When Is Cardiac Resynchronization Therapy with a Defibrillator Indicated in Patients with Heart Failure, Especially Elderly Patients?

One benefit of an implantable cardioverter-defibrillator is the prevention of sudden cardiac death (SCD). It is recommended for patients with a low left ventricular ejection fraction (LVEF). However, the choice of cardiac resynchronization therapy (CRT) with or without a defibrillator (CRT-D and CRT-P) in elderly patients is controversial. To understand the current situation for proper device selection, we investigated the impact of defibrillators on mortality in elderly patients with heart failure.Consecutive patients who underwent CRT implantation were retrospectively recruited. Baseline characteristics, all-cause mortality, cardiac death, and defibrillator implantation rates were investigated in patients aged > 75 or ≤ 75 years.A total of 285 patients (79 patients aged > 75 years) were analyzed. Elderly patients had more comorbidities, but a lower proportion had ventricular arrhythmia. During the mean follow-up of 47 months, 109 patients died (67 due to cardiac death). Kaplan-Meier analysis showed higher mortality in elderly patients (P = 0.0428) but no significant difference in cardiac death by age group (P = 0.7472). There were no significant differences in mortality between patients with CRT-D versus CRT-P (P = 0.3386).SCD was rare. A defibrillator had no significant impact on mortality. In elderly patients, comorbidities are common and related to mortality. The selection of CRT-D versus CRT-P should take those factors into account.

AV timing in pacemaker patients with first-degree AV block: which is preferable, intrinsic AV conduction or pacing?

Some patients with pacemakers present with first-degree atrioventricular (AV) block. To avoid right ventricular (RV) pacing, preserving intrinsic AV conduction as much as possible is recommended. However, there is no clear cutoff AV interval to determine whether intrinsic AV conduction should be preserved or RV pacing should be delivered. This study aimed to compare a pacing mode-preserving, intrinsic AV conduction with the DDD mode delivering RV pacing in terms of echocardiographic parameters in patients with first-degree AV block and to investigate whether RV pacing induces heart failure (HF). Stroke volume (SV) was measured to determine the optimal AV delay with the intrinsic AV conduction rhythm and the DDD pacing delivering RV pacing. Echocardiographic evaluation was performed for 6-month follow-up period. Seventeen patients were studied. At baseline, mean intrinsic PQ interval was 250 ± 40 ms. SV was greater with RV pacing with optimal AV delay of 160 ms than with intrinsic AV conduction rhythm in all patients. Therefore, pacemakers were set to the DDD to deliver RV pacing. During follow-up, seven patients developed HF. Mean baseline E/E' ratio in patients who developed HF (HF group) during RV pacing was higher than in patients without HF (non = HF group; 17.9 ± 8 versus 11.5 ± 2, P = 0.018) Even within HF group patients without a high baseline E/E' ratio, it increased with RV pacing (22.2 ± 6 versus 11.6 ± 2; P < 0.001). In patients with pacemaker and first-degree AV block, RV pacing with the optimal AV delay of 160 ms increased SV. However, the risk of HF may be increased with RV pacing if the E/E' ratio is > 15 during intrinsic AV conduction or RV pacing. RV pacing should be avoided in patients with high E/E' ratio under intrinsic AV conduction or RV pacing.

Clinical significance of the albumin-bilirubin score in patients with heart failure undergoing cardiac resynchronization therapy.

