A Patient With Asymptomatic Cerebral Lesions During AF Ablation: How Much Should We Worry?

Silent brain lesions due to thrombogenicity of the procedure represent recognized side effects of atrial fibrillation (AF) catheter ablation. Embolic risk is higher if anticoagulation is inadequate and recent studies suggest that uninterrupted anticoagulation, ACT levels above 300 seconds and administration of a pre-transeptal bolus of heparin might significantly reduce the incidence of silent cerebral ischemia (SCI) to 2%. Asymptomatic new lesions during AF ablation should suggest worse neuropsychological outcome as a result of the association between silent cerebral infarcts and increased long-term risk of dementia in non-ablated AF patients. However, the available data are discordant. To date, no study has definitely linked post-operative asymptomatic cerebral events to a decline in neuropsychological performance. Larger volumes of cerebral lesions have been associated with cognitive decline but are uncommon findings acutely in post-ablation AF patients. Of note, the majority of acute lesions have a small or medium size and often regress at a medium-term follow-up. Successful AF ablation has the potential to reduce the risk of larger SCI that may be considered as part of the natural course of AF. Although the long-term implications of SCI remain unclear, it is conceivable that strategies to reduce the risk of SCI may be beneficial.

Sudden Death After Transcatheter Aortic Valve Implantation. Are Bradyarrhythmias Always The Cause?

Transcatheter Aortic-Valve Implantation (TAVI) is considered to be highly effective in the treatment of high-risk patients with severe aortic stenosis. After TAVI, the rate of pacemaker implantation is 6.5%-40%. Some reports of sudden death after TAVI are mostly attributed to bradyarrhythmias. We report the case of three patients who experienced sudden cardiac death or aborted sudden cardiac death after TAVI. All patients were affected from ischemic heart disease with an ejection fraction of approximately 40% and underwent pacemaker implantation (PM) after the procedure due to 1rst degree atrioventricular block (AV) and left bundle branch block (LBBB). One of the patients died suddenly 30 days after the procedure. The PM interrogation revealed many episodes of non sustain ventricular tachycardias (NSVT) and one episode of ventricular fibrillation (VF) that led to death. The other two patients had syncope and during PM interrogation episodes of ventricular tachycardia >12 sec were recorded. Patients affected by ischemic heart disease undergoing TAVI, especially with borderline coronary lesions should receive particular attention in order to avoid potentially lethal ventricular arrhythmias. In addition, the physiopathologic mechanism of sudden arrhythmic death in these patients needs to be clarified.

Improved implant and postoperative lead performance in CRT-D patients implanted with a quadripolar left ventricular lead. A 6-month follow-up analysis from a multicenter prospective comparative study.

PURPOSE: Small single-center comparative studies suggest improved outcomes in cardiac resynchronization therapy (CRT) patients implanted with a quadripolar left ventricular (LV) lead in comparison with non-quadripolar (bipolar) leads. This study represents the first large multicenter prospective registry comparing implant and 6-month postoperative lead performance following CRT-defibrillator (CRT-D) implantation with quadripolar vs. bipolar leads. METHODS: During a 39-month period, 418 consecutive patients having CRT-D implantation attempts with either a quadripolar (n = 230) or bipolar LV lead (n = 188) were enrolled in the registry. The primary outcome of the study was LV lead failure defined as any abnormality, excluding infection, resulting in surgical lead revision or CRT termination. Additionally, operative and follow-up data were analyzed for significant difference between groups. RESULTS: Baseline characteristics of both groups were similar. In 72.9 % of quadripolar leads versus 65.0 % of bipolar leads, the LV lead successfully engaged the predefined ideal target side branch (p = 0.47). Implant duration and fluoroscopy times were significantly shorter when a quadripolar lead was used (p = 0.007 and p = 0.001, respectively). The primary end point occurred in six patients (2.7 %) in the quadripolar group and in 14 patients (8.0 %) in the bipolar group (p = 0.02). Clinically significant phrenic nerve stimulation (PNS) occurred in 4.6 vs. 14.2 % of quadripolar vs. bipolar patients, respectively (p = 0.002); all PNS were resolved noninvasively through programming in the quadripolar group vs. 84 % in bipolar group (p = 0.75). The use of a bipolar lead was associated with a higher risk of surgical LV lead revision (6.3 vs. 2.3 %; p = 0.057) and a higher incidence of dislodgment (5.7 vs. 2.7 %; p = 0.16). CONCLUSIONS: This multicenter study demonstrates that the use of a quadripolar LV lead results in significantly lower rates of lead-related problems and reduced procedural and fluoroscopic times for biventricular system implantation. This has important implications for LV pacing lead choice.

