Frequency Of Atrial Fibrillation Episodes Research Articles

Clinical and echographic parameters as risk factors for atrial fibrilation in patients with hypertophic cardiomyopathy

Abstract Introduction Hypertrophic cardiomyopathy is the most prevalent inherited cardiomyopathy characterized by left ventricular hypertrophy and manifests with atrial fibrillation in 25% of patients, correlating with heightened morbidity and mortality rates. Purpose To investigate the clinical and echocardiographic parameters associated with the occurrence and progression of atrial fibrillation in patients diagnosed with hypertrophic cardiomyopathy. Material and Methods The study sample consisted of 72 patients with hypertrophic cardiomyopathy attending the Hereditary Heart Disease Unit at a tertiary cardiac surgery center. Thorough examination of patients' medical records was conducted. Results Myocardial fibrosis was observed in 68.1% of the patients. Analysis of the data revealed that atrial fibrillation (AF) episodes were more prevalent in older individuals (p=0.035) with a lower ejection fraction (p=0.003). Additionally, a larger left atrial diameter of 49.8mm (p<0.001), functional stage according to NYHA III (p=0.015), a history of syncope/pre-syncope events (p=0.018), patients with an implanted pacemaker/defibrillator (p=0.003), and those with known coronary artery disease factors (p=0.032), particularly dyslipidemia (p=0.049) and diabetes mellitus (p=0.027), were associated with higher AF incidence. Conclusions . This study underscores the importance of recognizing clinical and echocardiographic factors that contribute to atrial fibrillation risk in hypertrophic cardiomyopathy, enabling early identification of high-risk individuals and implementation of preventive strategies to reduce the frequency of atrial fibrillation episodes and associated complications.

Serum magnesium and phosphorus values are lower among patients with paroxysmal atrial fibrillation: insights from the PLACEBO study

Abstract Background Magnesium and phosphorus comprise micronutrients in circulating blood, while associated disorders have been linked with increased risk of cardiovascular disease (CVD). Low serum magnesium has been connected to atrial fibrillation (AF) development among individuals without CVD, as patients with higher serum phosphorus levels, without chronic kidney disease (CKD), demonstrate an increased risk of AF plus higher rates of cardiovascular morbidity. Patients with paroxysmal atrial fibrillation (PAF) seem to hold the same cardiovascular risk as patients with permanent AF. The exact connection between serum magnesium and phosphorus levels and PAF has not been adequately explored. Purpose We aimed to investigate the potential relationship between serum magnesium and phosphorus levels and the number of AF paroxysms during the past 6 months from enrollment. Methods We analyzed preliminary data from the Ergospirometry in Paroxysmal Atrial Fibrillation Prognosis (PLACEBO) trial (NCT05246423), an observational, prospective, single-center cohort study aiming to examine the prognostic role of cardiopulmonary exercise testing variables in the future paroxysms of AF. We included 53 patients diagnosed with PAF, without CKD, and 30 healthy individuals. Normality was assessed with the Shapiro-Wilk test. Normally distributed variables are presented as mean±SD and significance was investigated with T-test while non-normally variables were distributed as median (IQR) and investigated with the Mann-Whitney U test. A p-value <0.05 was considered statistically significant. Results The study cohort comprised 54 patients with PAF, without CKD, and 30 healthy individuals. Baseline demographics are presented in the relevant table. Patients with PAF were older than controls and they had more comorbidities, as expected. Serum magnesium and phosphorus levels were significantly lower among patients with PAF compared to controls [1.9±0.22 versus 2.13±0.26 mg/dl and 3.95 (0.75) versus 3.3 (0.65) respectively (p>0.001)]. Higher serum phosphorus levels were associated with lowest frequency of AF paroxysms within the previous 6 months (R=-0.293, p=0.039). Conclusions Patients with PAF demonstrate lower serum magnesium and phosphorus levels compared to healthy individuals. This might be in part explained by the fact that serum phosphorus is known to be inversely associated with BMI; in our cohort, BMI was higher among patients with PAF. The lowest the frequency of AF episodes, the highest the serum phosphorus levels, a finding that comes in contrary with previous reports pointing towards an increased risk of AF development and higher cardiovascular mortality among individuals with higher serum phosphorus levels. Our findings may highlight novel potential therapeutic strategies targeting serum magnesium and phosphorus in patients with PAF, with an eye to minimize the number of AF paroxysms.Table