Despite emerging recognition of interactions between heart failure (HF) and liver dysfunction, the impact of cardiac hepatopathy on patients with HF undergoing cardiac resynchronization therapy (CRT) has not been fully elucidated. Albumin-bilirubin (ALBI) score is a new assessment of liver function. The relationship between liver dysfunction severity based on ALBI score and clinical outcomes of patients with HF receiving CRT is unclear. Clinical records of 274 patients who underwent CRT device implantation between March 2003 and October 2020 were retrospectively investigated. ALBI score was calculated based on serum albumin and total bilirubin levels obtained before CRT device implantation. Patients were divided into three groups based on ALBI score: first tertile (ALBI ≤ - 2.62, n = 91)), second tertile (- 2.62 < ALBI < - 2.13, n = 92), and third tertile (ALBI ≥ - 2.13, n = 91). The study endpoint was all-cause mortality. The third tertile group had more advanced NYHA functional class, lower hemoglobin levels, and higher total bilirubin, aspartate aminotransferase, γ-glutamyl transferase, and N-terminal Pro-B-type natriuretic peptide levels (all p < 0.05). The third tertile group also had a higher prevalence of moderate or severe tricuspid regurgitation and higher tricuspid regurgitation pressure gradient (all p < 0.05). CRT response rates were significantly lower in the third tertile group. During a median (interquartile range) follow-up of 30 (9-60) months, 104 (37.9%) patients died. The third tertile group had significantly higher rates of all-cause mortality (log-rank p < 0.001). Higher ALBI score was significantly associated with all-cause mortality, even after adjusting for clinically relevant factors, a conventional validated risk score, and echocardiographic parameters related to right HF (all p < 0.01). Higher ALBI score before CRT device implantation is associated with HF severity, hepatic congestion and impairment due to right HF, lower CRT response, and higher all-cause mortality in CRT recipients.

Bradyarrhythmia Suspected to be Associated with Sleep Apnea Syndrome.

Sleep apnea syndrome (SAS) is a condition in which apnea and hypoventilation at night cause hypoxemia and impaired wakefulness during the day, resulting in a general malaise and dozing. Sleep apnea has been implicated in the development of hypertension, ischemic heart disease, arrhythmia, heart failure, and cerebrovascular disease.1) Approximately 50% of patients with sleep-disordered breathing have an arrhythmia. In severe cases with an apnea-hypopnea index (AHI) of 30 or more, the frequency of arrhythmias during sleep is two to four times that of individuals without SAS. Bradyarrhythmias such as sinus bradycardia, sinus arrest, and atrioventricular block occurs at night in about 5%-10% of patients with sleep-disordered breathing.2)During nocturnal sleep, vagal excitation causes excessive muscle relaxation of the upper airway, leading to periodic airway diameter reduction, which increases snoring and obstructive apnea. As a result, hypoxemia is likely, further increasing vagal tone and leading to bradycardia. An increase in ventilation rate and volume quickly compensates for the decrease in arterial partial pressure of oxygen during apnea, which leads to new bradycardia due to a decrease in the partial pressure of oxygen in arterial blood, which suppresses vagal tone and respiration.3)We experienced a case of a 44-year-old patient with bradyarrhythmia that might be associated with SAS. After continuous positive airway pressure treatment, AHI decreased, and very long cardiac arrests resolved.

Prognostic Value of Serum N-Terminal Pro-Brain Natriuretic Peptide Level over Heart Failure for Stroke Events and Deaths in Patients with Atrial Fibrillation.

Atrial fibrillation (AF) and heart failure (HF) often coexist. The aims of this study were to explore the factors associated with the serum levels of N-terminal pro-brain natriuretic peptide (NT-proBNP), and the association between prognosis and a history of HF or the serum NT-proBNP level in Japanese patients with AF.The present sub-study was based on the SAKURA AF Registry, a Japanese multicenter observational registry that included 3267 AF patients (median follow-up period: 39 months). All the patients were receiving warfarin or any of four direct oral anticoagulants. Serum NT-proBNP levels were available for 2417 patients, and the median value was 508 (interquartile range 202-1095) pg/mL at the time of enrollment. Log NT-proBNP was associated with non-paroxysmal AF, creatinine clearance > 60 mL/minute, history of HF and ischemic heart disease, antiarrhythmic drug use, anemia, being elderly female, and history of AF ablation. The relative risk of adverse clinical events, except major bleeding, was significantly higher in the highest NT-proBNP quartile as compared to the lowest quartile (adjusted hazard ratios: 2.87 for death, 2.39 for stroke), but a history of HF was associated only with a higher incidence of all-cause death.Concomitant HF was associated with a higher mortality, but the high NT-proBNP was associated with higher mortality and stroke events. In Japanese AF patients receiving anticoagulant treatment, high serum NT-proBNP levels predict the risk for both stroke events and deaths, and intensive follow-up is needed in such patients.

