J. Christoph Geller

Pulmonary vein isolation using transvenous catheter cryoablation for treatment of atrial fibrillation without risk of pulmonary vein stenosis.

OBJECTIVES We sought to evaluate the efficacy and safety of pulmonary vein (PV) isolation using transvenous cryoablation for the treatment of atrial fibrillation (AF). BACKGROUND Although electrical isolation of PVs with radiofrequency energy for the treatment of AF is feasible, it is associated with a significant risk of PV stenosis. Cryoablation is a new alternative therapy allowing ablation of tissue while preserving its underlying architecture. METHODS In 52 patients with paroxysmal (n = 45) or persistent (n = 7) AF, PV isolation using the CryoCor cryoablation system (CyroCor Inc., San Diego, California) with a 10F deflectable transvenous catheter was performed as guided by ostial PV potentials. Cryoablation was applied twice at each targeted site (2.5 to 5 min/application). Computed tomography (CT) of the thorax was performed at baseline and at 3 and 12 months to evaluate for PV stenosis. RESULTS All targeted PVs were completely isolated in 49 (94%) of 52 of patients. Of 152 PVs targeted, 147 (97%) were successfully isolated (mean 3.0 PVs isolated per patient). After a mean period of 12.4 +/- 5.5 months of follow-up, 37 (71%) of 52 patients had no recurrence of AF or were clinically improved, including 29 patients (56%) who had no recurrence of AF with (n = 11) or without the use of anti-arrhythmic drugs. At 3 and 12 months, the CT scan showed no evidence of PV stenosis associated with cryoablation in any patients. CONCLUSIONS Transvenous catheter cryoablation is an effective method to create PV electrical isolation for the treatment of AF. A clinically satisfactory result can be achieved in 71% of patients with AF, without the risk of PV stenosis.

Rapid conversion of persistent atrial fibrillation to sinus rhythm by intravenous AZD7009.

This randomized, double‐blind trial compared cardioversion rates between AZD7009 infusion (15‐minute 3.25 mg/min, 15‐minute 4.4 mg/min, or 30‐minute 3.25 mg/min) and placebo infusion (15 or 30 minutes) in patients with atrial fibrillation (AF) scheduled for DC cardioversion. One hundred sixty‐eight patients were randomized, 167 received study treatment, and 159 were included in per‐protocol analyses. The mean duration of current AF episode was 47 days (range, 0.8–92). In the AZD7009 30‐minute 3.25 mg/min group, 21 of 42 patients converted within 90 minutes, compared with 7 of 39, 7 of 36, and 0 of 42 patients in the 15‐minute 3.25 mg/min, 15‐minute 4.4 mg/min, and combined placebo groups, respectively. Patients not converted within 90 minutes underwent DC cardioversion. In patients with AF episodes ≤30 days, conversion rates with AZD7009 30‐minute 3.25 mg/min and after placebo followed by DC cardioversion were 82% and 83%, respectively. AZD7009 was generally well tolerated. Mean QTc increased by 15% to 20% in the AZD7009 treatment groups. One patient experienced a ventricular tachyarrhythmia of 7 beats, with features of torsades de pointes. AZD7009 was associated with a 50% conversion rate in the best‐dose group. In patients with AF episodes ≤30 days, the conversion rates after AZD1305 and placebo followed by DC cardioversion were observed to be similar.

Prevalence and spectrum of abnormal electrocardiograms in patients with an isolated congenital left ventricular aneurysm or diverticulum

AIMS Congenital left ventricular aneurysm (LVA) and diverticulum (LVD) are rare cardiac anomalies and can be associated with ECG abnormalities and rhythm disturbances. We sought to investigate the prevalence and the spectrum of ECG abnormalities in such patients. METHODS AND RESULTS We assessed 125 patients with isolated LVA or LVD for the prevalence of ECG abnormalities and compared the findings to an age- and gender-matched control group. The 12-lead ECG patterns were evaluated according to commonly used criteria and were classified into three subgroups (distinct, mildly, and minor). Fifty-four of the 125 patients (43.2%) had normal and 71 (56.8%) abnormal ECGs. Mean age was 66 years. Forty-nine (39.2%) were male. Distinct abnormal ECG patterns were more prevalent in patients with LVD (38.2 vs. 15.8%, P = 0.04), and apical location of the anomaly (36.6 vs. 16.6%, P = 0.02). Older age (>66 years) was associated with a trend for a higher prevalence of abnormal ECG pattern (33 vs. 18%, P = 0.06), whereas gender had no influence (32 vs. 16%, P = 0.14). This study also shows that the sensitivity, specificity, positive predictive value and negative predictive value of a 12-lead ECG for the diagnosis of LVA or LVD are low. CONCLUSION This large single-centre study suggests that the prevalence of abnormal ECG patterns in patients with isolated LVA or LVD is as high as 56.8%. However, ECG is not specific and sensitive to be used as a screening tool in such patients.

