Tissue-Toxic Effects of Phosphatidylcholine/Deoxycholate after Subcutaneous Injection for Fat Dissolution in Rats and a Human Volunteer

BACKGROUND The safety of the lipodissolution procedure for the cosmetic treatment of fat is unknown.
OBJECTIVES The objective was to determine the subcutaneous tissue effects of phosphatidylcholine solubilized with deoxycholate (PC/DC) in rats and a human volunteer.
METHODS Rats were treated subcutaneously three times with 50, 300, or 600 μL of PC/DC formula on the abdomen in a chronic study (30 days). A human volunteer undergoing elective liposuction was similarly treated. Cell membrane lysis, cell viability, and histologic status were determined on fresh biopsies of subcutaneous fat from the injection sites.
RESULTS PC/DC dose-dependently reduced membrane integrity and cell viability. Histologic alterations induced by PC/DC included fibroplasia, bandlike fibrosis in the region of the cutaneous muscle, and partial muscle loss. The highest dose caused widespread fat necrosis, fat cyst formation, and necrotic changes of the walls of small blood vessels. Histologic sections of subcutaneous tissue from the human volunteer showed dose-dependent panniculitis, fat cysts, and vessel necrosis. DC (2.5%), tested for comparison in the rat, exerted membrane and histologic effects similar to those of PC/DC. Solvent controls caused negligible alterations.
CONCLUSIONS Injection lipolysis with PC/DC causes tissue fibrosis and necrosis of adipose and vascular tissues in rat and man, making the long-term safety of PC/DC for nonsurgical treatment of subcutaneous fat deposits uncertain.     

Pressure‐Guided Cryoballoon Isolation of the Pulmonary Veins for the Treatment of Paroxysmal Atrial Fibrillation

Pressure‐Guided Cryoballoon Pulmonary Vein Isolation. Background: Pulmonary vein (PV) isolation using a balloon‐mounted cryoablation system is a new technology for the percutaneous treatment of atrial fibrillation (AF). Complete PV occlusion during balloon ablation has been shown to predict successful electrical isolation. The aim of this study was to correlate mechanical PV occlusion with changes in a pressure curve recorded at the distal tip of the cryoballoon catheter. Methods and Results: We analyzed 51 PVs in 12 patients (61 ± 6 years old) with paroxysmal AF. At first, PV occlusion via the cryoballoon was documented by changes in the pressure curve. Once the PV is occluded, the pressure curve registered in the vein converts from a left atrial pressure curve to a pulmonary artery pressure curve: the PV wedge curve. Occlusion was then confirmed by transesophageal echocardiography (TEE). Following 2 cryoablation applications, electrical PV isolation was assessed with a circumferential mapping catheter. Under the exclusive guidance of changes in the pressure curve at the tip of the cryoballoon, mechanical occlusion confirmed by TEE was achieved in 47 of 51 PVs (92%). Three PVs required further TEE guidance to achieve occlusion. All 50 occluded veins were electrically isolated after cryoablation. One right inferior vein, which could not be occluded with the balloon, displayed conduction post cryoablation and was isolated by focal ablation. Conclusions: Occlusion and electrical isolation of PVs during cryoballoon ablation can be predicted by the appearance of a PV wedge curve at the tip of the catheter. This new straightforward parameter may facilitate the procedure. (J Cardiovasc Electrophysiol, Vol. 21, pp. 120‐125, February 2010)     

Transvenous Atrial Cardioversion Threshold in Patients with Implantable Cardioverter Defibrillator: Influence of Active Pectoral Can