Oral anticoagulant use and clinical outcomes in elderly Japanese patients: findings from the SAKURA AF Registry.

Direct-acting oral anticoagulants (DOACs) are widely used in aged Japanese patients with atrial fibrillation (AF), but outcome data for such patients are limited. We compared outcomes between 1895 (58.5%) patients aged < 75 years (non-elderly), 1078 (33.3%) 75-84 years (elderly) and 264 (8.2%) ≥ 85 years (very elderly) enrolled in a prospective multicenter registry. Kaplan-Meier analysis (median follow-up: 39.3 months) revealed a significantly high incidence of stroke/systemic embolism (SE) among the very elderly relative to that among the non-elderly or elderly (3.2 vs. 1.2 and 1.5 events per 100 patient-years, p < 0.001). Major bleeding in the non-elderly group was significantly infrequent relative to that among the elderly or very elderly group (1.1 vs. 1.6 vs. 1.8 events, p = 0.033). After multivariate adjustment, the stroke/SE incidence was comparable between DOAC and warfarin users, regardless of age, but major bleeding decreased significantly among very elderly DOAC users (adjusted HR 0.220, 95% CI 0.042-0.920). The greater increasing incidence of stroke/SE than major bleeding as patients age suggests that stroke prevention should outweigh the bleeding risk when anticoagulants are being considered for aged patients. Our data indicated that DOACs can be a therapeutic option for stroke prevention in very elderly patients.

Calcified Amorphous Tumor-Induced Acute Cerebral Infarction.

We report the case of a 38-year-old woman who was admitted for acute cerebral infarction linked to a cardiac calcified amorphous tumor (CAT) and related mitral annular calcification (MAC). The cardiac mass was removed, and mitral valve replacement surgery was performed. Pathological examination revealed an amorphous accumulation of degenerating material within both lesions, indicating that build-up of calcium along the mitral annulus and subsequent rupture of the fibrotic tissue may be involved in the initiation and progression of CAT.

Impact of Sinus Node Recovery Time after Long-Standing Atrial Fibrillation Termination on the Long-Term Outcome of Catheter Ablation.

Atrial electrical and structural remodeling is related to the perpetuation of atrial fibrillation (AF) subsequent to sinus node dysfunction. We investigated the relationship between AF recurrence after catheter ablation and sinus node dysfunction in long-standing persistent AF patients using the sinus node recovery time (SNRT) after defibrillation.Fifty-one consecutive patients who underwent a first ablation for long-standing persistent AF were enrolled. Intracardiac cardioversion was applied before ablation in the absence of any antiarrhythmic drugs, and the power required to defibrillate, number, and SNRT after defibrillation were measured. All patients underwent the same designed radiofrequency catheter ablation procedure.No patient required permanent pacemaker implantation due to sinus dysfunction after the ablation. During the follow-up period of 28.4 months (3.6-43.7), 35 out of 51 patients (69%) experienced an AF recurrence. The AF recurrence was significantly associated with an older age (60 ± 11 versus 52 ± 12 years in the non-recurrence group, P = 0.0196), longer SNRT after defibrillation (1722 [1410-2656] versus 1295 [676-1651] msec, P = 0.0125), and larger left atrial (LA) volume (59 ± 25 versus 41 ± 15 mL, P = 0.0119). There were no significant differences in the AF duration, AF cycle length, and right and total atrial conduction times between the 2 groups. A longer SNRT after defibrillation (adjusted HR 2.13, 95%CI 1.16-3.71, P = 0.0152) and larger LA volume (adjusted HR 1.03, 95%CI 1.01-1.04, P = 0.0054) were independent predictors of AF recurrence after ablation.Assessment of the SNRT after defibrillation may help to predict a successful ablation in patients with long-standing persistent AF.

