Atrial low voltage areas: A comparison between atrial fibrillation and sinus rhythm.

BACKGROUND: Atrial fibrosis can promote atrial fibrillation (AF). Electroanatomic mapping (EAM) can provide information regarding local voltage abnormalities that may be used as a surrogate marker for fibrosis. Specific voltage cut-off values have been reproduced accurately to identify fibrosis in the ventricles, but these values are not well defined in atrial tissue. METHODS: This study is a prospective single-center study. Patients with persistent AF referred for ablation were included. EAM was performed before ablation. We recorded bipolar signals, first in AF and later in sinus rhythm (SR). Two thresholds delimited low-voltage areas (LVA), 0.5 and 0.3 mV. We compared LVA extension between maps in SR and AF in each patient. RESULTS: A total of 23 patients were included in the study. The percentage of points with voltage lower than 0.5 mV and 0.3 mV was significantly higher in maps in AF compared with maps in SR: 38.2% of points < 0.5 mV in AF vs. 22.9% in SR (p < 0.001); 22.3% of points < 0.3 mV in AF vs. 14% in SR (p < 0.001). Areas with reduced voltage were significantly larger in maps in AF (0.5 mV threshold, mean area in AF 41.3 ± 42.5 cm2 vs. 11.7 ± 17.9 cm2 in SR, p < 0.001; 0.3 mV threshold, mean area in AF 15.6 ± 22.1 cm2 vs. 6.2 ± 11.5 cm2 in SR, p < 0.001). CONCLUSIONS: Using the same voltage thresholds, LVA extension in AF is greater than in SR in patients with persistent AF. These findings provide arguments for defining a different atrial fibrosis threshold based on EAM rhythm.

Usefulness of Sodium Bicarbonate for the Prevention of Contrast-Induced Nephropathy in Patients Undergoing Cardiac Resynchronization Therapy.

The use of contrast media during cardiac resynchronization therapy (CRT) devices implantation is associated with the risk of contrast-induced nephropathy (CIN). The aim of this study was to evaluate the possible beneficial role of periprocedural intravenous volume expansion with isotonic saline and sodium bicarbonate solution in patients who undergo CRT implantation. Eligible patients were randomly assigned in a 1:1 ratio to receive hydration plus one-sixth molar sodium bicarbonate (study group) or not (control group). Primary end point was CIN incidence. Secondary end points were (1) a combined end point of death, heart transplantation, or hospitalization for heart failure at 12 months, (2) incidence of death, and (3) the need for renal replacement therapy at 12 months. Final analysis was performed with 93 patients. In the hydration group CIN incidence was significantly reduced related to control group (0% vs 11%, p = 0.02). There was a trend to reduce the combined end point in hydration group (12.5% vs 22%, p = 0.14). Finally, CIN incidence was related to a higher 12 months mortality (25% vs 7%, p = 0.03). In conclusion, CIN incidence was 11% in a nonselected population of patients receiving a CRT device. CIN appearance could be reduced by using a hydration protocol based on sodium bicarbonate and isotonic saline.

Utility of high density multielectrode mapping during ablation of scar-related ventricular tachycardia.

INTRODUCTION: Multielectrode mapping catheters (MEMC) allow the performance of high resolution and density maps but the utility of these catheters in ventricular tachycardia (VT) ablation procedures has not been yet widely described. We sought to evaluate the utility of a MEMC during scar-related VT ablation procedures. METHODS: Eighty-five consecutive scar-related VT ablation procedures were performed in 81 patients. In the first 26 procedures, a standard 3.5-mm tip linear catheter was employed for endocardial/epicardial mapping (control group). In the following 59 procedures mapping was performed with a MEMC (study group). Procedural time, LV endocardial and epicardial mapping time, complications and ablation outcomes were compared. RESULTS: The use of the MEMC resulted in a significant shortening of the endocardial and epicardial mapping times (38 ± 15 minutes vs. 56 ± 24 minutes for endocardial LV mapping in the study and control group, respectively, P = 0.001; and 28 ± 9 minutes vs 41 ± 16 minutes, for epicardial mapping, P = 0.011) as well as the total procedural time (177 ± 53 minutes vs. 206 ± 50 minutes, respectively, P = 0.02). The mapping density was also significantly increased in the study group (mean endocardial LV points: 2,143 ± 1,419 vs. 485 ± 174, for the study and control group, respectively, P < 0.0001), specially within the scar area (49.6 ± 34 points/cm2 vs. 8.4 ± 4.6 points/cm2 , P < 0.001). No differences in acute and long-term follow-up outcomes were observed. CONCLUSIONS: High-density multielectrode mapping is associated with a significant reduction of procedural and mapping times and a significant increase of mapping density without affecting outcomes in patients with scar-related VT.

