Carlo Ceriotti

Mapping of Ventricular Repolarization Potentials in Patients With Arrhythmogenic Right Ventricular Dysplasia Principal Component Analysis of the ST-T Waves

BACKGROUND Nonuniform recovery of ventricular excitability has been demonstrated to facilitate the reentry circuits leading to the development of ventricular tachyarrhythmias. This can also occur in arrhythmogenic right ventricular dysplasia (ARVD). In fact, in patients with ARVD, abnormalities of ventricular repolarization are often observed on 12-lead ECGs, but their predictive value for the occurrence of malignant arrhythmias is yet to be established. Because body-surface potential mapping has been proved to be useful for the detection of heterogeneities in ventricular recovery even though they are not revealed by conventional 12-lead ECGs, we attempted to analyze repolarization potentials on the entire chest surface to find abnormalities that can be predictive of ventricular arrhythmias. METHODS AND RESULTS Body-surface potential maps were recorded from 62 anterior and posterior thoracic leads in 22 patients affected by ARVD, 9 with episodes of sustained ventricular tachycardias (VT) and 13 without. Thirty-five healthy subjects were also studied as control subjects. The 62 chest ECGs were simultaneously recorded, digitally converted at a rate of 2000 Hz, and stored on a hard disk of a body-surface mapping computer system. In each subject, the QRST integral map was obtained by calculating at each lead point the algebraic sum of all instantaneous potentials, from the QRS onset to the T-wave end, multiplied by the sampling interval. In most ARVD patients, we observed a larger-than-normal area of negative values on the right anterior thorax. This abnormal pattern could be explained by a delayed repolarization of the right ventricle. Nevertheless, it was not related to the occurrence of VT in our patient population. To detect minor heterogeneities of ventricular repolarization, the principal component analysis was applied to the 62 ST-T waves recorded in each subject. We assumed that a low value of the first or of the first three components (components 1, 2, and 3) indicates a greater-than-normal variety of the ST-T waves, a likely expression of a more complex recovery process. The mean values of the first three components were not significantly different in ARVD patients and control subjects. Nevertheless, considering the two subsets of patients with and without VT, the values of component 1, components 1 + 2, and component 1 + 2 + 3 were significantly lower in the group of ARVD patients with VT. Values of component 1 < 69% (equal to 1 SD below the mean value for control subjects) were found in 6 of 9 VT patients and in 1 patient without VT (sensitivity, 67%; specificity, 92%). A low value of component 1 was the only variable significantly associated with the occurrence of VT. CONCLUSIONS Principal component analysis provides a better quantitative assessment of the complexity of repolarization than other ECG measurements. When applied to ARVD patients, principal component analysis of the ST-T waves recorded from the entire chest surface revealed abnormalities not detected by conventional ECG that can be considered indexes of arrhythmia vulnerability.

Remission of left ventricular systolic dysfunction and of heart failure symptoms after cardiac resynchronization therapy: temporal pattern and clinical predictors.

BACKGROUND The aim of the study was to determine whether cardiac resynchronization therapy (CRT) may induce a heart failure (HF) remission phase (recovery to New York Heart Association functional class I-II and regression of left ventricular [LV] dysfunction: LV ejection fraction [EF] > or = 50%) and to define the incidence and predictors of such a process. METHODS Cardiac resynchronization therapy devices were successfully implanted in 520 consecutive HF patients from 1999 to 2006 (mean age 66 years, 82% male sex, New York Heart Association class > or = II, LVEF 28%, QRS 164 milliseconds, 6-minute hall walk distance 302 m) at our institution. Follow-up data were prospectively collected every 3 to 6 months. Continuous variables were stratified in tertiles. RESULTS Over a median follow-up of 28 months, 26% of patients achieved LV remission (rate: 16 per 100 person-years). At univariate analysis, female sex (P = .032), non-coronary artery disease (CAD) etiology (P < .001), mitral regurgitation < 2/4 (P = .022), higher EF tertile (P < .001), lower diameter and volume tertiles (both P < .001), previous conventional right ventricle pacing (P = .029), and post-CRT-paced QRS (P = .008) predicted remission. At multivariate analysis, non-CAD etiology, LVEF 30% to 35%, and LV end-diastolic volume < 180 mL were strongly associated with HF remission phase (all P < .001). Concomitance of these 3 factors yielded a significantly higher remission rate compared with either no or only 1 factor (respectively, 60 vs 7 and 11 per 100 person-years, P < .001). CONCLUSIONS Cardiac resynchronization therapy induces HF remission phase in 26% of patients, even after 3 years. Non-CAD etiology and moderately compromised LV function at baseline may easily predict this process.

Cardiac resynchronization therapy in heart failure patients with atrial fibrillation.

