Barbara Vidal

Physical activity, height, and left atrial size are independent risk factors for lone atrial fibrillation in middle-aged healthy individuals

AIMS The aetiology of atrial fibrillation (AF) remains unknown in some patients. The aim of the study was to identify new risk factors for developing lone AF (LAF). METHODS AND RESULTS A series of 107 consecutive patients younger than 65, seen in the emergency room for an episode of LAF of <48 h duration were included in the study. A group of 107 healthy volunteers matched for age and sex were recruited as controls. All subjects answered a validated questionnaire concerning leisure and occupational activities performed throughout their lifetimes to estimate accumulated hours of physical effort, classified in four levels of intensity. Demographic and echocardiographic measurements were also recorded. There were 69% of males and mean age was 48 +/- 11 years. AF was paroxysmal in 57% and persistent in the remaining 43%. Patients with AF performed more hours of both moderate and heavy intensity physical activity. They also were taller, and had a larger left atria, ventricle, and body surface area. At the multivariable analysis, only moderate and heavy physical activity, height, and anteroposterior atrial diameter were independently associated with LAF. CONCLUSIONS Accumulated lifetime physical activity, height, and left atrial size are risk factors for LAF in healthy middle-aged individuals.

Left atrial posterior wall isolation does not improve the outcome of circumferential pulmonary vein ablation for atrial fibrillation: a prospective randomized study.

Background—Ablation of the pulmonary veins (PVs) for atrial fibrillation treatment is often combined with linear radiofrequency lesions along the left atrium (LA) to improve the success rate. The study was designed to assess the contribution of LA posterior wall isolation to the outcome of circumferential pulmonary vein ablation (CPVA). Methods and Results—CPVA consisted of continuous radiofrequency lesions encircling both ipsilateral PVs plus an ablation line along the mitral isthmus. Patients were then randomized into 2 groups. In the first group, superior PVs were connected by linear lesions along the LA roof (CPVA-1 group). In the second group, the LA posterior wall was isolated by adding a second line connecting the inferior aspect of the 2 inferior PVs (CPVA-2 group). The study included 120 patients (53±11 years, 77% male, 60% paroxysmal atrial fibrillation, LA of 41.3±5.4 mm, 46% with hypertension, and 22% with structural heart disease). After a single ablation procedure and a mean follow-up of 10±4 months, 24 (40%) patients of the CPVA-1 group had atrial fibrillation recurrences and 3 (5%) had new-onset LA flutter. In the CPVA-2 group, recurrences were due to atrial fibrillation episodes in 23 patients (38%) and LA flutter in 4 (7%). Freedom from arrhythmia recurrences was not statistically different in the CPVA-1 group as compared with the CPVA-2 group (log rank P=0.943). Conclusion—Isolation of the LA posterior wall did not increase the success rate of CPVA.

Efficacy of circumferential pulmonary vein ablation of atrial fibrillation in endurance athletes

Aims Long-term endurance sport practice has been increasingly recognized as a risk factor for lone atrial fibrillation (AF). However, data on the outcome of circumferential pulmonary vein ablation (CPVA) in endurance athletes are scarce. The aim of the study was to evaluate the efficacy of CPVA in AF secondary to endurance sport practice. Methods and results Patients submitted to CPVA answered a questionnaire about lifetime history of endurance sport practice. Endurance athletes were defined as those who engaged in >3 h per week of high-intensity exercise for at least the 10 years immediately preceding their AF diagnosis. A series of 182 consecutive patients was included (51 ± 11 years, 65% with paroxysmal AF, 81% men, 42 ± 6 mm mean left atrial diameter); 107 (59%) patients had lone AF, and 42 of them (23% of the study population) were classified as endurance athletes (lone AF sport group). Freedom from arrhythmia after a single CPVA was similar in the lone AF sport group compared with the remaining patients (P = 0.446). Left atrial size and long-standing AF were the only independent predictors for arrhythmia recurrence after ablation. Conclusion Circumferential pulmonary vein ablation was as effective in AF secondary to endurance sport practice as in other aetiologies of AF.

Electrocardiographic Optimization of Interventricular Delay in Cardiac Resynchronization Therapy: A Simple Method to Optimize the Device

Introduction: Echocardiography is widely used to optimize CRT programming, but it is time‐consuming. This study aimed to correlate the optimal interventricular pacing (V‐V) interval obtained by echo with the optimal V‐V interval obtained by a simpler method based on the surface ECG.