Device monitoring of heart failure in cardiac resynchronization therapy device recipients: a single-center experience with a novel multivector impedance monitoring system.

OBJECTIVES: We investigated the performance of a new intrathoracic multivector impedance monitoring system for the prediction of heart failure events in consecutive device-implanted patients. METHODS: Eighty heart failure patients implanted with biventricular defibrillators with multivector impedance monitoring capability were prospectively enrolled. Clinical heart failure status and impedance data were assessed during follow-up and if patients presented with an alert or heart failure deterioration. RESULTS: During follow-up (8.0 ± 4.4 months), 56 events of device alert for fluid index increase were identified in 29 patients, and a total of 39 heart failure events (defined by worsening of heart failure signs and symptoms) occurred in 23 patients. The sensitivity and positive predictive value (PPV) for heart failure deterioration was 61.5 and 42.9%, respectively. False-positive alerts occurred in 23 of 80 patients (28.8%), for an episode rate of 0.60 a year. Among all clinical heart failure events, decompensation caused hospitalization in 13 cases (33.3%), seven of them were preceded by an alert condition (53.8%) resulting in a sensitivity of 53.8% and a PPV of 17.9%. CONCLUSION: The present study confirms the feasibility and clinical usefulness of this novel multivector impedance monitoring system. It would be worthwhile to perform larger studies to assess its actual clinical value in heart failure patients.

First clinical experience with the new four-pole standard connector for high-voltage ICD leads. Early results of a multicenter comparison with conventional implant outcomes.

PURPOSE: A new four-pole connector system (DF-4) for transvenous high-voltage implantable cardioverter defibrillators (ICD) is currently available in clinical practice. However, no clinical data demonstrating the safety and effectiveness of this complex electromechanical design is available. This study aims to test the safety and effectiveness of this newly designed system compared to the conventional DF-1 leads. METHODS: During a 3-year period, 351 consecutive patients were implanted with DF-4 leads as part of an ICD or ICD-cardiac resynchronization therapy system. Patients were matched for age, sex, and follow-up with 154 patients implanted with a standard DF-1 lead. The primary outcome of the study was defibrillation lead failure, defined as the need for lead removal or capping. Operative, electrical, and safety data were obtained at implant and during postoperative follow-up. RESULTS: Implantation success rate in both groups was 100 %. A trend towards shorter procedure time was observed in the DF-4 group but the difference did not reach statistical significance. Handling characteristics of the DF-4 leads were graded better than those of DF-1 models. During a total follow-up of 8,130.5 lead-months, there were nine ICD-lead failures (four system erosion/infections and five electrical lead dysfunctions). The overall incidence of electrical lead failure was 0.64 vs. 0.97 per 100 lead-years, for DF-4 and DF-1 leads, respectively (P = 0.2). CONCLUSIONS: This multi-center experience provides strong evidence that the feasibility and safety of this novel technology compare favorably with those of the conventional DF-1 leads.

A novel methodology for AV and VV delay optimization in CRT: results from a randomized pilot clinical trial.