Cardiac resynchronization therapy (CRT) is an important device-based, non-pharmacological approach that has shown, in large randomized trials, to improve left ventricular (LV) function and reduce both morbidity and mortality rates in selected patients affected by advanced heart failure (HF): New York Heart Association (NYHA) functional class III–IV, reduced LV systolic function with an ejection fraction (EF) ≤35%, QRS duration ≥120 ms, on optimal medical therapy, and who were in sinus rhythm. For the first time, the latest ESC and AHA/ACC/HRS Guidelines have considered atrial fibrillation (AF) patients, who constitute an important subgroup of HF patients, as eligible to receive CRT. Nevertheless, these Guidelines did not include a strategy for defining differentiated approaches according to AF duration or burden. In this review, the authors explain in which way AF may interfere with adequate CRT delivery, how to manage different AF burden, and finally present a brief overview on the effects of CRT in AF patients.

Longevity of implantable cardioverter-defibrillators for cardiac resynchronization therapy in current clinical practice: an analysis according to influencing factors, device generation, and manufacturer

Aims Device replacement at the time of battery depletion of implantable cardioverter-defibrillators (ICDs) may carry a considerable risk of complications and engenders costs for healthcare systems. Therefore, ICD device longevity is extremely important both from a clinical and economic standpoint. Cardiac resynchronization therapy defibrillators (CRT-D) battery longevity is shorter than ICDs. We determined the rate of replacements for battery depletion and we identified possible determinants of early depletion in a series of patients who had undergone implantation of CRT-D devices. Methods and results We retrieved data on 1726 consecutive CRT-D systems implanted from January 2008 to March 2010 in nine centres. Five years after a successful CRT-D implantation procedure, 46% of devices were replaced due to battery depletion. The time to device replacement for battery depletion differed considerably among currently available CRT-D systems from different manufacturers, with rates of batteries still in service at 5 years ranging from 52 to 88% (log-rank test, P < 0.001). Left ventricular lead output and unipolar pacing configuration were independent determinants of early depletion [hazard ratio (HR): 1.96; 95% 95% confidence interval (CI): 1.57–2.46; P < 0.001 and HR: 1.58, 95% CI: 1.25–2.01; P < 0.001, respectively]. The implantation of a recent-generation device (HR: 0.57; 95% CI: 0.45–0.72; P < 0.001), the battery chemistry and the CRT-D manufacturer (HR: 0.64; 95% CI: 0.47–0.89; P = 0.008) were additional factors associated with replacement for battery depletion. Conclusion The device longevity at 5 years was 54%. High left ventricular lead output and unipolar pacing configuration were associated with early battery depletion, while recent-generation CRT-Ds displayed better longevity. Significant differences emerged among currently available CRT-D systems from different manufacturers.

Huge left atrial thrombus after left atrial appendage occlusion with a Watchman device

The feasibility and safety of transcatheter left atrial appendage occlusion with the WatchmanTM Device (Atritech Inc., Plymouth, MN, USA) for stroke prevention in atrial fibrillation (AF) has recently been described. To our knowledge, a case of huge thrombus formation on the external surface of this device has not been described so far. A …

The importance of increased percentage of biventricular pacing to improve clinical outcomes in patients receiving cardiac resynchronization therapy.

Purpose of review To describe the growing evidence that a maximal biventricular pacing is needed to gain the maximal benefits from cardiac resynchronization therapy (CRT). Recent findings Even small gains in the biventricular (BIV) pacing percentage are clinically important both to prevent acute heart failure and, more importantly, to improve survival. Summary Every effort should be made in all patients receiving CRT to approach 100% BIV pacing by a correct device programming, a correct pharmacologic regimen and atrioventricular nodal ablation in atrial fibrillation patients.

Images in cardiovascular medicine. Hiccups and dysphonic metallic voice: a unique presentation of Twiddler syndrome.

Twiddler syndrome refers to a rare complication observed in patients with implanted pacemakers or defibrillators that causes device malfunction. The condition arises as a result of the patient’s conscious or unconscious manipulation of the device, causing its rotation in the pocket, resulting in torsion and dislodgment of the implanted lead(s). A 65-year-old obese woman with idiopathic dilated cardiomyopathy and diabetes mellitus had undergone implantation of a biventricular implantable cardioverter-defibrillator (CRT-D, Medtronic Insync Maximo 7304) with the positioning of 3 leads: a passive bipolar lead in the auricula of the right atrium (Medtronic Capsure Z Novus 5554), a bipolar, single-coil, screw-in lead (Medtronic Sprint 6931) in the apex of the right ventricle (RV), and a unipolar left-ventricular (LV) pacing lead (Medtronic Attain 4193) in an anterolateral tributary of the coronary sinus. Approximately 1 month after implantation, the patient presented to the emergency room with effort …Twiddler syndrome refers to a rare complication observed in patients with implanted pacemakers or defibrillators that causes device malfunction. The condition arises as a result of the patient’s conscious or unconscious manipulation of the device, causing its rotation in the pocket, resulting in torsion and dislodgment of the implanted lead(s). A 65-year-old obese woman with idiopathic dilated cardiomyopathy and diabetes mellitus had undergone implantation of a biventricular implantable cardioverter-defibrillator (CRT-D, Medtronic Insync Maximo 7304) with the positioning of 3 leads: a passive bipolar lead in the auricula of the right atrium (Medtronic Capsure Z Novus 5554), a bipolar, single-coil, screw-in lead (Medtronic Sprint 6931) in the apex of the right ventricle (RV), and a unipolar left-ventricular (LV) pacing lead (Medtronic Attain 4193) in an anterolateral tributary of the coronary sinus. Approximately 1 month after implantation, the patient presented to the emergency room with effort …

The values of defibrillation testing at implantable cardioverter defibrillator implantation: 'and then there were none'.

