Marzia Giaccardi

Near-zero x-ray in arrhythmia ablation using a 3-dimensional electroanatomic mapping system: A multicenter experience.

BACKGROUND Radiation exposure related to conventional tachyarrhythmia radiofrequency catheter ablation (RFCA) carries small but not negligible stochastic and deterministic effects on health. These effects are cumulative and potentially more harmful in younger individuals. Nonfluoroscopic mapping systems can significantly reduce the radiological exposure and in some cases it can completely eliminate it. OBJECTIVE The aim of this study was to assess the safety, feasibility, and efficacy of a complete nonfluoroscopic approach for RFCA compared with ablation procedures performed under fluoroscopic guidance. METHODS RFCA was performed in 442 consecutive patients (mean age 58 ± 19 years). The first 145 patients (group 1) were treated only under fluoroscopic guidance, and the following 297 patients (group 2) were treated using a nonfluoroscopic electroanatomic mapping system (EnSite Velocity). RFCA was completely performed without fluoroscopy in 255 of 297 patients in group 2 (86%). RESULTS The acute success rate did not differ between group 1 and group 2 (97% vs 96%; P = .46), and there were no differences in either procedure time (87 ± 57 minutes vs 91 ± 52 minutes; P = .41) or complication rate. Fluoroscopic exposure in group 2 was significantly reduced in comparison with group 1 (14 ± 6 seconds vs 1159 ± 833 seconds; P < .0001). CONCLUSION Compared with the conventional fluoroscopic technique, the near-zero radiation (RX) approach provides similar outcomes and may significantly reduce or eliminate ionizing radiation exposure in RFCA. These reductions are achieved without altering the duration or compromising the safety and effectiveness of the procedure.

‘Zero’ fluoroscopic exposure for ventricular tachycardia ablation in a patient with situs viscerum inversus totalis

Situs viscerum inversus totalis (SVIT) is a congenital disorder characterized by mirror reversal of the thoracic and abdominal organs. Different studies have shown that the ablation procedure can be performed without fluoroscopy with safety and effectiveness, in the setting of supraventricular tachycardia. We successfully performed an anatomical map and a radiofrequency catheter ablation of ventricular arrhythmia in a patient with SVIT without fluoroscopy.

Koch and the "ultimum moriens" theory—the last part to die of the heart

“What conclusions can be drawn from these observations of the dying heart? In any case the entry of the vena cava (into the heart) as the region of the ‘Ultimum moriens’ may be excluded. . . . One is therefore almost obliged to come to the conclusion that the last part of the coronary vein and its inlet region, the so called coronary vein funnel, where the stimulus conduction system finds its start and departure, must correspond to the sinus field as the source of the heart’s automatic stimulus”. Walter Karl Koch, 1907.

Mechanical and Electrophysiological Substrate for Recurrent Atrial Flutter Detected by Right Atrial Speckle Tracking Echocardiography and Electroanatomic Mapping in Myotonic Dystrophy Type 1

A 48-year-old patient with myotonic dystrophy (MD) type 1, recurrent typical atrial flutter (AF), and otherwise unremarkable history was hospitalized for an electrophysiological study. The diagnosis of MD type 1 had been made 25 years earlier and was based on typical clinical features and confirmation by genetic analysis. The ECG pattern of AF was characterized by negative waves in the inferior leads and positive waves in V1, a cycle length of 280 milliseconds, and 2:1 atrioventricular conduction. At the time of the study, the patient was asymptomatic and showed normal findings at the cardiac physical examination, ECG, and standard echocardiography. Preablation ECG showed sinus rhythm at 60 bpm with a normal PR interval (180 milliseconds), regular QRS duration and morphology, and normal ventricular repolarization. Average septal-lateral mitral annulus velocities (s′, 9.5 cm/s; e′, 10.3 cm/s; a′, 7.4 cm/s), the E/e′ ratio (7.3), and left ventricular global longitudinal and circumferential strain (−21.5% and −23.2%, respectively) were all normal, as well as right ventricular systolic function (tricuspid annulus systolic excursion and peak systolic velocity, 25 mm and 18.5 cm/s, respectively). Analysis of longitudinal right atrial deformation by speckle tracking showed impaired strain mechanics in the inferior segment of the atrial …

Ventricular tachycardia inducibility after radiofrequency ablation affects the outcomes in patients with coronary artery disease and implantable cardioverter-defibrillators: The role of left ventricular function.

