Search

Background: Myotonic dystrophy type 1 (DM1) is a multisystemic disorder characterized by progressive cardiac conduction impairment, arrhythmias, and sudden death. Mexiletine is a sodium channel blocker drug used by patients with DM1 for treatment of myotonia, even though definitive proof of its safety over long-term follow-up is lacking., Objective: The purpose of this study was to assess the impact of mexiletine for treatment of neurological symptoms on the composite endpoint of significant electrocardiogram modification (new onset or worsening of atrioventricular [AV] or intraventricular conduction delay) and bradyarrhythmic complications requiring pacemaker (PM) implantation (advanced AV block, symptomatic sinus pause >3 seconds)., Methods: This retrospective longitudinal study included a series of consecutive patients with genetically confirmed DM1 evaluated at our neurology and cardiology clinics from January 1, 2011, to January 1, 2020, who received mexiletine 200 mg twice daily. Patients with a PM, implantable cardioverter-defibrillator, or severe conduction abnormality (PQ interval ≥230 ms, complete bundle branch block, or atrial fibrillation) at enrollment were excluded., Results: The study comprised 18 mexiletine-treated patients and 68 mexiletine-free controls. Over median follow-up of 53 months, the endpoint was reached by 4 (22%) mexiletine-treated patients and 23 (33%) non-mexiletine-treated patients (log-rank P = .45). In 3 non-mexiletine-treated patients, bradyarrhythmic complications requiring PM implantation were observed. At univariable analysis, only the presence of mild conduction delay (first-degree AV block with PQ interval <230 ms or left anterior fascicular block) at baseline predicted the endpoint (hazard ratio 2.22; 95% confidence interval 1.04-4.76)., Conclusion: Mexiletine 200 mg twice daily is safe in patients with DM1 and no severe conduction abnormality., (Copyright © 2020 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Despite expanding indication of the subcutaneous implantable cardioverter defibrillator (S-ICD) in clinical practice, limited data exists on safety and efficacy of S-ICD in arrhythmogenic right ventricular cardiomyopathy (ARVC) patients. The aim of this multicenter study was to evaluate the safety and efficacy of S-ICD in ARVC patients., Methods: The study population included 44 consecutive patients with definite ARVC diagnosis according to the 2010 ITF criteria (57% male, mean age 37 ± 17 years [range 10-75 years]) who received an S-ICD. Eighteen (41%) patients were implanted for secondary prevention., Results: At implant, all inducible patients (34/44) had conversion of ventricular fibrillation at 65 J. No early complications occurred. During a median follow-up of 12 months (7-19), 3 (6.8%) patients experienced complications requiring surgical revision. No local or systemic device-related infections were observed. Six patients (14%) received a total of 61 appropriate and successful shocks on ventricular arrhythmias. Six (14%) patients experienced 8 inappropriate shocks for oversensing of cardiac signal (4 cases) and non-cardiac signal (4 cases) with one patient requiring device explantation. No patients had the device explanted due to the need for antitachycardia pacing., Conclusions: The study shows that S-ICD provides safe and effective therapy for termination of both induced and spontaneous malignant ventricular tachyarrhythmias with high energy shocks in ARVC patients, but the risk of inappropriate shocks and complications needing surgical revision should be considered., (Copyright © 2019. Published by Elsevier B.V.)

