Muhammet Ali Aydin

Persistence of Pulmonary Vein Isolation After Robotic Remote-Navigated Ablation for Atrial Fibrillation and its Relation to Clinical Outcome

Robotic Remote Ablation for AF. Aims: A robotic navigation system (RNS, Hansen™) has been developed as an alternative method of performing ablation for atrial fibrillation (AF). Despite the growing application of RNS‐guided pulmonary vein isolation (PVI), its consequences and mechanisms of subsequent AF recurrences are unknown. We investigated the acute procedural success and persistence of PVI over time after robotic PVI and its relation to clinical outcome.

Reduced fluoroscopy during atrial fibrillation ablation: benefits of robotic guided navigation.

Reduced Fluoroscopy in PVI Using RN. Background: Recently, a nonmagnetic robotic navigation system (RN, Hansen‐Sensei™) has been introduced for remote catheter manipulation.

Characterization, Mapping, and Catheter Ablation of Recurrent Atrial Tachycardias After Stepwise Ablation of Long-Lasting Persistent Atrial Fibrillation

Background—Atrial tachycardias (AT) often occur after ablation of long-lasting persistent AF (CAF) and are difficult to treat conservatively. This study evaluated mechanisms and success rates of conventional mapping and catheter ablation of recurrent ATs occurring late after stepwise ablation of CAF. Methods and Results—A total of 320 patients underwent de novo ablation of CAF using a stepwise ablation approach in 2006 to 2007 at our institution. This study comprised patients who presented with recurrent ATs at their first redo procedure after initial de novo CAF ablation. All procedures were guided by conventional mapping techniques exclusively. Sixty-one patients (63±10 years, 14 women) presented with their clinical AT at their redo procedure 7.7±4.4 months after initial de novo CAF ablation. A total of 133 ATs (2.2±0.9 per patient) were mapped. Forty-four (72%) were due to reentry; 17 (28%) were focal ATs. Reentry ATs were mainly characterized as roof and perimitral flutter (43% and 34%, respectively). Focal ATs mainly originated from the great thoracic veins (pulmonary veins: 41%, coronary sinus: 23%). Forty-five (74%) patients had conduction recovery of at least 1 pulmonary vein (mean, 1.2±0.8). Overall, 124 (93%) ATs could be ablated successfully. The mean procedure duration was 181±59 minutes, with a mean fluoroscopy time of 45±21 minutes. After a mean follow-up of 21±4 months, 50 (82%) patients were free of any arrhythmia recurrences after a single redo procedure. Conclusions—Although late recurrent ATs may have complex mechanisms, catheter ablation guided exclusively by conventional techniques is highly effective with excellent acute and long-term success rates.

Augmentation index relates to progression of aortic disease in adults with Marfan syndrome

BACKGROUND Noninvasive applanation tonometry (APT) is useful to assess aortic stiffness and pulse wave reflection. Moreover, APT can predict outcome in many conditions such as arterial hypertension. In this study, we test whether APT measurements relate to progression of aortic disease in Marfan syndrome (MFS). METHODS We performed APT in 50 consecutive, medically treated adults with MFS (19 men and 31 women aged 32 +/- 13 years), who had not undergone previous cardiovascular surgery. During 22 +/- 16 months of follow-up, 26 of these patients developed progression of aortic disease, which we defined as progression of aortic root diameters >or=5 mm/annum (18 individuals), aortic surgery >or=3 months after APT (seven individuals), or onset of acute aortic dissection any time after APT (one individual). RESULTS Univariate Cox regression analysis suggested an association of aortic disease progression with age (P = 0.001), total cholesterol levels (P = 0.04), aortic root diameter (P = 0.007), descending aorta diameter (P = 0.01), aortic root ratio (P = 0.02), and augmentation index (AIx@HR75; P < 0.006). Multivariate Cox regression analysis confirmed an independent impact on aortic disease progression exclusively for baseline aortic root diameters (hazard ratio = 1.347; 95% confidence interval (CI) 1.104-1.643; P = 0.003) and AIx@HR75 (hazard ratio = 1.246; 95% CI 1.029-1.508; P = 0.02). In addition, Kaplan-Meier survival curve analysis illustrated significantly lower rates of aortic root disease progression both with lower AIx@HR75 (P = 0.025) and with lower pulse wave velocity (PWV) values (P = 0.027). CONCLUSIONS We provide evidence that APT parameters relate to aortic disease progression in medically treated patients with MFS. We believe that APT has a potential to improve risk stratification in the clinical management of MFS patients.