Conventional and right-sided screening for subcutaneous ICD in a population with congenital heart disease at high risk of sudden cardiac death.

BACKGROUND: Information regarding suitability for subcutaneous defibrillator (sICD) implantation in tetralogy of Fallot (ToF) and systemic right ventricle is scarce and needs to be further explored. The main objective of our study was to determine the proportion of patients with ToF and systemic right ventricle eligible for sICD with both, standard and right-sided screening methods. Secondary objectives were: (i) to study sICD eligibility specifically in patients at high risk of sudden cardiac death, (ii) to identify independent predictors for sICD eligibility, and (iii) to compare the proportion of eligible patients in a nonselected ICD population. METHODS: We recruited 102 patients with ToF, 33 with systemic right ventricle, and 40 consecutive nonselected patients. Conventional electrocardiographic screening was performed as usual. Right-sided alternative screening was studied by positioning the left-arm and right-arm electrodes 1 cm right lateral of the xiphoid midline. The Boston Scientific ECG screening tool was utilized. RESULTS: In high-risk patients with ToF, eligibility was higher with right-sided screening in comparison with standard screening (61% vs. 44%; p = .018). Eligibility in high-risk right ventricle population was identical with both screening methods (77%, p = ns). The only independent predictor for sICD eligibility was QRS duration. CONCLUSION: In high-risk patients with ToF, right-sided implantation of the sICD could be an alternative to a conventional ICD. In patients with a systemic right ventricle, implantation of a sICD is an alternative to a conventional sICD.

The Role of Conventional and Right-Sided ECG Screening for Subcutaneous ICD in a Tetralogy of Fallot Population.

BACKGROUND: Information regarding suitability for subcutaneous implantable cardioverter-defibrillator (S-ICD) implant in tetralogy of Fallot (ToF) population is scarce and needs to be further explored. THE AIMS OF OUR STUDY WERE: (1) to determine the proportion of patients with ToF eligible for S-ICD, (2) to identify the optimal sensing vector in ToF patients, (3) to test specifically the eligibility for S-ICD with right-sided screening, and (4) to compare with the proportion of eligible patients in a nonselected ICD population. METHODS: We recruited 60 consecutive patients with ToF and 40 consecutive nonselected patients. Conventional electrocardiographic screening was performed as usual. Right-sided alternative screening was studied by positioning the left arm and right arm electrodes 1 cm right lateral to the xiphoid midline. The Boston Scientific electrocardiogram (ECG) screening tool was utilized. RESULTS: We found a higher proportion of patients with right-sided positive screening in comparison with standard screening (77 ± 0.4% vs. 67 ± 0.4%; P < 0.0001) and a trend to higher number of appropriate leads in right-sided screening (1.3 ± 1 vs. 1.1 ± 1 ms; P = 0.07). Patients who failed the screening had a longer QRS duration and longer QT interval. Standard and right-sided screening showed a higher percent of positive patients in the control group compared to ToF patients (P < 0.001). CONCLUSION: Right-sided screening was associated with a significant 10% increase in S-ICD eligibility in ToF patients. When comparing with an acquired cardiomyopathies group, ToF showed a lower eligibility for S-ICD. The most appropriate ECG vector was the alternate vector in contrast to what is observed in the general population.