Background: The subcutaneous implantable cardioverter-defibrillator (S-ICD) does not require the insertion of any leads into the cardiovascular system., Objective: The aims of the study were to describe current practice and to measure outcomes associated with S-ICD or standard single-chamber transvenous ICD (TV-ICD) use after TV-ICD explantation., Methods: We analyzed all consecutive patients who underwent transvenous extraction of an ICD and subsequent implantation of an S-ICD or a single-chamber TV-ICD at 12 Italian centers from 2011 to 2017., Results: A total of 229 patients were extracted and subsequently reimplanted with an S-ICD (90; 39%) or a single-chamber TV-ICD (139; 61%). S-ICD implantation increased from 9% in 2011 to 85% in 2017 (P < .001). Patients reimplanted with an S-ICD were younger (53 ± 13 years vs 60 ± 18 years; P = .011) and more frequently had undergone extraction owing to infection (73% vs 52%; P < .001). The rates of complications at follow-up were comparable between groups (hazard ratio 0.97; 95% confidence interval 0.49-1.92; P = .940). No lead failures, systemic infections, or system-related deaths occurred in the S-ICD group. In the TV-ICD group, 1 lead fracture occurred and 2 systemic infections were reported, resulting in death in 1 case. In the S-ICD group, the rate of complications was lower when the generator was positioned in a sub- or intermuscular pocket (hazard ratio 0.21; 95% confidence interval 0.05-0.87; P = .048)., Conclusion: Our results show an increasing use of S-ICD over the years in patients undergoing TV-ICD explantation. An S-ICD is preferably adopted in young patients, mostly in the case of infection. The complication rate was comparable between groups and decreased when a sub- or intermuscular S-ICD generator position was adopted., (Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: The European Society of Cardiology (ESC) Guidelines published in 2016 modified indications for cardiac resynchronization therapy (CRT) in comparison with the 2013 ESC Guidelines. The aim of this analysis was to evaluate the impact of the stricter criteria suggested by the 2016 ESC Guidelines on patient outcome in a real-world population., Methods: We collected data on 930 consecutive patients with complete outcome information who had undergone CRT implantation from 2011 to 2013 from the CRT-MORE registry. Patients were classified according to 2013 (Reference) and 2016 (Current) ESC Guidelines. The primary end-point of the study was death from any cause and heart failure hospitalization., Results: According to the Reference Guidelines, 650 (69.9%) patients met Class I indications, 190 (20.4%) Class IIa, 39 (4.2%) Class IIb and 51 (5.5%) Class III. According to the Current Guidelines, 563 (60.5%) patients met Class I indications, 145 (15.6%) Class IIa, 108 (11.6%) Class IIb and 114 (12.3%) Class III. On comparing the Reference and Current Guidelines, the 538 patients who confirmed their Class I indication had a better outcome in terms of freedom from the combined end-point of heart failure (HF) hospitalization or death from any cause (hazard ratio (HR) of 0.64; 95% CI 0.42 to 0.99; p = 0.0436) when compared to the 112 patients who lost their class I indication (84 moved to class IIb and 28 moved to class III)., Conclusions: The stricter criteria for Class I CRT indication suggested by the 2016 ESC Guidelines excluded about 20% of patients with a worse prognosis., Clinical Trial Registration: CRT MORE: Cardiac Resynchronization Therapy Modular Registry URL: http://clinicaltrials.gov/Identifier:NCT01573091., (Copyright © 2018 Elsevier B.V. All rights reserved.)

Background: Professional guidelines are based on the best available evidence. However, patients treated in clinical practice may differ from those included in reference trials., Objective: The aim of this study was to evaluate the effects of cardiac resynchronization therapy (CRT) in a large population of patients implanted with a CRT device stratified in accordance with the 2016 European heart failure (HF) guidelines., Methods: We collected data on 930 consecutive patients from the Cardiac Resynchronization Therapy MOdular REgistry. The primary end point was a composite of death and HF hospitalization., Results: Five hundred sixty-three (60.5%) patients met class I indications, 145 (15.6%) class IIa, 108 (11.6%) class IIb, and 114 (12.3%) class III. After a median follow-up of 1001 days, 120 (14.7%) patients who had an indication to CRT had died and 71 (8.7%) had been hospitalized for HF. The time to the end point was longer in patients with a class I indication (hazard ratio 0.55; 95% confidence interval 0.39-0.76; P = .0001). After 12 months, left ventricular (LV) end-systolic volume had decreased by ≥15% in 61.5% (320/520) of patients whereas in 57.5% (389/676) of patients the absolute LV ejection fraction improvement was ≥5%. Adherence to class I was also associated with an absolute LV ejection fraction increase of >5% (P = .0142) and an LV end-systolic volume decrease of ≥15% (P = .0055)., Conclusion: