Effect of Catheter Ablation vs Antiarrhythmic Medication on Quality of Life in Patients With Atrial Fibrillation: The CAPTAF Randomized Clinical Trial.

Importance: Quality of life is not a standard primary outcome in ablation trials, even though symptoms drive the indication. Objective: To assess quality of life with catheter ablation vs antiarrhythmic medication at 12 months in patients with atrial fibrillation. Design, Setting, and Participants: Randomized clinical trial at 4 university hospitals in Sweden and 1 in Finland of 155 patients aged 30-70 years with more than 6 months of atrial fibrillation and treatment failure with 1 antiarrhythmic drug or ß-blocker, with 4-year follow-up. Study dates were July 2008-September 2017. Major exclusions were ejection fraction <35%, left atrial diameter >60 mm, ventricular pacing dependency, and previous ablation. Interventions: Pulmonary vein isolation ablation (n = 79) or previously untested antiarrhythmic drugs (n = 76). Main Outcomes and Measures: Primary outcome was the General Health subscale score (Medical Outcomes Study 36-Item Short-Form Health Survey) at baseline and 12 months, assessed unblinded (range, 0 [worst] to 100 [best]). There were 26 secondary outcomes, including atrial fibrillation burden (% of time) from baseline to 12 months, measured by implantable cardiac monitors. The first 3 months were excluded from rhythm analysis. Results: Among 155 randomized patients (mean age, 56.1 years; 22.6% women), 97% completed the trial. Of 79 patients randomized to receive ablation, 75 underwent ablation, including 2 who crossed over to medication and 14 who underwent repeated ablation procedures. Of 76 patients randomized to receive antiarrhythmic medication, 74 received it, including 8 who crossed over to ablation and 43 for whom the first drug used failed. General Health score increased from 61.8 to 73.9 points in the ablation group vs 62.7 to 65.4 points in the medication group (between-group difference, 8.9 points; 95% CI, 3.1-14.7; P = .003). Of 26 secondary end points, 5 were analyzed; 2 were null and 2 were statistically significant, including decrease in atrial fibrillation burden (from 24.9% to 5.5% in the ablation group vs 23.3% to 11.5% in the medication group; difference -6.8% [95% CI, -12.9% to -0.7%]; P = .03). Of the Health Survey subscales, 5 of 7 improved significantly. Most common adverse events were urosepsis (5.1%) in the ablation group and atrial tachycardia (3.9%) in the medication group. Conclusions and Relevance: Among patients with symptomatic atrial fibrillation despite use of antiarrhythmic medication, the improvement in quality of life at 12 months was greater for those treated with catheter ablation compared with antiarrhythmic medication. Although the study was limited by absence of blinding, catheter ablation may offer an advantage for quality of life. Trial Registration: clinicaltrialsregister.eu Identifier: 2008-001384-11.

A decade of catheter ablation of cardiac arrhythmias in Sweden: ablation practices and outcomes.

AIMS: Catheter ablation is considered the treatment of choice for many tachyarrhythmias, but convincing 'real-world' data on efficacy and safety are lacking. Using Swedish national registry data, the ablation spectrum, procedural characteristics, as well as ablation efficacy and reported adverse events are reported. METHODS AND RESULTS: Consecutive patients (≥18 years of age) undergoing catheter ablation in Sweden between 01 January 2006 and 31 December 2015 were included in the study. Follow-up (repeat ablation and vital status) was collected through 31 December 2016. A total of 26 642 patients (57 ± 15 years, 62% men), undergoing a total of 34 428 ablation procedures were included in the study. In total, 4034 accessory pathway/Wolff-Parkinson-White syndrome (12%), 7358 AV-nodal re-entrant tachycardia (21%), 1813 atrial tachycardia (5.2%), 5481 typical atrial flutter (16%), 11 916 atrial fibrillation (AF, 35%), 2415 AV-nodal (7.0%), 581 premature ventricular contraction (PVC, 1.7%), and 964 ventricular tachycardia (VT) ablations (2.8%) were performed. Median follow-up time was 4.7 years (interquartile range 2.7-7.0). The spectrum of treated arrhythmias changed over time, with a gradual increase in AF, VT, and PVC ablation (P < 0.001). Decreasing procedural times and utilization of fluoroscopy with time, were seen for all arrhythmia types. The rates of repeat ablation differed between ablation types, with the highest repeat ablation seen in AF (41% within 3 years). The rate of reported adverse events was low (n = 595, 1.7%). Death in the immediate period following ablation was rare (n = 116, 0.34%). CONCLUSION: Catheter ablations have shifted towards more complex procedures over the past decade. Fluoroscopy time has markedly decreased and the efficacy of catheter ablation seems to improve for AF.

