Background-It has recently been recognized that atrial fibrillation can originate from focal sources in the pulmonary veins (PVs). However, the mechanisms of focal atrial fibrillation have not been well characterized. We assessed the electrophysiological characteristics of the PVs using high-resolution optical mapping. Methods and Results-Coronary-perfused, isolated whole-atrial preparations from 33 normal dogs were studied.Programmed electrical stimulation was performed, and a 4-cm 2 area of the PV underwent optical mapping of transmembrane voltage to obtain 256 simultaneous action potentials. Marked conduction slowing was seen at the proximal PV, compared with the rest of the vein, on both the epicardial (31.3Ϯ4.47 versus 90.2Ϯ20.7 cm/s, Pϭ0.001) and endocardial (45.8Ϯ6.90 versus 67.6Ϯ10.4 cm/s, Pϭ0.012) aspects. Pronounced repolarization heterogeneity was also noted, with action potential duration at 80% repolarization being longest at the PV endocardium. Nonsustained reentrant beats were induced with single extrastimuli, and the complete reentrant loop was visualized (cycle length, 155Ϯ30.3 ms); reentrant activity could be sustained with isoproterenol. Sustained focal discharge (cycle length, 330 to 1100 ms) was seen from the endocardial surface in the presence of isoproterenol; each focus was localized near the venous ostium. Conclusions-The normal PV seems to have the necessary substrate to support reentry as well as focal activity. Although reentry occurred more distally in the vein, focal activity seemed to occur more proximally.

No abstract

Low-dose score, representing the extent of viable myocardium, has incremental prognostic value as a predictor of long-term outcome in CABG patients with LV dysfunction.

No abstract

Aims Remote patient monitoring (RPM) in the management of heart failure (HF), including telemonitoring, thoracic impedance, implantable pulmonary artery pressure (PAP) monitors, and cardiac implantable electronic device (CIED)-based sensors, has had varying outcomes in single platform studies. Uncertainty remains regarding the development of single-centre RPM programs; additionally, no studies examine the effectiveness of dual platform RPM programs for HF. This study describes the implementation and outcomes of a dual platform RPM program for HF at a single centre. Methods and results An RPM program was developed to include two platforms (e.g. CardioMEMS ™ HF System and HeartLogic ™ HF Diagnostic). To examine changes within each participant over time, study-related outcomes including total hospitalizations (TH), total length of stay (TLOS), cardiac hospitalizations (CH), cardiac LOS (CLOS), and cardiac-related emergency department (ED) visits were compared in two timeframes: 12 months pre-enrolment and post-enrolment into RPM. For 141 participants enrolled, there was a significant reduction in the likelihood of experiencing a CH by 19% (0.77 vs. 0.61 events/patient-year; HR: 0.81, 95% CI: 0.67-0.97, P = 0.03) and a cardiac-related ED visit by 28% (0.48 vs. 0.34 events/patient-year; HR: 0.72, 95% CI: 0.55-0.93, P = 0.01). There was also a 51% decrease (SE = 1.41, 95% CI: 2.79-8.38 days, P < 0.001) and 62% decrease (SE = 1.24, 95% CI: 3.35-8.22 days, P < 0.001) in TLOS and CLOS, respectively. Conclusions A dual platform RPM program for HF using structured education, RPM-capable devices, and alert-specific medication titration reduces the likelihood of experiencing a cardiac hospitalization and cardiac-related ED visit in this single-centre study.