Predictors of Recurrence after Catheter Ablation of Paroxysmal Atrial Fibrillation in Different Follow-Up Periods.

Background and objectives: Pulmonary vein (PV) reconnection is a major reason for recurrence after catheter ablation of paroxysmal atrial fibrillation (PAF). However, the timing of the recurrence varies between patients, and recurrence >1 year after ablation is not uncommon. We sought to elucidate the characteristics of atrial fibrillation (AF) that recurred in different follow-up periods. Materials and Methods: Study subjects comprised 151 consecutive patients undergoing initial catheter ablation of PAF. Left atrial volume index (LAVi) and atrial/brain natriuretic peptide (ANP/BNP) levels were systematically measured annually over 3 years until AF recurred. Results: Study subjects were classified into four groups: non-recurrence group (n = 84), and short-term- (within 1 year) (n = 30), mid-term- (1-3 years) (n = 26), and long-term-recurrence group (>3 years) (n = 11). The short-term-recurrence group was characterized by a higher prevalence of diabetes mellitus (hazard ratio 2.639 (95% confidence interval, 1.174-5.932), p = 0.019 by the Cox method), frequent AF episodes (≥1/week) before ablation (4.038 (1.545-10.557), p = 0.004), and higher BNP level at baseline (per 10 pg/mL) (1.054 (1.029-1.081), p < 0.0001). The mid-term-recurrence group was associated with higher BNP level (1.163 (1.070-1.265), p = 0.0004), larger LAVi (mL/m2) (1.033 (1.007-1.060), p = 0.013), and longer AF cycle length at baseline (per 10 ms) (1.194 (1.058-1.348), p = 0.004). In the long-term-recurrence group, the ANP and BNP levels were low throughout follow-up, as with those in the non-recurrence group, and AF cycle length was shorter (0.694 (0.522-0.924), p = 0.012) than those in the other recurrence groups. Conclusions: Distinct characteristics of AF were found according to the time to first recurrence after PAF ablation. The presence of secondary factors beyond PV reconnections could be considered as mechanisms for the recurrence of PAF in each follow-up period.

A Long-Term Survivor with Tetralogy of Fallot Treated Only with the Classical Blalock-Taussig Shunt.

The prognosis of tetralogy of Fallot (TOF) treated only with Blalock-Taussig shunt (BTS) operation is unclear. A woman with TOF underwent classic BTS operation at 10 years of age. Despite no medication, she delivered two children and worked without apparent heart failure. At 72 years of age, she complained of dyspnea on exertion and leg edema. The cardiac angiogram revealed a well-patent BTS and severely stenotic right ventricular outflow tract. Right heart catheterization showed adequately maintained pulmonary blood flow with slight pulmonary arterial hypertension. Her unexpected yet favorable outcome reaffirms the importance of structural and functional self-adaptation even with cyanosis. If she had undergone a valve-sparing corrective surgery in adolescence, much better quality of life and outcome could have been expected.

Underrecognized entity of the transient rise in the atrial capture threshold early after dual-chamber pacemaker implantation.

BACKGROUND: Steroid-eluting pacemaker leads suppress acute rises in pacing threshold by preventing inflammatory processes. However, we occasionally encounter not persistent but transient rise in the atrial capture threshold (TRACT) early after pacemaker implantation. We believe that this phenomenon is underrecognized in clinical practice and may potentially lead to unnecessary reintervention. We aimed to clarify the prevalence, predictors, and possible mechanisms of TRACT. METHODS AND RESULTS: We reviewed clinical records from 239 consecutive patients who underwent dual-chamber pacemaker implantation for sick sinus syndrome (SSS) (N = 102) or atrioventricular block (AVB) (N = 137). Atrial capture threshold was measured at implantation and 7 days, 2 months, and 8 months postimplantation. TRACT was defined as a rise in the threshold at day 7 to ≥twice that at implantation, with an absolute value ≥1.0 V/0.4 ms, and full recovery by 8 months into follow-up. TRACT was observed in 15 patients (6%), of whom13 (87%) suffered from SSS but not AVB. Patients with TRACT had greater body mass index (BMI) (25 ± 5 kg/m2 vs 23 ± 4 kg/m2 , P = 0.01), larger left atrium (42 ± 5 mm vs 38 ± 7 mm, P = 0.03), and were more likely to suffer from paroxysmal atrial fibrillation (60% vs 31%, P = 0.02) than those without TRACT. In multivariable logistic regression analysis, BMI and SSS were the independent predictors of TRACT (odds ratio [OR], 1.172; 95% confidence interval [CI], 1.019-1.349; P = 0.03 and OR, 11.53; 95% CI, 2.010-66.21; P = 0.006, respectively). CONCLUSIONS: The distinct phenomenon of TRACT was not rare in clinical practice early after dual-chamber pacemaker implantation, and its occurrence was strongly associated with SSS.