Prevalence of obstructive sleep apnea in patients with lone atrial fibrillation

Abstract Purpose The aim of this study is to detect the prevalence of obstructive sleep apnea syndrome (OSAS) in patients having lone atrial fibrillation (AF). Patients and methods Fifty patients with lone AF were referred to our sleep unit from the Department of Cardiology at the University Hospital. Lone AF was defined as AF in patients without cardiac structural abnormality and less than 60 years of age. All patients were subjected to a detailed history with stress on the number and date of documented episodes of AF and how it was terminated, OSA symptoms (excessive daytime sleepiness, witnessed apnea, loud habitual snoring, and nocturnal choking), and OSA screening questionnaires. ENT and cardiac examination by a specialist was done. Full-night attended polysomnography was performed on full night. Results The median apnea–hypopnea index in the studied group was 10.8 (range, 0.4–69.4). There were 21 (42.0%) non-OSA patients, while there were 29 (58%) OSA patients. There were eight (27.6%) mild OSA patients. Moderate OSA patients were 10 (34.5%). Severe OSA patients were 11 (37.9%). Median of the frequency of AF episodes in the last 1 year was significantly higher in the OSA group than in the normal group (P=0.01). No significant difference was present between both groups as regards the number of nocturnal arrhythmias not related to respiratory events. The frequency of paroxysmal AF episodes during the last year shows a significant positive correlation with severity of OSA, desaturation index, and total arousal index. Conclusion The results of our study support our hypothesis that OSA is a risk factor for AF. We should investigate patients with lone AF for the possibility of OSA.

Insulin Treatment Reduces Susceptibility to Atrial Fibrillation in Type 1 Diabetic Mice.

Diabetes has been identified as an independent risk factor for atrial fibrillation (AF), the most common chronic cardiac arrhythmia. Whether or not glucose and insulin disturbances observed during diabetes enhance arrhythmogenicity of the atria, potentially leading to AF, is not well-known. We hypothesized that insulin deficiency and impaired glucose transport provide a metabolic substrate for the development and maintenance of AF during diabetes. Transesophageal atrial pacing was used to induce AF in healthy, streptozotocin-induced insulin-deficient type 1 diabetic, and insulin-treated diabetic mice. Translocation of insulin-sensitive glucose transporters (GLUTs) to the atrial cell surface was measured using a biotinylated photolabeling assay in the perfused heart. Fibrosis and glycogen accumulation in the atrium were measured using histological analysis. Diabetic mice displayed mild hyperglycemia, increased duration and frequency of AF episodes vs. age-matched controls (e.g., AF duration: 19.7 ± 6.8 s vs. 1.8 ± 1.1 s, respectively, p = 0.032), whereas insulin-treated diabetic animals did not. The translocation of insulin-sensitive GLUT-4 and -8 to the atrial cell surface was significantly downregulated in the diabetic mice (by 67 and 79%, respectively; p ≤ 0.001), and rescued by insulin treatment. We did not observe fibrosis or glycogen accumulation in the atria of diabetic mice. Therefore, these data suggest that insulin and glucose disturbances were sufficient to induce AF susceptibility during mild diabetes.