The aim of this work was to determine whether the use of a newly developed methodology (Alg1) for AV and VV optimization improves cardiac resynchronization therapy (CRT) clinical and echocardiographic (ECHO) outcomes. In this single-center pilot clinical trial, 80 consecutive patients (79 % male; 70.1 ± 11.2 years) receiving CRT were randomly assigned to AV and VV optimization using Alg1 (group A) or standard commercial procedures (group B). Clinical status and ECHOs were analyzed at baseline (_0) , 3 (fu1), and 6 months (fu2) of follow-up evaluating left ventricular end systolic (LVESV) and end diastolic (LVEDV) volumes, ejection fraction (EF), Minnesota test, and 6-min walk test (6MWT). Alg1 is based on a cardiovascular model fed with patient data. Baseline characteristics did not differ significantly between groups. Group A had a better clinical outcome and reverse remodeling. Remodeling was calculated as the difference (Δ) between fu1 and _0 and between fu2 and fu1, respectively: [LVESV (ml): ΔA_fu1 = -55.3, ΔB_fu1 = -13.5, p_fu1 = 0.002; ΔA_fu2 = -22.8, ΔB_fu2 = 3.0, p_fu2 = 0.04], [LVEDV (ml): ΔA_fu1 = -61.9, ΔB_fu1 = -16.1, p_fu1 = 0.01; ΔA_fu2 = -30.4, ΔB_fu2 = 11.3, p_fu2 = 0.02]; Minnesota test: total (p_fu1 = 0.01; p_fu2 = 0.04), physical (p_fu1 = 0.01; p_fu2 = 0.03) and emotional scores (p_fu1 = 0.04; p_fu2 = 0.03) and in 6MWT (m) (p_fu2 = 0.008). No statistically significant difference was observed in QRS width. Compared with current standard of care, CRT optimization using Alg1 is associated with better outcomes, showing the power of a tailored CRT.

Work burden with remote monitoring of implantable cardioverter defibrillator: is it time for reimbursement policies?

AIMS: The efficacy and accuracy, as well as patients' satisfaction, of device remote monitoring are well demonstrated. However, the workload of remote monitoring management has not been estimated and reimbursement schemes are currently unavailable in most European countries. This study evaluates the workload associated with remote monitoring systems. METHODS: A total of 154 consecutive implantable cardioverter defibrillator patients (age 66±12 years; 86.5% men) with a remote monitoring system were enrolled. Data on the clinician's workload required for the management of the patients were analyzed. RESULTS: A total of 1744 transmissions were received during a mean follow-up of 15.3±12.4 months. Median number of transmissions per patient was 11.3. There were 993 event-free transmissions, whereas 638 transmissions regarded one or more events (113 missed transmissions, 141 atrial events, 132 ventricular episodes, 299 heart failure-related transmissions, 14 transmissions regarding lead malfunction and 164 transmissions related to other events). In 402 cases telephonic contact was necessary, whereas in 68 cases an in-clinic visit was necessary and in 23 of them an in-clinic visit was prompted by the manufacturer due to technical issues of the transmitter. During follow-up, 316 work hours were required to manage the enrolled patients. Each month, a total of 14.9 h were spent on the remote monitoring of 154 patients (9.7 h for 100 patients monthly) with approximately 1.1±0.15 h per year for each patient. CONCLUSION: The clinician's work burden is high in patients with remote monitoring. In order to expand remote monitoring in all patients, reimbursement policies should be considered.

Clinical and procedural outcome of patients implanted with a quadripolar left ventricular lead: early results of a prospective multicenter study.

BACKGROUND: Recent studies suggest that cardiac resynchronization therapy (CRT) with a quadripolar left ventricular (LV) lead results in low rates of dislocation and phrenic nerve stimulation (PNS) acutely and at short-term follow-up. Confirmation of these results by long-term observational studies is needed. OBJECTIVE: To evaluate the long-term procedural and clinical outcomes of CRT patients implanted with a quadripolar LV lead. METHODS: A total of 154 consecutive heart failure patients (79% men, age 68 ± 10 years) having CRT implantation attempts with a quadripolar LV lead were included in this observational registry. Demographic and clinical data were preoperatively collected, and patients were followed up for at least 6 months. RESULTS: The overall implant success rate after coronary sinus cannulation was 97.4%. Mean overall duration and fluoroscopy time of successful procedures was 112 ± 22 and 16 ± 8 minutes, respectively, while 17 ± 13 minutes were necessary for the LV lead placement. After implant, the conventional bipolar configuration was used as the final pacing configuration in 33.3% of the patients. Four lead dislodgments (requiring reoperation) and 9 clinical PNS were reported during follow-up; reprogramming of the device was sufficient to prevent PNS in all patients. Once placed, the LV lead remained stable with excellent pacing thresholds during follow-up (15 ± 5 months). Overall, there were 71.3% CRT responders as assessed by 6-month echocardiography, and 66% improved at least 1 New York Heart Association class. CONCLUSION: Over the longer term, CRT with the quadripolar LV lead is associated with excellent pacing thresholds, low rates of dislocations, and PNS.