Electrophysiological relation between the superior vena cava and right superior pulmonary vein in patients with paroxysmal atrial fibrillation.

INTRODUCTION: The superior vena cava (SVC) is a main source of nonpulmonary vein (PV) ectopies initiating atrial fibrillation (AF). Empiric SVC isolation may improve rhythm outcomes after catheter ablation of AF. Because the SVC passes immediately adjacent to the right superior PV (RSPV), an electrophysiological relation could be present between the two structures. The present study aimed to estimate the interrelation between the SVC and RSPV by evaluating arrhythmogenic activities observed during catheter ablation of AF. METHODS AND RESULTS: Study subjects comprised 121 consecutive patients referred for catheter ablation of paroxysmal AF. Isoproterenol infusion was used to induce ectopies and AF. Patients were divided into two groups depending on the presence of arrhythmogenic SVC: arrhythmogenic-SVC (A-SVC) and nonarrhythmogenic SVC (Non-A-SVC) groups. The prevalence of females was higher and body surface area was smaller in the A-SVC group (N = 22) than Non-A-SVC group (N = 99). Arrhythmogenic activities were observed in 60 (49%) RSPVs, 24 (20%) right inferior PVs, 72 (59%) left superior PVs, and 31 (25%) left inferior PVs. Arrhythmogenic RSPVs were more prevalent in the A-SVC group than Non-A-SVC group (86% vs. 41%, P = 0.0001), whereas these prevalences in the other three PVs were not different between groups (P >0.3). In multivariable analysis, arrhythmogenic RSPV was the only independent predictor of arrhythmogenicity of the SVC (OR, 8.53; 95% CI 2.31-31.46; P = 0.001). CONCLUSIONS: An electrophysiological interrelation may be present between the SVC and RSPV in patients with paroxysmal AF. Semiempiric SVC isolation limited to patients with an arrhythmogenic RSPV may be a more efficient treatment strategy.

Comparison of Pulmonary Venous and Left Atrial Remodeling in Patients With Atrial Fibrillation With Hypertrophic Cardiomyopathy Versus With Hypertensive Heart Disease.

Left ventricular diastolic dysfunction in hypertrophic cardiomyopathy (HC) increases susceptibility to atrial fibrillation. Although phenotypical characteristics of the hypertrophied left ventricle are clear, left atrial (LA) and pulmonary venous (PV) remodeling has rarely been investigated. This study aimed to identify differences in LA and PV remodeling between HC and hypertensive heart disease (HHD) using 3-dimensional computed tomography. Included were 33 consecutive patients with HC, 25 with HHD, and 29 without any co-morbidities who were referred for catheter ablation of atrial fibrillation. Pre-ablation plasma atrial and brain natriuretic peptide levels, post-ablation troponin T level, and LA pressure were measured, and LA and PV diameters were determined 3 dimensionally. LA transverse diameter in the control group was smaller than that in the HHD or HC group (55 ± 6 vs 63 ± 9 vs 65 ± 12 mm, p = 0.0003). PV diameter in all 4 PVs was greatest in the HC group and second greatest in the HHD group (21.0 ± 3.1 vs 23.8 ± 2.8 vs 26.8 ± 4.1 mm, p <0.0001 for left superior PV). Differences in PV size between the HHD and HC groups were enhanced by indexing to the body surface area (12.4 ± 1.9 vs 13.1 ± 1.4 vs 16.1 ± 3.3 mm/m2, p <0.0001). The PV/LA diameter ratio was greater in the HC than in the other groups (0.38 ± 0.06 vs 0.38 ± 0.05 vs 0.42 ± 0.07, p = 0.01). Atrial natriuretic peptide, brain natriuretic peptide, troponin T levels, and LA pressure were highest in the HC group (all p <0.05). In conclusion, the stiff LA caused from atrial hypertrophy may account for higher levels of biomarkers, higher LA pressure, and PV-dominant remodeling in HC.