Ventriculoatrial Intervals ≤70 ms in Orthodromic Atrioventricular Reciprocating Tachycardia.

BACKGROUND: Although a ventriculoatrial interval (VAI) of ≤70 ms is used to distinguish atrioventricular nodal reentrant tachycardia from orthodromic atrioventricular reciprocating tachycardia (AVRT), a VAI of ≤70 ms is sometimes observed in cases of AVRT. The study aimed to evaluate the short VAI that is seen in AVRT and to understand its underlying mechanism. METHODS: Electrophysiologic studies of 46 consecutive patients with AVRT involving an accessory pathway (AP) were examined retrospectively. RESULTS: AP was right sided in seven patients and left sided in 39. A VAI (interval from QRS onset to the earliest intracardiac atrial electrogram recorded by any mapping catheter during AVRT) ≤70 ms during AVRT (short VAI) was observed in eight patients: six with a left lateral AP and two with a left posteroseptal AP. During AVRT involving a left-sided AP, the QRS-V interval (from the earliest QRS onset to the local ventricular electrogram at a site which showed earliest atrial electrogram recorded from the coronary sinus catheter) was significantly shorter (37 ± 7 ms vs 54 ± 13 ms, P = 0.001) and supernormal conduction (QRS duration or the QRS-V interval shortening by ≥10 ms during AVRT) was more frequently seen (63% vs 6%, P = 0.02) in the short VAI group than in the normal VAI group. Furthermore, these parameters were shown to be determinants for short VAI. CONCLUSIONS: A short VAI is sometimes observed during AVRT involving a left-sided AP. The short VAI may be caused by rapid propagation or supernormal conduction between the proximal Purkinje-muscle junction and basal left ventricular myocardium.

Difference Between Dormant Conduction Sites Revealed by Adenosine Triphosphate Provocation and Unipolar Pace-Capture Sites Along the Ablation Line After Pulmonary Vein Isolation.

Dormant pulmonary vein (PV) conduction revealed by adenosine/adenosine triphosphate (ATP) provocation test and exit block to the left atrium by pacing from the PV side of the ablation line ("pace and ablate" method) are used to ensure durable pulmonary vein isolation (PVI). However, the mechanistic relation between ATP-provoked PV reconnection and the unexcitable gap along the ablation line is unclear.Forty-five patients with atrial fibrillation (AF) (paroxysmal: 31 patients, persistent: 14 patients; age: 61.1 ± 9.7 years) underwent extensive encircling PVI (EEPVI, 179 PVs). After completion of EEPVI, an ATP provocation test (30 mg, bolus injection) and unipolar pacing (output, 10 mA; pulse width, 2 ms) were performed along the previous EEPVI ablation line to identify excitable gaps. Dormant conduction was revealed in 29 (34 sites) of 179 PVs (16.2%) after EEP-VI (22/45 patients). Pace capture was revealed in 59 (89 sites) of 179 PVs (33.0%) after EEPVI (39/45 patients), and overlapping sites, ie, sites showing both dormant conduction and pace capture, were observed in 22 of 179 (12.3%) PVs (17/45 patients).Some of the ATP-provoked dormant PV reconnection sites were identical to the sites with excitable gaps revealed by pace capture, but most of the PV sites were differently distributed, suggesting that the main underling mechanism differs between these two forms of reconnection. These findings also suggest that performance of the ATP provocation test followed by the "pace and ablate" method can reduce the occurrence of chronic PV reconnections.

Relation Between Left Atrial Wall Thickness in Patients with Atrial Fibrillation and Intracardiac Electrogram Characteristics and ATP-Provoked Dormant Pulmonary Vein Conduction.

