Pacing maneuvers from the aortic cusps: A useful technique during ablation of focal arrhythmias arising from the aortic root.

BACKGROUND: The ablation of arrhythmias arising near the His-bundle region in the non-coronary aortic cusp (NCAC) is challenging. Among the aortic sinuses of Valsalva, the NCAC is located between the right atrium and the left atrium. For this reason, pacing from the NCAC should result in atrial capture while pacing from the right and left coronary cusps (LCC) may result in ventricular capture. The objective of this study is to prove that atrial capture during pacing from the sinuses of Valsalva may be used to confirm a correct position in the non-coronary cusp. METHODS: A total of 30 patients with structurally normal heart undergoing left sided ablation procedures, underwent electrophysiological study of the aortic cusps. Each of the aortic valve cusps was paced with increasing outputs and analyzed offline to determine their unique electrocardiographic characteristics. RESULTS: In the NCAC, we obtained an atrial capture in 29 out of 30 patients (96.6%). The atrial capture was highly specific for a position in the NCAC (p < .001). The median output required to capture from the cusp was 10 mA (range 5-25 mA) at a pulse width of 2 ms. In the right coronary cusp (RCC) and LCC, we obtained ventricular capture in all patients (100%). The median output required to capture from the cusp was 10 mA (range 10-25 mA) in RCC and 25 mA (range 10-25 mA) in LCC at a pulse width of 2 ms. CONCLUSIONS: Atrial capture during a pacemapping from the aortic cusps can be considered proof of a correct position in NCAC.

Prognostic Role of Myocardial Edema as Evidenced by Early Cardiac Magnetic Resonance in Survivors of Out-of-Hospital Cardiac Arrest: A Multicenter Study.

Background Sudden cardiac arrest (SCA) may be caused by an acute and reversible myocardial injury, a chronic and irreversible myocardial damage, or a primary ventricular arrhythmia. Cardiac magnetic resonance imaging may identify myocardial edema (ME), which denotes acute and reversible myocardial damage. We evaluated the arrhythmic outcome of SCA survivors during follow-up and tested the prognostic role of ME. Methods and Results We included a consecutive series of 101 (71% men, median age 47 years) SCA survivors from 9 collaborative centers who underwent early (<1 month) cardiac magnetic resonance imaging and received an implantable cardioverter-defibrillator (ICD). On T2-weighted sequences, ME was found in 18 of 101 (18%) patients. According to cardiac magnetic resonance imaging findings, the arrhythmic SCA was ascribed to acute myocardial injury (either ischemic [n=10] or inflammatory [n=8]), to chronic structural heart diseases (ischemic heart disease [n=11], cardiomyopathy [n=20], or other [n=23]), or to primarily arrhythmic syndrome (n=29). During a follow-up of 47 months (28 to 67 months), 24 of 101 (24%) patients received an appropriate ICD intervention. ME was associated with a significantly higher survival free from both any ICD interventions (log-rank=0.04) and ICD shocks (log-rank=0.03) and remained an independent predictor of better arrhythmic outcome after adjustment for left ventricular ejection fraction and late gadolinium enhancement. The risk of appropriate ICD intervention was unrelated to the type of underlying heart disease. Conclusions ME on early cardiac magnetic resonance imaging, which denotes an acute and transient arrhythmogenic substrate, predicted a favorable long-term arrhythmic outcome of SCA survivors. These findings may have a substantial impact on future guidelines on the management of SCA survivors.

Oral procainamide as pharmacological treatment of recurrent and refractory ventricular tachyarrhythmias: A single-center experience.

