Heinz D. Gössinger

Frequency of Recurrence of Atrial Fibrillation Within 48 Hours After Ablation and Its Impact on Long-Term Outcome

Because of delayed structural and electrophysiologic effects of radiofrequency ablation of atrial fibrillation (AF), early recurrence of AF after ablation does not necessarily indicate long-term ablation failure. This study was intended to assess the prognostic value of early recurrence of AF within 48 hours after ablation. The study included 234 patients (aged 23 to 80 years; 72% men) with symptomatic drug-resistant paroxysmal (n = 165) or persistent AF (n = 69) who underwent either Lasso-guided segmental pulmonary vein isolation (n = 83) or CARTO-guided left atrial circumferential ablation (n = 151). After a median follow-up of 12.7 months, 64% of patients with paroxysmal and 45% of patients with persistent AF were AF free. Early recurrence of AF occurred in 43% of patients and was more frequently observed in the persistent-AF group (paroxysmal vs persistent 39% vs 54%; p = 0.037). Early recurrence of AF was a significant predictor of long-term ablation failure in univariate (hazard ratio [HR] 2.29, p <0.001) and multivariate (HR 2.17. p <0.001) Cox regression analysis. Nevertheless, 46% of patients with early recurrence of AF were AF free during long-term follow-up compared with 68% of patients without early recurrence of AF. The prognostic value of early recurrence of AF was found in patients with paroxysmal (HR 2.05, p = 0.005) and persistent AF (HR 2.35, p = 0.013). In conclusion, early recurrence of AF within 48 hours after ablation was a significant predictor of a poor long-term ablation outcome. However, because nearly half the patients with early recurrence of AF remained AF free during long-term follow-up, early recurrence of AF should not automatically result in an early repeated procedure.

Time course of markers of tissue repair after ablation of atrial fibrillation and their relation to left atrial structural changes and clinical ablation outcome

BACKGROUND Radiofrequency ablation of atrial fibrillation (AF) creates left atrial (LA) tissue damage with a subsequent healing process. We sought to prospectively assess the time course of biomarkers of tissue repair after ablation and to evaluate their association with clinical variables. METHODS 30 consecutive patients (57.9 ± 1.7 yrs, 63% males) with paroxysmal AF underwent a CARTO-guided LA circumferential ablation, Lasso-guided segmental pulmonary vein isolation and ablation of complex fractionated atrial electrograms. Matrix metalloproteinase-9 (MMP-9) and transforming growth factor-β1 (TGF-β1), both key regulators of tissue repair, and the aminoterminal propeptide of type III procollagen (PIIINP), reflecting collagen synthesis, were determined in blood samples before and 6h, 1, 2, 7, 30, 90 and 180 days post-ablation. RESULTS All markers showed a significant ablation-induced up-regulation (MMP-9: 1.8 ± 0.1-fold, TGF-β1: 2.4 ± 0.4-fold, PIIINP: 1.3 ± 0.1-fold). MMP-9 was significantly up-regulated until day 90, TGF-β1 only on day 2. PIIINP increased from day 2 to 7. The area under the curve (AUC) of MMP-9 and TGF-β1 correlated with the ablation-induced reduction of LA volume (both p<0.05). The AUC of MMP-9 was additionally associated with the amount of radiofrequency energy delivered during ablation (p < 0.05). At 12 months of follow-up 57% of patients were free of AF off antiarrhythmic drugs. The AUC of PIIINP independently predicted recurrent AF (p < 0.05). CONCLUSIONS Markers of healing showed a significant up-regulation after AF ablation detectable for up to 90 days. A more pronounced up-regulation of MMP-9 or TGF-β1 is associated with a greater reduction of LA size. High PIIINP levels after ablation predict a poor ablation outcome.