Incidence and predictors of clinically relevant cardiac perforation associated with systematic implantation of active-fixation pacing and defibrillation leads: a single-centre experience with over 3800 implanted leads.

AIMS: Active-fixation leads have been associated with higher incidence of cardiac perforation. Large series specifically evaluating this complication are lacking. We sought to evaluate the incidence and predictors of clinically relevant cardiac perforation in a consecutive series of patients implanted with active-fixation pacing and defibrillation leads. METHODS AND RESULTS: We conducted a retrospective observational study including all consecutive patients implanted with an active-fixation pacing/defibrillation lead at our institution from July 2008 to July 2015. The incidence of clinically relevant cardiac perforation and cardiac tamponade was evaluated. Univariate and multivariate analyses were used to identify predictors of cardiac perforation. Acute and long-term management of these patients was also investigated. A total of 3822 active-fixation pacing (n = 3035) and defibrillation (n = 787) leads were implanted in 2200 patients. Seventeen patients (0.8%) had clinically relevant cardiac perforation (13 acute and 4 subacute perforations), and 13 (0.5%) had cardiac tamponade resolved with pericardiocentesis. None of the patients with cardiac perforation required surgical treatment. In multivariate analysis, an age >80 years (OR 3.84, 95% CI 1.14-12.87, P = 0.029), female sex (OR 3.14, 95% CI 1.07-9.22, P = 0.037), and an apical position of the right ventricular lead (OR 3.37, 95% CI 1.17-9.67, P = 0.024) were independent predictors of cardiac perforation. CONCLUSIONS: Implantation of active-fixation leads is associated with a low incidence of clinically relevant cardiac perforation. Older and female patients have a higher risk of perforation as well as those patients receiving the ventricular lead in an apical position.

Essential ECG clues in patients with congenital heart disease and arrhythmias.

The prevalence of adults with congenital heart disease has dramatically increased during the last decades due to significant advances in the surgical correction of these conditions. As a result, patient's survival has been prolonged and arrhythmias have become one of the principal causes of morbidity and mortality for these patients. The surface 12-lead ECG may play a critical role in the identification of the underlying heart disease of the patient, the recognition of the arrhythmia mechanism and may also help in the planification of the ablation procedure in this setting. Finally, important prognostic information can be also obtained from the ECG in these patients. The present review will offer an overview of the principal utilities of the surface ECG in the diagnosis and management of patients with CHD and arrhythmias.

Safety and Feasibility of a Minimally Fluoroscopic Approach for Ventricular Tachycardia Ablation in Patients With Structural Heart Disease: Influence of the Ventricular Tachycardia Substrate.

BACKGROUND: We sought to evaluate the safety and feasibility of a minimally fluoroscopic approach using the CARTOUNIVU module during scar-related ventricular tachycardia (VT) ablation. METHODS AND RESULTS: Consecutive patients with structural heart disease undergoing VT ablation using the CARTOUNIVU module were prospectively included and classified depending on their VT substrate: (1) ischemic VT (IVT) and (2) nonischemic VT and depending on the presence of an epicardial access. Radiation exposure parameters and major and minor procedure-related complications were registered. A near-zero fluoroscopy exposure was defined as those procedures with an effective dose ≤1 mSv. A total of 44 VT ablation procedures were performed in 41 patients (22 IVT and 19 nonischemic VT). The use of the CARTOUNIVU module resulted in low levels of radiation exposure: median total fluoroscopy time and effective dose of 6.08 (1.51-12.36) minutes and 2.15 (0.58-8.22) mSv, respectively. Patients with IVT had lower radiation exposure than patients with nonischemic VT (total fluoroscopy time, 2.53 [1.22-11.22] versus 8.51 [5.55-17.34] minutes; P=0.016). Epicardial access was associated with significantly higher levels of radiation exposure. Complications occurred in 4.9% patients, none of them being related to the use of the image integration tool. A near-zero fluoroscopy ablation could be performed in 14 of 44 procedures (32%), 43% of IVT procedures, and 50% of procedures with endocardial access only. CONCLUSIONS: The use of the CARTOUNIVU module during scar-related VT ablation resulted in low levels of radiation exposure. A near-zero fluoroscopy approach can be achieved in up to half of the procedures, especially in IVT patients with endocardial ablation.