Insulin Deficiency Is a Major Contributor to Atrial Fibrillation

Diabetes has been identified as a major independent risk factor for atrial fibrillation (AF), the most common sustained cardiac arrhythmia. However, it is unknown whether glucose and insulin disturbances observed during diabetes directly affect the function of the atria, leading to AF. Thus, we hypothesized that insulin deficiency and impaired glucose transport provide a metabolic substrate for the development and maintenance of AF during diabetes. Transesophageal atrial pacing was used to induce AF in healthy, streptozotocin-induced type 1 diabetic and insulin-treated (via a subcutaneous pump) diabetic mice (n=4-11/group). Translocation of insulin-sensitive glucose transporters (GLUTs) was measured using a photolabeled biotinylation assay in the perfused heart. Atrial fibrosis and glycogen accumulation were measured using histological analyses. As expected, insulin-deficient diabetic mice displayed hyperglycemia (434 ± 50.9 mg/dl) while insulin-treated diabetic mice remained euglycemic (118.8 ± 3.3 mg/dl, p<0.05). At 8 weeks, diabetic mice displayed increased duration and frequency of AF episodes vs. age-matched controls (e.g., AF duration: 18.7 ± 6.2 s vs. 1.8 ± 1.1 s, respectively, p=0.032), whereas insulin-treated diabetic animals did not. In addition, the frequency of AF episodes was significantly correlated to blood glucose level (p=0.01). GLUT-4 and -8 translocation to the atrial cell surface was significantly downregulated in diabetic mice (by 67% and 79%, respectively; p≤0.001), and rescued by insulin treatment. We did not observe any fibrosis or glycogen accumulation in the atria of (treated and untreated) diabetic mice. We conclude that, in the absence of structural remodeling and atrial fibrosis, insulin and glucose disturbances were sufficient to induce AF during diabetes. Therefore, these data suggest that insulin deficiency during diabetes leads to alterations in glucose transport and energy production in the atria, which enhances its vulnerability to atrial fibrillation. Disclosure Z. Maria: None. A. Campolo: None. B.J. Scherlag: None. J.W. Ritchey: None. V. Lacombe: None.

Abstract 15799: Body Mass Index Modulates Symptomatic Atrial Fibrillation Burden

Introduction: Atrial fibrillation (AF) is the most common sustained arrhythmia and is associated with significant morbidity and increased mortality. Approximately fifty percent of patients have AF-related symptoms and require rhythm control therapy with antiarrhythmic drugs (AADs) or cathether ablation. Obesity is increasingly recognized as an important risk factor for the development of AF. Hypothesis: We assessed the hypothesis that body mass index (BMI) modulates AF symptom severity. Methods: Cross-sectional data was collected from 1429 patients in the Vanderbilt AF Registry. AF burden was assessed using the Toronto Atrial Fibrillation Severity Scale (AFSS), a validated survey tool measuring the frequency, duration and severity of AF episodes. BMI was categorized according to WHO guidelines, with BMIs of 18.5 kg/m 2 -25 kg/m 2 considered normal, 25 kg/m 2 -30 kg/m 2 overweight, 30 kg/m 2 -35 kg/m 2 obese and >35 kg/m 2 morbidly obese. Patients were grouped according to their current AF treatment regimen; no treatment (n=195), rate control with AV-nodal blocking agents (n=388), rhythm control with AADs (n=678) and prior AF ablation (n=220). Results: Morbidly obese patients had higher AFSS scores than normal and overweight patients in the rate control (43.57 vs 38.21: P=0.0057), AAD (46.61 vs. 41.08: P=0.00016) and ablation (44.01 vs. 39.02: P=0.047) groups. In univariate linear models, BMI was associated with an increase in the AFSS score in the rate control (0.27, 95% CI 0.05-0.5, P=0.0181), AAD (0.38, 95% CI 0.21-0.56, P=2.49 x 10 -5 ) and ablation (0.38, 95% CI 0.03-0.73, P=0.033) groups. The association remained significant in the AAD group after adjusting for age, gender, race, and comorbidities (0.29, 95% CI 0.11-0.49, P=0.0024). Conclusion: In conclusion, our results showed that obesity and increasing BMI were associated with a significant increase in patient-reported measures of AF symptom severity and frequency of AF episodes. The association was most significant in patients on rhythm control therapy with AADs. Further research is needed to determine whether this finding is due to an overlap between subjective obesity-related and AF-related symptoms, or whether obesity may modulate response to rhythm control therapies.

