Clinical implication of the patient's disease awareness and adherence to medications in patients undergoing atrial fibrillation ablation.

Background: The effects of the patient's disease awareness on the management of postablation of atrial fibrillation (AF) are unknown. Methods: One hundred thirty-three AF patients undergoing an initial ablation were given a disease awareness questionnaire with a score of 16 points (8 points about AF in general and 8 points about oral anticoagulants) for the Jessa Atrial Fibrillation Knowledge Questionnaire (JAKQ) before and 1-year-after ablation. We divided them into the poor disease awareness group and good disease awareness group according to the median value (75%) of the total JAKQ score about AF in general, and compared the baseline patient characteristics and the 1-year changes in the JAKQ score, medication adherence, blood pressure, laboratory data, echocardiographic parameters, and AF/atrial tachycardia (AT) recurrence rate between the two groups. Results: Forty-two (31.6%) patients were classified as having poor disease awareness (<75% of the total JAKQ score), which was closely associated with poor medication adherence, hypertension, diabetes, dyslipidemia, and greater left atrial volume (LAV). These trends in the poor disease awareness group remained unchanged 1 year after the ablation. During the 25.3-month follow-up, the AF/AT recurrence rate was significantly higher in the poor disease awareness than the good disease awareness group (23.8% vs. 7.7%; p = .003 by the log-rank test). Conclusions: Poor disease awareness was linked to poor medication adherence, lifestyle-related diseases, and greater LAV before and even 1 year after the ablation, making it a potential surrogate marker for AF/AT recurrence. These findings highlight the clinical significance of disease awareness in AF management.

Characteristics of tissue temperature during ablation with THERMOCOOL SMARTTOUCH SF versus TactiCath versus QDOT MICRO catheters (Qmode and Qmode+): An in vivo porcine study.

INTRODUCTION: High-power short-duration (HPSD) ablation at 50 W, guided by ablation index (AI) or lesion size index (LSI), and a 90 W/4 s very HSPD (vHPSD) setting are available for atrial fibrillation (AF) treatment. Yet, tissue temperatures during ablation with different catheters around venoatrial junction and collateral tissues remain unclear. METHODS: In this porcine study, we surgically implanted thermocouples on the epicardium near the superior vena cava (SVC), right pulmonary vein, and esophagus close to the inferior vena cava. We then compared tissue temperatures during 50W-HPSD guided by AI 400 or LSI 5.0, and 90 W/4 s-vHPSD ablation using THERMOCOOL SMARTTOUCH SF (STSF), TactiCath ablation catheter, sensor enabled (TacthCath), and QDOT MICRO (Qmode and Qmode+ settings) catheters. RESULTS: STSF produced the highest maximum tissue temperature (Tmax ), followed by TactiCath, and QDOT MICRO in Qmode and Qmode+ (62.7 ± 12.5°C, 58.0 ± 10.1°C, 50.0 ± 12.1°C, and 49.2 ± 8.4°C, respectively; p = .005), achieving effective transmural lesions. Time to lethal tissue temperature ≥50°C (t-T ≥ 50°C) was fastest in Qmode+, followed by TacthCath, STSF, and Qmode (4.3 ± 2.5, 6.4 ± 1.9, 7.1 ± 2.8, and 7.7 ± 3.1 s, respectively; p < .001). The catheter tip-to-thermocouple distance for lethal temperature (indicating lesion depth) from receiver operating characteristic curve analysis was deepest in STSF at 5.2 mm, followed by Qmode at 4.3 mm, Qmode+ at 3.1 mm, and TactiCath at 2.8 mm. Ablation at the SVC near the phrenic nerve led to sudden injury at t-T ≥ 50°C in all four settings. The esophageal adventitia injury was least deep with Qmode+ ablation (0.4 ± 0.1 vs. 0.8 ± 0.4 mm for Qmode, 0.9 ± 0.3 mm for TactiCath, and 1.1 ± 0.5 mm for STSF, respectively; p = .005), correlating with Tmax . CONCLUSION: This study revealed distinct tissue temperature patterns during HSPD and vHPSD ablations with the three catheters, affecting lesion effectiveness and collateral damage based on Tmax and/or t-T ≥ 50°C. These findings provide key insights into the safety and efficacy of AF ablation with these four settings.

Trends over the recent 6 years in ablation modalities and strategies, post-ablation medication, and clinical outcomes of atrial fibrillation ablation.

