrillation after cardiac surgery with any of the studied pharmacological or non‐pharmacological interventions may be favored because of its reduction in the rate of atrial fibrillation, decrease in the length of stay and cost of hospital treatment and a possible decrease in the rate of stroke. However, this review is limited by the quality of the available data and heterogeneity between the included studies. Selection of appropriate interventions may depend on the individual patient situation and should take into consideration adverse effects and the cost associated with each approach.
Pacemakers can automatically identify and catalog atrial high-rate episodes (AHREs). While most AHREs represent true atrial tachyarrhythmia/atrial fibrillation (AT/AF), a review of stored ...electrograms suggests that a substantial proportion do not. As AHREs may lead to the initiation of oral anticoagulation, it is crucial to understand the relationship between AHREs and true AT/AF.
To compare the positive predictive value of AHREs for electrogram-confirmed AT/AF for various atrial rates and episode durations.
By using data from 2580 patients who participated in the ASymptomatic atrial fibrillation and Stroke Evaluation in pacemaker patients and the AF Reduction atrial pacing Trial, all AHREs >6 minutes and >190 beats/min with available electrograms were reviewed to determine whether they represented true AT/AF. The positive predictive value of these AHREs was assessed for episode durations of 6 minutes, 30 minutes, 6 hours, and 24 hours at atrial rates of 190 and 250 beats/min.
Of 5769 AHREs >6 minutes and >190 beats/min, 82.7% were true AT/AF and 17.3% were false positives (predominantly due to repetitive non-re-entrant ventriculoatrial synchrony). False positives dropped to 6.8%, 3.3%, and 1.8% when the threshold duration was increased to 30 minutes, 6 hours, and 24 hours, respectively. Increasing the threshold heart rate to 250 beats/min added little to the positive predictive value when longer threshold durations were used.
By using a cutoff of >6 minutes and >190 beats/min, the rate of false-positive AHREs is 17.3%, making physician review of electrograms essential. For AHREs lasting >6 hours, the rate of false positives is 3.3%, making physician review less crucial.
Catheter-tissue contact is essential for effective lesion formation, thus there is growing usage of contact force (CF) technology in atrial fibrillation ablation. We conducted a meta-analysis to ...assess the impact of CF on clinical outcomes and procedural parameters in comparison to conventional catheter for atrial fibrillation ablation.
An electronic search was performed using major databases. Outcomes of interest were recurrence rate, major complications, total procedure, and fluoroscopic times. Continuous variables were reported as standardized mean difference; odds ratios were reported for dichotomous variables. Eleven studies (2 randomized controlled studies and 9 cohorts) involving 1428 adult patients were identified. CF was deployed in 552 patients. The range of CF used was between 2 to 60 gram-force. The follow-up period ranged between 10 and 53 weeks. In comparing CF and conventional catheter groups, the recurrence rate was lower with CF (35.1% versus 45.5%, odds ratio 0.62 95% CI 0.45-0.86, P=0.004). Shorter procedure and fluoroscopic times were achieved with CF (procedure time: 156 versus 173 minutes, standardized mean difference -0.85 95% CI -1.48 to -0.21, P=0.009; fluoroscopic time: 28 versus 36 minutes, standardized mean difference -0.94 95% CI -1.66; -0.21, P=0.01). Major complication rate was lower numerically in the CF group but not statistically significant (1.3% versus 1.9%, odds ratio 0.71 95% CI 0.29-1.73, P=0.45).
The use of CF technology results in significant reduction of the atrial fibrillation recurrence rate after atrial fibrillation ablation in comparison to the conventional catheter group. CF technology is able to significantly reduce procedure and fluoroscopic times without compromising complication rate.
A 66‐year‐old lady presented with shortness of breath and a Wenckebach atrioventricular (AV) conduction pattern on the ECG. The electrophysiologic study showed split‐His potentials and intra‐Hisian ...Wenckebach. The case highlights the interesting finding of Wenckebach conduction in the His bundle.
A 66‐year‐old lady presented with shortness of breath and a Wenckebach conduction pattern on the ECG. The EP study showed split his potentials and intrahisian Wenckebach. The case highlights the interesting finding of Wenckebach in the His bundle.
This pilot study assessed the safety and efficacy of left atrial appendage (LAA) occlusion, performed at the time of coronary artery bypass grafting (CABG).
At the time of CABG, 77 patients with risk ...factors for stroke were randomized to LAA occlusion or control. The LAA was occluded using sutures or a stapling device. Completeness of occlusion was assessed with transesophageal echocardiography. There were no significant differences in cardiopulmonary bypass duration, perioperative heart failure, atrial fibrillation, or bleeding between the 2 groups. During surgery, there were 9 appendage tears, all of which were repaired easily with sutures. Among patients having a postoperative transesophageal echocardiography, complete occlusion of the LAA was achieved in 45% (5/11) of cases using sutures and in 72% (24/33) using a stapler,
P = .14. The rate of LAA occlusion by individual surgeons increased from 43% (9/21) to 87% (20/23) after performing 4 cases (
P = .0001). After a mean follow-up of 13 ± 7 months, 2.6% of patients had thromboembolic events.