Association between the quality of life and asymptomatic episodes of paroxysmal atrial fibrillation in the J-RHYTHM II study

BackgroundParoxysmal atrial fibrillation (AF) patients have a reduced quality-of-life (QoL) despite the fact that the majority of AF episodes are asymptomatic. Asymptomatic AF is likely to be associated with substantial morbidity and mortality rates similar to those with symptomatic AF, whereas its effect on the QoL has not yet been clarified. PurposeWe studied the specific contribution of asymptomatic AF episodes to reducing the QoL. MethodsWe assessed the QoL in 233 patients with paroxysmal AF and hypertension (age 64.9±9.7 years, 71% male) enrolled in the Japanese Rhythm Management Trial II for Atrial Fibrillation (J-RHYTHM II study) using an AF-specific QoL questionnaire (AFQLQ). The AFQLQ comprised 3 components: AFQLQ1, the frequency and duration of symptoms; AFQLQ2, severity of symptoms; and AFQLQ3, limitations in daily activities and mental anxiety. Higher scores indicated a better QoL. Each patient transmitted electrocardiograms for 30s daily at a predetermined time as well as whenever arrhythmia-related symptoms were experienced. We examined the relationship between the 3 AFQLQ components and frequency of symptomatic and asymptomatic AF episodes (days/month) during 12 months of follow-up. ResultsThe symptomatic and asymptomatic AF frequencies were 0.9±3.1 days/month and 1.5±3.5 days/month, respectively. AFQLQ1 negatively correlated with the symptomatic AF frequency (Spearman's correlation coefficient: r=−0.332, p<0.001). AFQLQ2 and AFQLQ3 correlated with both the symptomatic AF frequency (r=−0.27, p<0.001 and r=−0.265, p<0.001, respectively) and asymptomatic AF frequency (r=−0.197, p<0.01 and r=−0.229, p<0.005, respectively). ConclusionThe asymptomatic AF episode frequency correlates with a reduced QoL in patients with paroxysmal AF, suggesting that there would be psychological benefits to its reduction.

147 Thromboembolic risk stratification, anti-thrombotic and anticoagulation use for patients with atrial fibrillation, a clinical audit

<h3>Introduction</h3> Atrial fibrillation (AF) is the most prevalent arrhythmia in primary and secondary healthcare settings. Thromboembolic (TE) risk assessment and initiation of anti-thrombotic or anticoagulation (AT/AC) therapy, according to level of risk, is recommended in both national and international guidelines. NICE guidance stratifies patients with AF in to low, moderate or high risk categories and recommends “aspirin”, “aspirin or warfarin” or “warfarin” therapy respectively. ACC/ESC guidance endorses use of the CHADS₂ scoring system and for scores of 0, 1, or ≥2 recommends “aspirin”, “aspirin or warfarin” or “warfarin” therapy respectively. In addition, it is recommended that AF episode frequency or subtype (paroxysmal (PAF), persistent (PersAF) or chronic (CAF)) does not influence TE risk assessment. We audited UK cardiologists and general practitioners (GPs) to assess adherence to these guidelines. <h3>Methods</h3> We designed an audit questionnaire assessing: (1) use of risk stratification tools, (2) choice of AT/AC for increasing levels of risk, and (3) choice of therapy for a number of hypothetical patients with variable TE risk and variable AF subtype. The questionnaire was distributed by electronic or postal mail to 1176 cardiologists and 621 randomly selected GPs. <h3>Results</h3> In total, 421 responses were received (306 cardiologists, 115 GPs). Overall, 91.4% of responders reported use of TE risk stratification tools (97.1% cardiologists, 76.5% GPs, p&lt;0.001). NICE risk assessment is used by 26.6% of responders (24.5% cardiologists, 32.2% GPs, p=0.14), CHADS₂ by 79.3% (90.2% cardiologists, 50.0% GPs, p&lt;0.001). The frequency of reported use of AT/AC for each risk level of the NICE assessment and CHADS₂ score are shown in Abstract 147 tables 1 and 2 respectively. Type of AF (PAF/PersAF/CAF) reportedly influences the use of AT/AC for 34.3% or responders (24.2% cardiologists, 46.3% GPs, p=0.001). Abstract 147 figure 1 demonstrates AT/AC usage for each of the following hypothetical patients: 1. 61 year old, hypertension, PAF episodes twice a year lasting 1–2 h (NICE risk: mod, CHADS₂ score 1/6). 2. 43 year old, diabetes, PAF episodes weekly lasting 10–12 h (NICE risk: mod, CHADS₂ score 1/6). 3. 53 year old, hypertension, CAF (NICE risk: mod, CHADS₂ score 1/6). 4. 78 year old, no other risk factors, CAF (NICE risk: mod, CHADS₂ score 1/6). 5. 76 year old, hypertension, diabetes, PAF episodes 3–4 times per year lasting &lt;1 hour (NICE risk: high, CHADS₂ score 3/6). 6. 77 year old, hypertension, diabetes, PAF episodes occurring weekly and lasting several hours (NICE risk: high, CHADS₂ score 3/6). 7. 80 year old, previous TIA, CAF (NICE risk: high, CHADS₂ score 3/6). <h3>Conclusions</h3> TE risk stratification tools are reportedly widely used in UK clinical practice. AT/AC use for NICE and CHADS₂ risk levels are mostly appropriate, although warfarin is under recommended for patients with a CHADS₂ score of 2/6. In addition, the use of AT/AC is influenced, inappropriately, by AF episode frequency and subtype.