La hiponatremia como marcador de riesgo en pacientes sometidos a implante de desfibrilador en prevención primaria / Prognostic impact of hyponatremia in patients receiving implantable cardioverter in primary prevention

Introducción y objetivos: La hiponatremia es un factor de mal pronóstico en pacientes con insuficiencia cardiaca. Nuestro objetivo fue valorar el impacto de la hiponatremia en la evolución de los pacientes sometidos a implante de desfibrilador en prevención primaria. Método: Se trata de un estudio observacional retrospectivo multicéntrico en el que se valoró la natremia periimplante y los eventos adversos (la mortalidad de cualquier causa y la cardiovascular, el primer ingreso por insuficiencia cardiaca, la primera terapia apropiada e inapropiada del desfibrilador), en una cohorte española sometida a implante de desfibrilador en la prevención primaria. Se comparó la hiponatremia ligera (Na ≤ 135 mEq/l) y la moderada-severa (Na ≤ 131 mEq/l) respecto a la ausencia de la hiponatremia. Resultados: Un total de 725 pacientes, con un valor medio de sodio en la sangre periimplante de 139 ± 3,6 mEq/l y un tiempo medio de seguimiento de 34,1 ± 18,5 meses. En los pacientes con Na ≤ 135 mEq/l (n = 105) se observó una mayor incidencia de primer ingreso por insuficiencia cardiaca (odds ratio: 1,701; p = 0,031). En los pacientes con hiponatremia moderada-severa (n = 18) se observó mayor mortalidad total (hazard ratio; 3,552; p = 0,002) y mayor mortalidad cardiovascular (hazard ratio: 4,24; p = 0,003). Ninguno de los grados de la hiponatremia estudiados se asoció con mayor incidencia de terapias apropiadas o inapropiadas. Conclusiones: La hiponatremia ligera en el momento del implante de un desfibrilador se asocia a una mayor incidencia de ingreso por insuficiencia cardiaca en el seguimiento, mientras que en el caso de una hiponatremia moderada-severa, se asocia a un riesgo de muerte 4 veces mayor.

Introduction and objectives: Hyponatremia is a prognostic factor in patients with heart failure. Our objective was to assess the impact of hyponatremia in the evolution of patients undergoing cardioverter implantation in primary prevention. Method: This is a multicenter retrospective observational study in which serum sodium periimplant and adverse events (all-cause and cardiovascular mortality, first admission for heart failure, first appropriate and inappropriate therapy) were assessed in a Spanish cohort receiving cardioverter in primary prevention. Patients with mild hyponatremia (Na ≤ 135 mEq/L) and those with moderate to severe hyponatremia (Na ≤ 131 mEq/L) were compared to those without hyponatremia. Results: 725 patients, with a mean value of sodium in blood peri-implant of 139 ± 3.6 mEq/L and a mean follow-up was 34.1 ± 18.5 months. In patients with Na ≤ 135 mEq/L (n = 105), an increased incidence of first admission for heart failure was observed (Odds Ratio: 1.701; P = .031). In patients with moderate to severe hyponatremia (n = 18), higher total mortality (Hazard Ratio: 3.552; P = .002) and increased cardiovascular mortality (Hazard Ratio: 4.24; P = .003) were observed. None of those values of hyponatremia were associated with increased incidence of appropriate or inappropriate therapies Conclusions: Mild hyponatremia at the time of cardioverter implantation is related with a higher incidence of hospitalization for heart failure during follow-up, while moderate to severe hyponatremia increases the risk of death during follow-up.

The use of multisite left ventricular pacing via quadripolar lead improves acute haemodynamics and mechanical dyssynchrony assessed by radial strain speckle tracking: initial results.