BACKGROUND: Antiarrhythmic therapy for recurrent ventricular arrhythmias in patients who have undergone catheter ablation, and in whom amiodarone and/or beta-blockers were ineffective or contraindicated, is a controversial issue. OBJECTIVE: The present study sought to evaluate the efficacy and tolerability of oral procainamide in patients with recurrent ventricular arrhythmias when the standard therapy strategy had failed. METHODS: All patients treated with procainamide for recurrent ventricular tachycardia (VT) or ventricular fibrillation (VF) in our institution between January 2010 and May 2019 were enrolled. The primary endpoint was the total number of implantable cardioverter-defibrillator (ICD) interventions after the beginning of procainamide therapy. Secondary endpoints were the total number of VTs and VFs recorded on the ICDs' controls and discontinuation of therapy. The events occurring during procainamide treatment were compared with a matched-duration period before the initiation of therapy with procainamide. Patients therefore served as self-controls. RESULTS: A total of 34 consecutive patients (32 male, 94.1%; mean age 74.4 ± 9.7 years) were included in the retrospective analysis. The mean time of procainamide treatment was 12.9 ± 13.7 months (median 9 [2-20] months). The mean dose of procainamide was 1207 ± 487 mg/day. Procainamide therapy significantly decreased ICD interventions (median 5 [0-22.5] vs 15.5 [3-32.25], P < .05). Procainamide also decreased the total number of VT/VF episodes (median 5.5 [0.75-30] vs 19 [7.5-30], P < .05). Only 3 patients (8.8%) presented severe side effects (dyspnea or hypotension), requiring discontinuation of therapy. CONCLUSION: Oral procainamide was associated with a significant decrease in ICD therapies and ventricular arrhythmias, showing an acceptable profile of tolerability.

Relation of Prolonged Pacemaker Dependency After Cardiac Surgery to Mortality.

Permanent pacemaker implantation (PPI) represents a rare complication after cardiac surgery, with no uniform agreement on timing and no information on follow-up. A multicenter retrospective study was designed to assess pacemaker dependency (PMD) and long-term mortality after cardiac surgery procedures. Between 2004 and 2016, PPI-patients from 18 centers were followed. Time-to-event data were evaluated with semiparametric regression Cox models and semiparametric Fine and Gray model for competing risk framework. Of 859 (0.90%) PPI-patients, 30% were pacemaker independent (PMI) at 6 months. PMD showed higher mortality compared with PMI (10-year survival 80.1% ± 2.6% and 92.2% +2.4%, respectively, log-rank p-value < 0.001) with an unadjusted hazard ratio for death of 0.36 (95% CI 0.20 to 0.65, p< 0.001 favoring PMI) and an adjusted hazard ratio of 0.19 (95% CI 0.08 to 0.45, p< 0.001 with PMD as reference). Crude cumulative incidence function of restored PMI rhythm at follow-up at 6 months, 1 year and 12 years were 30.5% (95% CI 27.3% to 33.7%), 33.7% (95% CI 30.4% to 36.9%) and 37.2% (95% CI 33.8% to 40.6%) respectively. PMI was favored by preoperative sinus rhythm with normal conduction (SR) (HR 2.37, 95% CI 1.65 to 3.40, p< 0.001), whereas coronary artery bypass grafting and aortic valve replacement were independently associated with PMD (HR 0.63, 95% CI 0.45 to 0.88, p = 0.006 and HR 0.807, 95% CI 0.65 to 0.99, p = 0.047 respectively). Time-to-implantation was not associated with increased rate of PMI. Although 30% of PPI-patients are PMI after 6 months, PMD is associated with higher mortality at long term.

Catheter ablation of arrhythmias in some European countries: Toy or tool?

In the last decades, catheter ablation of arrhythmias is rapidly evolving in Europe. Despite the high number of procedures performed, in some European countries, both the organization of the electrophysiology labs and the training of clinical electrophysiologists are still not completely effective and not in line with the standard recommendations of National Electrophysiology Societies. For these reasons, it is probably desirable for arrhythmia sections to become independent units in order to assure high quality and safety standards.

Unpredictable Fall of Severe Emergent Cardiovascular Diseases Hospital Admissions During the COVID-19 Pandemic: Experience of a Single Large Center in Northern Italy.

