Transvenous demand Pacemaker Treatment for intermittent complete Heart Block in a Cat

A 13-year-old male neutered domestic shorthaired cat had repeated syncopal episodes over a 6 month period, which had variable duration and continued to increase in frequency. Intermittent ventricular asystole, due to complete heart block, and hyperthyroidism were documented. As the syncopal episodes did not respond to a 4-week medical treatment and symptoms became severe, a transvenous ventricular demand pacemaker system (VVIM) was implanted via the external jugular vein. The unipolar lead was tunneled subcutaneously and connected with the generator in a preformed ventral abdominal muscle pocket. During follow up of 18-months there were no recurrences of the syncopal episodes.

Endogenous α-calcitonin-gene-related peptide promotes exercise-induced, physiological heart hypertrophy in mice.

AIM It is unknown how the heart distinguishes various overloads, such as exercise or hypertension, causing either physiological or pathological hypertrophy. We hypothesize that alpha-calcitonin-gene-related peptide (αCGRP), known to be released from contracting skeletal muscles, is key at this remodelling. METHODS The hypertrophic effect of αCGRP was measured in vitro (cultured cardiac myocytes) and in vivo (magnetic resonance imaging) in mice. Exercise performance was assessed by determination of maximum oxygen consumption and time to exhaustion. Cardiac phenotype was defined by transcriptional analysis, cardiac histology and morphometry. Finally, we measured spontaneous activity, body fat content, blood volume, haemoglobin mass and skeletal muscle capillarization and fibre composition. RESULTS While αCGRP exposure yielded larger cultured cardiac myocytes, exercise-induced heart hypertrophy was completely abrogated by treatment with the peptide antagonist CGRP(8-37). Exercise performance was attenuated in αCGRP(-/-) mice or CGRP(8-37) treated wild-type mice but improved in animals with higher density of cardiac CGRP receptors (CLR-tg). Spontaneous activity, body fat content, blood volume, haemoglobin mass, muscle capillarization and fibre composition were unaffected, whereas heart index and ventricular myocyte volume were reduced in αCGRP(-/-) mice and elevated in CLR-tg. Transcriptional changes seen in αCGRP(-/-) (but not CLR-tg) hearts resembled maladaptive cardiac phenotype. CONCLUSIONS Alpha-calcitonin-gene-related peptide released by skeletal muscles during exercise is a hitherto unrecognized effector directing the strained heart into physiological instead of pathological adaptation. Thus, αCGRP agonists might be beneficial in heart failure patients.

In vivo electroporation-mediated gene delivery to the beating heart

Gene therapy may represent a promising alternative strategy for cardiac muscle regeneration. In vivo electroporation, a physical method of gene transfer, has recently evolved as an efficient method for gene transfer. Here, we describe two protocols involving in vivo electroporation for gene transfer to the beating heart.

Advances and challenges in skeletal muscle angiogenesis.

The role of capillaries is to serve as the interface for delivery of oxygen and removal of metabolites to/from tissues. During the past decade there has been a proliferation of studies that have advanced our understanding of angiogenesis demonstrating tissue capillary supply is under strict control during health, but poorly controlled in disease - resulting in either excessive capillary growth (pathological angiogenesis) or losses in capillarity (rarefaction). Given that skeletal muscle comprises nearly 40% of body mass in humans, skeletal muscle capillary density has a significant impact on metabolism, endocrine function, and locomotion, and is tightly regulated at many different levels. Skeletal muscle is also high adaptable, and thus one of the few organ systems which can be experimentally manipulated (e.g. by exercise) to study physiologic regulation of angiogenesis. This review will focus on 1) the methodological concerns that have arisen in determining skeletal muscle capillarity, and 2) highlight the concepts that are reshaping our understanding of the angio-adaptation process. We also summarize selected new findings (physical influences, molecular changes and ultrastructural rearrangement of capillaries) that identify areas of future research with the greatest potential to expand our understanding of how angiogenesis is normally regulated, and that may also help to better understand conditions of uncontrolled (pathologic) angiogenesis.