PurposeWe hypothesized that inducibility of the VT responsible for ICD therapies at the end of RFCA, would also be associated with a differential risk, depending on left ventricular function.MethodsWe retrospectively studied 66 patients with previous myocardial infarction and with ICD who also underwent RFCA for recurrent refractory VTs.ResultsDuring the follow-up only 19 patients (29%) showed VTs. Among patients with ejection fraction (EF) ≤ 35%, 11 out of 25 still continued to have VT recurrences, independent of the inducibility of the VT. Among patients with EF >35% and <50%, no recurrent VT was any longer detected in the nine patients in whom the VT was not inducible, while VT recurrences still continued only in the eight patients in whom it was. Finally, all the 24 patients with EF ≥50% did not show any recurrent VT.ConclusionsOur findings confirm the role of RFCA in reducing ICD therapies and also place RFCA in the overall clinical management of recurrent post infarction VTs according to the left ventricular function.

Implantable Cardioverter-Defibrillators in Sudden Cardiac Death Prevention: What Guidelines Don't Tell

A guideline is a statement by which to determine a course of action. A guideline aims to streamline particular processes according to a set routine or sound practice. By definition, following a guideline is never mandatory. Guidelines are not binding and are not enforced [5]. In effect guidelines are derived from 3 sources of data: 1. randomized clinical trials; 2. observational data from cohorts of high-risk patients with less common diseases; and 3. ex‐ pert opinion on potential benefit for clinical condition or specific circumstances in which da‐ ta are limited or uncertain. For all 3 categories of clinical guidance, there are limitations in available data that reinforce the importance of physician judgment in decision making, based on circumstances of individual cases or subgroups of patients [6]. Understanding the value and limitations of current information is important not only for the clinical electro‐ physiologist, but also for general cardiologists and primary care physicians because of their roles in referring appropriate patients for consideration of implantable cardioverterdefib‐ rillator therapy and for the clinical management of patients at risk of sudden cardiac death. While the high stakes and unpredictable nature of sudden cardiac death justifiably provoke fear and uncertainty, emotional factors should not outweigh scientific evidence. In this con‐ text the obligation to adhere to guidelines could, in effects, to have paradoxically dulled our discriminatory senses as clinicians [7].

Prevention of Sudden Death – Implantable Cardioverter Defibrillator and/or Ventricular Radiofrequency Ablation

Sudden cardiac death (SCD) is defined as death from cardiac causes occurring unexpectedly within 1 hour of onset of symptoms. About 80% of SCDs are due to ventricular tachyarrhythmia that is, ventricular tachycardia and ventricular fibrillation. The remaining 20% consists of a number of conditions, including cardiomyopathies (10–15%), other structural heart defects (less than 5%) and bradycardia. SCD is responsible for more deaths than cancer, stroke, and AIDS combined (CDC, 2002). The overall incidence of SCD in the United States and Europe is 1 to 2 per 1000 people (0.1% to 0.2%) annually. Almost 80% of all SCDs occur at home. The 10%-25% survival rate is low and has not been improved by the automatic external defibrillator in patients with moderate risk (de Vreede-Swagemakers, 1997; Bardy, 2008; Myerburg, 2001). On the other hand, several clinical trials showed that the implantable cardioverter defibrillator (ICD) could prevent SCD and reduce overall mortality in some patients with severe left ventrocular dysfunction. For these reasons, ICD therapy has become the first choice strategy to prevent SCD from malignant ventricular tachyarrhythmia in high-risk patients. However, there are numerous well-recognized limitations to ICD therapy. These include the effects and the result of appropriate and inappropriate ICD shocks, the cost of the devices, complications related both to the implantation procedure and to subsequent device function, device malfunction, and restricted efficacy despite normal device function in presence of significant concomitant disease and in particular in presence of severe left ventricular disfunction. Several possible solutions have been proposed in the clinical practice, these include better patients’ selection for ICD implantation, better ICD programmation, better medical therapy and arrhythmic substrate ablation. The role of catheter ablation of ventricular tachycardia in patients with structural heart disease has been increasing in the last 2 decades. The mechanisms of ventricular tachycardia are now clearer, and the electroanatomic mapping systems have made precise activation and substrate mapping more feasible; therefore, the potential for doing catheter ablation of ventricular tachycardia has increased dramatically in the past

