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Background Available atrial electrograms in implantable cardioverter defibrillators (ICDs) improve arrhythmia diagnosis, allow monitoring for atrial fibrillation, and may reduce the risk of inappropriate therapies. A recently introduced ICD system using a single-lead with floating atrial electrodes provides diagnostic capability of a dual-chamber system without placing an additional lead. Data on long-term clinical performance of this system are limited. Methods We retrospectively analyzed data from 35 consecutive patients implanted with Biotronik VR-T DX devices and LinoxSmart DX leads. (Biotronik, SE & Co., Berlin, Germany) RESULTS: Of 35 patients (77% male, age 52 ± 11.28 years), 32 were followed for a mean of 432 ± 197 days (range 56-765). During implantation, average preamplified and amplified sinus P-wave amplitudes were 2.61 ± 1.39 mV (range 0.9-6.8 mV) and 8.7 ± 4.51 mV (range 1.4-18 mV), respectively. Despite statistically significant variations, the amplified P-wave amplitude measurements (calculated mean values over 3 months) remained within a clinically acceptable range during follow-up (5.4-8.7 mV). R-wave amplitude and ventricular pacing threshold measurements were stable over time. A total of 13 stored arrhythmia events (three ventricular tachycardia, eight supraventricular tachycardia, two atrial fibrillation) were reviewed. All of them showed readily interpretable atrial electrograms. Eight out of 10 (80%) supraventricular events were correctly classified by the device. Three patients received inappropriate ICD therapies. Conclusion The single-lead ICD system using a floating atrial dipole provides reliable recording of atrial signals during sinus rhythm and arrhythmias. Our data suggest that the system may offer diagnostic advantages of a dual-chamber device without potential risks of an additional atrial lead.

Background: This study aims to determine the impact of pre-procedural cardiac computerized tomography (CT) on procedural efficacy, clinical outcome and complications in patients who undergo radiofrequency or cryo-therapy catheter ablation to eliminate atrial fibrillation (AF). Methods: In this retrospective review, Radiofrequency or Cryoballoon ablation was done on 50 consecutive patients with atrial fibrillation with mean age of 63 (Min 47-Max 86) with paroxysmal (8 2 %) or persistent (18%) AF. Twenty-five patients underwent cryoablation and twenty-five patients underwent Radiofrequency ablation to isolate the pulmonary veins. Procedural and clinical outcomes were compared among patients who underwent catheter ablation with and without pre procedural Cardiac CT. Results: Out of 50 consecutive patients between 01/2014 and 08/2014 there were 26 patients who had a pre-procedural CT scan and 24 patients who did not undergo a pre-procedural CT scan. The mean duration of the procedure (303 ± 93 vs. 271 ± 43 min, P = 0.244) and fluoroscopy time (53 ± 25 vs. 43 ± 17 min, P = 0.086) was similar among patients who did and did not have pre-procedural cardiac CT. The occurrence of complications such as bleeding, pericardial tamponade, pneumothorax, infection and embolic events were also similar in both groups. Repeat ablation was performed in 4 (15%) and 7 (29%) of the patients who did and did not have cardiac CT, respectively (P = 0.249). At 3 months, 5 (19%) and 2(8%) of the patients who did and did not have pre-procedural cardiac CT had atrial fibrillation recurrence (P =0.323). At 12 months, 6 (23%) and 4 (17%) of the patients who did and did not have pre-procedural cardiac CT had atrial fibrillation recurrence (P = 0.467). There was statistically significant difference in Radiation exposure (1805 [IQR 998-2397] vs. 1195 [IQR 738-1363] P=0.0323) between patients who did and did not get pre-procedural cardiac CT, which did not include the radiation added by performing the CT itself. Conclusions: Pre-procedural structural anatomy obtained by cardiac CT scan before catheter ablation for atrial fibrillation in a center where operators used both Radiofrequency and Cryoablation does not appear to have a significant effect on AF recurrence at 3 months or 1 year. The procedural radiation exposure was significantly less in the group that did not have pre-procedure cardiac CT.

Correction for soft tissue signal attenuation can improve the diagnostic accuracy of single-photon emission computed tomography myocardial perfusion imaging (SPECT-MPI). The aim of this study was to correlate SPECT-MPI findings with clinical outcomes in patients who underwent stress imaging in the supine position, who also underwent "second look" stress imaging in the prone position.Patients without perfusion abnormalities were considered Normal (N = 270). Those with apparent supine stress perfusion abnormalities which all resolved during prone imaging formed the Normal-Prone group (N = 309). Patients with matched perfusion abnormalities during both supine and prone stress imaging were considered Abnormal (N = 169).During follow-up (187 ± 96 days), utilization rates for invasive coronary angiography were similar for Normal vs Normal-Prone patients (3.5% vs 3.8%; P = NS), but were significantly higher in Abnormal patients (42.4%, P.0001). Coronary revascularization occurred in 0.78%, 0.64%, and 17.7% of Normal, Normal-Prone, and Abnormal patients, respectively (P.001). Cardiac death or myocardial infarction occurred in 2.2%, 2.3%, and 6.3% of Normal, Normal-Prone, and Abnormal patients, respectively (P = .02).Second look SPECT-MPI identifies patients at low risk for death or myocardial infarction, who infrequently require invasive coronary angiography.

There is no current evidence regarding the safety and efficacy of various rate control strategies for rapid atrial fibrillation or atrial flutter (AF/AFL; heart rate > 100 bpm) in hospitalized patients with acute decompensated heart failure with reduced ejection fraction (ADHFrEF). Single center

Chiari network and atrial septal aneurysm (ASA) are considered “normal” anatomic variants though ASA has been associated with embolic events. The relationship of these variants with cardiomyopathy, cardiac conduction abnormalities and arrhythmias has not been described. From all adult patients