INTRODUCTION: Atrial remodeling plays a key role in development of the substrate for atrial fibrillation (AF). Whether the wall thicknesses of the left atrium (LA) and pulmonary vein (PV)-LA junction affect remodeling and AF ablation is unknown. We investigated the relationship between wall thicknesses, electrogram characteristics, and adenosine triphosphate (ATP)-provoked dormant PV conduction as they pertain to AF. METHODS: In 50 patients with AF and 25 patients without AF, wall thicknesses of the LA and PV-LA junction were measured on 320-slice computed tomography images. For the AF patients, NavX-based voltage maps generated during sinus rhythm were obtained, and ATP-provoked dormant PV conduction after PV isolation was evaluated. RESULTS: Walls of the LA and PV-LA junction were significantly thicker in the AF patients than in the control patients (1.83 ± 0.29 mm vs. 1.59 ± 0.28 mm, respectively; P = 0.0010; and 0.88 ± 0.14 mm vs. 0.65 ± 0.11 mm, P<0.0001, respectively). Wall thickness at the PV-LA junction was independently associated with AF (ß = 0.40, P = 0.0002). In AF patients, the walls of the PV-LA junction showed stepwise thickening across bipolar voltages indicative of severe (bipolar voltage <33rd percentile) to moderate (33rd-66th percentiles) to mild fibrosis/scarring (≥66th percentile). Walls of the PV-LA junction with dormant PV conduction were significantly thicker than those without it (0.94 ± 0.19 mm vs. 0.86 ± 0.21 mm, respectively; P = 0.0025). CONCLUSIONS: Together, the association between thickened PV-LA junction walls and AF and the increased bipolar voltage suggests that such wall thickening increases PV electrical activities, leading to initiation and maintenance of AF and perhaps to ATP-provoked dormant PV conduction.

Dramatic Response to Cardiac Resynchronization Therapy With AV Delay Optimization in Narrow QRS Heart Failure.

Cardiac resynchronization therapy (CRT) has been shown to be effective for heart failure. However, as outlined in the AHA/ACC/HRS Appropriate Use Criteria, CRT is not strongly recommended for patients with a narrow QRS complex. We describe a case of dilated cardiomyopathy and narrow QRS complex in which we obtained a dramatic response to CRT by optimizing the atrioventricular (AV) delay. The patient was a 61-year-old man with intractable heart failure. Echocardiography showed a low ejection fraction of 22% but no dyssynchrony. Because he had been hospitalized many times for congestive heart failure despite ß-blocker and diuretic treatment, we decided to use CRT. However, after implantation of the CRT device, the QRS complex widened abnormally, and his symptoms worsened. He was re-admitted 2 months after CRT implantation. We examined the pacemaker status and optimized the AV delay to obtain a "narrow" QRS complex. The patient's condition improved dramatically after the AV delay optimization. His clinical status has been good, and there has been no subsequent hospitalization. Our case points to the effectiveness of CRT in patients with a narrow QRS complex and to the importance of AV optimization for successful CRT.

Tissue velocity imaging-based atrial fibrillatory cycle length and wall motion for predicting atrial structural remodeling in patients undergoing catheter ablation.

BACKGROUND: Atrial fibrillation (AF) causes atrial electrical and structural remodeling, which are linked to recurrence of AF after ablation. Atrial fibrillatory cycle length (AFCL) and AF wall motion velocity (AFW-V) obtained by tissue velocity imaging (TVI) might characterize such atrial electrical and structural remodeling. The purpose of this study was to assess the clinical and electrophysiologic correlates of these parameters and their relation to ablation outcomes. METHODS AND RESULTS: The study group comprised 80 patients who underwent transthoracic echocardiography followed by AF ablation. Atrial TVI traces were used to determine AFCL-tvi and AFW-V-tvi at the left atrial septal wall. AFCL that was measured from intracardiac electrograms correlated well with AFCL-tvi (R=0.6094; P=0.0002). AFW-V-tvi was significantly lower and AFCL-tvi was significantly shorter in patients with non-paroxysmal AF than in those with paroxysmal AF (1.63±0.76 cm/s vs. 2.85±1.00 cm/s, respectively, P<0.0001; and 118.2±23.0 ms vs. 145.0±35.0 ms, respectively, P=0.0001). These findings held true for patients with and without post-ablation recurrence. Upon multivariate analysis, a reduced AFW-V-tvi remained the strongest predictor of post-ablation recurrence (hazard ratio for +1-cm/s change, 0.573; 95% confidence interval, 0.337-0.930; P=0.0234). CONCLUSIONS: TVI of atrial fibrillatory wall motion might enhance the non-invasive characterization of atrial remodeling in patients with AF and thus be used for predicting AF recurrence after ablation.