In our population, ∼60% of patients underwent implantation according to the 2016 European HF guidelines class I indication. Adherence to class I was associated with a lower death and HF hospitalization rates and better LV reverse remodeling., (Copyright © 2018 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Despite the improvements in transvenous lead extraction (TLE), patients with cardiac implantable device related infection (CIEDI) have a poor prognosis at long term. We explored the possible role of factors associated with development of CIEDI as predictors of post-TLE survival., Methods: We performed a multi-center prospective observational study in a population of consecutive patients referred for TLE for CIEDI. We adopted a previously developed 10-point scale for CIEDI risk stratification and assessed its performance in predicting post-TLE survival., Results: We enrolled 169 consecutive patients with CIEDI (systemic infection in 48.5% and vegetations in 24.5%). A Shariff score ≥3 was present in 102/169 (60.4%) of the enrolled patients. Complete radiological success of TLE was obtained in 163 patients. Twenty-seven patients (15.9%) died after a mean follow-up of 20.8±12.0months. Two factors were independently associated with post-TLE death: a Shariff score ≥3 (HR 10.833, 95% CI 2.544-46.129; p=0.001) and the presence of vegetations at transesophageal echocardiography (HR 3.324, 95% CI 1.530-7.221; p=0.002)., Conclusions: Risk factors for development of CIEDI are also predictive of post TLE mortality, together with the presence of vegetations. Improvement of our preventive strategies for CIEDI is crucial for enhancing the outcomes of CIED patients overall., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Aims: Despite optimal oral anticoagulation with vitamin K antagonist, left atrial (LA) thrombus could be detected in the left appendage (LAA) in >2% of patients with atrial fibrillation (AF) and CHA 2 DS 2 -VASc score≥1 but few data are available for patients treated with non-vitamin K antagonist oral anticoagulants (NOACs). We evaluated the occurrence and predictors of LA thrombi by means of transesophageal echocardiography (TOE) in consecutive patients with non-valvular AF who received for at least 3weeks Apixaban, Dabigatran, or Rivaroxaban., Methods: This study included 414 consecutive patients (male 252, 60.6%, mean age 67.3years) referred to our Centers for catheter ablation of AF (n=220, 53.1%) or scheduled electrical cardioversion (n=194, 46.9%). Patients were on Dabigatran (n=160), Rivaroxaban (n=150) or Apixaban (n=104). TOE was performed in all cases within 12h prior to ablation or cardioversion., Results: Preprocedural TOE revealed LA thrombus in 15/414 patients (3.6%), all located in the LAA (Apixaban 3/104 2.9%, Dabigatran 5/160 3.1%, and Rivaroxaban 7/150 4.7%, p=0.69). Of these, 14 patients had persistent AF. Patients with LAA thrombus had a mean CHA 2 DS 2 -VASc score of 3 (3-4). Higher CHA 2 DS 2 -VASc score (p=0.02), but not the type of NOAC, significantly predicted the presence of LA thrombus., Conclusion: The incidence of LAA thrombus in a cohort of patients anticoagulated with NOACs is low but not negligible, in any case similar among the 3 drugs. Preprocedural TOE should be considered in patients with a CHA 2 DS 2 -VASc score>3., (Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.)

Background: Transesophageal echocardiography (TEE) is routinely performed before atrial fibrillation (AF) transcatheter ablation to exclude the presence of left atrial (LA) or LA appendage (LAA) thrombi. The aim of the study is to evaluate if easily accessible clinical parameters may relate to the presence of LA or LAA thrombi to identify patients who could potentially avoid TEE., Methods and Results: Between January 2012 and September 2014, data from 1539 consecutive patients undergoing TEE, as a work-up before AF transcatheter ablation, in six large volume centers were collected. Baseline clinical features, CHA 2 DS 2 -VASc score, transthoracic echocardiography and presence of thrombi at TEE were recorded. Exclusion criteria were valvular, hypertrophic or dilated cardiomyopathy, previous heart surgery or an ejection fraction ≤35%. Mean age was 59.6±10.4years, 1215 (78.9%) were males; 951 (62.9%) presented in sinus rhythm (SR) on admission, 324 (21.1%) had undergone at least one previous ablation and 900 (58.5%) had CHA 2 DS 2 -VASc score 0-1. Thrombi were encountered in 12 patients (0.8%). SR at TEE independently related to the absence of thrombi (OR 5.15, 95% CI 1.38-19.02, p=0.015); in addition to this, no patient with a CHA 2 DS 2 -VASc score 0-1 and SR on admission presented thrombi at TEE (specificity 100%, p=0.011)., Conclusion: In a selected population of patients referred for AF ablation, LA/LAA thrombi prevalence is low. No patients in SR with CHA 2 DS 2 -VASc score 0-1 presented LAA thrombi at TEE, identifying a significant subset of patients who could potentially safely be spared from pre-procedural TEE., (Copyright © 2017 Elsevier B.V. All rights reserved.)