Long-Term Prognosis of Brugada-Type ECG and ECG With Atypical ST-Segment Elevation in the Right Precordial Leads Over 20 Years: Results From the Circulatory Risk in Communities Study (CIRCS).

BACKGROUND: Brugada syndrome is recognized as being associated with sudden cardiac death; however, the prevalence of non-type 1 Brugada-type ECG (BrS) or atypical ST-segment elevation in the right precordial leads (STERP) and the long-term prognosis for those patients remain unknown. METHODS AND RESULTS: We analyzed standard 12-lead ECGs of 7178 apparently healthy participants (age range 40-64 years) who underwent health checkups from 1982 to 1986 in the Circulatory Risk in Communities Study, a prospective, large, community-based cohort study in Japan. ECGs with J point amplitude ≥0.2 mV in the right precordial leads were divided into 3 groups: (1) type 1 BrS, (2) type 2 or 3 BrS (non-type 1 BrS), and (3) STERP. The others served as the non-ST-segment elevation group. We identified 8 participants (0.1%) with type1 BrS, 84 (1.2%) with non-type 1 BrS, and 228 (3.2%) with STERP. During a median follow-up of 18.7 years (133 987.0 person-years), sudden cardiac death was observed in no participants (0.0%) with type 1 BrS, in 1 (1.2%) with non-type 1 BrS, in 7 (3.1%) with STERP, and in 50 (0.7%) with non-ST-segment elevation. Participants with STERP had a markedly elevated risk of sudden cardiac death (multivariable hazard ratio 3.9, 95% CI 1.7-9.0). CONCLUSIONS: STERP was associated with an elevated risk of sudden cardiac death in a middle-aged population.

[Acquired Left Ventricular-right Atrial Communication due to Infective Endocarditis;Report of a Case].

A 77-year-old woman presented with a 3-week history of low grade fever, appetite loss and dizziness. An electrocardiogram showed complete heart block. Echocardiography demonstrated severe aortic valve stenosis and a mass of probable vegetation 2 cm in diameter on the atrioventricular septum in the right atrium (RA), but no obvious intra-cardiac fistula. There was no growth of organism in blood cul tures. In the 4th week after admission, a harsh and continuous cardiac murmur was detected for the 1st time. Portable echocardiography revealed disappearance of the mass in the RA, and showed an intra-cardiac shunt from the left ventricle( LV) to RA. The shunt was closed by autologous pericardial patch form LV side and directly with mattress suture form RA side during the emergency operation. The aortic valve was replaced with bio-prosthetic valve (SJM Trifecta 19 mm). No organism was detected in the excised tissue, but antibiotics were continued for 2 months until a permanent pacemaker was inserted.

Concomitant obstructive sleep apnea increases the recurrence of atrial fibrillation following radiofrequency catheter ablation of atrial fibrillation: clinical impact of continuous positive airway pressure therapy.

BACKGROUND: Recent studies have suggested an emerging link between obstructive sleep apnea (OSA) and atrial fibrillation (AF). Patients with OSA are less likely to remain in sinus rhythm after radiofrequency catheter ablation of AF. OBJECTIVE: To evaluate the efficacy of appropriate treatment with continuous positive airway pressure (CPAP) on recurrences of AF after ablation. METHODS: This study prospectively included 153 patients (128 men; 60 ± 9 years) who underwent extensive encircling pulmonary vein isolation for drug refractory AF. The standard overnight polysomnographic evaluation was performed 1 week after ablation, and the total duration and the number of central or obstructive sleep apnea or hypopnea episodes were examined. RESULTS: Of 153 patients, 116 patients were identified as having OSA. Data regarding the use of CPAP and recurrences of AF were obtained in 82 patients. The remaining 34 patients with OSA were defined as the no-CPAP group. Polysomnography revealed no sleep-disordered breathing in 37 patients. During a mean follow-up period of 18.8 ± 10.3 months, 51 (33%) patients experienced AF recurrences after ablation. A Cox regression analysis revealed that the left atrial volume (hazard ratio [HR] 1.11; 95% confidence interval [CI] 1.01-1.23; P<.05), concomitant OSA (HR 2.61; 95% CI 1.12-6.09; P<.05), and usage of CPAP therapy (HR 0.41; 95% CI 0.22-0.76; P<.01) were associated with AF recurrences during the follow-up period. CONCLUSIONS: Patients with untreated OSA have a higher recurrence of AF after ablation. Appropriate treatment with CPAP in patients with OSA is associated with a lower recurrence of AF.