Impact of continuous intracardiac ST-segment monitoring on mid-term outcomes of ICD-implanted patients with coronary artery disease. Early results of a prospective comparison with conventional ICD outcomes.

BACKGROUND: Although myocardial ischaemia monitored by some implantable cardioverter-defibrillators (ICDs) might improve patient care, the clinical usefulness of this technology has not yet been validated. OBJECTIVE: To investigate the potential impact of ICD-based ischaemia monitoring on clinical care and patient management of ICD recipients. DESIGN: Prospective, controlled, non-randomised study. SETTING: Single-centre, university hospital. PATIENTS: Consecutive patients with known coronary artery disease, followed up for at least 6 months. INTERVENTIONS: Patients implanted with either an ICD providing continuous intracardiac ST monitoring (n=53; ST group) or with an ICD without this capability (n=50). MAIN OUTCOME MEASURES: Major cardiovascular events, appropriateness of ST-shift episodes and unscheduled device-related visits. RESULTS: During follow-up (15.4±8.4 months), one patient experienced ST-shift events confirmed by angiography to be related to myocardial ischaemia. Myocardial infarction was a rare event and occurred in one patient (ST group) who had an ST-elevation myocardial infarction 3 weeks after the implant, but at this time the algorithm had not yet been activated. In the ST group, seven patients had one or more episodes of false-positive ST events (median 9, range 1-90). The programmable features of the device helped overcome the problem in six patients. Among patients with a remote monitoring system, unscheduled outpatient visits were significantly increased in the ST group (17 vs 4; p=0.032). CONCLUSIONS: Although, this study was underpowered by the small number of acute ischaemic events, ICD-based ST monitoring failed to provide a benefit over ICDs without this capability and increased unscheduled evaluations in patients with remote follow-up. The sensitivity and specificity of the algorithm still require validation.

An increased endothelial-independent vasodilation is the hallmark of the neurally mediated syncope.

BACKGROUND: The neurally mediated syncope (NMS) is sustained by complex cardiac and vascular reflexes, acting on and amplified by central autonomic loops, resulting in bradycardia and hypotension. HYPOTHESIS: Our aim was to assess whether the pathophysiology of NMS is also related to an abnormal peripheral vasoreactivity. METHODS: We evaluated by ultrasound the flow-mediated vasodilation (FMD) and the nitrate-mediated dilation (NMD) in 17 patients with NMS, induced by drug-free tilt test in 6 subjects and by nitrate-potentiated tilt test in the other 11 cases; the syncope was classified as vasodepressive (VD) in 8 cases, cardioinhibitory (CI) in 7, and mixed in 2. RESULTS: The FMD was not different from controls (10.2 ± 4.5 vs 11.4 ± 3.9, P = ns), with normal recovery times; the NMD was greater in fainting subjects than in controls (26.7 ± 7.3 vs 19.0 ± 3.6, P < 0.05), with higher values in VD than in CI syncope (31.1 ± 7.0 vs 23.1 ± 5.0, P = ns); compared to controls, subjects with NMS showed normal recovery times after FMD but longer recovery times after nitrate administration (13.0 ± 5.6 vs 6.3 ± 0.7 minutes, P < 0.05). CONCLUSIONS: The evaluation of endothelial function supports evidence that NMS is characterized by a marked and sustained endothelial-independent vasodilation, in the presence of a normal FMD; vascular hyperreactivity in response to nitrate administration is particularly overt in vasodepressive syncope and can explain the high rate of responses to nitrate administration during tilt test.

Early detection of chronic myocardial ischemia in a patient implanted with an ICD capable of intracardiac electrogram monitoring.

Although myocardial ischemia monitored by some implantable cardioverter-defibrillators has the potential to improve patient care, no clinical experience with this novel technology has been described yet. We report for the first time ischemic intracardiac ST changes detected in a patient with coronary artery disease.

Predictive value of fragmented QRS in primary prevention implantable cardioverter defibrillator recipients with left ventricular dysfunction.