Background: Randomized and controlled studies have reported the effect of catheter ablation (CA) for atrial fibrillation (AF) over a follow-up of 12-24 months., Objective: We report on the effect of CA plus antiarrhythmic drugs in comparison with antiarrhythmic drugs alone on the maintenance of sinus rhythm over 12-year follow-up., Methods: We extended the follow-up duration of the 137 patients who were enrolled in the Catheter Ablation for the Cure of Atrial Fibrillation Study between February 1, 2002, and June 30, 2003, and randomized to antiarrhythmic drugs (control group) or antiarrhythmic drugs plus CA (ablation group). The primary end point was time to first symptomatic or asymptomatic recurrence of atrial arrhythmia lasting >30 seconds during follow-up., Results: During follow-up, 19 of 68 (27.9%; 95% confidence interval [CI] 18.7%-39.6%) ablation group patients and 3 of 69 (4.3%; 95% CI 1.49%-12.0%) control group patients did not experience any relapse of atrial tachyarrhythmia (P < .001). The Kaplan-Meier analysis performed to determine the probability of survival free from atrial arrhythmias showed a statistical difference in favor of the ablation group (log-rank, P < .001). The effect of CA was consistent in both patients with paroxysmal AF and those with persistent AF. In the multivariate Cox regression analysis, belonging to the control group (hazard ratio 2.95; 95% CI 1.896-4.726; P < .001) and longer time since first AF episode (hazard ratio 1.004; 95% CI 1.002-1.084; P = .041) were predictors of atrial tachyarrhythmia recurrence., Conclusion: In patients with paroxysmal and persistent AF, CA significantly increased time to first recurrence of atrial arrhythmias during 12-year follow-up., (Copyright © 2016 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: The implantation strategy appears to play a pivotal role in determining response to cardiac resynchronization therapy (CRT)., Objective: The aim of our study was to determine the association between anatomic and electrical interlead distance and clinical outcome after CRT implantation., Methods: We included 216 first-time CRT recipients with left bundle branch block and sinus rhythm. On implantation, the electrical interlead distance (EID), defined as the time interval between spontaneous peak R waves detected at the right ventricular (RV) and left ventricular (LV) pacing sites, was measured. The anatomic distance between the RV and LV lead tips was determined on chest radiographs., Results: The mean EID was 74 ± 41 ms, and the mean horizontal corrected interlead distance (HCID) was 125 ± 73 mm. After 12 months, 87 patients (40%) displayed an improvement in their clinical composite score. The cutoff values that best predicted an improved clinical status were as follows: 84 ms for EID (area under the curve 0.59; confidence interval [CI] 0.52-0.66; P = .026) and 90 mm for HCID (area under the curve 0.62; CI 0.55-0.69; P = .004). On multivariate analysis, only EID >84 ms (hazard ratio 0.36; CI 0.14-0.89; P = .028) and HCID >90 mm (hazard ratio 0.45; CI 0.23-0.90; P = .025) were significantly associated with the composite endpoint of death or cardiovascular hospitalization. In particular, the presence of both conditions (EID <84 ms and HCID <90 mm) was associated with the highest rate of events (log-rank test P = .002)., Conclusions: The interlead anatomic and electrical distance are strongly and independently associated with patient outcome after CRT implantation. The 2 measures show an additive predictive value. (CRT MORE: Cardiac