Background: Ablation strategies and modalities for atrial fibrillation (AF) have transitioned over the past decade, but their impact on post-ablation medication and clinical outcomes remains to be fully investigated. Methods: We divided 682 patients who had undergone AF ablation in 2014-2019 (420 paroxysmal AFs [PAF], 262 persistent AFs [PerAF]) into three groups according to the period, that is, the 2014-2015 (n = 139), 2016-2017 (n = 244), and 2018-2019 groups (n = 299), respectively. Results: Persistent AF became more prevalent and the left atrial (LA) diameter larger over the 6 years. Extra-pulmonary vein (PV)-LA ablation was more frequently performed in the 2014-2015 group than in the 2016-2017 and 2018-2019 groups (41.1% vs. 9.1% and 8.1%; p < .001). The 2-year freedom rate from AF/atrial tachycardias for PAF was similar among the three groups (84.0% vs. 83.1% vs. 86.7%; p = .98) but lowest in the 2014-2015 group for PerAF (63.9% vs. 82.7% and 86.3%; p = .025) despite the highest post-ablation antiarrhythmic drug use. Cardiac tamponade was significantly decreased in the 2018-2019 group (3.6% vs. 2.0% vs. 0.33%; p = 0.021). There was no difference in the 2-year clinically relevant events among the three groups. Conclusion: Although ablation was performed in a more diseased LA and extra-PV-LA ablation was less frequent in recent years, the complication rate decreased, and AF recurrences for PAF remained unchanged, but that for PerAF decreased. Clinically relevant events remained unchanged over the recent 6 years, suggesting that the impact of the recent ablation modalities and strategies on remote clinically relevant events may be small during this study period.

Intravenous Semaphorin 3A Administration Maintains Cardiac Contractility and Improves Electrical Remodeling in a Mouse Model of Isoproterenol-Induced Heart Failure.

The effects of recombinant semaphorin 3A (Sema3A) on myocardial contractility and electrical remodeling in mice with isoproterenol (ISP) -induced heart failure were investigated.C57BL/6J mice intraperitoneally received ISP (480 mg/kg/day, ISP group; n = 24) or saline (control group; n = 31) for 14 days. Twenty-one ISP-treated mice received 0.5 mg/kg Sema3A intravenously on days 7 and 11 (ISP+Sema3A group). The sympathetic nervous system was activated upon ISP treatment, but was reduced upon Sema3A administration. Greater myocardial tissue fibrosis was observed in the ISP group than in the control group. However, fibrosis was not significantly different between the ISP+Sema3A and control groups. Fractional shortening of the left ventricle was lower in the ISP group than in the control group and was restored in the ISP+Sema3A group (control, 53 ± 8%; ISP, 37 ± 7%; ISP+Sema3A, 48 ± 3%; P < 0.05). Monophasic action potential duration at 20% repolarization (MAPD20) was prolonged in the ISP group (compared to control group), but this was reversed upon Sema3A administration (control, 29 ± 3 ms; ISP, 35 ± 6 ms; ISP+Sema3A, 29 ± 3 ms; P < 0.05). qPCR revealed Kv4.3, KChIP2, and SERCA2 downregulation in the ISP group and upregulation in the ISP+Sema3A group; however, Western blotting revealed similar changes only for Kv4.3 (P < 0.05).Intravenous Sema3A may maintain myocardial contractility by suppressing the sympathetic innervation of the myocardium and reducing myocardial tissue damage, in addition to restoring MAPD via Kv4.3 upregulation.

In vivo tissue temperatures during 90 W/4 sec-very high power-short-duration (vHPSD) ablation versus ablation index-guided 50 W-HPSD ablation: A porcine study.

INTRODUCTION: Neither the actual in vivo tissue temperatures reached with 90 W/4 s-very high-power short-duration (vHPSD) ablation for atrial fibrillation nor the safety and efficacy profile have been fully elucidated. METHODS: We conducted a porcine study (n = 15) in which, after right thoracotomy, we implanted 6-8 thermocouples epicardially in the superior vena cava, right pulmonary vein, and esophagus close to the inferior vena cava. We compared tissue temperatures close to a QDOT MICRO catheter, between during 90 W/4 s-vHPSD ablation during ablation index (AI: target 400)-guided 50 W-HPSD ablation, both targeting a contact force of 8-15 g. RESULTS: Maximum tissue temperature reached during 90 W/4 s-vHPSD ablation did not differ significantly from that during 50 W-HPSD ablation (49.2 ± 8.4°C vs. 50.0 ± 12.1°C; p = .69) and correlated inversely with distance between the catheter tip and the thermocouple, regardless of the power settings (r = -0.52 and r = -0.37). Lethal temperature (≥50°C) was best predicted at a catheter tip-to-thermocouple distance cut-point of 3.13 and 4.27 mm, respectively. All lesions produced by 90 W/4 s-vHPSD or 50 W-HPSD ablation were transmural. Although there was no difference in the esophageal injury rate (50% vs. 66%, p = .80), the thermal lesion was significantly shallower with 90 W/4 s-vHPSD ablation than with 50W-HPSD ablation (381.3 ± 127.3 vs. 820.0 ± 426.1 µm from the esophageal adventitia; p = .039). CONCLUSION: Actual tissue temperatures reached with 90 W/4 s-vHPSD ablation appear similar to those with AI-guided 50 W-HPSD ablation, with the distance between the catheter tip and target tissue being shorter for the former. Although both ablation settings may create transmural lesions in thin atrial tissues, any resulting esophageal thermal lesions appear shallower with 90 W/4 s-vHPSD ablation.