Impaired Transport Function of the Left Atrium in Patients with Lone Paroxysmal Atrial Fibrillation

Although lone paroxysmal atrial fibrillation (LPAF) is clinically defined as an arrhythmia that occurs in the absence of structural heart disease, it has been suggested that the presence of anatomical substrate is related to LPAF. The aim of the present study is to determine whether structural and functional remodeling of the left atrium (LA) occurs in patients with LPAF, and to identify whether frequent episodes of atrial fibrillation (AF) contribute to LA remodeling. Forty-five patients who diagnosed as LPAF and age-, gender-, and body mass index-matched healthy control subjects (n = 45) were enrolled. Patients were grouped based on the frequency of AF episodes. An echocardiography was performed >2 weeks after last episode of AF without antiarrhythmic drugs. There were no statistical differences in left ventricular (LV) diastolic and systolic functions as well as baseline characteristics between patients and controls, whereas, patients had significantly larger LA volume (LAV), lower active LA emptying fraction (LAEF(active) , P = 0.009) and total LAEF (LAEF(total) , P = 0.005) compared with controls. Passive LAEF (LAEF(passive) ) was not different between patients and controls (P = 0.664). LAEF(active) was significantly depressed in patients with frequent episodes of AF than the others (P = 0.034). Compared with healthy controls, patients with LPAF had increased LAV and depressed LAEF(active) and LAEF(total) without accompanying compensatory increase in LAEF(passive) . LAEF(active) was influenced by frequent episodes of AF. These findings may support the hypothesis that LPAF is "not-so-lone AF" and related to the concealed cardiac dysfunctions.

Randomized trial of angiotensin II-receptor blocker vs. dihydropiridine calcium channel blocker in the treatment of paroxysmal atrial fibrillation with hypertension (J-RHYTHM II Study)

Atrial fibrillation (AF) is a common arrhythmia frequently associated with hypertension. This study was designed to test the hypothesis that lowering blood pressure by angiotensin II-receptor blockers (ARB) has more beneficial effects than by conventional calcium channel blockers (CCB) on the frequency of paroxysmal AF with hypertension. The Japanese Rhythm Management Trial II for Atrial Fibrillation (J-RHYTHM II study) is an open-label randomized comparison between an ARB (candesartan) and a CCB (amlodipine) in the treatment of paroxysmal AF associated with hypertension. Using daily transtelephonic monitoring, we examined asymptomatic and symptomatic paroxysmal AF episodes during a maximum 1 year treatment. The primary endpoint was the difference in AF frequency between the pre-treatment period and the final month of the follow-up. The secondary endpoints included cardiovascular events, development of persistent AF, left atrial dimension, and quality-of-life (QOL). The study enrolled 318 patients (66 years, male/female 219/99, 158 in the ARB group and 160 in the CCB group) treated at 48 sites throughout Japan. At baseline, the frequency of AF episodes (days/month) was 3.8 ± 5.0 in the ARB group vs. 4.8 ± 6.3 in the CCB group (not significant). During the follow-up, blood pressure was significantly lower in the CCB group than in the ARB group (P < 0.001). The AF frequency decreased similarly in both groups, and there was no significant difference in the primary endpoint between the two groups. There were no significant differences between the two groups in the development of persistent AF, changes in left atrial dimension, occurrence of cardiovascular events, or changes in QOL. In patients with paroxysmal AF and hypertension, treatment of hypertension by candesartan did not have an advantage over amlodipine in the reduction in the frequency of paroxysmal AF (umin CTR C000000427).