Low rate of asymptomatic cerebral embolism and improved procedural efficiency with the novel pulmonary vein ablation catheter GOLD: results of the PRECISION GOLD trial

Abstract Aims This prospective, multicentre study (PRECISION GOLD) evaluated the incidence of asymptomatic cerebral embolism (ACE) after pulmonary vein isolation (PVI) using a new gold multi-electrode radiofrequency (RF) ablation catheter, pulmonary vein ablation catheter (PVAC) GOLD. Also, procedural efficiency of PVAC GOLD was compared with ERACE. The ERACE study demonstrated that a low incidence of ACE can be achieved with a platinum multi-electrode RF catheter (PVAC) combined with procedural manoeuvres to reduce emboli. Methods and results A total of 51 patients with paroxysmal atrial fibrillation (AF) (age 57 ± 9 years, CHA2DS2-VASc score 1.4 ± 1.4) underwent AF ablation with PVAC GOLD. Continuous oral anticoagulation using vitamin K antagonists, submerged catheter introduction, and heparinization (ACT ≥ 350 s prior to ablation) were applied. Cerebral magnetic resonance imaging (MRI) scans were performed within 48 h before and 16–72 h post-ablation. Cognitive function assessed by the Mini-Mental State Exam at baseline and 30 days post-ablation. New post-procedural ACE occurred in only 1 of 48 patients (2.1%) and was not detectable on MRI after 30 days. The average number of RF applications per patient to achieve PVI was lower in PRECISION GOLD (20.3 ± 10.0) than in ERACE (28.8 ± 16.1; P = 0.001). Further, PVAC GOLD ablations resulted in significantly fewer low-power (<3 W) ablations (15 vs. 23%, 5 vs. 10% and 2 vs. 7% in 4:1, 2:1, and 1:1 bipolar:unipolar energy modes, respectively). Mini-Mental State Exam was unchanged in all patients. Conclusion Atrial fibrillation ablation with PVAC GOLD in combination with established embolic lowering manoeuvres results in a low incidence of ACE. Pulmonary vein ablation catheter GOLD demonstrates improved biophysical efficiency compared with platinum PVAC. Trial registration ClinicalTrials.gov NCT01767558.

Incidence and predictors of ventricular arrhythmias after ST-segment elevation myocardial infarction.

BACKGROUND Sustained ventricular arrhythmias (VA) complicate 7% to 20% of acute myocardial infarctions. We hypothesized that primary angioplasty (percutaneous coronary intervention [PCI]) and contemporary medical treatment will result in a lower incidence of VA and shorten the time frame of their occurrence. Thus, an electrocardiographic monitoring period of 24 hours should be sufficient to detect more than 95% of all malignant VA. METHODS We continuously monitored all patients with ST-segment elevation myocardial infarction (STEMI) for 48 hours. RESULTS Of the 510 patients who underwent PCI for STEMI, 24 (4.7%) developed sustained VA. Sixty percent of sustained VA occurred during the first 24 hours; and 92%, during the first 48 hours. In univariate analysis, heart rate greater than 100 beats per minute, Thrombolysis in Myocardial Infarction flow grade less than 3, elevated creatinine (≥1 mg/dL), elevated C-reactive protein (≥0.8 mg/dL), higher white blood cell count (≥12 × 10(3)/μL), use of diuretics, and lower hematocrit (≤39%) were associated with an increased risk of VA. Symptom-onset-to-balloon time of 4 hours or more in patients with postprocedural Thrombolysis in Myocardial Infarction 3 flow, treatment with β-blockers, angiotensin-converting enzyme inhibitors or angiotensin receptor blockers, and statins were associated with a reduced risk of VA. After multivariate adjustment, independent predictors of sustained VA included total white blood cell count of 12 × 10(3)/μL or more, hematocrit of 39% or less, and lack of β-blocker medication. CONCLUSIONS In this study, we could demonstrate that primary PCI results in a lower incidence of VA compared with data from the literature but did not shorten the time frame of VA occurrence. Thus, an electrocardiographic monitoring period for VA of 48 hours should be performed in patients with STEMI.