Radiofrequency catheter ablation of persistent atrial fibrillation decreases a sleep-disordered breathing parameter during a short follow-up period.

BACKGROUND: Obstructive sleep apnea (OSA) is often associated with atrial fibrillation (AF), but the impact of radiofrequency catheter ablation (RFCA) for AF on sleep apnea syndrome is unknown. METHODS AND RESULTS: A total of 25 patients (3 women; 61 ± 6 years) with sleep apnea syndrome who underwent RFCA for drug-refractory, persistent AF were studied. Polysomnography was also performed 1 day before and 1 week after RFCA in all patients. The total number of central or OSA or hypopnea events was analyzed and compared. Among the 25 patients who all predominantly had obstructive apnea, the apnea-hypopnea index (AHI; median, 21, interquartile range [IQR]: 11-38 to median 15, IQR: 7-23; P=0.002) and obstructive type of apnea (median 10, IQR: 6-19 to median 7, IQR: 2-14; P=0.003) decreased after RFCA. In patients in whom sinus rhythm was restored and maintained after RFCA, the AHI decreased after RFCA (median 22, IQR: 15-38 to median 15, IQR: 7-23; P<0.01), but it did not in those who had AF recurrence (median 10, IQR: 9-11 to median 11, IQR: 10-16; P<0.05). There was a significant correlation between the outcome of RFCA and % change in the AHI (rs=0.569, P=0.003). CONCLUSIONS: In patients with sleep apnea syndrome and AF, restoring sinus rhythm by RFCA was significantly associated with a decrease in AHI (Clinical Trial Registration: Trial number, UMIN000005538).

Prognostic value of cardiopulmonary exercise testing in cardiac patients with atrial fibrillation.

Parameters obtained from cardiopulmonary exercise testing (CPX) are recognized for their high prognostic value in predicting future cardiac events in cardiac patients. Our group compared the prognostic value of CPX parameters between patients with sinus rhythm (SR) and patients with atrial fibrillation (AF).Peak O2 uptake (VO2), the ratio of the increase in VO2 to the increase in work rate (ΔVO2/ΔWR), and the slope of the increase in ventilation to the increase in CO2 output (VE-VCO2 slope) were obtained from CPX in 72 AF patients and 478 SR patients. The prognostic values of these indices were compared between the two groups.Six cardiac deaths and 25 cardiac events were observed in the AF group and 9 cardiac deaths and 96 cardiac events were observed in the SR group, over a prospective follow-up period of 1,192 days. The percentages of cardiac deaths and cardiac events were higher in the AF group than in the SR group. In a multivariate Cox proportional hazards analysis, peak VO2 was identified as a sole significant predictor of cardiac death and cardiac events in SR patients and VE-VCO2 slope was identified as a sole significant predictor of cardiac death and cardiac events in AF patients.Our results suggest that the VE-VCO2 slope is strongly predictive of future cardiac events in patients with AF and that peak VO2 is strongly predictive of future cardiac events in SR patients.

Overshoot phenomena of respiratory gas variables during exercise recovery in cardiac patients.

BACKGROUND: Transient increases (overshoot) in respiratory gas variables have been observed during exercise recovery, but their clinical significance is not clearly understood. Our group evaluated the relationship between the presence of overshoot of respiratory gas variables and the parameters obtained from cardiopulmonary exercise testing (CPX). METHODS AND RESULTS: In total, 227 patients with various cardiac diseases underwent CPX. The overshoot phenomena of O2 uptake (·VO2), ·VO2/heart rate (O2-pulse), and CO2 output (·VCO2) were analyzed by respiratory gas analysis during recovery after maximal exercise. The overshoot of ·VO2, O2-pulse, and ·VCO2 were recognized in 11 (5%), 43 (19%), and 12 (5%) patients, respectively. Compared with the patients without a ·VO2 overshoot, those with a ·VO2 overshoot had a significantly lower peak ·VO2 (12.3±3.7 vs. 17.9±6.2ml·min⁻¹·kg⁻¹, P=0.003), lower anaerobic threshold (9.4±1.7 vs. 12.4±3.3 ml·min⁻¹·kg⁻¹, P=0.001), higher ·VE-·VCO2 slope (38.0±5.2 vs. 33.2±9.6, P=0.013), and lower left ventricular ejection fraction (LVEF) (39.9±22.8 vs. 55.8±16.8%, P=0.003). Similar findings were obtained for the patients with an O2-pulse overshoot and those with a ·VCO2 overshoot. CONCLUSIONS: The overshoot phenomena of respiratory gas variables during recovery after maximal exercise are correlated with impaired cardiopulmonary function during exercise in cardiac patients.

