Impact of dexmedetomidine on electrophysiological properties and arrhythmia inducibility in adult patients referred for reentrant supraventricular tachycardia ablation.

BACKGROUND: Drugs used for sedation/analgesia may affect the basic cardiac electrophysiologic properties or even supraventricular tachycardia (SVT) inducibility. Dexmedetomidine (DEX) is a selective alpha-2 adrenergic agonist with sedative and analgesic properties. A comprehensive evaluation on use of DEX for reentrant SVT ablation in adults is lacking. The present study aims to systematically assess the impact of DEX on cardiac electrophysiology and SVT inducibility. METHODS: Hemodynamic, electrocardiographic, and electrophysiological parameters and SVT inducibility were assessed before and after DEX infusion in patients scheduled for ablation of reentrant SVT. RESULTS: The population of this prospective observational study included 55 patients (mean age of 58.7 ± 14 years, 29 males [52.7%]). A decrease in systolic and diastolic blood pressure and in heart rate was observed after DEX infusion (p = 0.001 for all). DEX increased corrected sinus node refractory time, atrial effective refractory period, AH interval, AV Wenckebach cycle length, and AV node effective refractory period without affecting the His-Purkinje conduction or ventricular myocardium refractoriness. No AV blocks or sinus arrests occurred during DEX infusion. Globally, there was no difference in SVT inducibility in basal condition or after DEX infusion (46/55 [83.6%] vs. 43/55 [78.1%] patients; p = 0.55), without a difference in isoprenaline use (p = 1.0). In 4 (7.3%) cases, the SVT was inducible only after DEX infusion. In 34.5% of cases, DEX infusion unmasked the presence of an obstructive sleeping respiratory pattern, represented mainly by snoring. CONCLUSIONS: DEX depresses sinus node function and prolongs atrioventricular refractoriness without significantly affecting the rate of SVT inducibility in patients scheduled for reentrant SVT ablation.

An operational approach to the execution of MR examinations in patients with CIED.

In the context of the increasing spread of cardiac active implantable heart devices (CIEDs) in the population and of the wide diagnostic/therapeutic utility of magnetic resonance (MRI) examinations, the goal of this paper is to provide the experience of the Santa Maria Nuova Hospital of the USL Tuscany Center in Florence and to report an organizational proposal to perform, in the hospital settings, MRI examinations on patients carrying CIED. This report is intended to show the operational choices of a Radiology Department which organizes this activity in accordance with the new Italian regulatory framework in the field of safety of MR sites (Ministero della Salute in Decreto Ministeriale 10 agosto 2018 Determinazione degli standard di sicurezza e impiego per le apparecchiature a risonanza magnetica, 2018).

Long-term outcomes after "Zero X-ray" arrhythmia ablation.

PURPOSE: Radiation exposure related to conventional tachyarrhythmia radiofrequency catheter ablation (RFCA) carries small but definite risk for both patients and operators. Today, non-fluoroscopic mapping systems enable to perform catheter ablation with minimal or zero fluoroscopy. The purpose of this study was to evaluate the long-term outcome of patients who had undergone "Zero X-ray" ablation, since no information is available on the very long-term benefits. METHODS: A total of 272 arrhythmias in 266 patients have been treated with catheter ablation by means of a zero-ray approach guided only by a nonconventional mapping system (EnSite NavX™, Ensite™ Velocity™ mapping system; subsequently Ensite™ Precision™ Abbott, St. Paul, MN). Fluoroscopy was never used. RESULTS: Over a period of 6 years, patients were followed up for an average of 2.9 ± 1.6 years. A 100% rate of acute success was observed in the study population, with a complication rate of 0.8%. Chronic success was achieved in 90.8% of the total number of procedures (272). Patients in whom the same arrhythmia recurred during follow-up underwent to a redo catheter ablation procedure in 60.0% of cases, while the remaining 40.0% underwent pharmacological treatment. A new post-ablation arrhythmia occurred in 7.7% of the sample. CONCLUSIONS: The non-fluoroscopic approach is a feasible and safe alternative to fluoroscopy for arrhythmias ablation. This method ensures low complications rates, high acute procedural success rates, and comparable long-term outcomes with clinical benefits for both patients and physicians. The complete elimination of fluoroscopy during catheter ablation is advantageous and does not reduce patient safety.

