Linac-based stereotactic arrhythmia radioablation of paroxysmal atrial fibrillation in elderly patients

Background

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia, occurring in 1–2% of the general population. Patients affected by AF have an increased risk of stroke and heart failure and European guidelines recommend catheter ablation of AF in symptomatic patients refractory to antiarrhythmic therapy. In elderly patients, the AF ablation procedure is associated with a higher rate of overall complications. Recently, stereotactic arrhythmia radioablation (STAR) with precise high-dose of radiation was used to treat ventricular arrhythmias.

Purpose

No data were reported in literature about the use of Linac-based STAR, so a prospective phase-II trial was designed to evaluate safety of Linac-based STAR in elderly patients with paroxysmal AF.

Methods

Fourteen patients (mean age 78±6 years; 57% male) were enrolled in the study. All patients had symptomatic paroxysmal AF refractory to antiarrhythmic drugs. All patients performed 1-week ECG-Holter monitoring (ECG-HM) and transthoracic echocardiogram before and after STAR. Primary end-point was defined as all the adverse events of special interest related to STAR treatment; secondary end-point was defined as AF recurrence after the treatment. The study was approved by the local Ethics Committee and all patients signed informed consent.

Results

All patients performed STAR with a mean overall treatment time of 3 minutes. No serious adverse events were documented acutely and after 6 months of follow up. Transthoracic echocardiogram did not show cardiac damage after STAR. The 1-week ECG-HM performed before STAR documented symptomatic AF episodes in all patients. The 1-week ECG-HM performed 1-month after procedure documented frequent symptomatic atrial ectopy and atrial tachycardias without AF recurrences. The 1-week ECG-HM performed 3 and 6 months after procedure did not revealed AF recurrences. Two patients had a single episode of sustained atrial tachycardia 6 months after STAR. Both patients performed a left atrial mapping using CARTO system and Pentaray mapping catheter documenting PV isolation without vein stenosis (figure); no phrenic nerve damage was documented in both patients. All patients had an improvement in quality of life.

Conclusion

Our preliminary data reported for the first time that the LINAC-based STAR approach could represent a valid alternative to perform PVI in elderly patients with paroxysmal AF.

Funding Acknowledgement

Type of funding sources: None.

Folates dysmetabolism promotes atrial cardiomyopathy/fibrillation through a cardiac-bone marrow networking involving endothelial progenitor cell dysfunction and erythropoiesis diversion

Funding Acknowledgements

Type of funding sources: Private hospital(s). Main funding source(s): dedicated cardiovascular research foud

Background

Recent advances support the concept that pre-persistent Atrial Fibrillation (AF) does not explain the wholeness of embolic strokes, suggesting the recently postulated hypothesis of a broad Atrial Cardiomyopathy (AC). In contrast to its worldwide distribution and its very inclusive definition, pathogenic mechanisms underlying AC are still largely unknown. Folate cycle disorders (FCD) are a yet underrated dysmetabolism only partly explained by methylene tetrahydrofolate reductase (MTHFR)-inherited defects. On a translational basis, FCD could hinder both endothelial and circulating endothelial progenitor cell (EPCs) functioning, therefore providing one-shot explanation to both atrial stasis (increasing atrial fibrosis and generating atrial hypocontractility) and endothelial dysfunction (ED). If such cardiac-bone marrow networking would be verified, a fundamental pathogenic mechanism of AC and subsequent AF would be unraveled.

Purpose

This study aims to enquire for the hypothesis that: 1) atrial fibrosis (AFib) would relate to FCD (intended as both: a)MTHFR C677T inherited mutations and b)bone-marrow function disorders, here referring to erythropoiesis diversions) and 2) AF patients would show dysfunctional EPCs.

Methods

We studied 59 consecutive patients admitted to the Cardiology Unit of the General Hospital "F.Miulli", with preserved EF, subjected to AF ablation. AFib was quantified by relative % of low-voltage (<0,5 mV) bipolar peak-to-peak points, with respect to the wholeness of the endocavitary mapping. Blood count cell was evaluated. MTHFR C677T genotypes were elucidated by RT-PCR. Folate were measured by a commercial laboratory test. EPCs isolation and characterization were performed by Ficoll-Hypaque gradient and flow cytometry analysis for cell surface antigens: CD45, CD34, CD133, VEGFR2 and KDR. EPCs functional wound healing assay was performed.

