BACKGROUND: Endless loop tachycardia (ELT) is the commonest pacemaker mediated tachycardia (PMT) encountered among patients with cardiac implantable electronic devices (CIEDs). Despite being enabled with various preventive algorithms, we encountered several cases having recurrent, long, and symptomatic ELT.
METHODS: We retrospectively analyzed consecutive device checkups at device clinic at a single center of eastern India between January 2019 to March 2023.
RESULTS: There were 20 cases of confirmed and sustained ELT among 4520 device checks. Although mostly benign, in two cases ELT led to clinical worsening in patients having left ventricular (LV) systolic dysfunction. Even with good ventricular function, ELT resulted in improper atrioventricular (AV) synchrony leading to disabling symptom in one case. The differentiation of ELT from sinus tachycardia and atrial tachycardia (AT) was not always easy. Magnet application is certainly useful to differentiate. The situations that provoked ELT in this study were-long AV delays, VIP (ventricular intrinsic preferences)/MVP (managed ventricular pacing), atrial non-capture, atrial under/over sensing, premature ventricular contractions (PVCs)/couplets, premature atrial contractions (PAC) and slower ventriculo-atrial (VA) conduction. Rate responsive shortening of post-ventricular atrial refractory period (PVARP) also promoted its occurrence and hindered troubleshooting. When ELT occurred despite post-PVC extension of PVARP, lowering the atrial sensitivity, switching to bipolar sensing and manual setting of longer PVARP after measuring VA conduction time were useful. \"Rate responsive PVARP\" had to be turned off in a few cases to prevent ELT. On the contrary, an over aggressive prolongation of PVARP led to repetitive non-reentrant ventriculo-atrial synchrony (RNRVAS) in two cases. Checking VA conduction during implantation and noninvasive program stimulation (NIPS) during follow up were useful to check the tendency for ELT.
CONCLUSIONS: Clinically significant ELT is rare but not uncommon among devices having in-built preventive algorithms. Manual adjustments are often useful to troubleshoot the same.

In this editorial we summarize the most viewed and downloaded contributing articles to the Research Topic \"Case Reports in Heart Failure and Transplantation: 2022\" of the journal Frontiers in Cardiovascular Medicine.

Hybrid closed-loop (HCL) therapy is rarely studied in pregnancy. We present three cases of women with type 1 diabetes who used the Medtronic 670G HCL system for most or all of gestation.
The Medtronic 670G system has a manual mode (no automated insulin delivery) and an auto mode (AM, HCL therapy). Women in this case series used AM off-label in gestation.
Case 1 started HCL therapy in the second trimester, her sensor glucose time spent <3.9 and >10 mmol/L improved thereafter. Case 1 had average sensor glucose (ASG) levels of 6.4 ± 2.4 mmol/L in the first trimester, 7.0 ± 2.7 mmol/L in the second trimester before HCL use, 7.1 ± 2.1 mmol/L in the second trimester after HCL use, and 6.8 ± 1.9 mmol/L in the third trimester. Case 1 continued AM during operative delivery and post-partum. Cases 2 and 3 used HCL therapy throughout gestation but with inconsistent time in AM. When they increased time in AM their glycaemic indices improved. Case 2 had ASG of 9.5 ± 3.4, 8.6 ± 2.9, and 7.9 ± 2.5 mmol/L in the first through third trimesters, respectively. Case 3 had ASG of 11.1 ± 4.8 and 3.9 to 10 mmol/L in the first and second trimesters, respectively. Case 2 continued HCL therapy post-partum, Case 3 did not.
CareLink® Clinical Software only reports the non-pregnant time in range. Nonetheless, this represents the first report of HCL therapy in pregnancy with a system approved by the Food and Drug Administration in non-pregnant populations.

BACKGROUND: Wide-necked intracranial aneurysms present unique treatment challenges in the setting of subarachnoid hemorrhage. New generations of endoluminal devices (stents) have expanded our ability to treat complex aneurysms. The PulseRider Aneurysm Neck Reconstruction Device (PulseRider [Cerenovus, Irvine, California, USA]) is new to the U.S. market after receiving Food and Drug Administration approval in June 2017. Official recommendation for use of the PulseRider is with dual antiplatelet therapy (DAPT). Its design has been hypothesized to carry a lower risk of thromboembolic complications in the circumstance that DAPT needs to be discontinued.
METHODS: Between March and June 2018, we treated 4 cases of ruptured wide-necked basilar tip aneurysms at the University of Colorado Hospital, Aurora, Colorado, with PulseRider-assisted coil embolization. Imaging and chart reviews were performed retrospectively on each of these patients.
RESULTS: All 4 aneurysms were successfully treated with PulseRider-assisted coil embolization. There were no periprocedural hemorrhages and no postprocedural reruptures. Two patients developed nonocclusive thrombi in the posterior cerebral arteries at the time of coiling, which was resolved with intra-arterial glycoprotein IIb/IIIa receptor antagonists. Two patients developed external ventricular drain-associated hemorrhages, only one of which developed after the administration of DAPT. All patients were eventually discharged to home.
CONCLUSIONS: The PulseRider device represents a novel design for stent-assisted coil embolization. We report a small but promising series of its successful use in the acute treatment of wide-necked, ruptured basilar artery aneurysms. Additional experience is needed to determine if this device has a place in our armamentarium for treatment of ruptured aneurysms.

The aim of this review is to describe the rationale and main underlying reasons for undertaking, during clinical development, the study of drug candidates used separately and/or in combination with other technologies. To ease comprehension, reference will be made to the case of SpinalonTM, a new fixed-dose combination (FDC) product composed of levodopa/carbidopa/buspirone. This drug is capable of triggering, within minutes after a single administration orally, 45 minute- episodes of basic involuntary \'reflex\' walking in paraplegic animals. Daily administration during one month was shown to lead to increased performance over time, with health benefits onto musculoskeletal and cardiovascular systems. A double-blind, dose-escalation, randomized phase I/IIa study with 45 spinal cord-injured subjects successfully provided the maximal tolerated dose (MTD) and preliminary evidence of efficacy. As an attempt to explore how efficacy may be optimized, a phase IIb study with 150 subjects was designed to compare the effects of repeated administration in different conditions (arms). Tests with a motorized treadmill, a harness for body weight support, a transdermal spinal cord stimulator and/or an exoskeleton were proposed because: 1) these devices are unlikely to alter safety but, 2) they are reasonably expected to increase spinal locomotor neuron activation, reflex walking induction, and musculoskeletal/cardiovascular benefits. This approach would normally allow the phase III study to demonstrate clearly, with fewer subjects and at lower costs, long-term benefits on health of SpinalonTM used in optimized conditions and settings. This innovative strategy in drug development may contribute to further describe the mechanisms of action as well as optimized conditions of use for patients. Adapted to the development of other products, such an approach may enable greater safety, efficacy, clinical utility and compliance to be sought for next-generation CNS drugs.