AIMS: The objective of the present study was to evaluate the effect of multipoint pacing (MPP) on acute haemodynamics, cardiac contractility, and left ventricle (LV) dyssynchrony, in comparison with conventional cardiac resynchronization therapy (CRT). METHODS AND RESULTS: An open-label, non-randomized, single-centre, prospective study was designed. Twenty-seven consecutive patients were included. Evaluation of pacing configurations was performed in a random order. Transthoracic echocardiography was used to obtain haemodynamic and dyssynchrony parameters. Left ventricular ejection fraction (LVEF) was significantly superior in MPP compared with baseline (38.4 ± 1.8% vs. 26.1 ± 2.2%; P < 0.001), and in conventional pacing configuration compared with baseline (33.2 ± 1.8% vs. 26.1 ± 2.2%; P = 0.007). Cardiac index (CI) was increased by 21.8 ± 5.4% and 34.7 ± 5.1% in conventional and MPP configurations, respectively (P = 0.19). Percentage of acute responders (CI increase ≥10%) was 62.9 and 85.2% in conventional and MPP, respectively (P < 0.001). LV dyssynchrony was defined by radial strain rate parameters. Baseline anteroseptal-to-posterior wall time delay was 168 ± 21 ms. It was reduced until 70.4 ± 29 ms in conventional and -6.6 ± 11 ms in MPP (conventional vs. baseline P = 0.04; MPP vs. conventional P = 0.05). Standard deviation of the time-to-peak radial strain of the 6 LV basal segments was 101 ± 9.7, 80.3 ± 9.2, and 66 ± 8.03 ms in baseline, conventional, and MPP configurations, respectively (MPP vs. basal P = 0.012). Finally, we observed a positive correlation (r = 0.69) between reduction in dyssynchrony and CI increase (P < 0.0001). CONCLUSION: MPP showed a further reduction in LV dyssynchrony compared with conventional biventricular pacing. Moreover, MPP resulted in an additional improvement in LVEF and in CI, and this was translated into a higher number of acute responders to CRT.

Electrical Isolation of Pulmonary Veins Using Laser Catheter in the Treatment of Paroxysmal and Persistent Atrial Fibrillation. One-year Results.

INTRODUCTION AND OBJECTIVES: A new laser balloon that allows visualization of atrial tissue has recently been introduced for pulmonary vein electrical isolation. The aim of this study was to evaluate the mid-term safety and efficacy of this catheter in the treatment of atrial fibrillation. METHODS: Laser balloon ablation was performed in 71 patients with paroxysmal (80%) or persistent (20%) atrial fibrillation. Arrhythmia recurrence was defined as any episode lasting longer than 30 seconds. During follow-up, regular visits were performed every 3 months with 24- to 48-hour Holter tests. RESULTS: Isolation was possible in 275 of 278 (99%) of pulmonary veins. Mean procedure and fluoroscopy times were 154 ± 25 and 34 ± 15minutes, respectively. A total of 89% of veins were isolated during the first attempt. The most common complication was phrenic nerve paralysis (5.6%), which appeared in only the first 18 cases. A total of 59 patients received follow-up for a mean of 420 ± 193 days, with a rate of arrhythmia recurrence of 12% and 30%, respectively, in paroxysmal and persistent atrial fibrillation (P = .155). CONCLUSIONS: The laser balloon is a safe and effective system for pulmonary vein electrical isolation. Its advantages include the capacity to adapt to pulmonary vein anatomy using a single catheter, the efficacy with which pulmonary vein electrical isolation is achieved, and the favorable mid-term clinical progress, even for patients with persistent atrial fibrillation.

Initial Experience with a New Image Integration Module Designed for Reducing Radiation Exposure During Electrophysiological Ablation Procedures.