Management and therapy of vasovagal syncope: A review

Vasovagal syncope is a common cause of recurrent syncope. Clinically, these episodes may present as an isolated event with an identifiable trigger, or manifest as a cluster of recurrent episodes warranting intensive evaluation. The mechanism of vasovagal syncope is incompletely understood. Diagnostic tools such as implantable loop recorders may facilitate the identification of patients with arrhythmia mimicking benign vasovagal syncope. This review focuses on the management of vasovagal syncope and discusses the non-pharmacological and pharmacological treatment options, especially the use of midodrine and selective serotonin reuptake inhibitors. The role of cardiac pacing may be meaningful for a subgroup of patients who manifest severe bradycardia or asystole but this still remains controversial.

Atrial fibrillation cycle length is a sole independent predictor of a substrate for consecutive arrhythmias in patients with persistent atrial fibrillation.

Background—Termination of persistent atrial fibrillation (AF) can be achieved through ablation, with the majority of patients terminating to an atrial tachycardia (AT) and fewer directly to sinus rhythm (SR). We aimed to identify potential predictors for the existence of a substrate for AT on termination to SR. Methods and Results—We assessed 95 persistent AF patients (age, 60±10 years) who underwent catheter ablation to the end point of AF termination. Forty patients terminated directly to SR (SRterm) and 55 to ATs (ATterm). Compared with the ATterm group, the SRterm group were younger (56±10 versus 63±9 years, P=0.001), had shorter durations of AF before ablation (9±26 versus 14±20 months, P<0.001), smaller left atrial diameters (41±5 versus 45±5 mm, P=0.015), and longer baseline AF cycle lengths (178±23 versus 159±31 ms, P=0.005). However, AF cycle length was the sole independent predictor of direct termination to SR. The most frequent AF termination site in SRterm patients was the pulmonary veins (53%), whereas in ATterm patients this was within the left atrium (58%). After follow-up of 12±6 months, there was a trend toward a greater proportion of patients in SR among those who terminated directly to SR after a single procedure. The most frequent type of recurrence was paroxysmal AF in SRterm patients and AT in ATterm patients. Conclusions—Patients who terminate to SR through ablation without an intermediate AT are characterized by a less altered arrhythmogenic substrate. Baseline AF cycle lengths emerged as a sole independent predictor of a substrate for consecutive arrhythmias.

Augmentation index and the evolution of aortic disease in marfan-like syndromes.

BACKGROUND The augmentation index at a heart rate of 75 beats/min (AIx@HR75) and central pulse pressure (CPP) can be measured noninvasively with applanation tonometry (APT). In this observational study, we investigated the relationship between AIx@HR75, CPP and aortic disease in patients with Marfan-like syndromes. METHODS We performed APT in 78 consecutive patients in whom classic Marfan syndrome (MFS) had been excluded (46 men and 32 women aged 34 +/- 13 years). These patients comprised 9 persons with MFS-like habitus, 6 with a bicuspid aortic valve (BAV), 5 with MASS phenotype, 3 with vascular type of Ehlers-Danlos syndrome (EDS), 3 with familial thoracic aortic aneurysm, 2 with Loeys-Dietz syndrome (LDS), 1 with mitral valve prolapse syndrome, 1 with familial ectopia lentis, and 48 persons with Marfan-like features but no defined syndrome. During 20 +/- 18 months after APT, we observed progression of aortic diameters in 15 patients, and aortic surgery or aortic dissection in 3 individuals. RESULTS All 11 patients with Marfan-like syndromes and progression of aortic disease exhibited AIx@HR75 > or =11%, including 8 individuals with aortic diameters < or =95th percentile of normal at baseline. Similarly, all 7 individuals without any defined syndrome but progression of aortic diameters exhibited AIx@HR75 >11%, including 6 individuals with aortic diameters < or =95th percentile at the time of APT. Aortic disease did not evolve at AIx@HR75 <11%. CPP is also related to aortic disease progression. CONCLUSIONS Aortic disease evolution relates to AIx@HR75 and CPP in Marfan like syndromes. Larger studies with comprehensive clinical and echocardiographic follow-up over long time intervals will be required to establish APT for prediction of aortic disease evolution in Marfan-like syndromes.