Symptoms in Atrial Fibrillation

In practice, although the objective goals of therapeutic intervention in atrial fibrillation (AF) are usually framed in terms of the prevention of stroke and of heart failure, the majority of clinical decisions in AF are driven by symptoms.1 The risk of stroke among those with AF is highly heterogeneous and difficult to predict for the individual patient, but there are extensive empirical data supporting current anticoagulation algorithms. A simple awareness of the presence or absence of the arrhythmia is a factor in decisions regarding anticoagulation and cardioversion, but it correlates poorly with arrhythmic episodes.2 The pathophysiological relationship between AF and heart failure is more complex, and data linking intervention for the arrhythmia to a reduction in the incidence of heart failure are much less robust. In the absence of rigorous data on mortality benefit for most interventions in AF, evaluation of the subjective symptom burden in each patient is a central component of the risk-benefit calculation.3 Article see p 268 Symptoms in AF are notoriously variable and difficult to compare among individual patients.1–3 The clinical syndromes associated with AF run the gamut from an incidental ECG finding through acute heart failure to syncope. Nevertheless, approximately 25% to 30% of those with the arrhythmia are asymptomatic. Clinicians managing AF also must deal with the wide range in symptom severity observed in those with substantively similar physiology.2 There is also significant variation in the correlation between symptoms and objective findings for any given individual. In the last few years, concerted efforts have been made to characterize symptoms in a number of clinical trials designed to test management strategies in AF.1,3,4 These efforts have largely relied on generic quality-of-life scales such as the SF-36 questionnaire. Such quality-of-life instruments, although time-consuming to administer, offer a multidimensional assessment of …

Running, esophageal acid reflux, and atrial fibrillation: A chain of events linked by evidence from separate medical literatures

Using a previously described approach to generating novel medical hypotheses, this paper shows how two separate medical literatures taken together can suggest new information not apparent in either literature alone. Many studies have demonstrated that aerobic exercise in healthy people can induce esophageal acidic reflux that increases with the duration and intensity of exercise. Separately, independently of exercise, it has been shown that, in patients with gastroesophageal reflux, esophageal acid exposure can lead to atrial fibrillation (AF) and to other heart dysrhythmias. The two arguments together suggest that a regimen of excessive exercise may be conducive to AF mediated by acid reflux, an implicit, but unpublished, hypothesis. Proton pump inhibitors are widely used to treat gastroesophageal reflux. Remarkably, several small clinical trials of these drugs have been shown also to reduce symptoms and frequency of AF episodes in patients with comorbid acid reflux. Plausible mechanisms have been suggested. These small-scale tests in a highly restricted population may be of particular interest in the light of a possible exercise-reflux-AF causal chain of events in a broader population of athletes. Because the minimum degree of esophageal acidity exposure required to induce AF is unknown, further tests of proton pump inhibitors for that purpose are therefore merited without regard to any known prior reflux in a population of runners with lone AF. The prospect of reducing AF burden with a relatively benign agent is attractive in view of the limited options for effective treatment otherwise available. The study of arrhythmia and esophageal reflux in athletes may offer insights on the origin and natural history of lone atrial fibrillation.

