Intracardiac echocardiography-guided pulsed-field ablation for successful ablation of atrial fibrillation: a propensity-matched analysis from a large nationwide multicenter experience.

BACKGROUND: Intracardiac echocardiography (ICE) is increasingly employed in atrial fibrillation (AF) ablation procedures, with the potential to enhance procedural efficacy. Nevertheless, there is currently a lack of evidence assessing the impact of ICE on the efficiency, effectiveness, and safety outcomes in the context of novel pulsed-field ablation (PFA) for AF. PURPOSE: We aimed to assess whether the use of ICE could improve procedural parameters in a large population undergoing AF ablation with FARAPULSE™ catheter. METHODS: Consecutive patients who had undergone PFA of AF from nine Italian centers were included. In procedures where the ICE catheter was employed for guidance (ICE-guided group), it was used to maneuver the PFA catheter within the left atrium to achieve optimal contact with atrial structures. RESULTS: We analyzed 556 patients: 357 (66%) with paroxysmal AF, 499 (89.7%) de novo PVI. ICE-guided procedures (n = 138) were propensity matched with patients with a standard approach (n = 138), and their outcomes were compared. During ICE-guided procedures, no improvement in procedural metrics was recorded (ICE vs Standard, 23 ± 6 min vs 18.5 ± 9 min for time to PVI, p < 0.0001; 38.8 ± 7 vs 32.5 ± 5 number of PFA deliveries to achieve PVI, p < 0.0001; 68.8 ± 19 min vs 71.8 ± 29 min for primary operator time, p = 0.5301; 16.1 ± 8 min vs 18.2 ± 10 min for fluoroscopy time, p = 0.5476) except for support time (76.8 ± 26 min vs 91.4 ± 37 min, p = 0.0046). No major procedure-related adverse events were reported. CONCLUSION: Our findings confirmed that PFA could be consistently performed in a rapid, safe, and efficacious manner. The use of ICE to guide PFA was not associated with an improvement in procedural metrics.

Focal atrial tachycardia arising from left superior pulmonary vein in a pediatric patient, safely treated by pulsed-field ablation.

INTRODUCTION: We describe the first case of the use of pulsed-field ablation (PFA) to treat focal atrial tachycardia (FAT) in a pediatric patient. METHODS: An 11-year-old girl with obesity was referred to our center for ablation of incessant atrial tachycardia. The earliest atrial activation was shown to be present in the left superior pulmonary vein. Radiofrequency ablation of FAT seems to be associated with a lower success rate and, especially, with a higher complication rate than in adult patients. RESULTS: We performed ablation by means of a novel nonthermal energy source (PFA) that is able to reduce the risk of complications due to injury to anatomic structures surrounding the heart. After the first application, stable sinus rhythm was restored. CONCLUSIONS: PFA can be used to treat FAT arising from pulmonary veins in young children as a good alternative to RFA ablation, thereby reducing the risk of potential procedure-related complications.

The PhysioVP-AF study, a randomized controlled trial to assess the clinical benefit of physiological ventricular pacing vs. managed ventricular pacing for persistent atrial fibrillation prevention in patients with prolonged atrioventricular conduction: design and rationale.

AIMS: In patients with prolonged atrioventricular (AV) conduction and pacemaker (PM) indication due to sinus node disease (SND) or intermittent AV-block who do not need continuous ventricular pacing (VP), it may be difficult to determine which strategy to adopt. Currently, the standard of care is to minimize unnecessary VP by specific VP avoidance (VPA) algorithms. The superiority of this strategy over standard DDD or DDD rate-responsive (DDD/DDDR) in improving clinical outcomes is controversial, probably owing to the prolongation of the atrialventricular conduction (PR interval) caused by the algorithms. Conduction system pacing (CSP) may offer the most physiological-VP approach, providing appropriate AV conduction and preventing pacing-induced dyssynchrony. METHODS AND RESULTS: PhysioVP-AF is a prospective, controlled, randomized, single-blind trial designed to determine whether atrial-synchronized conduction system pacing (DDD-CSP) is superior to standard DDD-VPA pacing in terms of 3-year reduction of persistent-AF occurrence. Cardiovascular hospitalization, quality-of-life, and safety will be evaluated. Patients with indication for permanent DDD pacing for SND or intermittent AV-block and prolonged AV conduction (PR interval > 180 ms) will be randomized (1:1 ratio) to DDD-VPA (VPA-algorithms ON, septal/apex position) or to DDD-CSP (His bundle or left bundle branch area pacing, AV-delay setting to control PR interval, VPA-algorithms OFF). Approximately 400 patients will be randomized in 24 months in 13 Italian centres. CONCLUSION: The PhysioVP-AF study will provide an essential contribution to patient management with prolonged AV conduction and PM indication for sinus nodal disease or paroxysmal 2nd-degree AV-block by determining whether CSP combined with a controlled PR interval is superior to standard management that minimizes unnecessary VP in terms of reducing clinical outcomes.