Clinical outcome of the 2nd generation cryoballoon for pulmonary vein isolation in patients with persistent atrial fibrillation - A sub-study of the randomized trial evaluating single versus dual cryoballoon applications.

AIMS: To assess the efficacy of the 2nd generation Cryoballoon for pulmonary vein isolation (PVI) in patients with persistent atrial fibrillation (PersAF), and to compare it to patients with paroxysmal atrial fibrillation (PAF). METHODS: The outcome (arrhythmia recurrence at 12 months) was prospectively assessed in patients with PersAF(n = 77) and compared to that in patients with PAF(n = 62), who underwent PVI within a randomized trial evaluating single versus dual applications with the 2nd generation cryoballoon. Other endpoints included symptoms of AF, quality of life, procedure related characteristics, redo ablation rates and adverse events. Variables predicting recurrences were studied including all patients. RESULTS: Freedom from arrhythmia recurrence was 64.9% after a single ablation and 68.8% after one or more procedures, which was significantly lower compared to PAF patients; 82.2% (p = 0.029) and 83.9% (p = 0.048) respectively, at 12 months. The improvements in EHRA score (-1.3 ±â€¯0.8, p < 0.0001), symptom severity score (SSQ) (-5.0 ±â€¯4.2, p < 0.0001) and EQ5D-5 L global score (+10.4 ±â€¯20.3, p = 0.0002) after ablation was significant compared to baseline. The re-ablation rate was 7/77 (9.1%) which did not differ from that in PAF patients, 9/62 (14.5%), p = 0.42. Procedure duration, 104.8 ±â€¯37.4 versus 113 ±â€¯31.2 min (p = 0.129), application time, 1605 ±â€¯659 versus 1521 ±â€¯557 s (p = 0.103) and total adverse events after 12 months, 8/77 (10.4%) versus 5/62 (8.1%) (p = 0.77) did not differ in PersAF versus PAF patients. CONCLUSION: Both symptoms and QoL improved significantly in patients with PersAF after ablation. Freedom from AF was clinically significant but lower than in PAF patients. The cryoballoon seems an effective technique also in patients with persistent AF.

Acute and long-term efficacy and safety with a single cryoballoon application as compared with the standard dual application strategy: a prospective randomized study using the second-generation cryoballoon for pulmonary vein isolation in patients with symptomatic atrial fibrillation.

Aims: A single cryoballoon (CB) application per vein for pulmonary vein isolation (PVI) in patients with atrial fibrillation (AF) could save time and was therefore compared to the standard approach of two consecutive CB applications for acute and long-term efficacy and safety. Methods and results: Patients with symptomatic AF were randomized to a single CB application per vein guided by an Achieve® catheter (Single cryo-arm) or to two CB applications using a standard guidewire (Routine cryo-arm). The primary endpoint was the rate of acute complete PVI. Secondary endpoints were freedom from AF evaluated by electrocardiogram and 7 days Holter at 6 and 12 months, symptoms by Symptom Severity Questionnaires and EHRA score and quality of life (QoL) by EQ5D-5L at 12 months. Among 140 patients included, PVI was achieved in 271 (100%) veins in the Single cryo-arm and in 269/271 (99.3%) veins in the Routine cryo-arm, P = 0.25. The procedure time was shorter in the Single cryo-arm, mean ± standard deviation 99.4 ± 33.3 min vs. 118.4 ± 34.3 min, P = 0.0015. Freedom from AF after one procedure at 12 months did not differ; 73.9.0% (Single cryo) vs. 71.4% (Routine), P = 0.74. Symptoms and QoL did also not differ between the two groups. There was a lower complication rate in the Single cryo-group, 2.9% vs. 12.9%, P = 0.03. Conclusion: A single CB application shortens the procedure time without affecting acute or long-term efficacy, as compared to the routine two-application strategy, which with the lower complication rates has important implications when defining standards for PVI.

Left atrial function after epicardial pulmonary vein isolation in patients with atrial fibrillation.

