Pierpaolo Lupo

An Entirely Subcutaneous Implantable Cardioverter–Defibrillator

BACKGROUND Implantable cardioverter-defibrillators (ICDs) prevent sudden death from cardiac causes in selected patients but require the use of transvenous lead systems. To eliminate the need for venous access, we designed and tested an entirely subcutaneous ICD system. METHODS First, we conducted two short-term clinical trials to identify a suitable device configuration and assess energy requirements. We evaluated four subcutaneous ICD configurations in 78 patients who were candidates for ICD implantation and subsequently tested the best configuration in 49 additional patients to determine the subcutaneous defibrillation threshold in comparison with that of the standard transvenous ICD. Then we evaluated the long-term use of subcutaneous ICDs in a pilot study, involving 6 patients, which was followed by a trial involving 55 patients. RESULTS The best device configuration consisted of a parasternal electrode and a left lateral thoracic pulse generator. This configuration was as effective as a transvenous ICD for terminating induced ventricular fibrillation, albeit with a significantly higher mean (+/-SD) energy requirement (36.6+/-19.8 J vs. 11.1+/-8.5 J). Among patients who received a permanent subcutaneous ICD, ventricular fibrillation was successfully detected in 100% of 137 induced episodes. Induced ventricular fibrillation was converted twice in 58 of 59 patients (98%) with the delivery of 65-J shocks in two consecutive tests. Clinically significant adverse events included two pocket infections and four lead revisions. After a mean of 10+/-1 months, the device had successfully detected and treated all 12 episodes of spontaneous, sustained ventricular tachyarrhythmia. CONCLUSIONS In small, nonrandomized studies, an entirely subcutaneous ICD consistently detected and converted ventricular fibrillation induced during electrophysiological testing. The device also successfully detected and treated all 12 episodes of spontaneous, sustained ventricular tachyarrhythmia. (ClinicalTrials.gov numbers, NCT00399217 and NCT00853645.)

J wave, QRS slurring, and ST elevation in athletes with cardiac arrest in the absence of heart disease marker of risk or innocent bystander?

Background—QRS-ST changes in the inferior and lateral ECG leads are frequently observed in athletes. Recent studies have suggested a potential arrhythmogenic significance of these findings in the general population. The aim of our study was to investigate whether QRS-ST changes are markers of cardiac arrest (CA) of unexplained cause or sudden death in athletes. Methods and Results—In 21 athletes (mean age, 27 years; 5 women) with cardiac arrest or sudden death, the ECG recorded before or immediately after the clinical event was compared with the ECG of 365 healthy athletes eligible for competitive sport activity. We measured the height of the J wave and ST elevation and searched for the presence of QRS slurring in the terminal portion of QRS. QRS slurring in any lead was present in 28.6% of cases and in 7.6% of control athletes (P=0.006). A J wave and/or QRS slurring without ST elevation in the inferior (II, III, and aVF) and lateral leads (V4 to V6) were more frequently recorded in cases than in control athletes (28.6% versus 7.9%, P=0.007). Among those with cardiac arrest, arrhythmia recurrences did not differ between the subgroups with and without J wave or QRS slurring during a median 36-month follow-up of sport discontinuation. Conclusions—J wave and/or QRS slurring was found more frequently among athletes with cardiac arrest/sudden death than in control athletes. Nevertheless, the presence of this ECG pattern appears not to confer a higher risk for recurrent malignant ventricular arrhythmias.

Nodo- and fasciculoventricular pathways: Electrophysiological features and a proposed diagnostic algorithm for preexcitation variants

Introduction Fasciculoventricular and nodoventricular pathways (FVP and NVP) are uncommon preexcitation variants that can be misleading during electrophysiology studies (EPSs), and differentiating them could be challenging. In this article, we describe 2 representative cases and then we present various electrophysiological features and phenomenon encountered in patients with these particular accessory pathways (APs).

The Entirely Subcutaneous Defibrillator - A New Generation and Future Expectations.

Although conventional implantable cardioverter-defibrillators (ICDs) have proved effective in the prevention of sudden cardiac death (SCD), they still appear to be limited by non-trivial acute and long-term complications. The recent advent of an entirely subcutaneous ICD (S-ICD) represents a further step in the evolution of defibrillation technology towards a less-invasive approach. This review highlights some historical and current issues concerning the S-ICD that may offer a viable therapeutic option in selected patients at high risk of SCD and in whom pacing is not required. After the CE Mark and US Food and Drug Administration (FDA) approvals, the S-ICD is being implanted worldwide with growing clinical data regarding its safety and efficacy (the EFFORTLESS Registry). The recently developed new generation of S-ICD (EMBLEM, Boston Scientific) demonstrates favourable features including a smaller device, longer longevity and remote-monitoring compatibility. Further innovations in the S-ICD system and potential integration with leadless pacing may play an important role in defibrillation therapy and prevention of SCD in the near future.