In vivo tissue temperature during lesion size index-guided 50W ablation versus 30W ablation: A porcine study.

BACKGROUND: Neither the actual in vivo tissue temperatures reached with lesion size index (LSI)-guided high-power short-duration (HPSD) ablation for atrial fibrillation nor the safety profile has been elucidated. METHODS: We conducted a porcine study (n = 7) in which, after right thoracotomy, we implanted 6-8 thermocouples epicardially in the superior vena cava, right pulmonary vein, and esophagus close to the inferior vena cava. We compared tissue temperatures reached during 50 W-HPSD ablation with those reached during standard (30 W) ablation, both targeting an LSI of 5.0 (5-15 g contact force). RESULTS: Tmax  (maximum tissue temperature when the thermocouple was located ≤5 mm from the catheter tip) reached during HPSD ablation was modestly higher than that reached during standard ablation (58.0 ± 10.1°C vs. 53.6 ± 9.2°C; p = .14) and peak tissue temperature correlated inversely with the distance between the catheter tip and the thermocouple, regardless of the power settings (HPSD: r = -0.63; standard: r = -0.66). Lethal temperature (≥50°C) reached 6.3 ± 1.8 s and 16.9 ± 16.1 s after the start of HPSD and standard ablation, respectively (p = .002), and it was best predicted at a catheter tip-to-thermocouple distance cut point of 2.8 and 5.3 mm, respectively. All lesions produced by HPSD ablation and by standard ablation were transmural. There was no difference between HPSD ablation and standard ablation in the esophageal injury rate (70% vs. 75%, p = .81), but the maximum distance from the esophageal adventitia to the injury site tended to be shorter (0.94 ± 0.29 mm vs. 1.40 ± 0.57 mm, respectively; p = .09). CONCLUSIONS: Actual tissue temperatures reached with LSI-guided HPSD ablation appear to be modestly higher, with a shorter distance between the catheter tip and thermocouple achieving lethal temperature, than those reached with standard ablation. HPSD ablation lasting <6 s may help minimize lethal thermal injury to the esophagus lying at a close distance.

Novel "red-bull sign" during cavotricuspid isthmus ablation: Indication of an ablation catheter stuck in the subeustachian pouch.

Background: A subeustachian pouch (SEP) often hinders the completion of a cavotricuspid isthmus (CTI) ablation of typical atrial flutter (AFL) and sometimes causes steam-pops during a power-controlled ablation. We hypothesized that real-time bull's-eye monitoring of the catheter surface temperature might be useful to locate the SEP where the temperature can rise rapidly, and a temperature-controlled ablation might avoid steam pops. This study aimed to demonstrate this hypothesis. Methods: A temperature-controlled CTI ablation with a QDOT MICRO™ catheter (n = 10) and a conventional power-controlled CTI ablation (n = 10) were performed with an output power of 35 W. During the RF application, the bull's eye monitor for monitoring the catheter surface temperatures was assessed. A "red-bull sign" was defined as an entire red-colored bull's-eye monitor, indicating that the catheter-tip temperature of all 6 thermocouples rose rapidly over 47°C. Results: In a total of 115 lesions (12 ± 3 per patient), a "red-bull sign" was observed in 39 (33.9%) lesions where the RF output was reduced to 26 ± 8 W. All 39 "red-bull sign" lesions corresponded to the location of the SEP as delineated by ICE before the ablation. The red-bull sign accurately indicated the presence of a SEP with a sensitivity of 84.7% and specificity of 100%. Bidirectional block of the CTI was completed in all patients in either catheter group without any steam-pops. Conclusion: Real-time surface temperature monitoring and a red-bull sign might be useful to detect the SEP. A temperature-controlled CTI ablation with the QDOT MICRO catheter might be safe for avoiding steam pops.