PURPOSE: Epicardial pulmonary vein isolation has become an increasingly used therapy for medically resistant atrial fibrillation. The purpose of the present study was therefore to evaluate if epicardial pulmonary vein isolation combined with ganglionated plexi ablation affects the size and mechanical function of the left atrium, and whether the effects are dependent on the extensiveness of the ablation applications. METHODS: A total of 42 patients underwent an echocardiographic examination prior to and 6 months after a minimal invasive epicardial pulmonary vein isolation procedure for the assessment of the effects on left atrial size and function. In 27 patients, who had sinus rhythm both at baseline and follow-up, was a comparison of atrial size and function possible at these time intervals. Fractional area changes were obtained from the left atrial end-systolic and end-diastolic areas in the apical four-chamber view. Pulsed-Doppler was used to assess the transmitral flow velocities to evaluate mechanical function. RESULTS: Left atrial size and function at 6-month follow-up had not changed significantly from those at baseline as indicated by left atrial maximal area (17.1 ± 4.6 vs. 18.7 ± 5.3, p = 0.118), minimal area (12.5 ± 3.8 vs. 13.4 ± 4.7, p = 0.248), fractional area change (27.4 ± 8.2 vs. 28.7 ± 10.6, p = 0.670), and E/A ratio (1.49 ± 0.47 vs. 1.54 ± 0.67, p = 0.855). CONCLUSIONS: Radiofrequency ablation for epicardial pulmonary vein isolation combined with ganglionated plexi ablation has no major effects on atrial function or size. A preserved atrial function for those maintaining sinus rhythm may have important implications for thromboembolic risk after surgery, but warrants confirmation in larger trials.

Thoracoscopic epicardial left atrial ablation in symptomatic patients with atrial fibrillation.

AIMS: The low efficacy rates reported for conventional catheter ablation of longstanding persistent atrial fibrillation (LPAF) have led to the development of alternative techniques such as minimal invasive surgical ablation, aiming for durable and contiguous transmural lesions. The aim was to evaluate the efficacy and safety of total thoracoscopic epicardial left atrial ablation (TELA-AF) procedures in a prospective study of severely symptomatic patients with either drug-resistant AF and/or failed attempts of catheter ablation. METHODS AND RESULTS: The TELA-AF surgical technique includes pulmonary vein isolation, left atrial (LA) 'box lesion', and partial vagal denervation. The LA appendage was excluded if deemed safe. Patients were followed with clinical evaluations and 12-lead electrocardiograms at 3, 6, and 12 months after the surgical intervention, complemented with a 7-day Holter monitoring after 6 and 12 months. Sixty patients, of whom 38 (63%) suffered from LPAF, underwent TELA-AF between November 2008 and December 2010. One patient with LPAF was lost to follow-up. At 12-month follow-up, 55/59 patients (93%) were free from atrial fibrillation (AF), while 7/59 patients (12%) suffered from recurrent LA tachycardia. Among patients with LPAF, 32/37 (86%) maintained sinus rhythm after 12 months. Adverse events included four perioperative bleedings requiring conversion to sternotomy in three cases, two ischaemic strokes and one transient ischaemic attack. CONCLUSION: The total thoracoscopic surgical ablation procedure is highly effective even in patients with LPAF, and it seems safe. The high rate of iatrogenic LA re-entrant tachycardia, however, warrants further improvement of the technique.

Ablation of atrial fibrillation with cryoballoon or duty-cycled radiofrequency pulmonary vein ablation catheter: a randomized controlled study comparing the clinical outcome and safety; the AF-COR study.

AIMS: The urge to facilitate the atrial fibrillation (AF) ablation procedure has led to the development of new ablation catheters specifically designed as 'one-shot tools' for pulmonary vein isolation (PVI). The purpose of this study was to compare the efficacy, safety, and procedure times for two such catheters using different energy sources. METHODS AND RESULTS: One hundred and ten patients, referred for ablation of paroxysmal or persistent AF, were randomized to treatment with either the cryoballoon or the circular multipolar duty-cycled radiofrequency-based pulmonary vein ablation catheter (PVAC). Complete PVI was achieved in 98 vs. 93% patients in the cryoballoon and PVAC group, respectively, with complication rates of 8 vs. 2% (P = 0.2). Complete freedom from AF, without antiarrhythmic drugs, after one single ablation procedure was seen in 46% in the cryoballoon vs. 34% after 12 months (P = 0.2). Procedure times were comparable, but fluoroscopy time was shorter for the cryoballoon (32 ± 16 min) than for the PVAC procedures (47 ± 17 min) (P < 0.001). A significant improvement of quality of life (QoL) and arrhythmia-related symptoms was seen in both groups after ablation. CONCLUSION: Both catheters proved comparably effective and safe in achieving acute PVI, apart from the shorter fluoroscopy times achieved with the cryoballoon. At follow-up, there was no statistically significant difference between the groups regarding freedom from AF and clinical success. The QoL increased to the same levels as for the general Swedish population in both groups.