Network meta-analysis on patent foramen ovale: is a stroke or atrial fibrillation worse?

OBJECTIVE: Systematic reviews suggest that patent foramen ovale closure (PFOc) is performed percutaneously with low complication rates. We did a network meta-analysis (NMA) comparing devices for PFO closures, evaluating safety and efficacy of transcatheter PFOc in preventing neurological events in patients with stroke when compared with medical therapy (MT), and assessing risk of atrial fibrillation (AF). METHODS: We searched 3 databases (MEDLINE, EMBASE, CENTRAL/CCTR) identifying six randomized controlled trials from 2012 until December 2019. We performed a Bayesian NMA; number-needed-to-treat and number-needed-to-harm were derived by applying the estimated odds ratios (ORs). The likelihood of being helped or harmed (LHH) was evaluated to estimate the risk-effectiveness balance. RESULTS: The 3560 patients allocated to PFOc were less subject to a stroke than patients with MT. The overall ORs of PFOc versus MT were 0.41 with fixed-effects, and 0.22 with random-effects model. NMA proves that PFOc induces AF episodes significantly higher than MT, even when analysis is limited to only new episodes of "serious AF." LHH (0.68 fixed-effects, 0.79 random-effects) showed that strokes saved are less than cases of AFs added. By considering only serious AF, strokes saved are higher than serious AFs induced by the PFOc (LHH was 3.46 and 4.00 respectively). CONCLUSIONS: NMA supported PFOc in patients with cryptogenic stroke, confirming that devices are better than MT, but increase the risk of AF by over 2/4 times (serious or unserious AF). Considering serious AFs (real risky clinical condition), patients have more advantages in being treated, since LHH is ≥ 3-4.

The Closure of Patent Foramen Ovale in Preventing Subsequent Neurological Events: A Bayesian Network Meta-Analysis to Identify the Best Device.

BACKGROUND: Randomized-controlled trials (RCTs) reported a finding on the safety and efficacy of percutaneous patent foramen ovale (PFO) closure to prevent stroke recurrence. It showed that the Amplatzer (AMP) device appears to be superior to medical therapy (MT) in preventing strokes and episodes of atrial fibrillation (AF), than other devices. We performed a network meta-analysis (NMA) to evaluate the closure of PFO in preventing subsequent neurological events while investigating the results obtained by specific devices. METHODS: We searched 3 databases (MEDLINE, EMBASE, CENTRAL/CCTR) and identified 6 RCTs until March 2019. We performed an NMA and used pooled ORs. Analyses were done in NetMetaXL1.6-WinBUGS1.4. RESULTS: Six RCTs with 3,560 patients (mean age 45.2-46.2 years) were included in the present NMA. Depending on the device, 4 groups of patients were compared with MT: 1,889 patients undergoing PFO closure were significantly less likely to experience a stroke than 1,671 patients treated with MT (ORs 0.41; 95% Cr.I. 0.27-0.60 with fixed-effects model and ORs 0.22; 95% Cr.I. 0.05-0.70 with random-effects model). The patients with AMP showed a similar risk than those treated with Helex/Cardioform (HLX/CF) or with a group of 11 multiple devices. This suggests the equality between the 2 most currently used devices. When assessing TIA and, for the safety analysis, major bleeding, both models confirm no significant difference between any devices and MT. PFO closure increased the risk of new-onset AF: MT induces AF significantly less than all the devices. In favor of the AMP, there is a reduced number of cases of AF versus MT; however, no device superiority has been established in comparing HLX/CF and other devices in a random effect model. CONCLUSIONS: Our NMA provides evidence in favor of PFO closure with all the devices currently in use. We can conclude that these devices are better than MT, but not that 1 device is better than the rest in reducing stroke recurrences and AF episodes in the follow-up.