Sinus Node Dysfunction After Orthotopic Heart Transplantation: The Vienna Experience 1987–1993

In the present study, the annual incidence of postoperative sinus node dysfunction and the type of sinus node abnormality after cardiac transplantation were followed over a 6½‐year period in 185 patients. Each year the sinus node function was systematically characterized by rhythm and corrected sinus node recovery time in a significant number of patients. Over the entire study period, there were 131 patients with normal sinus node function (corrected sinus node recovery time 318 ± 55 msec) while 54 patients had latent (n = 24, sinus rhythm, corrected sinus node recovery time 8,053 ± 2,198 msec) or manifest (n = 30, absence of sinus rhythm or pacemaker dependence) sinus node dysfunction. Twenty‐nine patients had pacemaker placement. The incidence of sinus node dysfunction declined in absolute terms and when indexed by the actual number of patients transplanted per year (index 1987: 38.5; 1998: 17.6; 1989: 23.2; 1990: 29.1; 1991: 10.4; 1992: 7.5; 1993: 2.2). Among those with sinus node dysfunction, the annual percentage of patients presenting with prolonged recovery time, escape rhythm, and those reverting back to sinus rhythm until discharge did not change significantly over the study period (P = 0.22). On multivariate analysis, only the date of transplantation was significantly associated with the occurrence of postoperative sinus node deficiency (P = 0.0007) while age of recipient (P = 0.85) or donor (P = 0.96), the type of cardioplegia used (P = 0.09) and ischemic time (P = 0.09) were insignificant. This decline in the annual incidence of sinus node dysfunction most probably may be interpreted in terms of improvements in management (learning curve). It is unclear which changes in particular are responsible for this development. In view of the lack of other significant associations, this might be an indication that operative trauma plays a role in the etiology of sinus node dysfunction after cardiac transplantation.

Evaluation of left atrial function by multidetector computed tomography before left atrial radiofrequency-catheter ablation: Comparison of a manual and automated 3D volume segmentation method

INTRODUCTION The purpose of this study was to compare a manual and automated 3D volume segmentation tool for evaluation of left atrial (LA) function by 64-slice multidetector-CT (MDCT). METHODS AND MATERIALS In 33 patients with paroxysmal atrial fibrillation a MDCT scan was performed before radiofrequency-catheter ablation. Atrial function (minimal volume (LAmin), maximal volume (LAmax), stroke volume (SV), ejection fraction (EF)) was evaluated by two readers using a manual and an automatic tool and measurement time was evaluated. RESULTS Automated LA volume segmentation failed in one patient due to low LA enhancement (103HU). Mean LAmax, LAmin, SV and EF were 127.7 ml, 93 ml, 34.7 ml, 27.1% by the automated, and 122.7 ml, 89.9 ml, 32.8 ml, 26.3% by the manual method with no significant difference (p>0.05) and high Pearsons correlation coefficients (r=0.94, r=0.94, r=0.82 and r=0.85, p<0.0001), respectively. The automated method was significantly faster (p<0.001). Interobserver variability was low for both methods with Pearsons correlation coefficients between 0.98 and 0.99 (p<0.0001). CONCLUSIONS Evaluation of LA volume and function with 64-slice MDCT is feasible with a very low interobserver variability. The automatic method is as accurate as the manual method but significantly less time consuming permitting a routine use in clinical practice before RF-catheter ablation.

Intramural left atrial haematoma mimicking cardiac tamponade after catheter ablation of atrial fibrillation.

Catheter ablation is an established treatment modality for patients with drug refractory atrial fibrillation (AF). This procedure carries a 6% major complication rate including cardiac tamponade due to cardiac perforation. We report on a patient with clinical signs of cardiac tamponade due to a diffuse intramural left atrial haematoma obstructing left ventricular filling after catheter ablation of AF.