Ablation of recurrent malignant idiopathic ventricular tachycardia: When proper diagnosis and success is a matter of contact.

Effective and stable contact between the catheter tip and the tissue is crucial for both mapping and lesion formation during cardiac ablation procedures. Contact force catheter may be not only a therapeutic approach to arrhythmias, but also a tool for achieving accurate characterization of the arrhythmic substrate.

Severe obstructive sleep apnea: first screening with an implanted pacemaker.

Sleep apnea syndrome (SAS) is a chronic condition associated with cardiovascular disease. In some pacemakers, an advanced algorithm using transthoracic impedance may be used to identify SAS. This algorithm may be also a useful tool for a long-term monitoring helping physicians to optimize therapy, reducing risk factors, and improving therapeutic compliance.

Recurrences in the Blanking Period and 12-Month Success Rate by Continuous Cardiac Monitoring After Cryoablation of Paroxysmal and Non-Paroxysmal Atrial Fibrillation.

INTRODUCTION: Recurrences within the blanking period (early recurrences) are common after atrial fibrillation (AF) ablation by pulmonary vein isolation (PVI), but their clinical significance is still controversial. We aimed at evaluating the significance of within-blanking recurrences at 12-month follow-up after cryoballoon (CB) PVI, and to assess the real procedural success rate by continuous monitoring of cardiac rhythm. METHODS AND RESULTS: Sixty consecutive AF patients (34 paroxysmal, 56.7%) underwent their first CB-PVI at one Italian center (May 2013 to April 2015), and subsequent implantation of an implantable loop recorder (ILR). Overall, 12-month success rate after the blanking period was 55%. The shortest detected event was 7 minutes long. Late recurrences were more frequent in non-paroxysmal (19/26, 73.1%) than in paroxysmal AF (8/34, 23.5%; P <0.001). Early recurrences occurred in 17 (28.3%) patients, with 14 also having late recurrences (82.3%), while only 13 out of 43 (30.2%) without within-blanking recurrences experienced post-blanking events (P <0.001). Overall, early recurrences showed 51.8% sensitivity (95% CI 31.9-71.3%) and 90.9% specificity (95% CI 75.7-98.1%) for later recurrences, with 82.3% (95% CI 56.6-96.2%) positive and 69.8% (95% CI 53.9-82.8%) negative predictive value. The positive likelihood ratio was 5.7 (95% CI 1.8-17.8). At multivariable analysis, non-paroxysmal AF (HR: 3.113; 95% CI 1.309-7.403; P = 0.010) and within-blanking recurrences (HR: 3.453; 95% CI 1.544-7.722; P = 0.003) were independent predictors of post-blanking AT/AF. CONCLUSION: CB-PVI for paroxysmal AF shows a 12-month success rate of 76.5% after one single procedure, as assessed by continuous cardiac rhythm monitoring. Within-blanking recurrences predict the ablation failure in more than 80% of patients.

Cryoablation of typical AVNRT: Younger age and administration of bonus ablation favor long-term success.