Pocket related complications in 163 patients receiving anticoagulation or dual antiplatelet therapy: D-Stat Hemostat™ versus standard of care

BACKGROUND Pocket hematoma is a common complication after cardiac rhythm device implantation (CRDI) in patients receiving anticoagulation or dual antiplatelet therapy (DAPT). We sought to assess the safety and effectiveness of D-Stat Flowable Hemostat ([D-Stat]-a mixture of thrombin and collagen) in these patients. METHODS We conducted a prospective case control study and enrolled all patients admitted for CRDI receiving anticoagulation or DAPT. Participants received either D-Stat into the pectoral pocket as an adjunct to standard of care versus the standard of care (UC) alone. The primary endpoint was a composite of hematoma needing evacuation, and pocket infection. RESULTS We included a total of 163 patients (mean age 72 ± 8 years). 119 (73%) were male. 82 patients (50%) received D-stat and 81 (50%) usual care; 82 patients (50%) were treated with anticoagulation, 62 patients (38%) received DAPT, and 19 patients (12%) both. The primary endpoint occurred in 12/82 patients from the D-Stat group and 3/81 patients of the control group (14.6% versus 3.7%; p=0.03). The use of D-Stat tended for a higher incidence of pocket hematoma requiring evacuation (8.5% versus 2.4%; p=0.12), and an increased rate of pocket infections (6.1% versus 1.2%; p=0.21). Postoperative Immunoglobulin E levels (86 ± 147 IU/ml (D-Stat) versus 120 ± 231 IU/ml (UC)) and increase of C-reactive protein (D-Stat: ∆19 mg/l versus UC: 14 mg/l) were similar in both groups (p=0.26 and p=0.4, respectively). CONCLUSIONS Administration of D-Stat does not decrease the frequency of clinically relevant pocket hematomas. The observed rate of pocket infections in the D-Stat group is a matter of concern.

The Use of a Quadripolar Left Ventricular Lead Increases Successful Implantation Rates in Patients with Phrenic Nerve Stimulation and/or High Pacing Thresholds Undergoing Cardiac Resynchronisation Therapy with Conventional Bipolar Leads

Background Phrenic nerve stimulation (PNS) and high pacing thresholds (HPT) hinder biventricular stimulation in patients (pts) undergoing cardiac resynchronization therapy (CRT). A new quadripolar left ventricular (LV) lead (Quartet 1458Q, St. Jude Medical) with increased number of pacing configuration, might overcome this problem. Methods All consecutive pts in whom a standard bipolar lead intraoperatively resulted in PNS and/or HPT (≥4.00V/1mV), received, during the same implant, a quadripolar LV lead. Aim of the study was to evaluate acute and short term outcome. Results 26 pts [24 (92%) male, mean age 74±6 years)] with PNS (22 pts; 85%) and HPT (4 pts; 15%) were included. Permanent right ventricular pacing was the reason for broad QRS complex in 4 (15%) pts, whereas all other pts had a left bundle branch block. Severely symptomatic (NYHA Class ≥3) heart failure with reduced ejection fraction (EF 31±9%) was mostly caused by ischemic heart disease (14 pts; 54%). Idiopathic dilated cardiomyopathy and valvular heart disease were diagnosed in 6 (23%) pts each. In most (24/26, 92%) pts the use of the Quartet lead led to successful biventricular pacing due to a significant reduction in intraoperative pacing threshold (5.2V/1.0ms vs. 1.4V/0.8ms; p=0.03), which was maintained (1.2V/0.7ms) at follow-up. PNS never represented reason for failed LV pacing, neither acutely nor during follow-up. Conclusion Excessively HPT and/or PNS are frequently encountered when conventional bipolar leads are used for CRT. A new quadripolar LV lead increases the rate of successful biventricular stimulation. Lower pacing threshold and freedom from PNS are maintained at follow-up.