Predictors of Zero X-Ray Ablation for Supraventricular Tachycardias in a Nationwide Multicenter Experience.

BACKGROUND: This multicenter, prospective study evaluated the determinants of zero-fluoroscopy (ZFL) ablation of supraventricular tachycardias. METHODS AND RESULTS: Four hundred thirty patients (215 male, 55.4±22.1 years) with indication to electrophysiological study or ablation of supraventricular tachycardias were enrolled. All participating physicians agreed to follow the as low as reasonably achievable policy. A procedure was defined as ZFL when no fluoroscopy was used. The total fluoroscopy time inversely correlated to the number of procedures previously performed by each operator since study start (r=-0.112; P=0.02). Two hundred eighty-nine procedures (67.2%) were ZFL; multivariable analysis identified as predictors of ZFL: procedure after the 30th for each operator, compared with procedures up to the ninth (P=0.011; hazard ratio, 3.49; 95% confidence interval [CI], 1.79-6.80); the type of arrhythmia (P=0.031; electrophysiological study and atrioventricular nodal reentry tachycardia ablation having the highest probability of ZFL; hazard ratio, 6.87; 95% CI, 2.08-22.7 and hazard ratio, 2.02; 95% CI, 1.04-3.91, respectively); the operator's (P=0.002) and patient's age (P=0.009). Among operators, achievement of ZFL varied from 0% to 100%; 8 (22.8%) operators achieved ZFL in <25% of their procedures; 17 (48.6%) operators achieved ZFL in >75% of their procedures. The probability of ZFL increased by 2.8% (hazard ratio, 0.98; 95% CI, 0.97-0.99) as patient's age decreased by 1 year. Acute procedural success was obtained in all cases. CONCLUSIONS: The use of 3-dimensional mapping system completely avoided the use of fluoroscopy in most cases, with very low fluoroscopy time in the remaining and high safety and effectiveness profiles. Achievement of ZFL was predicted by the type of arrhythmia, operator's experience, and patient's age.

Multicentre comparison Of shock efficacy using single-vs. Dual-coil lead systems and Anodal vs. cathodaL polarITY defibrillation in patients undergoing transvenous cardioverter-defibrillator implantation. The MODALITY study.

PURPOSE: An optimal active-can lead configuration during implantable cardioverter defibrillator (ICD) placement is important to obtain an adequate defibrillation safety margin. The purpose of this multicenter study was to evaluate the rate of the first shock success at defibrillation testing according to the type of lead implant (single vs. dual coil) and shock polarity (cathodal and anodal) in a large series of consecutive patients who received transvenous ICDs. METHODS: This was a multicenter study enrolling 469 consecutive patients. Single- versus dual-coil leads and cathodal versus anodal polarity were evaluated at defibrillation testing. In all cases, the value of the energy for the first shock was set to 20 J less than the maximum energy deliverable from the device. RESULTS: A total of 469 patients underwent defibrillation testing: 158 (34 %) had dual-coil and 311 (66 %) had single-coil lead systems configuration, 254 (54 %) received anodal shock and 215 (46 %) received cathodal shock. In 35 (7.4 %) patients, the shock was unsuccessful. No significant differences in the outcome of defibrillation testing using single- versus dual-coil lead were observed but the multivariate analysis showed an increased risk of shock failure using cathodal shock polarity (OR 2.37, 95 % CI 1.12-5.03). CONCLUSIONS: Both single- and dual-coil transvenous ICD lead systems were associated with high rates of successful ICD implantation, and we found no significant differences in ventricular arrhythmias interruption between the two ICD lead systems configuration. Instead, anodal defibrillation was more likely to be successful than cathodal defibrillation.

Long-term complications related to biventricular defibrillator implantation: rate of surgical revisions and impact on survival: insights from the Italian Clinical Service Database.