Comparison of effects on coagulation and inflammatory markers using a duty-cycled bipolar and unipolar radiofrequency pulmonary vein ablation catheter vs. a cryoballoon catheter for pulmonary vein isolation.

AIMS: Thrombo-embolic events are one of the most feared complications related to atrial fibrillation (AF) ablation. Since radiofrequency (RF) energy is thought to be associated with a higher risk of thrombus formation than cryoenergy, the purpose of this study was to assess if the degree of activation of coagulation and inflammatory markers differed between ablation procedures performed with a cryoballoon catheter vs. a RF energy-based pulmonary vein ablation catheter (PVAC), respectively. METHODS AND RESULTS: Thirty patients referred for AF ablation were randomized to pulmonary vein isolation with either the cryoballoon or the PVAC. Biomarkers were studied for endothelial damage (von Willebrand factor antigen), platelet activation (soluble P-selectin), and coagulation activity [prothrombin fragment 1 + 2 (F1 + 2) and D-dimer] at five different time points during the procedure. Troponin I (Trop I) and C-reactive protein were analysed to reflect myocardial destruction and inflammatory activity. Markers of endothelial damage and platelet activation increased after ablation in both the cryo and the RF group. Similarly, the D-dimer levels increased significantly (P = 0.001) in both groups, whereas the F1 + 2 levels increased after the transseptal puncture only (P = 0.001). The overall activation of the coagulation system was, however, comparable between the groups. The cryoballoon was associated with higher Trop I compared with the PVAC (P < 0.001), but the ratios between biomarkers and Trop I were higher with the PVAC than with the cryoballoon. CONCLUSION: Even though the cryoballoon causes a higher degree of myocardial destruction than the PVAC, markers of coagulation, endothelial damage, and inflammation were comparable between the two techniques.

Right ventricular contractility as a measure of optimal interventricular pacing setting in cardiac resynchronization therapy.

AIMS: The aim of the present study was to assess whether right ventricular (RV) contractility can be used for optimization of the interventricular (VV) interval and to study the acute hemodynamic effect of different VV intervals on right and left ventricular (LV) contractility in patients referred for cardiac resynchronization therapy (CRT). METHODS AND RESULTS: Intracardiac LV and RV dP/dt were measured with a 0.014-in. sensor-tipped pressure guidewire during pacing at nine different VV intervals ranging from +80 ms (LV pre-excitation) to -80 ms (RV pre-excitation) in 26 patients who received a biventricular pacemaker. No correlation was found between the optimal VV intervals identified by maximum LV dP/dt and RV dP/dt, which were identical in only seven cases (27%). Only when testing slightly broader intervals (+/-20 ms) was there a statistically significant correlation (P= 0.037) between the optimized VV intervals. In the majority of patients (58%) either LV or RV pre-excitation was superior to simultaneous pacing according to LV dP/dt(max) measurements. CONCLUSION: RV dP/dt(max) failed to identify the optimal VV interval when compared with LV dP/dt(max) and can therefore not be recommended for VV optimization in CRT patients.

A high quality of life is maintained late after Maze III surgery for atrial fibrillation.