BACKGROUND: Cryoablation (CA) is an emerging tool for the treatment of supraventricular tachyarrhythmias. Determinants of long-term success still need clarification. OBJECTIVE: The purpose of this study was to assess which patients' and procedural features affect the long-term efficacy of CA for typical atrioventricular nodal reentrant tachycardia (AVNRT). METHODS: Eighty-five consecutive patients undergoing CA for typical AVNRT were divided into 3 groups of age: group A, ≤20 years, n = 20 (23.5%); group B, 21-50 years, n = 30 (35.3%); group C, ≥51 years, n = 35 (41.2%). CA was performed for 5 minutes at -75°C in all; 4-minute bonus CA was delivered if not contraindicated (ie, transient PR interval lengthening during the first application and narrow triangle of Koch). The efficacy end point was the absence of recurrences at 12-month follow-up. RESULTS: CA was acutely successful in all 85 patients (100%). Bonus ablation was performed in 69 (81.2%). No permanent complications were observed. At follow-up, AVNRT recurrences occurred in 9 patients (10.6%): group A, 0 (0%); group B, 2 (6.7%), group C, 7 (20%). Incidence of recurrences was significantly different between age groups (P = .047) and between patients receiving (7.2%) and not receiving (25.0%) bonus CA (P = .038). In multivariable analysis, age groups (odds ratio [OR] 5.917; 95% confidence interval [CI] 1.372-25.518; P = .017) and bonus CA (OR 0.115; 95% CI 0.018-0.724; P = .021) were the only independent predictors of recurrences. Furthermore, age as a continuous variable remained statistically associated with recurrences (OR 1.046; 95% CI 1.002-1.091; P = .038). CONCLUSION: CA is effective and safe for typical AVNRT ablation. Younger age and bonus CA administration are independent predictors of success at 12 months. Incidence of recurrences is low in patients younger than 21 years.

QRS duration in left bundle branch block does not affect left ventricular twisting in chronic systolic heart failure.

PURPOSE: Left ventricular (LV) torsion is an important parameter of LV performance and can be influenced by several factors. Aim of this investigation was to evaluate whether QRS prolongation in left bundle branch block (LBBB) may influence global LV twist and twisting/untwisting rate in chronic systolic heart failure (HF) patients. METHODS: We prospectively evaluated 30 healthy subjects (control group) and 100 chronic HF patients with severely impaired LV systolic function (ejection fraction ≤ 35%). Patients were divided into three groups according to QRS duration: A: QRS < 120 ms (n 49), B: 120 ≤ QRS ≤ 150 ms (n 28) and C: QRS > 150 ms (n 23). Patients in groups B and C presented LBBB. All subjects underwent standard trans-thoracic echocardiography and two-dimensional speckle-tracking echocardiography evaluation. Categorical variables were compared by the chi-square or the Fisher's exact test. Continuous variables were compared using the ANOVA test. Correlations between variables were analysed with linear regression. RESULTS: Control subjects presented higher torsion parameters, when compared with patients in any HF group. Among the three HF groups, no differences were detected in global twist (4.79 ± 3.54, 3.8 ± 3.0 and 4.15 ± 3.14 degrees, respectively), twist rate max (44.81 ± 25.03, 37.94 ± 19.09 and 37.61 ± 24.49 degrees s(-1), respectively) and untwist rate max (-36.31 ± 30.89, -27.68 ± 34.67 and -39.62 ± 26.27 degrees s(-1), respectively) (P>0.05 for all). At linear regression analysis, there was no relation between QRS duration and any torsion parameter (P>0.05 for all). CONCLUSIONS: In patients with chronic severe systolic heart failure, QRS duration and LBBB morphology do not affect LV twisting and untwisting.

Hemodynamic sensor in cardiac implantable electric devices: the endocardial accelaration technology.

There have been substantial progresses in the technology of cardiac implantable electric devices (CIEDs) during the past decades. One of the progresses is represented by the development of a hemodynamic sensor embedded at the tip of a pacing lead that measures myocardial contractility by the analysis of myocardial mechanical vibrations occurring during the cardiac cycle. This sensor, providing continuous hemodynamic monitoring, could play an important role in clinical practice because of several clinical applications in CIEDs recipients. The objectives of this work are to report how this sensor operates and to review the main findings about its clinical applications.

Isolated lichen planus of the lip.

Lichen planus (LP) is an inflammatory disease that may involve multiple skin sites as well as mucous membranes, hair follicles and nails. It rarely occurs on the lips and usually then in association with oral lesions. We report a 43-year-old man with a 7-month history of inflammation and erosive lesions of the lower lip. Histopathological and immunofluorescence studies showed features of LP. Local treatment with betamethasone dipropionate 0.5% ointment led to complete resolution within 1 month. Four months later, the patient developed typical cutaneous LP. Isolated LP of the lip is unusual, although this condition may be underestimated and therefore under-reported in the literature.