BACKGROUND: Long-term data on device-related untoward events in patients receiving defibrillators for resynchronization therapy (CRT-D) are lacking. We quantified the frequency of repeat invasive procedures and the nature of long-term complications in current clinical practice and examined possible predictors of device-related events and their association with long-term patient outcome. METHODS AND RESULTS: We analyzed data from 3253 patients who underwent de novo successful implantation of CRT-D and were followed up for a median of 18 months (25th to 75th percentiles: 9 to 30) in 117 Italian centers. Device-related events were reported in 416 patients, and, specifically, surgical interventions for system revision were described in 390 patients. Four years after the implantation procedure, 50% of patients underwent surgical revision for battery depletion and 14% for unanticipated events. For comparison, at 4 years battery depletion occurred in 10% and 13% of patients who received single- and dual-chamber defibrillators at the study centers, and unanticipated events were reported as 4% and 9%, respectively. In CRT-D, infections occurred at a rate of 1.0%/y, and the risk of infections increased after device replacement procedures (hazard ratio, 2.04; 95% confidence interval, 1.01 to 4.09; P=0.045). Left ventricular lead dislodgements were reported at a rate of 2.3%/y and were predicted by longer fluoroscopy time and higher pacing threshold on implantation. Device-related events were not associated with a worse clinical outcome; indeed, the risk of death was similar in patients with and without surgical revision (hazard ratio, 0.90; 95% confidence interval, 0.56 to 1.47; P=0.682). CONCLUSIONS: In current clinical practice device-related events are more frequent in CRT-D than in single- or dual-chamber defibrillators, and are frequently managed by surgical intervention for system revision. However, a worse clinical outcome is not associated with these events. CLINICAL TRIAL REGISTRATION: URL: http://www.clinicaltrials.gov. Unique identifier: NCT01007474.

Primary percutaneous coronary intervention in 'early' latecomers with ST-segment elevation acute myocardial infarction: the role of the infarct-related artery status.

A high proportion of patients with ST-segment elevation myocardial infarction (STEMI) are evaluated more than 12 h after symptom onset. In this setting, current guidelines suggest that mechanical reperfusion should be considered for patients with clinical and/or electrocardiographic evidence of ongoing ischaemia, re-infarction, cardiogenic shock, haemodynamic instability, or documented ejection fraction less than 40% and serious ventricular arrhythmias. Moreover, some adjunctive aspects like the stuttering course of acute myocardial infarction, the chance of an existing coronary collateral circulation, the ischaemic preconditioning and the infarct-related artery patency should be taken into consideration for patients with STEMI presenting from 12 to 72 h after symptom onset. These patients are known as 'early' latecomers. The aim of the present review is to summarize the current knowledge of the pathophysiology related to this topic and to suggest some new indications for primary percutaneous coronary intervention in 'early' latecomers.

Physiopathologic correlates of intrathoracic impedance in chronic heart failure patients.

BACKGROUND: Increased plasma levels of amino-terminal fraction of brain natriuretic peptide (NT-proBNP) and alterations of diastolic filling as described by Doppler transmitral flow pattern are well-known markers of decompensated heart failure (HF). Recently, some implantable defibrillators have allowed monitoring of intrathoracic impedance, which is related to lung water content, potentially indicating HF deterioration. The aim of this study was to assess the correlation between intrathoracic impedance and NT-proBNP and echo-Doppler transmitral flow indexes. METHODS: Data were collected from 111 HF patients, in six Italian centers. All patients were on optimal medical therapy. Device diagnostics, echographic data, NT-proBNP determination, and clinical status as assessed by the Heart Failure Score (HFS) were registered at baseline, at bimonthly visits, and at unscheduled examinations due to HF decompensation or device alerts. RESULTS: Over a median follow-up of 413 days, 955 examinations were performed. Intrathoracic impedance was significantly correlated with NT-proBNP (P = 0.013) and with mitral E-wave deceleration time (DtE) (P = 0.017), but not with HFS. At the time of confirmed alert events, NT-proBNP was significantly higher than during confirmed nonalert event examinations; DtE did not differ, whereas impedance was significantly lower. CONCLUSION: A decrease in intrathoracic impedance is inversely correlated with NT-proBNP and directly correlated with DtE. Intrathoracic impedance monitoring therefore has the physiologic basis for being a useful tool to identify early HF decompensation.

Efficacy and safety of catheter ablation versus antiarrhythmic drugs for atrial fibrillation: a meta-analysis of randomized trials.