Biphasic versus Monophasic Shock for External Cardioversion of Atrial Flutter

Background: External cardioversion is effective to terminate persistent atrial flutter. Biphasic shocks have been shown to be superior to monophasic shocks for ventricular defibrillation and atrial fibrillation cardioversion. The purpose of this trial was to compare the efficacy of rectilinear biphasic versus standard damped sine wave monophasic shocks in symptomatic patients with typical atrial flutter. Methods: 135 consecutive patients were screened, 95 (70 males, mean age 62 ± 13 years) were included. Patients were randomly assigned to a monophasic or biphasic cardioversion protocol. Forty-seven patients randomized to the monophasic protocol received sequential shocks of 100, 150, 200, 300 and 360 J. Forty-eight patients with the biphasic protocol received 50, 75, 100, 150 or 200 J. Results: First-shock efficacy with 50-Joule, biphasic shocks (23/48 patients, 48%) was significantly greater than with the 100-Joule, monophasic waveform (13/47 patients, 28%, p = 0.04). The cumulative second-shock efficacy with the 50- and 75-Joule, biphasic waveform (39/48 patients, 81%) was significantly greater than with the 100- and 150-Joule, monophasic waveform (25/47 patients, 53%, p < 0.05). The cumulative efficacy for the higher energy levels showed naturally no significant difference between the two groups. The amount of the mean delivered energy was significantly lower in the biphasic group (76 ± 39 J) compared to the monophasic one (177 ± 78 J, p < 0.05). Conclusions: For transthoracic cardioversion of typical atrial flutter, biphasic shocks have greater efficacy and the mean delivered current is lower than for monophasic shocks. Therefore, biphasic cardioversion with lower starting energies should be recommended.

Event recorder monitoring to compare the efficacy of a left versus biatrial lesion set in patients undergoing concomitant surgical ablation for atrial fibrillation.

OBJECTIVES Various lesion sets and subsequent success rates have been reported in patients receiving concomitant surgical ablation for atrial fibrillation. However, most of these results have been obtained by discontinuous monitoring. We report results using continuous event recorder rhythm monitoring to compare more accurately the efficacy of a left versus biatrial lesion set to treat patients with persistent atrial fibrillation. METHODS Between July 2008 and December 2011, 66 patients with persistent or long-standing persistent atrial fibrillation underwent concomitant surgical atrial fibrillation ablation with a biatrial lesion set and subcutaneous event recorder implantation. The results and outcomes were compared with a propensity score-matched cohort of 66 patients with a left atrial lesion set and event recorder implantation. Event recorder interrogation was performed at 3, 6, and 12 months follow-up. RESULTS The mean patient age was 70.2±7.4 years, and 70.3% were male. No major ablation-related complications occurred. One-year survival was 94.8% with no statistically significant differences between the 2 groups. The overall rate of freedom from atrial fibrillation was 57.3% and 64.4% after 3 and 12 months follow-up, respectively. Three months postoperatively, patients in the biatrial group had a slightly higher rate of freedom from atrial fibrillation (63.6% vs 52.3% P=.22), but it did not reach statistical significance. At 12 months follow-up, a statistically significant higher rate of freedom from atrial fibrillation was observed in patients with a biatrial lesion set (74.4% vs 55.8%; P=.026). The mean atrial fibrillation burden in all patients was 15.1%±12.5% in the biatrial group and 21.2%±14.4% in the left atrial group 12 months postoperatively (P=.03). CONCLUSIONS Continuous rhythm monitoring by subcutaneous event recorder implantation was safe and feasible. In patients undergoing biatrial ablation, a statistically significant higher rate of freedom from atrial fibrillation was observed at 12 months follow-up.

Comparison of Antero-Lateral Versus Antero-Posterior Electrode Position for Biphasic External Cardioversion of Atrial Flutter†

External cardioversion is an established and very important tool to terminate symptomatic atrial flutter. The superiority of the biphasic waveform has been demonstrated for atrial flutter, but whether electrode position affects the efficacy of cardioversion in this population is not known. The aim of this trial was to evaluate whether anterior-lateral (A-L) compared with anterior-posterior (A-P) electrode position improves cardioversion results. Of 130 screened patients, 96 (72 men, mean age 62 +/- 12 years) were included and randomly assigned to a cardioversion protocol with either A-L or A-P electrode position. In each group, 48 patients received sequential biphasic waveform shocks using a step-up protocol consisting of 50, 75, 100, 150, or 200 J. The mean energy (65 +/- 13 J for A-L vs 77 +/- 13 J for A-P, p = 0.001) and mean number of shocks (1.48 +/- 1.01 for A-L vs 1.96 +/- 1.00 for A-P, p = 0.001) required for successful cardioversion were significantly lower in the A-L group. The efficacy of the first shock with 50 J in the A-L electrode position (35 of 48 patients [73%]) was also highly significantly greater than the first shock with 50 J in the A-P electrode position (18 of 48 patients [36%]) (p = 0.001). In conclusion, the A-L electrode position increases efficacy and requires fewer energy and shocks in external electrical cardioversion of common atrial flutter. Therefore, A-L electrode positioning should be recommended for the external cardioversion of common atrial flutter.