Clinical and electrocardiographic features of complete heart block after blunt cardiac injury: A systematic review of the literature

The underlying mechanisms and temporal course of complete heart block (CHB) after blunt cardiac injuries (BCIs) are poorly understood, and a systematic analysis of available data is lacking. In this systematic review, PubMed was searched for publications of reported cases of CHB-BCI analyzing clinical findings, electrocardiographic features, temporal course, and outcomes. Case reports on CHB-BCI were available for 50 patients, mainly secondary to traffic or sport accidents. A fatal outcome occurred in 10 of 50 (20%) of patients, while a structural damage of the atrioventricular (AV) conductive system was evident in 4 of 8 (50%) of necropsy studies. Clinical manifestation of CHB-BCI occurred within 72 hours of injury in 38 of 47 (∼80%) of patients, and 1:1 AV conduction was restored within 7-10 days in about half of early survivors. Permanent pacemaker implantation was indicated in 22 of 42 (∼50%) of early survivors because of recurrent or permanent CHB. Cardiac troponins, when analyzed, were elevated in 12 of 13 (∼90%) of patients, and electrocardiographic features of aberrancy were present in 29 of 40 (>70%) of patients. In conclusion, CHB secondary to BCI is associated with 20% mortality mainly occurring in the early posttraumatic period and most of the deaths are due to or triggered by this malignant arrhythmia. Recurrent or permanent CHB requiring pacemaker implantation occurs in ∼50% of survivors. A structural damage of the AV conductive system can be found in 50% of necropsy studies.

Negative concordance pattern in bipolar and unipolar recordings: An additional mapping criterion to localize the site of origin of focal ventricular arrhythmias.

BACKGROUND The relevance of the temporal relationship between a unipolar electrogram (UEGM) and a bipolar electrogram (BEGM) in determining the site of origin (SOO) of focal arrhythmias has been largely demonstrated. OBJECTIVE We sought to demonstrate that a negative concordance in the initial forces of these EGMs is also helpful in predicting the SOO of premature ventricular contractions (PVCs). METHODS Mapping and radiofrequency (RF) ablation were performed in 41 patients with symptomatic PVCs in the absence of structural heart disease. Simultaneous recordings of the minimally filtered (0.5-500 Hz) UEGM and filtered BEGM (30-500 Hz) were analyzed at 247 mapping sites, where RF was attempted. EGMs of 63 mechanically induced PVCs were separately analyzed as a validation group. All ablation sites had a QS pattern in the UEGM. Acute PVC suppression was defined as a complete disappearance of ventricular ectopic beats after a 60-second pulse of RF. RESULTS RF ablation obtained PVC suppression (RF+) in 33 of 247 sites (13.3%). A negative concordance pattern (NCP) during the initial 20 ms of both UEGM and BEGM was observed in 31 of 33 (94%) RF+ sites compared with 10 of 214 (4%)RF- sites (P < .0001). The NCP criterion demonstrated to be an additional powerful predictor of acute RF success with sensitivity, specificity, positive predictive value, and negative predictive value of 94%, 95%, 76%, and 99%, respectively. Similarly to RF+ sites, the NCP was observed in 60 of 63 sites (95.2%) in the mechanical PVC group. CONCLUSION An NCP in both UEGM and BEGM may be an additional criterion that helps to localize the SOO of focal ventricular arrhythmias.

Diagnostic capabilities of devices for cardiac resynchronization therapy.

Atrial fibrillation and chronic heart failure often coexist. Asymptomatic atrial fibrillation is common in patients with known atrial fibrillation but also in patients with no history of previous atrial fibrillation. The enhanced diagnostic capabilities of modern implantable devices for cardiac resynchronization therapy allow collecting of data on the clinical status of the patient in addition to information on device performance and cardiac rhythm. We present a paradigmatic case of newly diagnosed atrial fibrillation with hemodynamic consequences detected by the diagnostics of a biventricular implantable cardioverter-defibrillator. We discuss the clinical utility of device-based monitoring and the potential advantages of wireless remote-control systems of implantable devices in the management of heart failure patients.

Entirely subcutaneous defibrillator and complex congenital heart disease: Data on long-term clinical follow-up

AIM To describe the long-term follow-up of patients with complex congenital heart disease who underwent subcutaneous implantable cardiac defibrillator (S-ICD), focusing on local complications, appropriate and inappropriate shocks. METHODS Patients with complex congenital heart disease underwent S-ICD implant in two centers with the conventional technique. Data at follow-up were retrieved from clinical notes and institutional database. RESULTS Eight patients were implanted in two centres between 2010 and 2016. Median age at implant was 37.5 years (range 13-57). All patients who were deemed suitable for S-ICD implant passed the pre-procedural screening. Three patients were previously implanted with a anti-bradycardia device, one of whom with CRT. In one patient the device was explanted due to local infection. During the total median follow-up of 874 d, one patient had an appropriate and one inappropriate shock triggered by fast atrial tachycardia. None of the patients had inappropriate shocks secondary to T wave oversensing or electrical interference with anti- bradycardia devices. CONCLUSION S-ICD appears to be effective and safe in patients with complex congenital heart disease.

Commotio Cordis and complete heart block: Where is the block level?☆

Ventricular fibrillation is typically the initial arrhythmia in commotio cordis following precordium impacts that occur within an electrically vulnerable period of the cardiac cycle. Conversely, complete heart block is very rare in this context, and its mechanism and temporal course are poorly understood. The presented case concerns a 12-year-old boy, athletic skier, who developed a transient complete heart block following commotio cordis. The electrocardiographic features, the proposed block level and mechanisms of complete heart block following commotio cordis are discussed.

Adenosine and Preexcitation Variants: Reappraisal of Electrocardiographic Changes

Intravenous adenosine is a short‐acting blocker of the atrioventricular node that has been used to unmask subtle or latent preexcitation, and also to enable catheter ablation in selected patients with absent or intermittent preexcitation. Depending on the accessory pathway characteristics, intravenous adenosine may produce specific electrocardiographic changes highly suggestive of the preexcitation variant. Herein, we view different ECG responses to this pharmacological test in various preexcitation patterns that were confirmed by electrophysiological studies. Careful analysis of electrocardiographic changes during adenosine test, with emphasis on P‐delta interval, preexcitation degree, and atrioventricular block, can be helpful to diagnose the preexcitation variant/pattern.