Purpose of review Since its advent, implantable cardioverter defibrillator (ICD) intra-operative defibrillation testing (DFT) has been a standard practice to confirm its optimal configuration. However, due to advances in device and lead technology, which now facilitate successful device implantation, and due to growing number of ICD primary prevention patients, the need for DFT has recently been questioned. The purpose of this review is to summarize the pro and contra DFT arguments, according to benefits, risk and clinical relevance, trying to identify the candidates for whom DFT is really indicated. Recent findings There is an ongoing debate on the need for DFT at ICD implant due to significant DFT-related complications; recently, many electrophysiologists have chosen not to perform DFT in many cases. Recent literature findings document large differences of practice between different centres and countries. In particular, there has been major debate and concern over performing DFT in patients with heart failure, indicated for CRT-D implants (cardiac resynchronization therapy with defibrillator). Summary Due to the potential for serious complications during DFT and expanding primary prevention ICD candidates, we agree with the growing tendency not to routinely perform DFT at implant, as the risks may overweigh the benefits.

Hiccups and Dysphonic Metallic Voice A Unique Presentation of Twiddler Syndrome

Twiddler syndrome refers to a rare complication observed in patients with implanted pacemakers or defibrillators that causes device malfunction. The condition arises as a result of the patient’s conscious or unconscious manipulation of the device, causing its rotation in the pocket, resulting in torsion and dislodgment of the implanted lead(s). A 65-year-old obese woman with idiopathic dilated cardiomyopathy and diabetes mellitus had undergone implantation of a biventricular implantable cardioverter-defibrillator (CRT-D, Medtronic Insync Maximo 7304) with the positioning of 3 leads: a passive bipolar lead in the auricula of the right atrium (Medtronic Capsure Z Novus 5554), a bipolar, single-coil, screw-in lead (Medtronic Sprint 6931) in the apex of the right ventricle (RV), and a unipolar left-ventricular (LV) pacing lead (Medtronic Attain 4193) in an anterolateral tributary of the coronary sinus. Approximately 1 month after implantation, the patient presented to the emergency room with effort …Twiddler syndrome refers to a rare complication observed in patients with implanted pacemakers or defibrillators that causes device malfunction. The condition arises as a result of the patient’s conscious or unconscious manipulation of the device, causing its rotation in the pocket, resulting in torsion and dislodgment of the implanted lead(s). A 65-year-old obese woman with idiopathic dilated cardiomyopathy and diabetes mellitus had undergone implantation of a biventricular implantable cardioverter-defibrillator (CRT-D, Medtronic Insync Maximo 7304) with the positioning of 3 leads: a passive bipolar lead in the auricula of the right atrium (Medtronic Capsure Z Novus 5554), a bipolar, single-coil, screw-in lead (Medtronic Sprint 6931) in the apex of the right ventricle (RV), and a unipolar left-ventricular (LV) pacing lead (Medtronic Attain 4193) in an anterolateral tributary of the coronary sinus. Approximately 1 month after implantation, the patient presented to the emergency room with effort …

The economic impact of battery longevity in implantable cardioverter-defibrillators for cardiac resynchronization therapy: the hospital and healthcare system perspectives

Abstract Aims Patients receiving cardiac resynchronization therapy defibrillators (CRT-Ds) are likely to undergo one or more device replacements, mainly for battery depletion. We assessed the economic impact of battery depletion on the overall cost of CRT-D treatment from the perspectives of the healthcare system and the hospital. We also compared devices of different generations and from different manufacturers in terms of therapy cost. Methods and results We analysed data on 1792 CRT-Ds implanted in 1399 patients in 9 Italian centres. We calculated the replacement probability and the total therapy cost over 6 years, stratified by device generation and manufacturer. Public tariffs from diagnosis-related groups were used together with device prices and hospitalization costs. Generators were from 3 manufacturers: Boston Scientific (667, 37%), Medtronic (973, 54%), and St Jude Medical (152, 9%). The replacement probability at 6 years was 83 and 68% for earlier- and recent-generation devices, respectively. The need for replacement increased total therapy costs by more than 50% over the initial implantation cost for hospitals and by more than 30% for healthcare system. The improved longevity of recent-generation CRT-Ds reduced the therapy cost by ∼6% in both perspectives. Among recent-generation CRT-Ds, the replacement probability of devices from different manufacturers ranged from 12 to 70%. Consequently, the maximum difference in therapy cost between manufacturers was 40% for hospitals and 19% for the healthcare system. Conclusions Differences in CRT-D longevity strongly affect the overall therapy cost. While the use of recent-generation devices has reduced the cost, significant differences exist among currently available systems.