Effects of intravenous amiodarone and ibutilide on action potential duration and atrial conduction kinetics in patients with persistent atrial fibrillation.

Class III antiarrhythmic drugs have been shown to be effective for termination of atrial fibrillation (AF). The aim of this study was to determine the steady state and non-steady state effects of amiodarone and ibutilide on the atrial monophasic action potential (MAP) duration (MAPD), effective refractory period (ERP), and intra-atrial conduction time (IACT) in human persistent AF.Fourteen patients with persistent AF who underwent internal atrial defibrillation were included in the study. The atrial MAP was recorded at the high right atrium. IACT was measured from the pacing spike to the distal coronary sinus. MAPD and IACT were assessed during the steady state and at the shortest diastolic interval (DI) at a basic cycle length (CL) of 600 msec and after a premature stimulus. Amiodarone did not affect MAPD or the ERP at the basic CL, but it increased MAPD at the shortest DI. Amiodarone increased IACT at both the basic CL and the shortest DI. Ibutilide increased the MAPD and ERP at the basic CL and at the shortest DI. Ibutilide did not affect IACT at the basic CL or the shortest DI.Ibutilide increases atrial MAPD not only in the steady state but also at the shortest DI, but it does not affect IACT in patients with persistent AF. Amiodarone does not affect MAPD or ERP, but it increases IACT in the steady state, and it increases MAPD and IACT at the shortest DI.

Multicenter prospective observational study to clarify the current status and clinical outcome in Japanese patients who have an indication for implantable cardioverter defibrillator (ICD) or wearable cardioverter defibrillator (WCD) (TRANSITION JAPAN-ICD/WCD study): Rationale and design of a prospective, multicenter, observational, comparative study.

Background: Despite the positive impact of implantable cardioverter defibrillators (ICDs) and wearable cardioverter defibrillators (WCDs) on prognosis, their implantation is often withheld especially in Japanese heart failure patients with reduced left ventricular ejection fraction (HFrEF) who have not experienced ventricular tachycardia (VT) or ventricular fibrillation (VF) for uncertain reasons. Recent advancements in heart failure (HF) medications have significantly improved the prognosis for HFrEF. Given this context, a critical reassessment of the treatment and prognosis of ICDs and WCDs is essential, as it has the potential to reshape awareness and treatment strategies for these patients. Methods: We are initiating a prospective multicenter observational study for HFrEF patients eligible for ICD in primary and secondary prevention, and WCD, regardless of device use, including all consenting patients. Study subjects are to be enrolled from 31 participant hospitals located throughout Japan from April 1, 2023, to December 31, 2024, and each will be followed up for 1 year or more. The planned sample size is 651 cases. The primary endpoint is the rate of cardiac implantable electronic device implementation. Other endpoints include the incidence of VT/VF and sudden death, all-cause mortality, and HF hospitalization, other events. We will collect clinical background information plus each patient's symptoms, Clinical Frailty Scale score, laboratory test results, echocardiographic and electrocardiographic parameters, and serial changes will also be secondary endpoints. Results: Not applicable. Conclusion: This study offers invaluable insights into understanding the role of ICD/WCD in Japanese HF patients in the new era of HF medication.

Effect of catheter tip-tissue surface contact on three-dimensional left atrial and pulmonary vein geometries: potential anatomic distortion of 3D ultrasound, fast anatomical mapping, and merged 3D CT-derived images.