Changes in AV Node Conduction Curves Following Slow Pathway Modification

GELLER, J.C., et al.: Changes in AV Node Conduction Curves Following Slow Pathway Modification. Dual AV node physiology often persists after successful slow pathway (SP) ablation, and the mechanism of tachycardia elimination is unresolved. Therefore, AV node conduction curves were analyzed following successful ablation (4 ± 1 energy applications) in 85 consecutive patients (58 women, age 50 ± 2 years) with typical AVNRT. Twenty‐seven patients (32%) had complete elimination (group 1) whereas 58 (68%) patients had persistence (group 2) of dual AV node physiology. A significant increase in the AV node Wenckebach cycle length (WB‐CL) was observed in both groups (310 ± 9 to 351 ± 15 ms in group 1, and 325 ± 8 to 369 ± 9 ms in group 2, P < 0.05). A decrease in the fast pathway (FP) ERP (339 ± 15 to 279 ± 12 ms) and an increase in the maximum FP AH interval (141 ± 5 to 171 ± 7) were observed only in group 1 (P < 0.05). In group 2, no change in the SP ERP (267 ± 7 to 280 ± 10 ms) was observed, and the change in the maximum SP‐AH following ablation showed a significant inverse relation to the maximum SP‐AH at baseline in group 2. In conclusion, (1) an increase in the WB‐CL is observed independent of the persistence or elimination of dual physiology after successful ablation; (2) when dual physiology is eliminated, significant changes in the FP ERP and the maximum FP‐AH occur; (3) when dual physiology persists, FP physiology and the SP ERP remain unchanged, and a significant inverse relation between the change in the maximum SP‐AH following ablation and the maximum baseline SP‐AH is observed.

Thromboembolic stroke after cardioversion with incomplete left atrial appendage closure

Sirs: A 73-year-old man with persistent Atrial Fibrillation (AF) and a CHA2DS2VASc Score of 3 underwent uneventful percutaneous left atrial appendage (LAA) closure (Watchman, 21 mm, Atritech, Inc., Plymouth, Minnesota) guiding fluoroscopy and transesophageal echocardiogram (TEE) in 2011 because of the inability to keep the INR within the therapeutic range (Fig. 1). TEE revealed residual flow into the LAA after implantation and also during follow-up, no flow was seen directly around the device. Warfarin was stopped 6 weeks and clopidogrel 3 months after implantation, aspirin was continued. Due to progressive arrhythmia symptoms, 15 months after implantation, successful electrical cardioversion was performed on aspirin alone after exclusion of intracardiac thrombi with TEE. The following day, the patient developed right-sided weakness and aphasia, cerebral computed tomography (CT) showed ischemia in the territory of the left medial cerebral artery. Repeat analysis of the previous TEE images revealed residual narrow flow (speed [40 cm/s) in the lateral portion of the LAA (Fig. 2). On cardiac CT, the occluder was positioned in one of the two LAA lobes and the other lobe was not occluded (Fig. 3). There was no evidence of intracardiac thrombus. The neurologic symptoms resolved quickly, and oral anticoagulation (Dabigatran, 2 9 150 mg/day) was started. Interventional LAA closure is as effective as oral anticoagulation in patients with non-valvular AF [1–6], and some case reports [7, 8] pointed out that a combined mitral valve treatment and interventional LAA closure in patients with AF and mitral valve disease is effective in reducing thromboembolic complications. In one analysis, residual peri-device flow was not associated with an increased risk of thromboembolism in PROTECT-AF [9]. However, the risk of thromboembolic complications in patients undergoing cardioversion is unknown, and there is no clear evidence that cardioversion can be performed without anticoagulant treatment after mechanical LAA occlusion. In this case, there are several important points: (1) the cause of ischemia was presumably cardiac embolic in origin (although the TEE before cardioversion did not show any thrombus). Therefore, as suggested in the guidelines, effective anticoagulant treatment is mandatory for 4 weeks after cardioversion despite closure of the LAA. The role of residual flow into the LAA after interventional LAA occlusion in increasing the risk of thromboembolic complications after cardioversion is unknown. In addition, thrombi might also evolve in the left atrium cavity due to atrial stunning after cardioversion. (2) The CT (Fig. 3) revealed a more complex 3D anatomy of the LAA, which was not seen with TEE or fluoroscopy (Fig. 1) during the procedure. Therefore, it is recommended to assess LAA anatomy with different two-dimensional views (preferably with 3D) in Electronic supplementary material The online version of this article (doi:10.1007/s00392-014-0724-0) contains supplementary material, which is available to authorized users.

Electrocardiographic and Electrophysiological Characteristics of Atrial Tachycardia With Early Activation Close to the His-Bundle.

Radiofrequency (RF) ablation of atrial tachycardia (AT) with earliest activation at the His‐bundle may be associated with the risk of AV block, and detection of this AT origin using the electrocardiogram (ECG) would be helpful in planning ablation. Aim of this study was to characterize the P‐wave morphology and intracardiac electrograms at the successful ablation site for this group of ATs.