LAA occlusion at the time of CABG is safe. The rate of complete occlusion improves, to acceptable levels, with increased experience and the use of a stapling device. A large trial is needed to determine if LAA occlusion prevents stroke.
Interventional cardiac electrophysiology (EP) is a rapidly evolving field in Canada; a nationwide registry was established in 2011 to conduct a periodic review of resource allocation.
The registry ...collects annual data on EP lab infrastructure, imaging, tools, human resources, procedural volumes, success rates, and wait times. Leading physicians from each EP lab were contacted electronically; participation was voluntary.
All Canadian EP centres were identified (n = 30); 50 and 45 % of active centres participated in the last 2 instalments of the registry. A mean of 508 ± 270 standard and complex catheter ablation procedures were reported annually for 2015-2016 by all responding centres. The most frequently performed ablation targets atrial fibrillation (PVI) arrhythmia accounting for 36 % of all procedures (mean = 164 ± 85). The number of full time physicians ranges between 1 and 7 per centre, (mean = 4). The mean wait time to see an electrophysiologist for an initial non-urgent consult is 23 weeks. The wait time between an EP consult and ablation date is 17.8 weeks for simple ablation, and 30.1 weeks for AF ablation. On average centres have 2 (range: 1-4) rooms equipped for ablations; each centre uses the EP lab an average of 7 shifts per week. While diagnostic studies and radiofrequency ablations are performed in all centres, point-by-point cryoablation is available in 85 % centres; 38 % of the respondents use circular ablation techniques.
This initiative provides contemporary data on invasive electrophysiology lab practices. The EP registry provides activity benchmarks on national trends and practices.
Celotno besedilo
Dostopno za:
CEKLJ, DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Although QRS duration (QRSd) is an important determinant of cardiac resynchronization therapy (CRT) response, non-responder rates remain high. QRS fragmentation can also reflect electrical ...dyssynchrony. We hypothesized that quantification of abnormal QRS peaks (QRSp) would predict CRT response.
Forty-seven CRT patients (left ventricular ejection fraction = 23±7%) were prospectively studied. Digital 12-lead ECGs were recorded during native rhythm at baseline and 6 months post-CRT. For each precordial lead, QRSp was defined as the total number of peaks detected on the unfiltered QRS minus those detected on a smoothed moving average template QRS. CRT response was defined as >5% increase in left ventricular ejection fraction post-CRT.
Sixty-percent of patients responded to CRT. Baseline QRSd was similar in CRT responders and non-responders, and did not change post-CRT regardless of response. Baseline QRSp was greater in responders than non-responders (9.1±3.5 vs. 5.9±2.2, p = 0.001) and decreased in responders (9.2±3.6 vs. 7.9±2.8, p = 0.03) but increased in non-responders (5.5±2.3 vs. 7.5±2.8, p = 0.049) post-CRT. In multivariable analysis, QRSp was the only independent predictor of CRT response (Odds Ratio 95% Confidence Interval: 1.5 1.1-2.1, p = 0.01). ROC analysis revealed QRSp (area under curve = 0.80) to better discriminate response than QRSd (area under curve = 0.67). Compared to QRSd ≥150ms, QRSp ≥7 identified response with similar sensitivity but greater specificity (74 vs. 32%, p<0.05). Amongst patients with QRSd <150ms, more patients with QRSp ≥7 responded than those with QRSp <7 (75 vs. 0%, p<0.05).