Fate of left atrial function as determined by real-time three-dimensional echocardiography study after radiofrequency catheter ablation for the treatment of atrial fibrillation.

Radiofrequency catheter ablation has been demonstrated to be effective in the treatment of patients with atrial fibrillation. However, its impact on left atrial (LA) function has not been widely studied. The purpose of the present study was to evaluate the impact of radiofrequency catheter ablation on LA function in patients with atrial fibrillation. Thirty-eight patients with symptomatic drug-refractory atrial fibrillation were treated with circumferential pulmonary vein ablation (CPVA). LA volumes and function were assessed with real-time 3-dimensional echocardiography before and 6 months after the procedure. The effectiveness of CPVA was evaluated at 6-month follow-up. Recurrence of the arrhythmia was defined as any documented (clinically or on 24-hour Holter electrocardiography) atrial tachyarrhythmia lasting>30 seconds after the first 12 weeks after the procedure. CPVA induced a reduction of maximum LA volume (from 55+/-15 to 48+/-16 ml, p<0.001), without impairment in LA function, measured as the active emptying percentage of total volume (32+/-29% vs 39+/-33%, p=NS). At follow-up, 21 patients (61.8%) had no recurrences. Maximum LA volumes were significantly larger in patients who presented with recurrences compared with those who did not (64+/-18 vs 50+/-11 ml, p=0.01). In conclusion, CPVA induces a reduction in LA volume without a deleterious impact on function, and, of importance, real-time 3-dimensional echocardiography is a useful noninvasive imaging tool to follow up LA remodeling and function in these patients.

Mechanism of Decrease in Mitral Regurgitation After Cardiac Resynchronization Therapy: Optimization of the Force–Balance Relationship

Background—Cardiac resynchronization therapy (CRT) has been shown to reduce functional mitral regurgitation (MR). It has been proposed that the mechanism of MR reduction relates to geometric change or, alternatively, changes in left ventricular (LV) contractile function. Normal mitral valve (MV) function relies on a balance between tethering and closing forces on the MV leaflets. Functional MR results from a derangement of this force–balance relationship, and CRT may be an important modulator of MV function by its ability to enhance the force–balance relationship on the MV. We hypothesized that CRT improves the comprehensive force balance acting on the valve, including favorable changes in both geometry and LV contractile function. Methods and Results—We examined the effect of CRT on 34 patients with functional MR before and after CRT (209±81 days). MR regurgitant volume, closing forces on MV (derived from Doppler transmitral pressure gradients), including dP/dt and a factor (closing pressure ratio) expressing how long the peak closing gradient is maintained over systole (closing pressure ratio=velocity time integral/MR peak velocity×mitral regurgitation time), and dyssynchrony by tissue Doppler were measured. End-diastolic volume, end-systolic volume, mitral valve annular area (MAA) and contraction (percent change in MAA from end-diastole to midsystole), leaflet closing area (leaflet area during valve closure), and tenting volume (volume under leaflets to annular plane) were measured by 3D echocardiography. After CRT, end-diastolic volume (253±111 versus 221±110 mL, P<0.001) and end-systolic volume (206±97 versus 167±91 mL, P<0.001) decreased and ejection fraction (19±6 versus 27±9%, P<0.001) increased. MR regurgitant volume decreased from 35±17 to 23±14 mL (P<0.001), MAA from 11.6±3.5 to 10.5±3.1 cm2 (P<0.001), leaflet closing area from 15.4±5 to 13.7±3.8 cm2 (P<0.001), and tenting volume from 5.7±2.6 to 4.6±2.2 mL (P<0.001). Peak velocity (and therefore transmitral closing pressure) was more sustained throughout systole, as reflected by the increase in the closing pressure ratio (0.77±0.1 versus 0.84±0.1 before CRT versus after CRT, P=0.01); dP/dt also improved after CRT. There was no change in dyssynchrony or MAA contraction. Conclusions—Reduction in MR after CRT is associated with favorable changes in MV geometry and closing forces on the MV. It does so by favorably affecting the force balance acting on the MV in 2 ways: reducing tethering through reversal of LV remodeling and increasing the systolic duration of peak transmitral closing pressures.