The Impact of New Imaging, Mapping and Energy Delivery Technology on the Current Approach to Ablation of Atrial Fibrillation

Atrial fibrillation (AF) is the most common arrhythmia encountered in clinical practice. It is frequently symptomatic and contributes to significant morbidity and mortality, independent of all other cardiac comorbidities [1]. Providing effective treatment of AF is one of the challenges of electrophysiology, and it is the focus of major research initiatives in the scientific community. The level of concern and interest regarding AF has increased over the years with the advent of curative ablative techniques.

19. Sudden Death: ECG and Biological Risk Factors

The aim of the study was to investigate sympathetic and parasympathetic balance and arrhythmic risk in patients undergoing bypass surgery (CABG) and early Rehabilitation using “Extended-length electrocardiogram” (XL-ECG). Methods 48 patients undergoing CABG (13 women-68.6 yrs) were investigated using five-min XL-ECG at their admission to the Rehabilitation and after three and six months. Echographic systolic and diastolic function was also recorded. Results R-R interval (ms) increased only between baseline (B) and 6-months (6) (p<0.05), QT interval dispersion (QTd-ms) decreased only between B and 3-months (3) (p<0.05), Activation-Recovery Interval dispersion (ARId-ms) decreased between B and 3 (p<0.05), between 3 and 6 (p<0.01) and between B and 6 (p<0.01). A wave peak velocity (A) increased only between B and 3. Results remained unchanged after multivariate regression. Conclusions The decrease of QTd and ARId, suggests that early cardiac rehabilitation after revascularization, increase repolarization homogeneity thus reducing arrhythmic risk. The increase of A suggests an improvement in left atrial booster pump function. XL-ECG is a low time-consuming and low cost tool useful for a quick evaluation of autonomic balance and arrhythmologic risk.

Extended-Length ECG in Patients who Undergo Cardiac Surgery and Early Rehabilitation: 6 Months Follow-Up

The aim of the study was to investigate sympathetic and parasympathetic balance and arrhythmic risk in patients undergoing bypass surgery (CABG) and early Rehabilitation using “Extended-length electrocardiogram” (XL-ECG). Methods 48 patients undergoing CABG (13 women-68.6 yrs) were investigated using five-min XL-ECG at their admission to the Rehabilitation and after three and six months. Echographic systolic and diastolic function was also recorded. Results R-R interval (ms) increased only between baseline (B) and 6-months (6) (p<0.05), QT interval dispersion (QTd-ms) decreased only between B and 3-months (3) (p<0.05), Activation-Recovery Interval dispersion (ARId-ms) decreased between B and 3 (p<0.05), between 3 and 6 (p<0.01) and between B and 6 (p<0.01). A wave peak velocity (A) increased only between B and 3. Results remained unchanged after multivariate regression. Conclusions The decrease of QTd and ARId, suggests that early cardiac rehabilitation after revascularization, increase repolarization homogeneity thus reducing arrhythmic risk. The increase of A suggests an improvement in left atrial booster pump function. XL-ECG is a low time-consuming and low cost tool useful for a quick evaluation of autonomic balance and arrhythmologic risk.