Background Northern Italy is one of the epicenters of severe acute respiratory syndrome coronavirus 2 (SARS-CoV 2) pandemic in Europe. The impact of the pandemic and the consequent lockdown on medical emergencies other than those SARS-CoV 2 pandemic related is largely unknown. The aim of this study was to analyze the epidemiologic impact of coronavirus disease 2019 pandemic on hospital admission for severe emergent cardiovascular diseases (SECDs) in a single Northern Italy large tertiary referral center. Methods and Results We quantified SECDs admissions to the Cardiology Division of Udine University Hospital between March 1, 2020 and March 31, 2020 and compared them with those of the same time frame during 2019. Compared with March 2019, we observed a significant reduction in all SECDs admissions: -30% for ST-segment-elevation acute coronary syndromes, -66% for non-ST-segment-elevation acute coronary syndromes and -50% for severe bradyarrhythmia. Conclusions A significant decrease in all SECDs admissions has been observed during the SARS-CoV 2. pandemic and was unlikely caused by a reduction in the incidence of cardiovascular diseases. Fear of contagion may have contributed to the unpredictable drop of SECDs. Social education about early recognition of symptoms of life-threatening cardiac conditions requiring appropriate care in a timely fashion may help to reduce this counterproductive phenomenon.

Prognostic role of non-sustained ventricular tachycardia detected with remote interrogation in a pacemaker population.

BACKGROUND: Non-sustained ventricular tachycardia (NSVT) can occur asymptomatically and can be incidentally detected in the internal records of pacemakers (PM). The clinical value of NSVT in the population of PM patients is still uncertain.Our aim was to assess the prevalence of NSVT detected by remote PM control, to describe the clinical and demographic characteristics of patients with NSVT, and to assess the prognostic significance of NSVT in terms of both overall and cardiovascular mortality. METHODS: Consecutive patients followed with PM remote interrogations from September 2010 to December 2015 were included. The transmissions pertaining to the first 12 months of remote control were analysed and the patients were divided by those presenting NSVT and those without NSVT. The two groups were compared in terms of total mortality and cardiovascular mortality based on the administrative data provided by the regional administration of the Italian National Health System. RESULTS: The prevalence of NSVT in 408 patients (62% males, mean age 75.6; SD 10.6 years old) was 21% in a year. During a mean follow-up duration of 44 months, NSVT did not emerge as independently associated with overall mortality, but was associated with cardiovascular mortality in a competing risk regression model with older age, male gender, diabetes, chronic renal insufficiency, ischemic cardiomyopathy and chronic obstructive pulmonary disease. CONCLUSIONS: We show that NSVT episodes recorded by remote control in a PM population are independently associated with cardiovascular mortality with possible implications for risk stratification and therapeutic options.

Management of untreatable ventricular arrhythmias during pharmacologic challenges with sodium channel blockers for suspected Brugada syndrome.

Pharmacologic challenge with sodium channel blockers is part of the diagnostic workout in patients with suspected Brugada syndrome. The test is overall considered safe but both ajmaline and flecainide detain well known pro-arrhythmic properties. Moreover, the treatment of patients with life-threatening arrhythmias during these diagnostic procedures is not well defined. Current consensus guidelines suggest to adopt cautious protocols interrupting the sodium channel blockers as soon as any ECG alteration appears. Nevertheless, the risk of life-threatening arrhythmias persists, even adopting a safe and cautious protocol and in absence of major arrhythmic risk factors. The authors revise the main published case studies of sodium channel blockers challenge in adults and in children, and summarize three cases of untreatable ventricular arrhythmias discussing their management. In particular, the role of advanced cardiopulmonary resuscitation with extra-corporeal membrane oxygenation is stressed as it can reveal to be the only reliable lifesaving facility in prolonged cardiac arrest.

Comparison of strategies for catheter ablation of focal atrial tachycardia originating near the His bundle region.