UNLABELLED: Anatomic Distortion of 3D Mapping. BACKGROUND: Although catheter tip-tissue contact is known as a reliable basis for mapping and ablation of atrial fibrillation (AF), the effects of different mapping methods on 3-dimensional (3D) map configuration remain unknown. METHODS AND RESULTS: Twenty AF patients underwent Carto-based 3D ultrasound (US) evaluation. Left atrium (LA)/pulmonary vein (PV) geometry was constructed with the 3D US system. The resulting geometry was compared to geometries created with a fast electroanatomical mapping (FAM) algorithm and 3D US merged with computed tomography (merged 3D US-CT). The 3D US-derived LA volumes were smaller than the FAM- and merged 3D US-CT-derived volumes (75 ± 21 cm(3) vs 120 ± 20 cm(3) and 125 ± 25 cm(3) , P < 0.0001 for both). Differences in anatomic PV orifice fiducials between 3D US- and FAM- and merged 3D US-CT-derived geometries were 6.0 (interquartile range 0-9.3) mm and 4.1 (0-7.0) mm, respectively. Extensive encircling PV isolation guided by 3D US images with real-time 2D intracardiac echocardiography-based visualization of catheter tip-tissue contact generated ablation point (n = 983) drop-out at 1.9 ± 3.8 mm beyond the surface of the 3D US-derived LA/PV geometry. However, these same points were located 1.5 ± 5.4 and 0.4 ± 4.1 mm below the FAM- and merged 3D US-CT-derived surfaces. CONCLUSIONS: Different mapping methods yield different 3D geometries. When AF ablation is guided by 3D US-derived images, ablation points fall beyond the 3D US surface but below the FAM- or merged 3D US-CT-derived surface. Our data reveal anatomic distortion of 3D images, providing important information for improving the safety and efficacy of 3D mapping-guided AF ablation. (J Cardiovasc Electrophysiol, Vol. 24, pp. 259-266, March 2013).

Rate-dependent electrophysiologic effects of the class III antiarrhythmic drugs nifekalant, amiodarone, and ibutilide on the atrium in patients with persistent atrial fibrillation.

Persistent atrial fibrillation (AF) is characterized by electrical remodeling, ie, marked decreases in the atrial effective refractory period (ERP), ERP rate adaptation, and atrial conduction velocity. Little information is available on the effects of class III antiarrhythmic drugs on the remodeled atrium. We studied the effects of the class III antiarrhythmic drugs nifekalant, ibutilide, and amiodarone on rate-dependent changes in atrial action potential duration in patients with persistent AF. Right atrial (RA) monophasic action potential duration (MAPD) and intra-atrial conduction time (IACT) were measured at pacing cycle lengths (CLs) of 800, 700, 600, 500, 400, 350, 300, and 250 ms before and after administration of nifekalant (0.4 mg/kg + 0.3 mg/kg/hr, iv), amiodarone (5 mg/kg, iv), or ibutilide (0.01 mg/kg, iv) in 31 patients after successful internal cardioversion of chronic AF of > 2 months duration. Nifekalant and ibutilide significantly increased RA MAPD and the ERP at each CL in a reverse rate-dependent manner. Amiodarone did not affect RA MAPD. Nifekalant did not affect IACT, whereas amiodarone increased IACT at each CL in a rate-dependent manner, and ibutilide increased IACT at CLs ≤ 350 ms. The atrial electrophysiologic effects of the class III antiarrhythmic drugs nifekalant, amiodarone, and ibutilide differ, depending on the degree of electrical and structural remodeling and the effects of the drugs on the depolarizing and repolarizing currents.

Three-dimensional high-density bipolar contact mapping of left atrial endocardial activation during sinus rhythm in patients with atrial fibrillation.