BACKGROUND: Cox Maze surgery for atrial fibrillation (AF) has been found to have high efficacy in maintaining sinus rhythm and has been shown to improve quality of life early after surgery, but reports on long-term effects in this respect are lacking. This study was therefore undertaken to evaluate the effect of the Maze procedure on health-related quality of life in the long term. METHODS: Patients with drug-refractory AF undergoing the 'cut and sew' Maze III procedure without any modification were assessed with the SF-36 Health Survey regarding quality of life at baseline and late after surgery. Totally 61 patients, mean age 55 years (range: 29-74 years), were evaluated. At the time of surgery, 34 patients (56%) had paroxysmal or persistent AF and the remainder had permanent AF. RESULTS: At late follow-up, at a mean of 55+/-12 months, 54 patients (89%) were free from AF recurrences and another five patients (8%) had experienced only one or a few AF episodes. All eight scales on the SF-36 Health Survey were significantly improved at long-term follow-up compared to baseline. The quality-of-life improvement was seen both in patients with paroxysmal/persistent AF and in those with permanent AF. At long-term follow-up, the quality-of-life scores were comparable with those of the general population. CONCLUSIONS: The Cox Maze III procedure has good long-term efficacy for rhythm control in patients with medically refractory AF, resulting in a quality-of-life improvement, which is maintained late after surgery.

The use of impedance cardiography for optimizing the interventricular stimulation interval in cardiac resynchronization therapy-a comparison with left ventricular contractility.

The present study aimed to assess whether impedance cardiography (IC) can correctly identify the optimal interventricular (VV) pacing interval in cardiac resynchronization therapy (CRT). Twenty four patients received a biventricular pacemaker and underwent IC for cardiac output (CO) measurements to identify the optimal VV interval. Invasive measurements of left ventricular (LV) dP/dt(max) were used as a reference. During optimization the VV interval was changed with 20 ms steps from +80 (LV pre-excitation) to-80 ms (RV pre-excitation). The optimal VV interval was defined as the one that resulted in the highest LV dP/dt(max) value and the highest CO obtained by IC, respectively. During simultaneous biventricular pacing both LV dP/dt(max) and CO increased (mean 16.6% and 16.2%, respectively) as compared to baseline. Biventricular pacing with optimized VV intervals resulted in a further absolute increase of LV dP/dt (max) and CO (5.6% and 41.3%, respectively). The average decrease in LV dP/dt(max) was 79.6 +/- 51.6 mmHg/s when the optimal VV interval was programmed according to the IC measurements. Cross spectral analysis showed no correlation between the optimal VV intervals identified by the two methods (p > 0.05) and identical optimal VV intervals were identified in only six of the 24 patients. When broader VV time intervals were compared the correlation between the two methods was statistically significant (p = 0,0166). In conclusion, the use of IC for VV interval optimization is questionable since these optimized time intervals do not seem to correlate well with those obtained by measuring LV dP/dt.

The effects of aetiology on outcome in patients treated with cardiac resynchronization therapy in the CARE-HF trial.

AIMS: Cardiac dyssynchrony is common in patients with heart failure, whether or not they have ischaemic heart disease (IHD). The effect of the underlying cause of cardiac dysfunction on the response to cardiac resynchronization therapy (CRT) is unknown. This issue was addressed using data from the CARE-HF trial. METHODS AND RESULTS: Patients (n = 813) were grouped by heart failure aetiology (IHD n = 339 vs. non-IHD n = 473), and the primary composite (all-cause mortality or unplanned hospitalization for a major cardiovascular event) and principal secondary (all-cause mortality) endpoints analysed. Heart failure severity and the degree of dyssynchrony were compared between the groups by analysing baseline clinical and echocardiographic variables. Patients with IHD were more likely to be in NYHA class IV (7.5 vs. 4.0%; P = 0.03) and to have higher NT-proBNP levels (2182 vs. 1725 pg/L), indicating more advanced heart failure. The degree of dyssynchrony was more pronounced in patients without IHD (assessed using mean QRS duration, interventricular mechanical delay, and aorta-pulmonary pre-ejection time). Left ventricular ejection fraction and left ventricular end-systolic volume improved to a lesser extent in the IHD group (4.53 vs. 8.50% and -35.68 vs. -58.52 cm(3)). Despite these differences, CRT improved all-cause mortality, NYHA class, and hospitalization rates to a similar extent in patients with or without IHD. CONCLUSION: The benefits of CRT in patients with or without IHD were similar in relative terms in the CARE-HF study but as patients with IHD had a worse prognosis, the benefit in absolute terms may be greater.

A prospective randomised comparison of large-tip cryoablation and 8-mm-tip radiofrequency catheter ablation of atrial flutter.