INTRODUCTION: Reduction of radiation exposure during cardiac arrhythmia ablation procedures is desirable. We sought to evaluate the utility of a new image integration module (CARTOUNIVU(TM) ) in reducing fluoroscopy times and dosages during left atrial arrhythmia (LAA) and ventricular tachycardia (VT) ablation procedures. METHODS AND RESULTS: Consecutive patients undergoing LAA (n = 28)/VT (n = 13) ablation using the CARTOUNIVU(TM) module were included. Total fluoroscopy time, radiation dose (total dose area product [tDAP], effective dose [ED]), and procedure duration were evaluated. A retrospective cohort of patients who underwent LAA (n = 16)/VT(n = 8) ablation without the new image integration module served as a control group. The use of the new image integration module significantly reduced mean fluoroscopy time (5.2 minutes [IQR 1.9;6.8] in the LAA ablation UNIVU group vs. 28.2 minutes [IQR 15.3;37.8] in the control group, P<0.001; 9.8 minutes [IQR 4.5;13.1] vs. 25.5 minutes [IQR 14.1;30.9] for VT ablation, P = 0.013), tDAP (2,088 cGy*cm(2) [IQR 664;2911] vs. 5,893 cGy*cm(2) [IQR 3088;8483], P< 0.001 for LAA ablation; 3,917 cGy*cm(2) [IQR 948;4217] vs. 12,377 cGy*cm(2) (IQR 3385;23157) for VT ablation patients, P = 0.025) and ED (4.1 mSv [IQR 1;5.8] vs. 11.8 mSv [IQR 6.2;16.9] for LAA ablation patients, P< 0.001; 7.8 mSv [IQR 1.9;8.4] vs. 24.7 mSv [IQR 6.8;46.3] for VT ablation patients, P = 0.025). Procedure duration did not significantly change (174 ± 45 minutes vs. 197 ± 36 minutes for LAA ablation, P = 0.083; 201 ± 51 minutes vs. 201 ± 63 minutes for VT ablation, P = 0.860). No serious adverse events related to the use of the CARTOUNIVU(TM) module occurred. CONCLUSIONS: The new image integration module significantly reduced total fluoroscopy time and mean radiation dose without influence in procedure duration during ablation of complex atrial and ventricular arrhythmias.

Systematic Implantation of Pacemaker/ICDs under Active Oral Anticoagulation Irrespective of Patient's Individual Preoperative Thromboembolic Risk.

BACKGROUND: A wide variability in the perioperative management of oral anticoagulation (OAC) has been documented in patients receiving cardiac rhythm management devices (CRMDs). We sought to evaluate the safety and feasibility of a new perioperative strategy consisting in systematically continuing OAC in all patients irrespective of their individual thromboembolic (TE) risk. METHODS: A total of 278 consecutive patients on chronic OAC receiving CRMDs were prospectively included. Patients were classified in high and low TE risk according to current guidelines for the perioperative management of antithrombotic therapy, but underwent implantation under active OAC (international normalized ratio 2-4) irrespective of their preoperative TE risk. Bleeding and TE complications were evaluated as well as other procedure-related complications, hospital stays, and the feasibility of outpatient implantations. RESULTS: A total of 117 patients were considered at high TE risk and 161 at low TE risk. Overall, the incidence of pocket hematoma was 2.9% with only three patients requiring pocket revision. Low TE risk patients had a very low incidence of pocket hematoma (1.9%) without needing pocket revision. The mean hospital stay was 1.17 ± 1.8 days and 169 patients (61%) received their CRMD in an outpatient basis, including 77 patients who were implanted with an implantable cardioverter defibrillator. No TE events were detected during the 30-day postimplant observation period in any patient. No other significant complications related with the implant (pneumothorax, hemothorax, cardiac tamponade) were registered. CONCLUSIONS: Systematic continuation of OAC in all patients undergoing implantation of CRMDs is safe and feasible, thus simplifying and standardizing the perioperative management in this setting.

Value of the Electrocardiogram as a Predictor of Right Ventricular Dysfunction in Patients With Chronic Right Ventricular Volume Overload.

