Multifocal atrial tachycardia (MAT) is a cardiac rhythm disorder frequently diagnosed in elderly patients affected by several comorbidities. However, MAT can be observed also in younger ages as an incidental finding or in association with heart and lung diseases. MAT is characterized by heart rate >100 beats/min and at least three different P waves when compared to sinus P wave. Recent guidelines recommend the use of beta-blockers and verapamil for rate control and ongoing management of MAT. Unfortunately, electrical cardioversion and antiarrhythmic drugs have been demonstrated not always effective in MAT treatment. Intravenous magnesium seems a promising therapy in restoring sinus rhythm in patients who developed MAT. Moreover, in the last years, innovative strategies such as atrioventricular junction modification, ablate and pace approach, and electrophysiological isolation of firing sites have been successfully tested as curative treatment in selected cases of MAT resistant to drug therapy.

Background: The practice of antibiotic prophylaxis for permanent pacemaker implantation varied widely in the real world of clinical practice due to no guidelines. The present study aims to investigate the use of antibiotic prophylaxis peri- and postimplantation of pacemaker in China. Materials and Methods: A total of 141 adult heart centers performing device implantation were asked using an E-mail or paper questionnaire to collect data regarding the use of antibiotics before or at implantation and duration of postimplantation. Subsequent telephone calls and E-mails were used to ascertain dubious data if necessary. Results: The final analysis included 135 centers (95.7% of total contacted) covering 7 main geographic regions of China. One hundred and twenty-six of the 135 centers (93.3%) used prophylactic antibiotics peri- and postimplantation. Among these centers, 107 centers (84.9%) selected first- or second-generation cephalosporins. In 100 centers (79.4%) of those used systemic antibiotics, an initial dose was given 0.5–2 h before surgery. With respect to duration of antibiotics administration, 99 centers of those used prophylactic antibiotics (78.6%) continued antibiotic therapy for 24–72 h while only 10 centers (7.9%) just administrated a single dose of antimicrobial agent before commencement of a procedure. Forty-eight of the 135 centers (35.6%) used intrapocket antibiotics at implantation, and gentamicin was the most commonly used antimicrobial agent (in 39/48 centers). Conclusion: Although the administration of prophylactic antibiotics before permanent pacemaker implantation has been implemented widely and routinely, our results showed that some electrophysiological centers still used no systemic antibiotic prophylaxis before or at the implantation. A significant difference exists in the timing, duration, and type of antibiotics use. Clinical trial evidence are required to guide optimal antibiotic prophylaxis for device implantation.

Background: Continuing warfarin therapy is considered safe for patient undergoing pacemaker or implantable cardioverter defibrillator procedures, but less evidence exists for patients undergoing cardiac resynchronization therapy (CRT) device implantation. Subjects and Methods: We retrospectively evaluated 136 consecutive patients who received a CRT device. Three periprocedural anticoagulation strategies were utilized: Group 1, continuation of therapeutic warfarin; Group 2, cessation of warfarin with heparin bridging; and Group 3, cessation of anticoagulation temporarily. Groups were compared on the incidence of complications. Results: Of the 136 patients, 87 (64%) were in Group 1, 18 (13%) were in Group 2, and 31 (23%) were in Group 3. Group 1 patients had an international normalized ratio of 2.3 ± 0.5, which was significantly higher than the other two groups. Coronary sinus dissection occurred in four patients: Three in Group 1 and one in Group 2, but no patient experienced pericardial effusion or tamponade. Group 2 experienced a higher incidence of pocket hematoma (P = 0.0065) and a longer length of hospital stay (P = 0.0069) than Group 1. Transient ischemic attack occurred in one patient in Group 3. Conclusion: Continuing warfarin with therapeutic international normalized ratio seems to be safe in individuals undergoing CRT device implantation.

Objectives: Cryoballoon ablation (CBA) has become a routine treatment option for paroxysmal atrial fibrillation (PAF). The third-generation CB (CB3) also known as “Arctic Front Advance ST” (CB-ST) was designed with a shorter distal tip. There have been several publications describing the characteristics of the CB3 system. We, therefore, undertook this systemic review and meta-analysis to compare the efficacy and safety of CB3 versus the second-generation CB (CB2) also known as “Arctic Front Advance.” Methods and Results: We performed a search on PubMed, Embase, and Web of Science database for studies published by August 2016 using the keywords “CB3,” “short-tip cryoballoon,” “Arctic Front Advance ST,” “CB3,” “cryoablation,” and “CBA.” Six studies with a total of 1625 patients were identified. There were 351 patients underwent CBA with CB3, and 1274 underwent CBA with CB2. Overall analyses indicated that there was a significant improvement in the real-time pulmonary vein isolation (RT-PVI) recording rate with CB3 compared to CB2 (odds ratio of 3.08, P < 0.00001). The procedure time (PT) was shorter for CB3 (weighted mean difference [WMD], 95% confidence interval CI: −10.27, [ − 19.2, −1.35], P = 0.02), while fluoroscopic time (WMD, 95% CI: 0.71, [ − 1.27, 2.68], P = 0.48) was not statistically different between the two groups. Conclusions: In this meta-analysis involving 1625 patients, the CB3 system decreased PT, enhanced RT-PVI recording rate while maintaining a similar safety profile.

Background: Atrial fibrosis plays a vital role in the pathogenesis of atrial fibrillation. However, the complex interplay between inflammation and remodeling remains incompletely understood. In this study, we examined the potential beneficial effects of the immunosuppressant rapamycin on reverse atrial remodeling in a 5/6 nephrectomized (5/6Nx) rat model of chronic kidney disease (CKD). Materials and Methods: Sprague-Dawley male rats were housed under controlled conditions with constant temperature and humidity for 1 week before the operation. They were assigned randomly to the following groups: (1) sham procedure with vehicle treatment, (2) 5/6Nx group with vehicle treatment, and (3) 5/6Nx with rapamycin treatment. The 5/6Nx group underwent nephrectomy by resection of the upper and lower thirds of the left kidney, followed by right nephrectomy. The rapamycin group received daily rapamycin (1 mg/kg/day) from the 4^th week to the 8^th after operation. Results: A significant increase in the protein expression levels of mammalian target of rapamycin (mTOR), p38, and extracellular signal-regulated kinase was observed in the 5/6Nx + vehicle group (1.56 ± 0.12 vs. 0.72 ± 0.06; 2.64 ± 0.40 vs. 1.20 ± 0.20; and 3.02 ± 0.71 vs. 1.42 ± 0.34; all P < 0.05), which were suppressed by rapamycin treatment (0.88 ± 0.08 vs. 1.56 ± 0.12; 1.96 ± 0.21 vs. 2.64 ± 0.40; and 1.87 ± 1.87 vs. 3.02 ± 0.71; all P < 0.05). Cardiomyocyte hypertrophy and extensive interstitial fibrosis of the atrium were observed in the 5/6Nx + VEH group (P < 0.05). These changes were attenuated in the 5/6Nx + rapamycin group (P < 0.05). Conclusions: In this 5/6Nx CKD rat model, atrial fibrosis was mediated via the mTOR pathway, which was attenuated by rapamycin.