BACKGROUND: Recent studies have suggested that para-Hisian atrial tachycardia (AT) can be successfully ablated from the right atrium (RA), left atrium (LA), or noncoronary cusp (NCC) in the aorta; however, the best approach remains unclear. OBJECTIVE: This study aimed to compare different approaches to radiofrequency catheter ablation (RFCA) of para-Hisian AT. METHODS: We retrospectively analyzed 68 consecutive patients (49[72%] women; mean age 61 ± 13 years) treated with RFCA for this type of AT. Mapping of the RA (n = 68), LA (n = 21), and NCC (n = 52) was performed during AT to identify the earliest activation site and to apply RFCA. RESULTS: RFCA successfully terminated AT in the RA in 13 of 28 patients (46.4%), in the LA in 4 of 16 patients (25.0%), and in the NCC in 46 of 52 patients (88.5%) after 1 procedure (P < .05). Atrioventricular block occurred only during RFCA in the RA in 4 of 28 patients (14.3%). After a mean follow-up of 33.5 ± 25.4 months, AT recurrence was observed in 5 of 13 patients (38.5%) ablated in the RA, 1 of 4 (25.0%) ablated in the LA, and 2 of 46 (4.4%) ablated in the NCC (P < .05). RFCA in the LA was effective only if the local activation time (LAT) was earlier than that in the RA. RFCA in the NCC was successful regardless of the LAT (P < .05). CONCLUSION: Mapping and ablation in the NCC should be always considered in cases of AT originating from the His bundle region, regardless of the LAT.

Efficacy and Safety of Catheter Ablation of Atrial Tachycardia Through a Direct Approach from Noncoronary Sinus of Valsalva.

Noncoronary aortic cusp (NCAC) in the aorta represents a challenging location for catheter ablation of focal atrial tachycardias (ATs) arising near the His-bundle region. The purpose of this study was to provide an updated report on the methods, efficacy, and safety of catheter ablation of ATs originating from NCAC. The study population includes 23 patients (18 women [78%], mean age 65 ± 12 years) with highly symptomatic AT. The atrial mapping was performed during tachycardia to define the earliest atrial activation site. Electrophysiological mapping of the right atrium was initially performed, followed by aortic root mapping when earliest activation was recorded in the proximal electrode of the His-bundle catheter. A direct ablation approach from NCAC was used in every patient independently by the local activation time. Ablations were performed using a steerable 4-mm tip nonirrigated catheter in all patients. Radiofrequency energy resulted in the disappearance of arrhythmias in 22 of the 23 patients (95%). In all procedures, there were no complications. During a mean follow-up of 41 ± 25 months, no patient presented with a recurrence, except the 1 patient where the ablation was not effective. In conclusion, catheter ablation of para-hisian ATs through a direct approach from NCAC shows to be safe and effective after 1 procedure per patient.

Revolving thrombus within the left atrium at atrial fibrillation ablation.

A 68-year-old man was referred for pulmonary vein (PV) isolation. Access to the left atrium was obtained via a single transseptal puncture. A heparin bolus was given immediately after puncture. Angiography of the left PV was performed. After the contrast wash-out, a contrasted longitudinal thrombus was shown revolving within the left atrium for several seconds before being expelled through the mitral and aortic valves. It is common practice in these procedures to administer an intravenous bolus of heparin immediately after the transseptal puncture. However, heparin has latency to become effective, and this can result in thromboembolic events.

Prevalence and prognostic value of concealed structural abnormalities in patients with apparently idiopathic ventricular arrhythmias of left versus right ventricular origin: a magnetic resonance imaging study.