Our novel automated QRSp metric independently predicts CRT response and decreases in responders. Electrical dyssynchrony assessed by QRSp may improve CRT selection and track structural remodeling, especially in those with QRSd <150ms.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Background Action potential alternans can induce ventricular tachyarrhythmias and manifest on the surface ECG as T-wave alternans (TWA) and QRS alternans (QRSA). We sought to evaluate microvolt QRSA ...in cardiomyopathy patients in relation to TWA and ventricular tachyarrhythmia outcomes. Methods and Results Prospectively enrolled cardiomyopathy patients (n=100) with prophylactic defibrillators had 12-lead ECGs recorded during ventricular pacing from 100 to 120 beats/min. QRSA and TWA were quantified in moving 128-beat segments using the spectral method. Segments were categorized as QRSA positive (QRSA+) and/or TWA positive (TWA+) based on ≥2 precordial leads having alternans magnitude >0 and signal:noise >3. Patients were similarly categorized based on having ≥3 consecutive segments with alternans. TWA+ and QRSA+ occurred together in 31% of patients and alone in 18% and 14% of patients, respectively. Although TWA magnitude (1.4±0.4 versus 4.7±1.0 µV,
<0.01) and proportion of TWA+ studies (16% versus 46%,
<0.01) increased with rate, QRSA did not change. QRS duration was longer in QRSA+ than QRSA-negative patients (138±23 versus 113±26 ms,
<0.01). At 3.5 years follow-up, appropriate defibrillator therapy or sustained ventricular tachyarrhythmia was greater in QRSA+ than QRSA-negative patients (30% versus 8%,
=0.02) but similar in TWA+ and TWA-negative patients. Among QRSA+ patients, the event rate was greater in those without TWA (62% versus 21%,
=0.02). Multivariable Cox analysis revealed QRSA+ (hazard ratio HR, 4.6; 95% CI, 1.5-14;
=0.009) and QRS duration >120 ms (HR, 4.1; 95% CI, 1.3-12;
=0.014) to predict events. Conclusions Microvolt QRSA is novel phenomenon in cardiomyopathy patients that can exist without TWA and is associated with QRS prolongation. QRSA increases the risk of ventricular tachyarrhythmia 4-fold, which merits further study as a risk stratifier.
Background The relationship between health care utilization and outcomes in patients with atrial fibrillation is unknown. The objective of this study was to investigate whether cardiologists' billing ...amounts in a fee-for-service environment are associated with better patient-level clinical outcomes. Methods and Results A retrospective cohort study was conducted using administrative claims data of cardiologists in Ontario, Canada between April 1, 2011 and March 31, 2016. The cardiologists were stratified into quintiles based on their median billing patterns per patient over the observation period. The primary outcomes were patient-level receipt of repeat visits, cardiac diagnostic tests, and medications ≤1 year of index date. The secondary clinical outcomes were death, emergency department visits, and all-cause hospitalization 1-year post-index visit. The patient cohort comprised 182 572 patients with atrial fibrillation (median age 74 years, 58% male) from 467 cardiologists. Patients with atrial fibrillation seen by higher-billing cardiologists were 26% more likely to have an echocardiogram (adjusted odds ratio aOR, 1.26 95% CI, 1.10-1.43 for quintile 5 versus 2), 28% a stress test (aOR, 1.28 1.12-1.46 for quintile 5 versus 2), 25% continuous electrocardiographic monitoring (aOR, 1.25 1.08-1.46 for quintile 4 versus 2), and 79% more likely to get a stress echocardiogram (aOR, 1.79 1.32-2.42 for quintile 5 versus 2). They also had a higher rate of all-cause hospitalization (aOR, 1.13 1.07-1.20). Mortality rates were similar across cardiologists billing quintiles (eg, aOR, 0.98 0.87-1.11 for quintile 4 versus 2). Conclusions Higher-billing cardiologists ordered more diagnostic tests per patient with atrial fibrillation but these are not associated with improvements in outcomes.
The majority of patients receiving implantable cardioverter-defibrillator (ICD) implantation under current guidelines never develop sustained ventricular arrhythmia; therefore, better markers of risk ...for sustained ventricular tachycardia and/or ventricular fibrillation are needed.
The purpose of this study was to identify cardiac magnetic resonance arrhythmic risk predictors of ischemic cardiomyopathy before ICD implantation.
Forty-three subjects (mean age, 64.5 ± 11.9 years) with previous myocardial infarction who were referred for ICD implantation were evaluated by cardiac magnetic resonance imaging (MRI). The MRI protocol included left ventricular functional parameter assessment using steady-state free precession and late gadolinium enhancement MRI using inversion recovery fast gradient echo. Left ventricular functional parameters were measured using cardiac magnetic resonance software. Subjects were followed up for 6-46 months, and the events of appropriate ICD treatments (shocks and antitachycardia pacing) were recorded.
Twenty-eight patients experienced 46 spontaneous episodes during a median follow-up duration of 30 months. The total myocardial infarct (MI) size (18.05 ± 11.44 g vs 38.83 ± 19.87 g; P = .0006), MI core (11.63 ± 7.14 g vs 24.12 ± 12.73 g; P = .0002), and infarct gray zone (6.43 ± 4.64 g vs 14.71 ± 7.65 g; P = .0004) were significantly larger in subjects who received appropriate ICD therapy than in those who did not experience an episode of ventricular tachycardia and/or ventricular fibrillation. Multivariate regression analyses for the infarct gray zone and MI core adjusted for New York Heart Association class, diabetes, and etiology (primary or secondary prevention) revealed that the gray zone and MI core were predictors of appropriate ICD therapies (P = .0018 and P = .007, respectively).
The extent of MI scar may predict which patients would benefit most from ICD implantation.
PDF