Resynchronization Therapy Modular Registry; www.clinicaltrials.gov, unique identifier: NCT01573091.), (Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: Permanent atrial pacing usually involves lead placement in the right atrial appendage (RAA). Anatomical studies addressing features predisposing to complications are scanty., Objective: To assess the morphology of RAA in the perspective of pacing, including the morphology of tenia sagittalis (TS) and the spatial relationship with the aorta., Methods: The gross anatomy of the RAA has been analyzed in a consecutive series of 100 hearts following a case of iatrogenic perforation of the aorta by active fixation lead located in the RAA. Transmural RAA sections were taken from 40 hearts to assess the wall thickness at the level of pectinate muscles (PMs) and of inter-PMs spaces and the distance between adjacent PMs., Results: The TS was present in 90% of cases (single trunk, 76%; double trunk, 13%; and triple trunk, 1%), demarcating the proximal antral RAA region (facing the adjacent aorta) from the distal saccular RAA region (facing the pulmonary infundibulum). The RAA free wall in the inter-PMs spaces is usually paper-thin and translucent. Histomorphometric analysis reveals that the RAA wall mean thickness was 1.38 ± 0.05 mm (range 0.64-4.25 mm) at the level of PMs and 0.39 ± 0.23 mm (range 0.09-1.05 mm) at the level of inter-PMs spaces. The mean distance between adjacent PMs was 0.88 ± 0.99 mm (range 0.04-4.12 mm)., Conclusion: In 90% of hearts, a well-defined TS separates the distal saccular from the proximal antral RAA, the latter being closely adjacent to the ascending aorta. The paper-thin wall between PMs is potentially at risk of perforation, and aortic injury could occur when active fixation leads are anchored in the antral RAA, as demonstrated in an iatrogenic fatal case., (Copyright © 2015 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: The aim of this study was to investigate the efficacy of catheter ablation in the treatment of persistent atrial fibrillation (AF) and the predictors of arrhythmia recurrence., Methods: Absence of atrial tachyarrhythmia (AT) recurrence during a mid-term follow-up was correlated with several clinical and procedural characteristics in a population of 82 patients aged 20-70 years who had experienced at least one documented relapse of persistent AF during a single trial of antiarrhythmic drug therapy. Electrophysiological success of ablation was declared when all identified PVs were isolated (confirmation of entry and exit block). Patients were followed for a maximum of 24 months after the blanking period with outpatient visits, ECG recordings, 24-hour Holter monitoring, and weekly transtelephonic monitoring for 30s., Results: Electrophysiological success was documented in 38/82 (46.3%) patients. During a mean follow-up of 24.7 ± 4.2 months, 69/82 (84.1%) patients presented at least one episode of AT after the 2 month blanking period. According to univariate and multivariate logistic regression analyses, only an electrophysiologically successful ablation significantly correlated with the absence of documented AT relapse (OR 5.32, 95% CL 1.02-27.72; p=.0472)., Conclusions: Mid-term outcome of a single procedure of catheter ablation without the adjunction of antiarrhythmic drug therapy is poor in patients with persistent AF. Documented PV isolation is useful to increase the success rate of circumferential PV ablation even in persistent AF patients., (Copyright © 2013. Published by Elsevier Ireland Ltd.)