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.

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.

Prognostic value of the MELD-XI score in patients undergoing cardiac resynchronization therapy.

AIMS: Multi-organ dysfunction was recently reported to be a common condition in patients with heart failure (HF). The Model for End-stage Liver Disease eXcluding International normalized ratio (MELD-XI) score reflects liver and kidney function. The prognostic relevance of this score has been reported in patients with a variety of cardiovascular diseases who are undergoing interventional therapies. However, the relationship between the severity of hepatorenal dysfunction assessed by the MELD-XI score and the long-term clinical outcomes of HF patients receiving cardiac resynchronization therapy (CRT) has not been evaluated. METHODS AND RESULTS: Clinical records of 283 patients who underwent CRT implantation between March 2003 and October 2020 were retrospectively evaluated (mean age 67 ± 12, 22.6% female). Blood samples were collected before CRT implantation. Patients were divided into three groups based on tertiles of the MELD-XI score: first tertile (MELD-XI = 9.44, n = 95), second tertile (9.44 < MELD-XI < 13.4, n = 94), and third tertile (MELD-XI ≥ 13.4, n = 94). The primary endpoint was all-cause mortality. Compared with the other groups, the third tertile group exhibited significantly older age, higher prevalence of diabetes mellitus and hypertension, lower haemoglobin level, and higher N-terminal pro-brain natriuretic peptide level (all P < 0.05). The functional CRT response rate was also significantly lower in the third tertile group (P = 0.011). During a median follow-up of 30 months (inter-quartile range, 9-67), 105 patients (37.1%) died. Kaplan-Meier analysis revealed that patients with a higher MELD-XI score had a greater risk of all-cause mortality (log-rank test: P < 0.001). Even after adjustment for clinically relevant factors and a conventional risk score, the MELD-XI score was still associated with mortality (adjusted hazard ratio: 1.04, 95% confidence interval: 1.00-1.07, P = 0.014, and adjusted hazard ratio: 1.04, 95% confidence interval: 1.01-1.09, P = 0.005, respectively). A higher MELD-XI score was associated with a greater risk of all-cause mortality than a lower MELD-XI score regardless of whether a pacemaker or defibrillator was implanted (log-rank test: P = 0.010 and P < 0.001, respectively). CONCLUSIONS: Impaired hepatorenal function assessed by the MELD-XI score was associated with older age, higher prevalence of multiple co-morbidities, severity of HF, lower CRT response rates, and subsequent all-cause mortality in HF patients undergoing CRT implantation. These results suggest that the MELD-XI score can provide additional prognostic information and may be useful for improving risk stratification in this population.

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.

Modified ablation index: a novel determinant of a successful first-pass left atrial posterior wall isolation.

Although a left atrial posterior wall isolation (LAPWI) in addition to a pulmonary vein isolation is a well-accepted option for persistent atrial fibrillation (AF), a complete isolation can be challenging. This study aimed to evaluate the performance of a modified ablation index (AI) (AI/bipolar voltage along the ablation line) for predicting a durable LAPWI. The study included 55 consecutive patients, aged 65 ± 11 years, who underwent an electroanatomic mapping-guided LAPWI of AF. The association between the gaps (first-pass LAPWI failure and/or acute LAPW reconnections), voltage amplitude along the roof and floor lines, and thickness of the LAPW was investigated. Gaps occurred in 22 patients (40%) and in 26 (8%) of the 330 line segments. Gaps were associated with a relatively high bipolar voltage (3.38 ± 1.83 vs. 1.70 ± 1.12 mV, P < 0.0001) and thick LA wall (2.52 ± 1.15 vs. 1.42 ± 0.44 mm, P < 0.0001). A modified AI ≤ 199 AU/mV, bipolar voltage ≥ 2.64 mV, wall thickness ≥ 2.04 mm, and roof ablation line ≥ 43.4 mm well predicted gaps (AUCs: 0.783, 0.787, 0.858, and 0.752, respectively). A high-voltage zone, thick LAPW, and long roof ablation line appeared to be determinants of gaps, and a modified AI ≥ 199 AU/mV along the ablation lines appeared to predict an acute durable LAPWI.

Actual tissue temperature during ablation index-guided high-power short-duration ablation versus standard ablation: Implications in terms of the efficacy and safety of atrial fibrillation ablation.