INTRODUCTION: In primary prevention implantable cardioverter defibrillator (ICD) patients, the incidence of appropriate ICD therapy is relatively low, prompting better risk stratification. Fragmented QRS (fQRS) on a 12-lead ECG has been associated with adverse outcomes. The aim of this study was to evaluate the prognostic value of fQRS in ICD recipients. METHODS: Consecutive ICD patients implanted at our institution for primary prevention of sudden cardiac death (SCD) were retrospectively evaluated. Patients were divided in two groups based on the presence or the absence of fQRS on the ECG obtained before ICD implantation. The endpoint of the study was all-cause mortality or the occurrence of any appropriate ICD-delivered therapy, whether shock or antitachycardia pacing. RESULTS: Among 394 ICD recipients (334 men, age 66.4  ±  11.0), fQRS was observed in 103 patients (26.1%). There were 189 patients (48.0%) with wide QRS at the time of implantation. Among these patients, fQRS was found in 29 individuals (28.2%). Patients in fQRS(+) group were more likely to have coronary artery disease and a lower QRS duration than those without fQRS. During a mean follow-up of 26.3  ±  17.5 months, mortality or ICD therapy were 19.4 and 22.4%, respectively, for fQRS(+) patients, and 15.2 and 22.8% for fQRS(-) patients (P = NS). By Kaplan-Meier analysis, event-free survival was similar in the two groups. CONCLUSION: In ICD recipients for primary prevention of SCD, fQRS is not helpful in selecting a subgroup of patients who benefit from prophylactic ICD implantation.

Partners in crime in the setting of recurring cardiac arrest.

No previous reports are available about the potential dramatic effects resulting from the combination of acquired long QT interval not associated to bradycardia and myocardial ischemia. We report the case of a man that during acute necrotic pancreatitis presented QT interval prolongation without bradycardia, TdP, and two episodes of cardiac arrest. A coronary angiogram revealed a subocclusive stenosis of left anterior descending coronary artery, treated with a percutaneous coronary intervention. After myocardial revascularization, even in presence of long QT interval, no arrhythmic events occurred suggesting the key role of myocardial ischemia in triggering TdP in acquired long QT even without bradycardia. ECG performed six months later, after complete recovery from pancreatitis, showed a normal QT interval.

Left ventricular pacing with a new quadripolar transvenous lead for CRT: early results of a prospective comparison with conventional implant outcomes.

BACKGROUND: Flexible left ventricular (LV) pacing configurations are a useful component of cardiac resynchronization therapy (CRT) systems for preventing high LV pacing thresholds and phrenic nerve stimulation (PNS). A quadripolar LV lead has recently been designed with the purpose of allowing more choices in lead placement location and programming capability. OBJECTIVE: To verify the effectiveness of quadripolar LV leads compared to conventional bipolar LV leads implant outcomes. METHODS: Forty-five consecutive patients underwent implantation with either the quadripolar (n = 22; quadripolar group) or a conventional bipolar LV lead (n = 23; bipolar group). The primary outcome of the study was LV lead failure, defined as the need for lead revision or reprogramming during the first 3 months after implantation. Additionally, operative and follow-up data were prospectively noted and checked for significance between groups. RESULTS: The implantation success rate in both groups was 100%. Baseline characteristics, procedure duration, and fluoroscopy time did not differ significantly between groups. Two lead dislodgments (requiring reoperation) and 4 clinical PNS were reported in the bipolar group; reprogramming of the device was sufficient to prevent PNS in 3 patients, the fourth is pending solution. One PNS successfully managed noninvasively occurred in the quadripolar group. By Kaplan-Meier analysis, event-free survival for the combined primary outcome was significantly lower in patients with quadripolar leads (P = .037). CONCLUSION: This prospective, controlled study provides strong evidence that CRT with the quadripolar LV lead results in low rates of dislocations and phrenic nerve stimulation.

Safety and efficacy of a new magnetic resonance imaging-compatible pacing system: early results of a prospective comparison with conventional dual-chamber implant outcomes.