Hybrid Therapy with Right Atrial Catheter Ablation and Previously Ineffective Antiarrhythmic Drugs for the Management of Atrial Fibrillation

Many patients with paroxysmal atrial fibrillation (AF) become refractory to antiarrhythmic drugs (AADs). Early studies suggested that linear catheter ablation in the right atrium may provide sufficient substrate modification to reestablish therapeutic efficacy of previously ineffective AADs. This prospective before-after multicenter trial evaluated the safety and effectiveness of hybrid therapy that included right atrial catheter ablation coupled with a regimen of previously ineffective AADs on AF episode frequency and symptoms in drug refractory patients with paroxysmal AF. A standard linear lesion set (lateral, septal, isthmus) was used in all subjects. AF episode frequency, clinical arrhythmia symptoms, condition-specific (AFSS) and global health-related quality of life (SF-36) were assessed prior to ablation and at 6 months. Ninety-three subjects, refractory to an average 2.9 AADs at baseline, qualified for inclusion and underwent right atrial catheter ablation. Eighty-four subjects (90%) provided 6 month AF episode frequency data which demonstrated a significant decrease compared to baseline (3.4 vs. 9.5, p < 0.0001). Forty-nine subjects (58%) were considered a clinical success by virtue of achieving a pre-specified target level episode frequency reduction of 50% or greater. Substantial and statistically significant improvements were realized almost uniformly for all measured arrhythmia symptoms as well as for both quality of life measures. The incidence of major complications was 5.4%. The addition of right atrial catheter ablation to a regimen of previously ineffective AADs is associated with a significant reduction in the frequency, duration and severity of AF episodes and symptoms.

Percutaneous Transvenous Mitral Commissurotomy and Radiofrequency Catheter Ablation in Patients With Mitral Stenosis Initial Experience and Results

The purpose of this study was to evaluate the short- and long-term results of radiofrequency catheter ablation (RFCA) for the treatment of atrial fibrillation (AF) in patients with mitral stenosis (MS) following percutaneous transvenous mitral commissurotomy (PTMC). Four patients (2 males, age 59+/-6 years) underwent simultaneous PTMC and pulmonary vein (PV) ablation. All patient had AF and MS (2 had persistent AF >1 month, 2 had paroxysmal AF), and the mean duration of AF was 3.4+/-3.3 years. The mean left atrial dimension was 47+/-7 mm and the mean ejection fraction was 58+/-4%. After PTMC, RFCA was performed in all patients (3 underwent PV isolation and 1 had PV focal ablation). The mitral valve area increased from 1.11 +/-0.19 to 1.90+/-0.20 cm(2) (p < 0.01). The frequency of AF episodes was dramatically reduced in the 2 patients with paroxysmal AF, and the 1 with persistent AF maintained sinus rhythm, but 1 patient with persistent AF developed recurrent AF. No complications or cardiac events occurred in any of the patients. The combination of RFCA and PTMC was safe and feasible, and may be useful in patients with MS and AF.

Transvenous Catheter Cryoablation for Treatment of Atrial Fibrillation:

Pulmonary vein (PV) isolation using radiofrequency (RF) ablation can induce PV stenosis. Cryoablation may offer a safer alternative energy source for PV isolation. PV isolation with cryoablation was attempted in 31 patients with paroxysmal atrial fibrillation (AF). Event monitors were used to measure the AF episode burden. Serial spiral CT scans were obtained to monitor PV stenosis pre- and postcryoablation. Cryoablation was immediately successful for PV isolation in 29 of 31 patients (94%), with 5.9 +/- 1.2 months of follow-up. Additional RF ablation was performed for AF recurrences in seven patients. The remaining 22 patients with a single cryoablation procedure demonstrated a time-dependent, long-term reduction in the frequency of AF episodes. At 6 months of follow-up, 18 of 22 of cryo-treated only patients (82%) were free of symptomatic AF episodes, and antiarrhythmic drugs were discontinued in 12 of 22 patients. Serial spiral CT scans demonstrated no change in the cryo-treated PV ostial diameter. PV cryoablation was effective to control paroxysmal AF in most patients. Early recurrences of AF postcryoablation were common, though tended to resolve within 6 months postablation, consistent with a process of reverse atrial remodeling. Cryoablation of the PVs did not cause PV stenosis or other serious adverse events.