PURPOSE: Although radiofrequency (RF) energy is routinely used for tricuspid isthmus (TI) ablation, it is often associated with discomfort. The paucity of studies comparing the feasibility and efficacy of cryo- versus RF energy for TI-ablation urged us to conduct a prospective, randomised trial. METHODS: Forty patients with atrial flutter (AFl) were randomised to RF- or cryoenergy for TI-ablation. Perceived pain was scored from 1 to 10 on a Visual Analogue Scale. RESULTS: Significantly lower pain scores were recorded for cryoablation versus RF ablation (0.96 +/- 0.73 versus 4.2 +/- 2.4, p = 0.00004). Cryoablation was associated with significantly longer procedure duration and ablation time (137 +/- 35 versus 111 +/- 29 min, p = 0.016 and 81 +/- 40 versus 48 +/- 30 min, p = 0.007) and lower acute success rate (56% versus 100%, p = 0.001) than RF ablation. The recurrence of AFl was 20% (cryo) versus 15% (RF; p = 0.45) after a mean of 15.1 months follow-up. CONCLUSION: Cryoablation results in significantly less pain and discomfort compared to RF ablation of AFl, which is offset by the significantly lower acute success rate.

Acute and clinical effects of cryoballoon pulmonary vein isolation in patients with symptomatic paroxysmal and persistent atrial fibrillation.

AIMS: To assess the acute effects, safety, and clinical outcome of atrial fibrillation (AF) ablation using a cryoballoon catheter. METHODS AND RESULTS: Forty patients with paroxysmal or persistent AF underwent pulmonary vein (PV) isolation with a cryoballoon catheter (Arctic Front, CryoCath). Electrocardiograms were recorded in case of symptomatic AF recurrences, and a 24 h Holter recording was performed at last follow-up. Complete PV isolation was achieved in 39 (91%) of the 43 procedures (56% with the cryoballoon catheter alone, 44% with an additional conventional ryocatheter). The number of balloon applications per procedure was 9.6 +/- 1.6. The PV isolation rate was significantly higher (83.9%) if total vessel occlusions were obtained than if intermediate (63.6%, P = 0.01) or poor occlusions were achieved (38.1%, P = 0.0002). The mean procedure time was 239 +/- 48 min. At follow-up (mean 8.9 +/- 4.6 months), 52.5% of patients were free from arrhythmia-related symptoms and another 17.5% had reduction of arrhythmia-related symptoms. Two cases each of phrenic nerve paralysis and dysphagia occurred. CONCLUSIONS: Cryoballoon PV isolation is a feasible technique with a high acute success rate and comparable clinical outcome to radiofrequency ablation. Although complications were rare, the need for an additional conventional cryocatheter warrants further development of the technique.

Long-term effects of the maze procedure on atrial size and mechanical function.

BACKGROUND: The Maze procedure is effective in restoring sinus rhythm, but the extensive procedure may have negative effects on atrial mechanical function. Decreased atrial contractility has been observed early after the Maze procedure. The purpose of this study was to determine the long-term effect of the Maze procedure on atrial size and mechanical function. METHODS: Fifty-two patients with symptomatic atrial fibrillation, without structural heart or valvular disease, underwent the Cox Maze III procedure. Atrial size and mechanical function were assessed by echocardiographic examination at baseline and postoperatively at a mean +/- SD of 6 +/- 1 and 56 +/- 12 months. RESULTS: The left atrial area was decreased 6 months after the procedure compared with baseline (mean, 15.4 +/- 3.3 vs 17.6 +/- 3.2 cm2, p < 0.01). By 56 months, however, the left atrial area had increased compared with the 6-month follow-up (19.5 +/- 3.9 vs 15.4 +/- 3.3 cm2, p < 0.001), resulting in no difference in left atrial size compared with the baseline values. The left atrial contractility, measured as fractional area change, was significantly reduced at 6 and 56 months of follow-up (0.20 +/- 0.09 and 0.19 +/- 0.07 vs baseline 0.36 +/- 0.09), as was the transmitral A-wave velocity (30 +/- 12 and 28 +/- 8 cm/s vs baseline 40 +/- 15). The same pattern was seen for the right atrium. CONCLUSIONS: This study shows that the Maze procedure results in a sustained decrease in atrial contractility. The initial reduction in atrial size is later reversed. These findings contradict late improvements in atrial mechanical function after Maze surgery and may have important implications for the risk of thromboembolic complications.