Recent studies have shown that transvenous atrial cardioversion is feasible with lead configurations primarily designed for implantable cardioverter defibrillators (ICD). The purpose of this study was to examine the influence of an active pectoral ICD can on the atrial cardioversion threshold (ADFT). Forty consecutive patients received a transvenous single lead system (Endotak DSP 0125, CPI, St. Paul, MN, USA) in combination with a left subpectoral ICD (Ventak Mini, CPI) for treatment of malignant ventricular tachyarrhythmias. Patients were randomized into two groups: 21 received a Hot Can 1743 and 19 patients a Cold Can 1741. Step-down testing of the ventricular defibrillation threshold (VDFT) was performed intraoperatively and evaluation of the ADFT for induced atrial fibrillation (AF) at predischarge. After testing, each patient received a 2-J shock and was asked to quantify discomfort on a numerical scale ranging from 0 to 10. Both groups were comparable with regard to all clinical parameters studied. The mean VDFT in patients with a Hot Can device was significantly lower than in patients with a Cold Can (7.5 ± 2.3 J vs 9.8 ± 3.8 J; P < 0.03). The mean ADFT in the Hot Can group tended to be lower than in the group with Cold Cans (3.4 ± 1.4 J vs 4.5 ± 2.4 J; P = 0.07), and the proportion of patients in whom atrial cardioversion was accomplished at low energies (≤ 3 J) was higher in patients with active compared with patients with inactive pulse generators (57% vs 26%; P < 0.04). The mean discomfort reported after delivery of a 2-J shock was comparable in both groups (Hot Can 5.2 ± 1.9; Cold Can: 5.3 ± 2.1; P = NS). We conclude that the inclusion of an active left subpectoral can in the defibrillation vector of a ventricular ICD seems to reduce the energy requirements for atrial cardioversion without increasing the discomfort caused by low energy shocks.     

Stenting of Native Right Ventricular Outflow Tract Obstructions in Symptomatic Infants

Objective

To assess feasibility, safety and effectiveness of right ventricular outflow tract (RVOT) stenting in symptomatic young infants.

Methods

Multicentre evaluation of 35 patients intended to undergo RVOT stenting in 11 pediatric cardiac centres from 2009 to August 2011.

Results

Median age and weight at the time of first stent implantation were 8 weeks and 3.3 kg, with 40% of patients <3 kg. A total of 19 patients had suffered from hypoxemic spells, 8 patients were ventilated, 6 on inotropic support and 5 on prostaglandin infusion. Severe concomitant malformations were present in 11 patients, and acute infections in 2. Stenting of the RVOT was successfully performed in 33 patients, improving oxygen saturation from a median of 77 to 90% 2 days after intervention. Besides the 2 patients in whom RVOT stenting was not successful for technical reasons, there were no procedural complications. In 17 of 33 patients, 1–3 reinterventions were performed during follow‐up, less than half of those were reinterventions in the RVOT. A total of 27 patients have undergone successful surgical repair 4–162 (median 19.5) weeks after initial RVOT stent implantation, 2 patients are still waiting. There were no perioperative deaths.

Conclusions

Stenting of the RVOT provides a safe and effective management strategy for initial palliation in symptomatic young infants, including those patients not suitable or at higher risk for surgical therapy. (J Interven Cardiol 2015;28:279–287)

     

EFFECTS OF GROWTH HORMONE ON PROTEIN METABOLISM Acute Changes in Plasma Amino Acids in Growth Retarded Patients with and without Growth Hormone Deficiency

Abstract 39 patients with growth retardation were investigated: 21 (group H) were suffering from GH deficiency and 18 (group N) had no endocrine disease except for two adequately treated patients with mild hypothyroidism. Analysis of 15 plasma amino acid concentrations was carried out before and 1 and 2 hours after intravenous HGH injection at a dosage of 2 mg per m². Except for one amino acid no significant difference between mean pre-treatment amino acid values was observed in the two groups of patients. In group H there was a highly significant decrease in plasma concentration of 14 amino acids already 1 hour after HGH injection and of all 15 amino acids after 2 hours. This response of plasma amino acids to HGH was less pronounced in group N. For 5 amino acids a moderate correlation was found in group H between acute metabolic response to HGH and growth response to long-term HGH treatment. Our results following HGH injection may reflect increased plasma amino acid transfer into cells due to HGH.     

What Is the Most Appropriate Stimulation Mode in Patients with Sinus Node Dysfunction?