Combined circular multielectrode catheter and point-by-point ablation is superior to point-by-point ablation alone in eliminating atrial fibrillation

BACKGROUND Besides conventional point-by-point ablation, novel multielectrode catheters emerge for ablation of atrial fibrillation (AF). We sought to evaluate the clinical utility of a pulmonary vein (PV) isolation approach combining the advantages of both technologies. METHODS The study included 240 consecutive AF patients (60±11 years, 68% males, 62% paroxysmal). In the combined ablation group (n=120), PV isolation was performed with a circular multielectrode catheter (PVAC, Medtronic Ablation Frontiers) and completed by conventional point-by-point ablation (NaviStar ThermoCool Catheter, Lasso/CARTO technology, Biosense Webster). In the point-by-point ablation group (n=120), PV isolation was performed with point-by-point ablation alone. RESULTS Complete 1-year ablation success (freedom from any atrial arrhythmia off antiarrhythmic drugs) was more frequently observed in the combined ablation group (58.0% versus 43.3%, hazard ratio 1.72, 95% confidence interval 1.19-2.48, p=0.004). Also clinical success (≥90% reduction of arrhythmia burden on/off antiarrhythmic drugs) was significantly associated with the combined ablation approach (p=0.001). These associations remained significant after multivariable adjustment (both p≤0.005) and were not dependent on the type of AF. The rate of major adverse events (3.3% versus 2.5%) and the procedure time did not differ between groups. The fluoroscopy time, however, was significantly shorter in the combined ablation group (p<0.001) reflecting the reduced need for radiation during multielectrode catheter ablation. CONCLUSIONS A combined PV isolation approach based on multielectrode catheter ablation and complementary point-by-point ablation is superior to point-by-point ablation alone and reveals to be safe. A potential explanation for these findings is the improved durability of ablation lesion after the combined ablation approach.

Radiofrequency catheter ablation can be performed with high success rates and very low complication rates in children and adolescents

Radiofrequency catheter ablation is a standard treatment for tachyarrhythmia in children. Recently, several centres using cryoenergy for ablation have reported high success and low complication rates, but an increased risk of recurrence of arrhythmia. The aim of this study was to report success, complications and recurrence rates for radiofrequency catheter ablation in children under current conditions.

Prognostic value of induction of atrial fibrillation before and after pulmonary vein isolation

BACKGROUND Apart from pulmonary vein isolation, catheter ablation of atrial fibrillation (AF) lacks reliable electrophysiological endpoints. The present study investigated the prognostic value of changes in AF inducibility due to ablation. METHODS Between 10/2006 and 10/2009 121 patients referred for catheter ablation of symptomatic, drug refractory paroxysmal AF were included. Sinus rhythm immediately before ablation was a prerequisite for study entry. Two respective attempts to induce AF (>1min) by decremental coronary sinus stimulation before and after ablation were performed. RESULTS A total of 121 patients aged 59.5±10.4years undergoing pulmonary vein isolation due to paroxysmal AF were included. The median follow-up duration was 12.1months [quartiles: 6.5-20.3months]. In 36 (30%) patients AF was inducible before, but not after ablation. Forty-nine (41%) patients were neither inducible before nor after the procedure, whereas 25 patients (21%) displayed unchanged inducibility. In 11 patients (9%) AF was inducible only after ablation. Patients with inducibility solely after the ablation had the highest risk of AF recurrence (HR 6.71 [95%-CI 2.76-16.30], p=0.0005) compared to patients without inducibility before and after the procedure. CONCLUSION The results of attempted AF induction before and after ablation have significance with respect to ablation outcome. Both patient groups with either unchanged inducibility or facilitated induction after ablation had the highest recurrence rates of AF.

Treatment of a recurrent atrial tachycardia by isolation of the right inferior pulmonary vein using a multi-electrode duty cycled ablation catheter

We report on a 29-year-old man who underwent an ablation procedure for a focal atrial tachycardia. Three-dimensional mapping located the site of origin to the ostium of the right inferior pulmonary vein. By using a novel multi-electrode duty cycled ablation catheter, pulmonary vein isolation and elimination of tachycardia was achieved.