Background: Phrenic nerve stimulation (PNS), occurring in 33%-37% of the patients with cardiac resynchronization therapy (CRT), is a limiting factor when implanting left ventricular (LV) leads from coronary veins., Objective: To test the hypothesis that PNS occurrence is related to bipolar electrode spacing., Methods: During standard CRT defibrillator implant procedures, a 5-F diagnostic electrophysiology catheter with 10 electrodes, spaced 2-5-2 mm, was positioned in a cardiac vein suitable for permanent LV lead placement. Pacing in the unipolar configuration identified the site with the lowest PNS threshold. PNS and left ventricular pacing (LVP) thresholds were then measured in different configurations at 0.5 ms: unipolar, each LV electrode served as the cathode in turn; and bipolar with different electrode spacing, cathode being the electrode with the lowest unipolar PNS threshold., Results: From February to September 2010, 40 patients undergoing CRT implantation were enrolled in 4 centers in Italy. It was possible to identify PNS and perform a complete set of measurements in 23 patients. A bipolar electrode spacing of 2 mm resulted in higher PNS thresholds in bipolar configurations han did a bipolar electrode spacing of ≥ 5 mm. However, no significant increase in the LVP threshold was observed (P = ns)., Conclusions: This experience suggests that LVP with a bipolar electrode spacing of 2 mm significantly increases the PNS threshold without affecting the LVP threshold, thereby increasing the possibility of delivering CRT when the LV lead is placed in proximity to the phrenic nerve., (Copyright © 2013 Heart Rhythm Society. Published by Elsevier Inc. All rights reserved.)

Background: The role of additional left atrial linear lesions performed during pulmonary vein isolation (PVI) to prevent atrial tachycardias (ATs) is not yet clear., Objective: To analyse successful ablation sites of late-onset post-PVI AT, and to understand whether additional ablation lines at mitral isthmus and left atrium (LA) roof could have been useful in preventing these jatrogenic ATs., Methods: From March, 2002 to August, 2008, 366 patients underwent PVI alone for drug-refractory atrial fibrillation (AF). Twenty-six (7.1%) of these patients developed late AT during follow-up, and were referred for ablation. Successful discrete ablation sites were analysed. In no patient the index AT was terminated by a linear lesion in mitral isthmus or LA roof., Results: Twenty-seven ATs were mapped; mean CL was 261 ± 71.6 ms. In 3/26 patients (11.5%), mapping was unsuccessful, while 23/26 (88.5%) patients underwent a successful procedure (24 AT morphologies in 23 patients - 3/24 were mapped as mitral isthmus, and 1/24, as LA roof-dependent AT). Among the 24 successfully mapped ATs, 17/24 (70.8%) displayed a macroreentrant activation and the remaining 7/24 (29.1%), a focal pattern. Finally, in 22/26 (84.6%) patients, ATs were no more inducible. At a mean f/u of 22.4 ± 12.2 months, 23/26 (88.4%) patients remained AT-free (antiarrhythmic drugs prescribed in 5/26, 19.2% patients for AF prevention)., Conclusions: In our case series, less than one-fifth of late-onset post-PVI ATs were mapped as mitral isthmus- or LA roof-dependent circuits., (Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.)

Background: Data on the procedural safety of pulmonary vein radiofrequency catheter ablation for atrial fibrillation (AF) are as yet scant., Objective: The aims of the present study were to prospectively evaluate the incidence of early complications of pulmonary vein ablation for AF in an unselected population of consecutive patients, and to identify possible predictors., Methods: From April 2005 to October 2006, data from 1,011 consecutive patients who were undergoing radiofrequency catheter ablation for every type of AF in 10 Italian centers were collected. All complications occurring from the admission of the patient up to the 30th day were considered., Results: No procedure-related death was observed. Complications occurred in 40 patients (3.9%): 12 (1.2%) had peripheral vascular complications, 8 (0.8%) had conservatively treated pericardial effusion, 6 (0.6%) had cardiac tamponade (successfully drained), 5 (0.5%) had cerebral embolisms, 4 (0.4%) presented pulmonary vein stenosis >50%, and 5 (0.5%) presented other isolated adverse events. History of coronary artery disease (odds ratio 5,603, 95% confidence interval 1,559 to 20,139, P < .008) characterized patients who presented with hemorrhagic complications., Conclusion: Early complications of pulmonary vein catheter ablation seem to be fewer than in the early years of AF ablation, but still occur in 3.9% of procedures.