Effect of right atrial overdrive pacing in the prevention of symptomatic paroxysmal atrial fibrillation: a multicenter randomized study, the PAF-PACE study.

The aim of this study was to assess if right atrial overdrive pacing can suppress symptomatic episodes of paroxysmal atrial fibrillation (PAF) in patients without bradyarrhythmias. Forty-two patients with frequent and symptomatic PAF without other pacing indication had a pacemaker implanted after a 4-week run-in period, during which the frequency of symptomatic PAF episodes and the mean heart rate were objectively documented. Depending on the mean heart rate recorded during run-in, the pacemaker was programmed in random order to right atrial AAI pacing at 10-19 beats/min > mean heart rate (medium overdrive [MO]), at 20-29 beats/min > mean heart rate (high overdrive [HO]) and to no pacing (OAO mode) for 4-12 weeks each using a crossover design. In the 35 patients who completed the protocol, the number of symptomatic episodes of PAF (>30-second duration) per week was significantly lower during MO pacing (median 0.88, P = 0.001, n = 35) and during HO pacing (median 0.75, P = 0.002, n = 20) than during OAO (median 2.02 and 2.04, respectively). There was no difference between MO and HO pacing in the 20 patients paced at both rates (0.97 vs 0.75, P = 0.33). Seven patients did not complete the protocol due to persistent atrial fibrillation (n = 4), angina pectoris requiring surgery (n = 1), and unwillingness to continue the study due to improvement (n = 1) or worsening (n = 1) of symptoms during the study periods. Right atrial overdrive pacing can reduce the number of symptomatic PAF episodes in patients with frequent and drug refractory PAF but without bradyarrhythmias.

Autonomic denervation after the Maze procedure.

The Maze III procedure is a surgical operation for curative treatment of AF. The procedure is extensive, however, with multiple incisions in both atria, and its effects on autonomic regulation of the heart rhythm are not known. This study comprises 17 patients, 10 with paroxysmal AF and 7 with chronic AF, who had no concurrent cardiac disease known to affect heart rate variability (HRV). A 24-hour Holter recording was performed preoperatively and 2 months (early) and 7 months (late) after surgery, for analysis of HRV in the time and frequency domains. Early after the Maze procedure all HRV components were markedly reduced compared to baseline (mean +/- 1 SD): SDNN 73 +/- 13 versus 148 +/- 50 (ms), total power 168 +/- 126 versus 560 +/- 1567 (ms2), low frequency (LF) power 47 +/- 67 versus 826 +/- 677 (ms2), high frequency (HF) power 47 +/- 40 versus 678 +/- 666 (ms2), and LF:HF 1.22 +/- 0.9 versus 2.55 +/- 1.4. Late after the Maze procedure all variables were still reduced. Only total power increased significantly between early and late follow-up (168 +/- 126 vs 496 +/- 435 ms2). Late after Maze surgery, values of the different HRV components did not differ between the patients with paroxysmal AF and chronic AF. Early after the Maze procedure there is a marked decrease of all HRV components, which is maintained 7 months after surgery, a pattern consistent with denervation of the heart.

Atrial size and transport function after the Maze III procedure for paroxysmal atrial fibrillation.

BACKGROUND: The Maze procedure is a curative surgical therapy for atrial fibrillation, restoring sinus rhythm and improving quality of life. Because the procedure results in tissue scarring, the atrial transport function is most likely affected. METHODS: Seventeen patients with paroxysmal atrial fibrillation underwent the Maze III procedure without any concomitant valve operation. Atrial size and transport function were measured before and at 2, 6, and 24 months after operations with two-dimensional echocardiography and pulsed-wave Doppler. RESULTS: Fifteen patients (88%) had signs of left atrial contractions as shown by the presence of a transmitral atrial filling wave on Doppler echocardiography at 6 months follow-up. The transmitral early filling wave and atrial filling wave were measured to calculate the early filling/atrial filling wave ratio, which increased from 1.2 before to 1.9 at 2 months after the Maze procedure (nonsignificant), and further to 2.8 at 24 months (p = 0.02). A decrease in the right and left atrial size was seen at 2 months after an operation, but no further decrease occurred. CONCLUSIONS: In patients with paroxysmal atrial fibrillation, there is a progressive increase in the transmitral early filling/atrial filling wave ratio after the Maze procedure, consistent with a gradual decrease in the left atrial transport function.