INTRODUCTION AND OBJECTIVES: Pulmonary regurgitation is a common complication in patients with repaired tetralogy of Fallot or congenital pulmonary stenosis. Electrocardiographic variables have been correlated with parameters used to evaluate right ventricular function. We aimed to analyze the diagnostic value of the width and fragmentation of the electrocardiogram in the identification of patients with right ventricular dysfunction and/or dilation. METHODS: We selected 107 consecutive patients diagnosed with severe pulmonary insufficiency after repair of pulmonary stenosis or tetralogy of Fallot. The tests included electrocardiography, echocardiography, and magnetic resonance. Each electrocardiogram was analyzed manually to measure QRS duration. We defined QRS fragmentation as the presence of low-voltage waves in the terminal portion of the QRS complex in at least 2 contiguous leads. RESULTS: We found a significant negative correlation between QRS width and right ventricular function, as well as a positive correlation with right ventricular volume. The receiver operating characteristic curve indicated a cut-off point for QRS width of 140ms, which showed good sensitivity for a diagnosis of right ventricular dilation (> 80%) and dysfunction (> 95%). In logistic regression models, a QRS duration > 140ms was found to be the only independent predictor of right ventricular dilation and dysfunction. CONCLUSIONS: Electrocardiography is a rapid, widely available, and reproducible tool. QRS width constitutes an independent predictor of the presence of right ventricular dilation and dysfunction. This study is the first to provide a cutoff value for QRS width to screen for right ventricle involvement.

The use of quadripolar left ventricular leads improves the hemodynamic response to cardiac resynchronization therapy.

BACKGROUND: The objective of the present study was to evaluate the usefulness of a left ventricle (LV) quadripolar lead in improving the hemodynamic response to cardiac resynchronization therapy (CRT). METHODS AND RESULTS: We included 27 consecutive patients implanted with a CRT device with an LV quadripolar lead. Hemodynamic parameters were evaluated at 3-month follow-up by using impedance cardiography. We assessed the highest cardiac output and the highest stroke volume (SV) obtained after atrioventricular and interventricular optimization with pacing from each of the four electrodes of the LV lead. Each patient was evaluated according to three different pacing configurations: unipolar-simulated, bipolar, and quadripolar. Biventricular pacing improved hemodynamics in comparison to the nonpaced measurements: cardiac index (CI): 2.69 L/min/m(2) versus 2.17 L/min/m(2) (P = 0.001). The hemodynamic response was highest in the quadripolar in comparison to unipolar-simulated and bipolar configurations, with an increase of 29%, 23%, and 27%, respectively, in relation to the reference CI and with an increase of 22%, 11%, and 18%, respectively, in relation to the reference indexed SV (P < 0.05, for the comparison between unipolar-simulated and quadripolar configurations). Twelve patients (44%) showed the best hemodynamic response by pacing from any of the two distal electrodes and 15 patients (56%) by pacing from the two proximal electrodes. Finally, CRT responder rates were higher in quadripolar versus bipolar and unipolar-simulated configurations: 90%, 85%, and 75%, respectively. CONCLUSIONS: The quadripolar LV lead was associated with a better hemodynamic response and higher CRT responder rates when compared with unipolar-simulated and bipolar LV leads.

Use of a "CNI holidays" strategy in acute renal dysfunction late after heart transplant. Report of two cases.

BACKGROUND: Acute renal dysfunction (ARD) may appear in heart transplant (HTx) patients both in the early postoperative period and during follow-up, even after several years. CD25 is a subunit of the interleukin-2 receptor which is found exclusively on activated CD4 T lymphocytes. CD25 is crucial for clonal expansion of anti-allograft host lymphocytes that mediate in acute rejection. There are experiences supporting the use of Anti-CD25 monoclonal antibodies (MAb) immediately after HTx in patients with ARD as a bridge to renal function recovery, allowing the temporary suspension of treatment with CNI. METHODS: In this study we report two cases of successful use of weekly MAb (basiliximab) in HTx patients who developed late ARD after HTx. CONCLUSIONS: In coclusion, we think that in cases of ARD where CNI therapy plays a key role, the use of weekly doses of basiliximab allows CNI discontinuation until the restoration of renal function is achieved.