BACKGROUND: Atrial fibrillation is the most common arrhythmia in clinical practice. Its treatment is still widely debated due to the large variety of therapeutic options. Radiofrequency catheter ablation (RFCA) around pulmonary vein ostia and in the left atrium has been proposed as a technique to cure atrial fibrillation and is now performed with increasing success worldwide. However, few randomized controlled trials (RCTs) are available. Some of these have been published recently and are not yet included in meta-analyses. OBJECTIVES: We conducted a meta-analysis to summarize the current evidence base for the efficacy and safety of RFCA in patients with atrial fibrillation. METHODS: We searched electronic databases for relevant RCTs comparing RFCA with antiarrhythmic drugs for the management of atrial fibrillation. Recurrence of any atrial tachyarrhythmia (including atrial fibrillation, atrial flutter and atrial tachycardia) and rate of complications and adverse events were the end-points of the analysis. The results are reported as relative risk and 95% confidence interval, calculated using RevMan 5. RESULTS: A total of eight RCTs were identified including 844 patients. Overall, 98 (23.2%) of 421 patients in the treatment group and 324 (76.6%) of 423 patients in the control group had atrial tachyarrhythmia recurrence. RFCA decreased atrial tachyarrhythmia recurrence by 71% (relative risk 0.29, 95% confidence interval 0.20-0.41, P < 0.00001, with random effects model). Fewer complications and adverse events were reported in the ablation group compared with the control group (relative risk 0.72, 95% confidence interval 0.40-1.30, P = 0.28, with random effects model). CONCLUSION: In selected patients with atrial fibrillation, RFCA is a relatively effective and well-tolerated procedure to cure atrial fibrillation. Even though the results of our systematic review favour ablation therapy, large, well-designed RCTs are needed to confirm the efficacy and safety of RFCA for the management of atrial fibrillation.

Heart rate variability monitored by the implanted device predicts response to CRT and long-term clinical outcome in patients with advanced heart failure.

BACKGROUND: Few data exist on the long-term changes and the prognostic value of heart rate variability (HRV) assessed by implanted devices in heart failure (HF) patients treated with resynchronization therapy (CRT). AIMS: To analyze the long-term changes in the standard deviation of 5-minute median atrial-atrial sensed intervals (SDANN), and assess its role in predicting CRT efficacy and major cardiovascular events. METHODS AND RESULTS: We included 509 consecutive patients implanted with CRT devices. At 12-month follow-up, 44 patients had died and 86 patients had at least one HF hospitalisation. A significant increase in SDANN occurred after 4 weeks of CRT (from 69+/-22 ms to 82+/-27 ms, p<0.001). A further increase in SDANN was observed 6 months after implantation. Multivariable analysis identified SDANN as the sole predictor of major cardiovascular events (p=0.03) among several baseline parameters. SDANN< or =65 ms at the first week and SDANN< or =76 ms after 4 weeks of CRT yielded the best prediction of all-cause mortality and urgent heart transplantation on Kaplan-Meier analysis (log-rank test p=0.015 and p=0.011, respectively for week 1 and 4 values). Moreover, relative reduction in LVESV after CRT significantly correlated with SDANN at week 1 (r=-0.596, p=0.012), and week 4 (r=-0.703, p=0.001). CONCLUSIONS: Device-monitored HRV is a useful tool to identify, early after implantation, patients with a low likelihood of long-term benefits from CRT and at high risk for cardiovascular events.

Radiofrequency ablation of drug-refractory atrial fibrillation: an observational study comparing 'ablate and pace' with pulmonary vein isolation.

AIMS: To compare clinical characteristics, procedure complexity, acute and long-term outcome of 'ablate and pace' (A&P) with pulmonary vein isolation (PVI) in patients with drug-refractory atrial fibrillation (AF). So far, only few small studies have compared the two procedures. METHODS AND RESULTS: We analysed retrospectively a cohort of symptomatic consecutive patients with drug-refractory AF. Group 1 included 100 patients treated with A&P and Group 2 included 144 patients treated with PVI. Group 1 patients were older (74 +/- 8 vs. 56 +/- 9 years; P < 0.0001), had lower left ventricular ejection fraction (50 +/- 13% vs. 59 +/- 7%; P < 0.05), and a lower prevalence of paroxysmal AF (46% vs. 65%; P < 0.05). Acute success was not statistically different (98% vs. 92.3%, P = ns). Group 1 patients had shorter procedure time and lower radiation exposure with respect to Group 2 patients (70 +/- 15 vs. 204 +/- 58 min, and 8 +/- 4 vs. 57 +/- 22 min; P < 0.0001, respectively). After a median follow-up of 29 months (I, III quartile; 15, 40 months) vs. 25 months (I, III quartile; 8, 36 months) (P = ns), all the patients in Group 1 were free of symptomatic AF, while 113 patients (79%) of Group 2 were in stable sinus rhythm (P < 0.0001). Persistent or permanent AF has been documented in 58 patients (58%) of Group 1 vs. 11 (8%) of Group 2 (P < 0.0001). CONCLUSION: In this series (i) patients treated with A&P and PVI for drug-refractory AF showed significant differences in clinical profile; (ii) A&P is a shorter and less complex procedure, but is associated with a higher rate of persistent AF; (iii) symptomatic recurrences of paroxysmal AF were more frequent in PVI group. Randomized studies appear necessary to identify the best strategy in selected cases.