Motion-insensitive determination of B1+ amplitudes based on the bloch-siegert shift in single voxels of moving organs including the human heart.

PURPOSE To reliably determine the amplitude of the transmit radiofrequency ( B1+) field in moving organs like the liver and heart, where most current techniques are usually not feasible. METHODS B1+ field measurement based on the Bloch-Siegert shift induced by a pair of Fermi pulses in a double-triggered modified Point RESolved Spectroscopy (PRESS) sequence with motion-compensated crusher gradients has been developed. Performance of the sequence was tested in moving phantoms and in muscle, liver, and heart of six healthy volunteers each, using different arrangements of transmit/receive coils. RESULTS B1+ determination in a moving phantom was almost independent of type and amplitude of the motion and agreed well with theory. In vivo, repeated measurements led to very small coefficients of variance (CV) if the amplitude of the Fermi pulse was chosen above an appropriate level (CV in muscle 0.6%, liver 1.6%, heart 2.3% with moderate amplitude of the Fermi pulses and 1.2% with stronger Fermi pulses). CONCLUSION The proposed sequence shows a very robust determination of B1+ in a single voxel even under challenging conditions (transmission with a surface coil or measurements in the heart without breath-hold). Magn Reson Med, 2015. © 2015 Wiley Periodicals, Inc.

Ultrathin Strut Biodegradable Polymer Sirolimus-Eluting Stent Versus Durable-Polymer Everolimus-Eluting Stent for Percutaneous Coronary Revascularization: 2-Year Results of the BIOSCIENCE Trial.

BACKGROUND No data are available on the long-term performance of ultrathin strut biodegradable polymer sirolimus-eluting stents (BP-SES). We reported 2-year clinical outcomes of the BIOSCIENCE (Ultrathin Strut Biodegradable Polymer Sirolimus-Eluting Stent Versus Durable Polymer Everolimus-Eluting Stent for Percutaneous Coronary Revascularisation) trial, which compared BP-SES with durable-polymer everolimus-eluting stents (DP-EES) in patients undergoing percutaneous coronary intervention. METHODS AND RESULTS A total of 2119 patients with minimal exclusion criteria were assigned to treatment with BP-SES (n=1063) or DP-EES (n=1056). Follow-up at 2 years was available for 2048 patients (97%). The primary end point was target-lesion failure, a composite of cardiac death, target-vessel myocardial infarction, or clinically indicated target-lesion revascularization. At 2 years, target-lesion failure occurred in 107 patients (10.5%) in the BP-SES arm and 107 patients (10.4%) in the DP-EES arm (risk ratio [RR] 1.00, 95% CI 0.77-1.31, P=0.979). There were no significant differences between BP-SES and DP-EES with respect to cardiac death (RR 1.01, 95% CI 0.62-1.63, P=0.984), target-vessel myocardial infarction (RR 0.91, 95% CI 0.60-1.39, P=0.669), target-lesion revascularization (RR 1.17, 95% CI 0.81-1.71, P=0.403), and definite stent thrombosis (RR 1.38, 95% CI 0.56-3.44, P=0.485). There were 2 cases (0.2%) of definite very late stent thrombosis in the BP-SES arm and 4 cases (0.4%) in the DP-EES arm (P=0.423). In the prespecified subgroup of patients with ST-segment elevation myocardial infarction, BP-SES was associated with a lower risk of target-lesion failure compared with DP-EES (RR 0.48, 95% CI 0.23-0.99, P=0.043, Pinteraction=0.026). CONCLUSIONS Comparable safety and efficacy profiles of BP-SES and DP-EES were maintained throughout 2 years of follow-up. CLINICAL TRIAL REGISTRATION URL: https://www.clinicaltrials.gov. Unique identifier: NCT01443104.