Background: Little information is available on the natural history of patients with AVNRT. The purpose of this study was to compare the outcome of patients with Atrioventricular node reentrant tachycardia (AVNRT) who underwent ablation with those on antiarrhythmic therapy and those not receiving drugs., Methods: 93 consecutive patients (mean age=33.5+/-18.1 years) with AVNRT referred to our institution from 1988 to 1993 were prospectively followed-up for a mean of 13.2+/-2.0 years (range=11.4-16.1 years)., Results: 18 patients underwent ablation (group 1), 24 received antiarrhythmic therapy (group 2), 38 received no drugs or remained on drug therapy for only few months (group 3), 3 died and 10 were lost to follow-up. The frequency of symptoms at the baseline was higher in group 1 than in groups 2 and 3 (7.8+/-3.7, 3.5+/-2.3, 2.3+/-1.9 episodes/month, respectively; p<0.02 in group 1 vs. group 3). At the end of the follow-up 18/18 (100%) of group 1, 14/23 (61%) of group 2 and 17/38 of group 3 (44.7%) reported being asymptomatic for the previous 3 years. Group 3 patients who became asymptomatic had a shorter duration of symptoms before enrolment (3.7+/-1.5 vs. 7.1+/-3.6 years, p<0.05) and a shorter mean length of the tachycardia episodes (3.8+/-2.4 vs. 42.6+/-17.8 min, p<0.02) than patients from the same group who remained symptomatic., Conclusions: The main result of this study is that during a long-term follow-up a considerable number of untreated patients with AVNRT become asymptomatic. This finding should be considered for choosing treatment modality and for calculating healthcare costs of ablation vs. medical therapy.

While verapamil has been proposed as a treatment for reducing electrophysiological remodeling due to atrial fibrillation and atrial tachyarrhythmias, no previous study has tested its effects in brady-tachy patients implanted with a dual-chamber pacemaker. Fourteen patients with frequent episodes of atrial fibrillation (> or =2 episodes/month) in the setting of brady-tachy syndrome, implanted with a DDDR pacing system with extensive monitor function (Selection 900, Vitatron) were enrolled. Four months after implantation, they were randomly allocated to a 2-month period of treatment with verapamil (240 mg/day) or to no treatment, followed by a crossover. The burden of atrial tachyarrhythmias, the total number of hours spent in atrial tachyarrhythmia and the mean number of hours per day spent in atrial tachyarrhythmia were retrieved from diagnostic devices. The accuracy of atrial tachyarrhythmias detection was confirmed independently by two observers. The main results showed that treatment with verapamil was associated with a trend towards an higher percentage of atrial pacing in comparison with control (mean value+/-S.D.=63.2+/-29.9% vs. 57.3+/-30.6%, median value 53% vs. 49%, P value at Wilcoxon signed rank test=0.069), but without any significant reduction in atrial tachyarrhythmia burden (4.5+/-11.8 vs. 3.3+/-9.1%) or total hours spent in atrial tachyarrhythmia (65+/-161 vs. 48+/-131 h). Palpitation episodes were not significantly reduced by verapamil treatment in comparison with control (10.3+/-7.8 vs. 6.1+/-6.5). In conclusion, verapamil does not exert any beneficial effect on documented episodes of atrial tachyarrhythmia in patients with brady-tachy syndrome implanted with a DDDR device. Moreover, this drug was ineffective in reducing the number of palpitation episodes reported by the patient.

Background: The aim of this study was to correlate early atrial fibrillation (AF) relapses with heart rate variability (HRV) parameters immediately recorded after electrical cardioversion (EC) of persistent AF., Methods and Results: We performed the spectral analysis of short-term HRV 30 min after EC in 25 patients with persistent AF. The numbers of patients who maintained sinus rhythm at 48 h, 7, and 30 days were 22, 16, and 14, respectively. A very low low frequency/high frequency ratio (0.93+/-0.08 vs. 1.89+/-1.30; p<0.003) significantly identified patients with AF recurrence at 48 h in comparison to patients without AF recurrence. On the contrary, HRV parameters did not identify patients with AF recurrence at 7 or 30 days., Conclusions: AF relapsed within the first 48 h more frequently in patients who presented a predominant vagal tone immediately after the restoration of sinus rhythm.