Abnormal end-tidal PO(2) and PCO(2) at the anaerobic threshold correlate well with impaired exercise gas exchange in patients with left ventricular dysfunction.

BACKGROUND: The aim of the present study was to compare the end-tidal O(2) pressure (PETO(2)) to end-tidal CO(2) pressure (PETCO(2)) in cardiac patients during rest and during 2 states of exercise: at anaerobic threshold (AT) and at peak. The purpose was to see which metabolic state, PETO(2) or PETCO(2), best correlated with exercise limitation. METHODS AND RESULTS: Thirty-eight patients with left ventricular (LV) ejection fraction <40% underwent cardiopulmonary exercise testing (CPX). PETO(2) and PETCO(2) were measured during CPX, along with peak O(2) uptake (VO(2)), AT, slope of the increase in ventilation (VE) relative to the increase in CO(2) output (VCO(2)) (VE vs. VCO(2) slope), and the ratio of the increase in VO(2) to the increase in work rate (ΔVO(2)/ΔWR). Both PETO(2) and PETCO(2) measured at AT were best correlated with peakVO(2), AT, ΔVO(2)/ΔWR and VE vs. VCO(2) slope. PETO(2) at AT correlated with reduced peak VO(2) (r=-0.60), reduced AT (r=-0.52), reduced ΔVO(2)/ΔWR (r=-0.55) and increased VE vs. VCO(2) slope (r=0.74). PETCO(2) at AT correlated with reduced peak VO(2) (r=0.67), reduced AT (r=0.61), reduced ΔVO(2)/ΔWR (r=0.58) and increased VE vs. VCO(2) slope (r=-0.80). CONCLUSIONS: PETCO(2) and PETO(2) at AT correlated with peak VO(2), AT and ΔVO(2)/ΔWR, but best correlated with increased VE vs. VCO(2) slope. PETO(2) and PETCO(2) at AT can be used as a prime index of impaired cardiopulmonary function during exercise in patients with LV failure.

Prevalence and characteristics of asymptomatic excessive transmural injury after radiofrequency catheter ablation of atrial fibrillation.

BACKGROUND: Even with a low energy setting, radiofrequency energy applications on the left atrial (LA) posterior wall may cause excessive transmural injury (ETI) during catheter ablation of atrial fibrillation (AF). OBJECTIVE: The purpose of this study was to clarify the prevalence and characteristics of ETI. METHODS: This study included 104 patients with AF who underwent extensive encircling pulmonary vein isolation (EEPVI) followed by an endoscopic examination (≤48 hours after EEPVI). EEPVI was performed under conscious sedation, and the ablation settings at the LA posterior wall were a maximum energy of 20 to 25 W and duration of ≤30 seconds. The ETI was defined as any injury that resulted from EEPVI, including esophageal damage or periesophageal nerve injury. RESULTS: ETIs were found in 10 (9.6%) patients and were all asymptomatic; esophageal damage in 4 patients and periesophageal nerve injury in the remaining 6. All patients with ETI were below normal weight (body mass index [BMI] < 24.9 kg/m(2)), and consisted of 17% of those below normal weight. The procedural parameters such as the type of energy source, total duration of energy applications to the LA posterior wall, additional LA linear ablation, and biochemical markers were not related to the ETI. In the logistic multiadjusted model, the BMI (per 1 kg/m(2)) was the only independent predictor of ETI (odds ratio = 0.76; 95% confidence interval = 0.59 to 0.97, P < .05). CONCLUSION: Asymptomatic ETIs were not rare even with a low energy setting in patients below normal weight. Tailored energy settings based on the patient's BMI may be required when performing EEPVI.

A case of 24 years longevity of an Ionescu-Shiley bioprosthesis in the mitral position.

Valve dysfunction, attributed to primary tissue failure several years after implantation of Ionescu-Shiley bioprostheses, has led to re-operation in most cases. We report a rare case of this bioprosthesis showing stenosis and regurgitation after implantation in the mitral position 24 years previously. No cusp tears, but severe calcification and well-grown neointima over the Dacron cloth of the inner surface were observed. This may explain how the valve functioned for such a long period of time. We replaced it with a Carpentier-Edwards pericardial bioprosthesis.