Non-contact array mapping studies have demonstrated the existence of a line of conduction block along the septopulmonary bundle area and the posterior left atrial (LA) roof during sinus rhythm (SR). However, little is known of the global LA activation pattern during SR using a high-density contact bipolar mapping system. High-density contact bipolar isochronal mapping (bipolar mapping sites: 292 [IQR 250-348] points) of the LA was performed during SR with the NavX mapping system in 20 patients with paroxysmal atrial fibrillation (AF) and 11 patients with non-paroxysmal AF. The earliest endocardial breakthrough in the the LA from the right atrium (RA) during SR occurred in the anterosuperior LA (77%) or anterior to the right pulmonary veins (23%), and the breakthrough site did not differ between patients with paroxysmal and non-paroxysmal AF. Regardless of the site of breakthrough, the LA activation pattern was homogeneous, and no line of functional block was observed in any patient. Total LA activation time was significantly longer in non-paroxysmal AF patients than in paroxysmal AF patients (95.1 ± 4.3 ms versus 78.3 ± 3.2 ms, P = 0.0040). Contact-based bipolar LA endocardial activation mapping revealed a homogeneous LA activation pattern during SR, regardless of the between-group difference in activation time and the between-patient difference in sites of earliest LA endocardial breakthrough from the RA.

Identification of Nutritional Factors to Evaluate Periodontal Clinical Parameters in Patients with Systemic Diseases.

Nutritional factors reflect the periodontal parameters accompanying periodontal status. In this study, the associations between nutritional factors, blood biochemical items, and clinical parameters were examined in patients with systemic diseases. The study participants were 94 patients with heart disease, dyslipidemia, kidney disease, or diabetes mellitus. Weak negative correlation coefficients were found between nine clinical parameters and ten nutritional factors. Stage, grade, mean probing depth (PD), rate of PD 4−5 mm, rate of PD ≥ 6 mm, mean clinical attachment level (CAL), and the bleeding on probing (BOP) rate were weakly correlated with various nutritional factors. The clinical parameters with coefficients of determinations (R2) > 0.1 were grade, number of teeth, PD, rate of PD 4−5 mm, CAL, and BOP rate. PD was explained by yogurt and cabbage with statistically significant standardized partial regression coefficients (yogurt: −0.2143; cabbage and napa cabbage: −0.2724). The mean CAL was explained by pork, beef, mutton, and dark green vegetables with statistically significant standardized partial regression coefficients (−0.2237 for pork, beef, and mutton; −0.2667 for dark green vegetables). These results raise the possibility that the frequency of intake of various vegetables can be used to evaluate periodontal stabilization in patients with systemic diseases.

Linear catheter ablation of the right atrium for rapid atrial pacing-induced sustained atrial fibrillation in dogs.

Catheter ablation of persistent/long-persistent atrial fibrillation (AF) has been shown to be less effective by pulmonary vein isolation (PVI) and additional left atrial (LA) complex fractionated atrial electrograms and long linear lesions are often required. Recent reports have demonstrated right atrial (RA) ablation increases the success rate of maintaining sinus rhythm in persistent/long-persistent AF. The aim of this study was to investigate whether effective RA linear lesions can terminate AF and render it noninducible in a canine model of rapid atrial pacing-induced sustained AF. Sustained AF was induced by rapid atrial pacing in 20 dogs. AF duration was 21-126 days (median, 50 days). Four RA linear lesions (superior vena cava-inferior vena cava, septal line, transverse line, and cavo-tricuspid line) were created with the use of 1 of 3 different ablation catheters (large-tip [8-mm tip], coil-tip, and cooled-tip catheters). AF was terminated with the large-tip catheter in 4/7 dogs (1 dog died of ventricular fibrillation [VF]), with the coil-tip catheter in 3/7 dogs (1 dog died of VF), and with the cooled-tip catheter in 1/6 dogs. In 6 dogs in which AF could not be terminated acutely by RA ablation, AF terminated spontaneously at 7-78 days (median, 14 days) after ablation. RA linear ablation terminated AF with limited success in our dog model of rapid atrial pacing-induced AF, but late AF termination was noted in the surviving dogs. Therefore, RA linear lesions in addition to the PVI and LA lesions may have additional effects on the catheter ablation for the persistent AF.