A trial fibrillation (AF) is the most common human arrhythmia and is associated with increased risk for ischemic stroke and cardiovascular mortality. The pulmonary veins (PV) are important trigger sites of paroxysmal AF, 1 and their electric isolation from the left atrium (LA) is associated with a high rate of freedom from AF in patients without comorbidities.2 In persistent AF, however, additional arrhythmogenic atrial sites are responsible for AF maintenance and pulmonary vein isolation (PVI) is much less successful with reported 5-year AF freedom rate of 20% after a single and 45% after multiple procedures.3,4 Additional ablation strategies have been developed to improve outcomes including linear lesions and ablation of complex-fractionated atrial electrograms (CFAE) in the left and right atrium (RA), both as a stand-alone approach 5 or in addition to PV isolation. 6 Albeit improving the rate of AF-free survival in some studies, these ablation strategies are inconsistent because of the variable definition and significance of CFAE and require prolonged radiofrequency delivery times. Moreover, the recent multicenter trial, Substrate and Trigger Ablation for Reduction of Atrial Fibrillation 2 (STAR AF 2), did not reveal significant differences in rate of arrhythmia freedom between PVI only versus PVI+CFAE ablation versus PVI+linear ablation: all the 3 strategies resulted in a 1-year arrhythmia freedom of about 50%. 8,9 Recent clinical and experimental studies have identified more specific electrograms in a discrete point or within a region suggestive of a localized reentry during ongoing AF and have been associated with higher ablation impact on AF. Original ArticleBackground-Complex-fractionated atrial electrograms and atrial fibrosis are associated with maintenance of persistent atrial fibrillation (AF). We hypothesized that pulmonary vein isolation (PVI) plus ablation of selective atrial low-voltage sites may be more successful than PVI only. Methods and Results-A total of 85 consecutive patients with persistent AF underwent high-density atrial voltage mapping, PVI, and ablation at low-voltage areas (LVA<0.5 mV in AF) associated with electric activity lasting >70% of AF cycle length on a single electrode (fractionated activity) or multiple electrodes around the circumferential mapping catheter (rotational activity) or discrete rapid local activity (group I). The procedural end point was AF termination. Arrhythmia freedom was compared with a control group (66 patients) undergoing PVI only (group II). PVI alone was performed in 23 of 85 (27%) patients of group I with low amount (<10% of left atrial surface area) of atrial low voltage. Selective atrial ablation in addition to PVI was performed in 62 patients with termination of AF in 45 (73%) after 11±9 minutes radiofrequency delivery. AF-termination sites colocalized within LVA in 80% and at border zones in 20%. Singleprocedural arrhythmia freedom at 13 months median follow-up was achieved in 59 of 85 (69%) patients in group I, which was significantly higher th...

A 50-year-old nonsmoker with paroxysmal atrial fibrillation was referred to our hospital for pulmonary vein isolation (PVI). He had a known 1-vessel coronary artery disease. Because of stable angina, a drug-eluting stent had been implanted into the midportion of the left anterior descending artery in 2010. Otherwise he was healthy. His medical treatment included warfarin, sotalol, an angiotensin-converting enzyme-inhibitor and a statin. Cryoballoon-PVI (Arctic Front Advance 28 mm; Medtronic) was scheduled under general anesthesia (international normalized ratio, 2-9; minimal activated clotting time, 300 s). After transseptal access, the left PV were targeted first, followed by the right inferior PV and right superior PV, respectively. PVI of all PVs could be visualized in real-time and gained within 40 s. Two freezethaw cycles were used for each PV, except for the left superior PV, which had to be treated 3×, because of an initially ineffective freeze (Table I in the Data Supplement ). The procedure had been uneventful, until a sudden blood pressure drop occurred (70/40 mm Hg), immediately after the second right superior PV-freeze. Cardiac tamponade was excluded. Twelve-lead ECG revealed global ST-depression and progressive ST-elevation in aVR, consistent with coronary main stem occlusion ( Figure 1). Pulseless electric activity developed rapidly, necessitating cardiopulmonary resuscitation. Coronary angiography showed a severe spasm of the left coronary main stem, without evidence for air-or thromboembolism (Figure 2A), which could be completely reverted by balloon dilatation and intracoronary nitroglycerine administration ( Figure 2B). The right coronary artery showed a less severe spasm, which was treated by nitroglycerine alone (Figure 3A and 3B). Immediately after coronary reperfusion, ventricular fibrillation occurred, affording several direct current shocks. Because of severe global myocardial stunning, without effective myocardial contractions, an extracorporeal cardiac life support system (veno-arterial extracorporeal cardiac life support system) had to be implanted. Myocardial stunning reverted completely during the following 5 days, and the patient could be weaned from the extracorporeal cardiac life support system. He survived without any major focal neurologic deficit, but impairment of short-term memory was apparent during follow-up. Predischarge echocardiography showed normal biventricular function without wall motion abnormalities. About the used cryoballoon device, the manufacturer excluded a technical malfunction. DiscussionIn this case report, to date, we describe an unreported serious complication of a near-fatal coronary artery main stem spasm during cryoballoon-PVI. We suspect cryoenergy-induced blood cooling, as the most likely trigger, rather than a direct ablation effect, given the distance between the pulmonary veins and the left main stem ( Figure I in the Data Supplement). Further evidence for this theory is provided in Figure 1, which retrospectively showed progressive development of...

From 30 min onward, prasugrel 60 mg achieved a stronger platelet inhibition than clopidogrel loading in stable patients undergoing a PCI. Compared with clopidogrel, prasugrel 60 mg was associated with a twice as fast onset of platelet inhibition. (Impact of Extent of Clopidogrel-Induced Platelet Inhibition during Elective Stent Implantation on Clinical Event Rate-Advanced Loading Strategies [ExcelsiorLOAD]; DRKS00006102).

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