Sinus node disease (SND) has caused many controversies about the appropriate stimulation mode. We compared the advantages and disadvantages of VVI, AAI, DDD, and DDI mode. In an additional study, left ventricular function at rest [R] and during exercise [E] was investigated in dual chamber and ventricular stimulation mode with a stimulation rate of 70 ppm [R] and 110 ppm [E]. A total of 223 patients [pts] was investigated (67 AAI, 87 VVI, 69 DDI]. Hemodynamic disadvantages in VVI mode resulted in a 55% actuarial incidence of atrial fibrillation after five years. In AAI mode, we found another 25% complication rate due to impaired AV conduction [n = 9] or a bradyarrhythmia [n = 6] with slow ventricular response. DDD mode implies the possibility of sustaining a pacemaker mediated tachycardia. Single ventricular stimulation with a high stimulation rate (110 ppm] under E showed a worse left ventricular performance as compared to dual chamber stimulation. DDI mode shows none of the aforementioned disadvantages. To sum it up: Until a dual chamber rate responsive pacemaker becomes available, the DDI mode represents the best stimulation mode for patients with a SND.     

Cryoballoon Pulmonary Vein Isolation Guided by Transesophageal Echocardiography: Novel Aspects on an Emerging Ablation Technique

Background: Pulmonary vein (PV) isolation using a balloon-mounted cryoablation system is a new technology for the percutaneous treatment of atrial fibrillation (AF). Transesophageal echocardiography (TEE) allows real-time visualization of cryoballoon positioning and successful vein occlusion via color Doppler. We hypothesized that PV mechanical occlusion monitored with TEE could predict effective electrical isolation.
Methods: We studied 124 PVs in 30 patients. Under continuous TEE assessment, a cryoballoon was placed in the antrum of each PV aiming for complete PV occlusion as documented by color Doppler. At the end of the procedure, PV electrical isolation was evaluated using a circumferential mapping catheter.
Results: Of the 124 PVs studied, 123 (99.2%) could be visualized by TEE: the antrum was completely visualized in 80 of them (64.5%), partially in 36 (29.0%), and only disappearance of proximal flow could be observed in the remaining 7 PVs (5.7%). Vein occlusion could be achieved in 111 of the 123 (90.2%) visualized PVs. Postinterventional mapping demonstrated electrical isolation in 109 of 111 occluded PVs (positive predictive value 98.2%) and only in 1 of 12 nonoccluded PVs (negative predictive value 91.7%, P < 0.001). After a mean follow-up of 7.4 ± 3.7 months, 73.3% of patients remained in sinus rhythm without antiarrhythmic drugs.
Conclusion: Color Doppler documented PV occlusion during cryoballoon ablation can predict effective electrical isolation.     

Spectrotemporal Mapping of High-Resolution ECGs in Experimental Myocardial Infarction: Comparison with Time-Domain Analysis and Epicardial Electrograms

The study was undertaken to evaluate the relationship of signal-averaged ECG (SA-ECG) readings in the frequency domain (STM) and epicardial electrograms (EE) recorded before and after acute myocardial infarction (AMI) in pigs and to compare the changes with findings in time-domain analysis (TDA). In 20 pigs the left anterior descending artery (LAD) was ligated. Prior to ligation, a SA-ECG was recorded (method of Simson) and bipolar electrodes were used to register EE in the areas supplied by the LAD and the circumflex artery (CIRC). Five minutes after LAD ligation, all measurements were repeated. Time-domain parameters were QRS duration (QRS D) and the duration of the signal below 30 microV (LAS 30). Beginning at a point of 20 ms before the QRS end, the frequency spectra (0-200 Hz) of 25 segments of 80-ms duration at the QRS end were analyzed. The volumes below the 25 curves were analyzed separately for 0-50 Hz, 51-100 Hz, 101-150 Hz, and 151-200 Hz. After AMI, five pigs died within 7 minutes. In 15 pigs, QRS D as well as LAS 30 lengthened significantly (P<0.05; P<0.001). Spectrotemporal mapping (STM) showed a significant decrease of the frequencies above 50 Hz (51-200 Hz) in the entire group and in the animals with late potentials (P<0.05). EE of the LAD area were significantly prolonged (P<0.01); this did not correlate with the changes in STM parameters. In pigs acute myocardial infarction causes a shift towards lower frequencies in the STM which most likely reflects the slowed depolarisation in the ischemic area.