Results

Baseline characteristics did not differ between Sample and Control groups (Fig. 1 – Left Table). % of Afib significantly differs between C677T MTHFR homozigosis patients (n=15) with respect to non-C677T MTHFR homozygosis patients (n=44) (Fig.1 – Right graph. - p < 0,02). Once univariate analysis was performed, subsequent multivariate analysis highlights highest fit once merged RBC, RDW-SD and folates values were inputed: Goodness of fit was proper, modelling good (Fig.2 – superior graph. - R2=0,39; p=0,0001). Either RBC, RDW-SD and folates coefficient reached significance (p < 0,0001; p < 0,01; p < 0,05 respectively). Number of EPCs significantly differs between AF patients and matched controls (Fig 2 – inferior graph. – p < 0,001).

Conclusions

Our findings support the hypothesis that genetically determined folates dysmetabolism (MTHFR dysfunction) promotes AFib via a complex cardiac-bone marrow networking involving circulating EPCs and unraveled by erythropoiesis diversions. Such results suggest a pathogenic role of folate cycle disorders in the AC development.

Peribulbar anesthesia in sclero-retinal surgery: two quadrants vs single injection

PURPOSE

To evaluate the advantage of peribulbar anesthesia in two quadrants (infero-temporal and upper nasal) vs single injection technique (infero-temporal) for scleral rhegmatogenous retinal detachment surgery (RRD).

PATIENTS AND METHODS

57 patients, aged between 33 and 75 years (57.01 ± 8.68), waiting for retinal detachment surgery, were randomized in two groups: a group S (29 patients), with single quadrant injection technique and a group C (28 patients) with two quadrants injection. Patients in Group S were injected in two quadrants with a 10 ml mixture containing Mepivacaine 2% 5 ml and Ropivacaine 0.75% 5 ml, with hyaluronidase 10 IU/ ml. Patients in group C were injected with the same anesthetic mixture in one quadrant. Number of additional injection, during surgery, in two groups, were reported. Pain was tested with VAS (Verbal Analogue Scale 0-10) after regional block, when muscles were insulated, during scleral buckling positioning, when conjunctive was closed and 6, 12, 24 hours after surgery.

RESULTS

The need for a second peribulbar injection of anesthetic occurred in 9 patients of group C (32.14%); further injection was necessary in 1 patient (3.57%) of group S during scleral buckling (VAS = 7), statistically significant (p <0.05). Postoperative VAS 6 - 12 - 24 hours after surgery was not significant.

CONCLUSIONS

The peribulbar anesthesia may be proposed in scleral surgery of retinal detachment; the injection in two quadrants secured solid and satisfactory anesthesia, increasing the outcome of retinal surgery in loco-regional anesthesia.

Fast glycorrhachia and cerebrospinal fluid protein as predictors of sensory block in anesthesia with subarachnoid Ropivacaine

BACKGROUND

Identify if glycorrhachia and cerebrospinal fluid protein could influence the time of sensory block to T10, the duration and the metameric block's level, after a standard dose of Ropivacaine.

METHODS

80 patients, ASA I - III undergoing to transurethral prostate resection with spinal anesthesia in a prospected open study were recruited. A 0.2 ml liquor's sample was taken; glycorrhachia, by glycemic stix and CSF protein, by urinary stix, were got, before Ropivacaine 0.5% 15 mg injection (0.10 - 0.15 mlsec). After anti-trendelemburg, with 30 ° tilting for 15 min, the onset of sensory block to T10, the maximum metameric level to 15' and the time of sensory block were reported. The data collection were analyzed using the software language R.

RESULTS

A significant correlation liquor specific weigh preoperative glycemia (0.749), liquoral specific weigh glycorrhachia (rho = 0.751; R2 = 0.564; P 0.05) and specific weigh CSF protein (rho = 0.684; R2 = 0.468; P 0.05) were reported. Inverse relation CSF weightsensory block level (rho -0.789, P 0.05, R2 0.621) was evidenced. Inverse relation onset time to T10 glycorrhachia (84%) and cephalic block glycorrhachia (76%) were found. Inverse correlation onset time to T 10 CSF protein and cephalic block proteinorrachia was respectively 84% and 67%. A rho of 0.712 with R2 of 51% BMI onset to T10 and rho of 0.681 with R2 of 51% BMI maximum cephalic block with P 0.05 were reported.

CONCLUSIONS

The predictability of a iso-hypobaric local anesthetic could reduce the risk of procedure failure and adverse events by further cephalic spread.

Transcranial Doppler ultrasound. Examination technique and normal reference values

A newly developed Transcranial Doppler system (TCD) has been used in a group of subjects without any cerebrovascular disease (CVD) in order to establish the standard criteria for transcranial basal cerebral arteries examination and settle normal velocimetric and hemodynamic parameters. TCD examination in patients suffering from CVD provides useful information for clinical management of such pathological conditions.