The aim of this prospective, randomized study was to investigate the effect of pretreatment with two different intracellular calcium-lowering drugs (verapamil and metoprolol) on recovery from atrial effective refractory period (AERP) shortening after internal electrical cardioversion (EC) of persistent atrial fibrillation (AF) in patients on amiodarone. Twenty-one patients on amiodarone for at least 30 days were referred to our hospital for internal EC of a persistent AF refractory to external EC. They were randomized to receive only amiodarone (group AMI, n=7), or amiodarone and verapamil 240 mg/day (group VER, n=7), or amiodarone and metoprolol 100 mg/day (group MET, n=7). Left AERP was measured 10 min and 24 h after EC. AERP was also determined in 13 controls. The AERP after 10 min was significantly shorter in group AMI (201 (31) ms, P<0.02) and group MET (203 (34) ms, P<0.03) than in controls (249 (45) ms), but not in group VER (237 (51) ms, P=NS). The AERP after 24 h was still significantly shorter in group AMI (204 (38) ms, P<0.04) than in controls, but not in group MET (225 (52) ms, P=NS) or in group VER (290 (36) ms, P=NS). Pretreatment with amiodarone and verapamil prevents AERP shortening, while pretreatment with amiodarone and metoprolol only accelerated AERP recovery.

In order to evaluate the influence of aging on cardiovascular adaptations to endurance training and detraining, 12 young (range 19-25 years) and 12 older (range 50-65 years) male cyclists were examined during the training and after 2 months of detraining. Twelve young and 12 older healthy sedentary males matched for age and body surface area were used as control groups. Each subject underwent a maximal exercise test using a cycle-ergometer in order to measure maximum oxygen consumption, an M-mode and 2D echocardiography in order to assess left ventricle morphology and systolic function, and a Doppler echocardiography for evaluating the diastolic filling pattern. During the training period both groups of athletes showed higher values of maximum oxygen consumption, left ventricular wall thicknesses, end-diastolic diameter and volume, as well as left ventricular mass, than their control subjects; in the older subjects the adaptation of the heart to aerobic training seems to be obtained mainly through a higher increase in left ventricular diastolic filling. In both groups no significant modifications in the ejection fraction and diastolic function parameters were recorded. After the detraining period the wall thicknesses decreased only in young athletes, while left ventricular mass and end-diastolic diameter and volume reduced only in older athletes. In conclusion, training and detraining induced nearly similar left ventricular morphological modifications in the two age groups, even though greater in the older athletes with respect to the ventricular mass and volume. No relevant differences were observed in the Doppler filling pattern between athletes and sedentary controls.

This study was undertaken to assess if the introduction of new angioplasty devices (autoperfusion balloon catheters, stent and atherectomy) could ameliorate early and late results of prompt percutaneous transluminal coronary angioplasty (PTCA) in patients with refractory unstable angina. From January 1993 to June 1995, 59 of 278 patients (14 female, 45 male; mean age: 61 +/- 10 years; range: 38-78) admitted to our Coronary Care Unit with the diagnosis of unstable angina had more than one episode of chest pain at rest with dynamic electrocardiographic ST-T changes and without signs of cardiac necrosis while on medical therapy including oxygen, aspirin, heparin, nitroglycerin and either a beta-blocker or a calcium-antagonist. Coronary angiography was performed within 48 h from the last ischemic attack and a culprilesion technically suitable for PTCA was identified. PTCA was performed in 73 lesions. Elective stent implantation was considered for 16 type B or C lesions in 14 patients. The procedure was initially successful in 52/59 patients (88%), uncomplicated unsuccessful in 4/59 (7%) and complicated in 3/59 (5%). Elective stent insertions were all successful (16/16, 100%). All successfully treated patients were followed up for a mean of 12 +/- 7 months (range: 6-27): 2/52 patients (3.8%) suffered from non-transmural myocardial infarction, 14/52 (26.9%) had a recurrence of angina and 2/52 (3.8%), asymptomatic, had a positive stress test. We conclude that prompt PTCA in refractory unstable angina using 1990s 'state of the art' equipment compares favorably to previous study and that stent delivery might become the elective treatment of complex lesions in this subset of patients.