BACKGROUND: A new pacing system has been designed and tested preclinically for safe use in the magnetic resonance imaging (MRI) environment. Experience with this innovative system has not yet been reported. OBJECTIVE: The purpose of this study was to verify the safety and effectiveness of this newly designed system compared to conventional DDD implant outcomes. METHODS: Over an 11-month period, 107 consecutive patients (71 men and 36 women; age 72.6 +/- 8.5 years) were implanted with either the MRI system (n = 50; MRI group) or a dual-chamber, active-fixation lead (Medtronic 4076) non-MRI system (n = 57; DDD group). Data were collected at implant and during postoperative follow-up at 1, 3, 6, and 12 months. Procedural and fluoroscopic times at implant, as well as lead measurements, handling characteristics, and procedural-related complications, were prospectively analyzed. RESULTS: The implantation success rate in both groups was 100%. Cephalic access was 63% for MRI patients and 70% for DDD patients (P = NS). Follow-up was obtained for all patients (median 6.8 months, range 3-12 months). At implant and at the end of follow-up, stimulation thresholds, sensing, and impedance were acceptable. No cases of high pacing thresholds or inadequate sensing were noted. No complications occurred, and no patient experienced subsequent lead displacement. CONCLUSION: This prospective, controlled study provides strong evidence that the feasibility and safety of this novel technology compare favorably with those of the conventional technique.

Transthoracic versus transesophageal cardioversion of atrial fibrillation under light sedation: a prospective randomized trial.

BACKGROUND: Electrical cardioversion (ECV) of atrial fibrillation (AF) is limited by a 5-10% failure rate and by the expense arising from a perceived need for general anesthesia. A transesophageal approach using light sedation has been proposed as a means of augmenting the success rate and avoiding the need for general anesthesia. We hypothesized that the high rate of success and the lower energy requirement associated with biphasic cardioversion might eliminate any advantage of the transesophageal approach. METHODS: We randomly assigned 60 patients attending for ECV of persistent AF to a transesophageal or a transthoracic approach. Sedation of moderate depth was achieved with intravenous midazolam. The dose of midazolam was titrated in the same manner in both groups. RESULTS: Sinus rhythm was restored in 29/30 patients (97%) in each group using a similar number of shocks for both groups (1.3 +/- 0.6 transesophageal vs 1.4 +/- 0.7 transthoracic, P = NS) with a similar procedure duration (14.1 +/- 8.2 minutes vs 13.8 +/- 7.5 minutes, P = NS). Both groups received similar doses of midazolam (4.2 +/- 2.7 mg vs 4.4 +/- 2.8 mg, P = NS) and both reported a similar discomfort score in (0.9 +/- 1.3 vs 1.1 +/- 1.8, P = NS). No complication occurred in either group. CONCLUSION: AF may be cardioverted safely and effectively by either a transthoracic or a transesophageal approach. The use of sedation of moderate depth renders cardioversion by either approach acceptable. As transesophageal ECV shows no clear advantage, transthoracic cardioversion should remain the approach of first choice.

Outpatient oesophageal-precordial electrical cardioversion of atrial fibrillation: an effective and safe technique to restore sinus rhythm.

OBJECTIVE: External electrical cardioversion is commonly used in the management of atrial fibrillation (AF), but usually involves general anaesthesia. We tested the efficacy, safety and tolerability of a minimally invasive cardioversion technique, not requiring general anaesthesia, performed on an outpatient basis. METHODS: We performed outpatient oesophageal cardioversion in 87 consecutive patients (mean age: 67.5 +/- 9.6 years; weight: 77.47 +/- 12.34 kg; left atrium diameter: 46.25 +/- 6.85 mm; LVEF: 55.5 +/- 16%) with persistent AF (mean duration: 6.99 +/- 11.55 months). A biphasic shock was delivered via an oesophageal decapolar lead (cathode) and two precordial patches (anode) under a mild sedation (midazolam 2.5-5 mg). In the first 25 patients, a step-up protocol (from 10 to 100 J) was performed whereas, in the other 62, a first shock at 50 J and a second one at 100 J, were delivered. RESULTS: Patients described the level of discomfort caused by the procedure according a five-grade scale. Cardioversion was achieved in 97.7% of patients using a mean effective energy of 51.2 +/- 15.7 J. In 88.5% of patients, sinus rhythm was restored by using 50 J or less. No complications occurred and no patient required hospital admission. Mean discomfort score was 1.56 +/- 0.74 out of 5. Sinus rhythm persisted in 62.6% of patients at the 1-month follow-up. CONCLUSIONS: Outpatient oesophageal cardioversion is a safe, acceptable and effective way to cardiovert patients with AF. It may be a useful alternative to external cardioversion. A relatively high starting energy (50 J) was demonstrated to be superior to a low-energy step-up technique.