Left Atrial Contractility is Preserved After Successful Circumferential Pulmonary Vein Ablation in Patients with Atrial Fibrillation

Introduction: Circumferential pulmonary vein ablation (CPVA) for atrial fibrillation (AF) consists of creating extensive lesions in the left atrium (LA). The aim of the study was to evaluate changes in LA contractility after ablation and their relationship with procedure outcome.

Decreased likelihood of response to cardiac resynchronization in patients with severe heart failure

We hypothesized that a very advanced stage of dilated cardiomyopathy is associated with lower response to cardiac resynchronization therapy (CRT).

Long-term effect of cardiac resynchronization therapy on functional mitral valve regurgitation.

Cardiac resynchronization therapy (CRT) has been shown to reduce functional mitral regurgitation (MR). The aims of this study were to analyze the underlying mechanisms leading to this reduction and to identify the best candidates with functional MR for this therapy. Changes in mitral geometry, left ventricular (LV) remodeling, and LV synchrony were studied in patients who underwent CRT acutely and at 6- and 12-month follow-up. Of 151 patients (mean age 69 +/- 9 years, 82% men) who underwent CRT, 57 (38%) had nontrivial MR (regurgitant orifice area > or =10 mm(2)). The median reduction of MR with CRT was 18% acutely and 38% at 12-month follow-up. CRT induced an acute improvement in LV systolic function (LV dP/dt from 508 +/- 143 to 700 +/- 249 mm Hg, p <0.05) and a reduction in dyssynchrony (interventricular delay from 51 +/- 31 to 29 +/- 27 ms, p <0.05). At 12-month follow-up, additional reverse global and local LV remodeling (LV end-systolic volume from 183 +/- 77 to 151 +/- 50 ml, tenting area from 3.36 +/- 0.98 to 2.78 +/- 0.75 cm, p <0.05 for both) and a reduction in LV dyssynchrony (septal-lateral delay from 90 +/- 63 to 53 +/- 42 ms, p <0.05) were found. Significant reductions in MR were found in 28 patients (49%) and similarly observed in either ischemic MR or functional MR of other causes. Baseline mitral tenting area was the strongest predictor of significant MR reduction with CRT. In conclusion, CRT induced acute and sustained reductions in functional MR in almost 50% of patients by initially improving LV systolic function and dyssynchrony; long-term reverse LV remodeling contributed to this sustained effect. Patients with larger mitral valve tenting areas are less amenable to benefit from CRT.

Radial Artery Spasm in Transradial Cardiac Catheterization. Assessment of Factors Related to Its Occurrence, and of Its Consequences During Follow-Up

INTRODUCTION AND OBJECTIVES Radial artery spasm is the most frequent complication of transradial cardiac catheterization. It causes patient discomfort and reduces the procedures success rate. The aims of this study were to identify variables associated with this complication, such as clinical parameters, angiographic characteristics of the radial artery and factors related to the procedure, and to analyze the clinical consequences of spasm, both generally and for radial artery patency, during follow-up. PATIENTS AND METHOD The study included 637 patients who were undergoing transradial cardiac catheterization. Radial artery spasm was recorded using a scale that reflected the presence of pain and the technical difficulty of the procedure. RESULTS Radial artery spasm was reported in 127 patients (20.2%). Multivariate analysis showed that the variables associated with radial artery spasm were radial artery anatomical anomalies (odds ratio [OR]=5.1; 95% confidence interval [95% CI]: 2.1-11.4), use of >size-3 catheters (OR=3.0; 95% CI: 1.9-4.7), moderate-to-severe pain during radial artery cannulation (OR=2.6; 95% CI: 1.4-4.9), the use of phentolamine as a spasmolytic (OR=1.8; 95% CI: 1.1-2.9), and postvasodilation radial artery diameter (OR=0.98; 95% CI: 0.98-0.99). At follow-up [20 (18) days], severe pain in the forearm was more frequent in patients who presented with radial artery spasm (12.4% vs 5.3%), but there was no significant difference in the radial artery occlusion rate (4.5% vs 2.2%). CONCLUSION Radial artery spasm during transradial catheterization mainly depends on radial artery characteristics and procedural variables. At follow-up, radial artery spasm was associated with more frequent severe pain in the forearm, but the radial artery occlusion rate was not increased.