BACKGROUND: Routine diagnostic work-up occasionally does not identify any abnormality among patients with monomorphic ventricular arrhythmias (VAs) of left ventricular (LV) origin. Aim of this study was to investigate the value of cardiac MRI (cMRI) for the diagnostic work-up and prognostication of these patients. METHODS AND RESULTS: Forty-six consecutive patients (65% males; mean age, 44±15 years) with monomorphic VAs of LV origin and negative routine diagnostic work-up were included. Seventy-four consecutive patients (60% males; mean age, 40±17 years) with apparently idiopathic monomorphic VAs of right ventricular origin served as control group. Both groups underwent comprehensive cMRI study and were followed-up for a median of 14 months (25th-75th percentiles, 7-37 months). The outcome event was an arrhythmic composite end point of sudden cardiac death or nonfatal episode of ventricular fibrillation or sustained ventricular tachycardia requiring external cardioversion or appropriate implantable cardioverter defibrillator therapy. The 2 groups of patients did not differ in age (P=0.14) and sex (P=0.57). No significant difference was observed between patients with VAs of LV origin and VAs of right ventricular origin about biventricular volumes and systolic function. cMRI demonstrated myocardial structural abnormalities in 19 (41%) patients with VAs of LV origin versus 4 (5%) patients with VAs of right ventricular origin (P<0.001). The outcome event occurred in 9 patients; myocardial structural abnormalities on cMRI were significantly related to the outcome event (hazard ratio, 41.6; 95% confidence interval, 5.2-225.0; P<0.001). CONCLUSIONS: Myocardial structural changes are detected by cMRI in a non-negligible proportion of patients with apparently idiopathic monomorphic VAs of LV origin and are associated with worse outcome.

Long-term independent predictors of positive response to cardiac resynchronization therapy.

AIMS: Cardiac resynchronization therapy (CRT) is currently considered an important breakthrough in the treatment of selected patients with refractory heart failure. However, long-term predictors of mortality, morbidity and time to recovery of ventricular function for those patients who respond positively to CRT remain poorly investigated. METHODS: This is a retrospective follow-up study involving one hospital. Between August 2004 and October 2008, 211 consecutive patients with refractory heart failure received a CRT device in the Cardiology Division of Ospedale Civile Maggiore in Verona. The clinical characteristics studied were age, sex, heart rhythm, left ventricular end-systolic volume/body surface area (LVESV/BSA), left ventricular ejection fraction, QRS duration, type of bundle-branch block, cause, New York Heart Failure Association functional class, pharmacological therapy and lead position. The objective of this study was to evaluate the effect of several baseline characteristics on long-term prognosis in heart failure patients treated with CRT. RESULTS: Nonischemic cause, left bundle-branch block and a basal LVESV/BSA of 106 ml/m or less were the only independent predictors of a positive response to CRT (P < 0.005). Additionally, a reduction in LVESV/BSA after CRT was associated both with increased survival and reduced rehospitalization for heart failure (P < 0.005). CONCLUSION: A better selection of patients on the basis of cause, type of bundle-branch block and basal LVESV/BSA can increase the number of patients that would benefit from CRT.

How many leads through persistent left superior vein cava and coronary sinus?

In the modern implanting era with progressive expanding indications to resynchronization therapy, upgrading procedure is a relatively common event. Persistent left superior vena cava (PLSVC), the most common venous abnormality, may exacerbate technical difficulties. We describe the procedure of upgrading from a dual chamber pacemaker to resynchronization/defibrillation system with a total of 4 leads through a PLSVC entering a dilated coronary sinus (CS) never described before. The case report, in addition to the description of a unique technical approach, raises a lot of clinical questions about how many leads we can introduce in such a venous structure and inside CS without hemodynamic impact on venous drainage potentially leading to life-threatening situations.

Myocardial infarction in a young patient with a previous history of repeated thrombophlebitis: combination of factor V Leiden and prothrombin G20210A gene polymorphisms with coronary artery disease.

We report a case of myocardial infarction at a young age in a person with a medical history of repeated thrombophlebitis, who was heterozygous for the prothrombin G20210A mutation and homozygous for factor V Leiden mutation. A coronary angiography revealed the presence of a moderate atherosclerotic plaque (60%) in the left anterior descending coronary artery, which gave rise to suspicion of a relationship between prothrombotic gene mutations and atherosclerosis. Genetic screening for inherited thrombophilia, especially in the presence of a strong familiarity or previous venous thrombosis, and the evaluation of atherosclerotic risk factors, may be critical information for primary prevention of arterial thrombosis.