Low Rate of Atrial Fibrillation Recurrence Verified by Implantable Loop Recorder Monitoring Following a Convergent Epicardial and Endocardial Ablation of Atrial Fibrillation

Implantable Loop Recorder Monitoring Outcomes for the Convergent AF Procedure . Objective: Evaluate long‐term outcomes in patients undergoing the Convergent procedure (CP) for the treatment of atrial fibrillation (AF). Background: The CP provides a multidisciplinary approach, combining endoscopic creation of epicardial linear lesions followed by endocardial mapping and ablation and targets persistent and longstanding persistent AF patients who are at increased risk of heart failure, stroke, and mortality. Methods: Outcomes from a prospective nonrandomized study were recorded for consecutive patients by interrogation of implanted Reveal® monitors. Rhythm status and AF burden were quantified 6–24 months postprocedure, and compared relative to AF type, gender, age, body mass index, left atrial size, left ventricular ejection fraction, and congestive heart failure, hypertension, age >75 years, age between 65 and 74 years, stroke/TIA/TE, vascular disease (previous MI, peripheral arterial disease or aortic plaque), diabetes mellitus, female (CHA₂DS₂VASc). Results: A total of 50 patients were enrolled with 94% having persistent or longstanding persistent AF. There were 2 atrioesophageal fistulas reported. In one patient, the fistula resulted in death at 33 days postprocedure; in the second, the fistula was surgically repaired but patient died 8 months postprocedure from a CVI. After CP, 95% of patients were in sinus rhythm at 6‐month follow‐up; 88% at 12 months; and 87% at 24 months. The median AF burden recorded with Reveal XT monitors was 0.0%, 0.1%, and 0.1% at 6, 12, and 24 months with 81%, 81%, and 87% of patients reporting a burden less than 3%, respectively. Conclusion: Using 24 × 7 continuous loop recording, the CP demonstrated success in treating persistent and longstanding persistent AF patients. Endocardial mapping and catheter ablation with diagnostic confirmation of procedural success complemented the endoscopic creation of epicardial linear lesions in restoring sinus rhythm. (J Cardiovasc Electrophysiol, Vol. 23 pp. 1059‐1066, October 2012)     

Coronary Artery Disease Alters Ventricular Repolarization Dynamics in Type 2 Diabetes

Ventricular repolarization dynamics (VRD) is an important predictor of outcome in diabetes.We examined the potential impact of coronary artery disease (CAD) on VRD in type 2 diabetic patients. We recorded 5-minute high-resolution resting electrocardiograms in 38 diabetic patients undergoing elective coronary angiography, and in 38 age- and gender-matched apparently healthy subjects (controls). Using leads-I and -II, time-domain indices of VRD were calculated. Coronary angiography was regarded as positive if ≥ 50% stenosis was found. Angiography was positive in 21 diabetic patients (55%). Patients with CAD had a significantly higher degree of VRD than controls (SDNN(QT): 15.81 ± 7.22 ms versus 8.94 ± 6.04 ms; P < 0.001, rMSSD(QT): 21.02 ± 7.07 ms versus 11.18 ± 7.45 ms; P < 0.001). Ventricular repolarization dynamics in diabetic patients with negative angiograms did not differ from VRD in controls (SDNN(QT): 8.94 ± 6.04 ms versus 7.44 ± 5.72 ms; P = 0.67, rMSSD(QT): 11.18 ± 7.45 ms versus 10.22 ± 5.35 ms; P = 0.82). CAD increases VRD in patients with type 2 diabetes. Therefore, changes in ventricular repolarization in diabetic patients may be due to silent CAD rather than due to diabetes per se.     

Long-Term Thresholds of Nonsteroidal Permanent Pacing Leads: A 5-Year Study

The present commercial market supports many nonsteroidal endocardial pacing leads of differing construction. In order to compare the performance of these configurations, we studied the long-term pacing properties of three representative lead types by randomized clinical trial in 99 patients undergoing a first elective VVl implant. Thirty-one patients received sintered platinum leads, 36 activated pyrolytic carbon leads, and 32 vitreous carbon leads. All received generators capable of noninvasive threshold testing. Acute sensing parameters were R wave amplitude and ST segment elevation measured from the endocardial electrogram. Noninvasive voltage thresholds were measured at implantation, 2 days, 1, 3, and 6 months, and yearly thereafter for 5 years. There were no significant differences between leads in pacing or sensing capabilities at implantation. All three demonstrated similar increases in thresholds, peaking at 1 month, then falling to a plateau by 6 months and did not vary significantly thereafter. There were no significant differences in thresholds between leads during 5 years of follow-up. The lowest mean threshold at 5 years was 0.93 V at 0.5 ms. This study suggests that: (1) although these lead types all perform well, none offers any particular clinical advantage over another; (2) the degree of early threshold peaking precludes immediate postimplant output reduction, but later thresholds are sufficiently low to enable reductions in pacing output; (3) safe low energy pacing requires greater attention to the lead-generator combinations; (4) data obtained at subsequent annual follow-up provided no additional useful clinical information to that obtained at 1 year, and (5) in the absence of other differences, cost can be the deciding factor in lead selection.     

Exertional syncope in a patient with aortic stenosis and right coronary artery disease

A female with advanced aortic valvular stenosis and moderateright coronary artery disease experienced an exertional syncopeduring 24-h ambulatory electrocardiographic monitoring. A progressivebradycardia with 90-s sinus node arrest (cardio-inhibitory response)and premonitory angina pectoris with significant ST segmentchanges were demonstrated. Our report supports the concept of a neurocardiogenie (vasovagal)mechanism of exertional syncope in patients with aortic stenosis.The predominant left ventricular inferior-wall myocardial iscliaemiain our patient might be an additional stimulus to left ventricularmechanoreceptors, resulting in a profound cardio-inhibitoryresponse.