Acute haemodynamic effects of intra-aortic balloon pump and cardiac resynchronization therapy.

We report two cases in which intra-aortic balloon pump (IABP) was used successfully as a bridge to cardiac resynchronization therapy (CRT) to treat patients with refractory systolic heart failure. The study was designed to assess the acute haemodynamic effects of IABP coupled with CRT using standard haemodynamic monitoring. In both cases, a marked elevation of V-wave in pulmonary capillary wedge pressure (PCWP) was shown, and a moderate-to-severe functional mitral regurgitation was observed. IABP and CRT resulted in a significant acute improvement in aortic pressure, PCWP, and V-wave amplitude compared with baseline measurements and IABP alone. These results provide a basis for studies examining the haemodynamic effects of IABP support associated with CRT in patients with heart failure refractory to medical therapy.

Autonomic modulation of the sinus node following electrical cardioversion of persistent atrial fibrillation: relation with early recurrence.

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.

Effects of cardiac resynchronization therapy on disease progression in patients with congestive heart failure.

BACKGROUND: Cardiac resynchronization therapy (CRT) represents a new therapeutic modality of proven efficacy for selected patients with heart failure and ventricular asynchrony. The aim of this study was to assess the effects of CRT on clinical variables and cardiac remodeling in patients with moderate-to-severe congestive heart failure and inter/intraventricular conduction delays. METHODS: Thirty-seven patients (32 males, 5 females, mean age 73 +/- 7 years), in NYHA functional class III-IV, with left ventricular ejection fraction (LVEF) < or = 35%, QRS > or = 150 ms, and left ventricular end-diastolic diameter (LVEDD) > or = 55 mm, underwent CRT by biventricular pacing (InSync, InSync III, InSync ICD; Medtronic Inc.). Fourteen (37.8%) had a previous pacemaker, and 11 (29.7%) were in permanent atrial fibrillation. The QRS width, NYHA functional class, LVEDD, left ventricular end-systolic diameter (LVESD), left ventricular end-diastolic volume (LVEDV), left ventricular endsystolic volume (LVESV), and LVEF were retrospectively evaluated in the period before CRT. For the purposes of the present study, the pre-CRT period was divided in two: T(-2) (from 6 to 3 years) and T(-1) (from 3 years to CRT). Moreover, these parameters were measured at the time of CRT (T0) and prospectively in the post-CRT follow-up (Tp). RESULTS: Before CRT, a progressive worsening of the parameters was observed. The QRS duration steadily increased from T(-2) to T(-1) and T0 (both p = 0.000). The NYHA functional class increased from T(-2) to T(-1) and T0 (both p = 0.000). LVEDD and LVESD also increased and were higher at T(-1) (p = 0.001 and p = 0.000, respectively) and at T0 (both p = 0.000) compared to T(-2). Similar results were observed for LVEDV and LVESV. Finally, LVEF was higher at T(-2) than T(-1) and T0 (both p = 0.000). After CRT, there was a reduction in the QRS duration and an improvement in the NYHA functional class compared to T0 (both p = 0.000). LVEDD and LVESD were also reduced (p = 0.005 and p = 0.016, respectively), LVEDV and LVESV decreased (both p = 0.000), and LVEF increased (p = 0.000) with respect to T0. A highly significant correlation was found between LVEDD and LVESD both in the pre- and post-CRT time intervals, with a non-significant difference between the two linear regression lines. Similar results were obtained for the correlations between LVEDV and LVESV. CONCLUSIONS: Congestive heart failure is associated with a progressive widening of the QRS complex and a worsening of the clinical status and results in anatomic remodeling with deterioration of the left ventricular function. CRT induces opposite changes in QRS duration, clinical status, and left ventricular remodelling.