BACKGROUND: Actual in vivo tissue temperatures and the safety profile during high-power short-duration (HPSD) ablation of atrial fibrillation have not been clarified. METHODS: We conducted an animal study in which, after a right thoracotomy, we implanted 6-8 thermocouples epicardially in the superior vena cava, right pulmonary vein, and esophagus close to the inferior vena cava. We recorded tissue temperatures during a 50 W-HPSD ablation and 30 W-standard ablation targeting an ablation index (AI) of 400 (5-15 g contact force). RESULTS: Maximum tissue temperatures reached with HSPD ablation were significantly higher than that reached with standard ablation (62.7 ± 12.5 vs. 52.7 ± 11.4°C, p = 0.033) and correlated inversely with the distance between the catheter tip and thermocouple, regardless of the power settings (HPSD: r = -0.71; standard: r = -0.64). Achievement of lethal temperatures (≥50°C) was within 7.6 ± 3.6 and 12.1 ± 4.1 s after HPSD and standard ablation, respectively (p = 0.003), and was best predicted at cutoff points of 5.2 and 4.4 mm, respectively. All HPSD ablation lesions were transmural, but 19.2% of the standard ablation lesions were not (p = 0.011). There was no difference between HPSD and standard ablation regarding the esophageal injury rate (30% vs. 33.3%, p > 0.99), with the injury appearing to be related to the short distance from the catheter tip. CONCLUSIONS: Actual tissue temperatures reached with AI-guided HPSD ablation appeared to be higher with a greater distance between the catheter tip and target tissue than those with standard ablation. HPSD ablation for <7 s may help prevent collateral tissue injury when ablating within a close distance.

Different Determinants of the Recurrence of Atrial Fibrillation and Adverse Clinical Events in the Mid-Term Period After Atrial Fibrillation Ablation.

BACKGROUND: It is unclear whether there are differences in the clinical factors between atrial fibrillation (AF) recurrence and adverse clinical events (AEs), including stroke/transient ischemic attack (TIA), major bleeding, and death, after AF ablation.Methods and Results:We examined the data from a retrospective multicenter Japanese registry conducted at 24 cardiovascular centers between 2011 and 2017. Of the 3,451 patients (74.1% men; 63.3±10.3 years) who underwent AF ablation, 1,046 (30.3%) had AF recurrence and 224 (6.5%) suffered AEs (51 strokes/TIAs, 71 major bleeding events, and 36 deaths) over a median follow-up of 20.7 months. After multivariate adjustment, female sex, persistent and long-lasting persistent AF (vs. paroxysmal AF), and stepwise increased left atrial diameter (LAd) quartiles were significantly associated with post-ablation recurrences. A multivariate analysis revealed that an age ≥75 years (vs. <65 years), body weight <50 kg, diabetes, vascular disease, left ventricular (LV) ejection fraction <40% (vs. ≥50%), Lad ≥44 mm (vs. <36 mm), and creatinine clearance <50 mL/min were independently associated with AE incidences, but not with recurrences. CONCLUSIONS: This study disclosed different determinants of post-ablation recurrence and AEs. Female sex, persistent AF, and enlarged LAd were determinants of post-ablation recurrence, whereas an old age, comorbidities, and LV and renal dysfunction rather than post-ablation recurrence were AEs determinants. These findings will help determine ablation indications and post-ablation management.

Resetting of atrial tachycardia by a scanned extrastimulus at a downstream site on a multielectrode catheter: a simple diagnostic maneuver for locating the macroreentrant atrial tachycardia circuit.

PURPOSE: Entrainment is a useful method for locating reentrant atrial tachycardia (AT) circuits, but alterations or termination of the AT can derail this process. We assessed whether resetting an upstream site of a neighboring electrode by a scanned extrastimulus at a downstream site (when the upstream tissue was refractory) could diagnose that site within the AT circuit. METHODS: The procedure was applied to 48 ATs with a cycle length (CL) of 238 ± 42 ms (26 common flutters, 8 perimitral flutters, 7 left atrial [LA] roof-dependent AT, 3 LA scar-related macroreentrant ATs, 2 pulmonary vein-gap reentry tachycardias, 1 right atrial scar-related macroreentrant AT, and 1 with an unidentified circuit). Entrainment and scanned extrastimulation were attempted at the cavotricuspid isthmus, LA roof, and mitral isthmus and/or critical AT isthmus. RESULTS: Within the circuit, the post-pacing interval minus the ATCL after entrainment was < 30 ms for all ATs and resetting of the AT cycle by ≥ 5 ms occurred in 94% of the ATs. No ATs were reset by extrastimulation outside the circuit. The positive predictive value of both maneuvers for locating the circuit was 100%, and the negative predictive value of the extrastimulation was similar to that of entrainment (96% vs. 100%, P = 0.25). The incidence of an AT alteration was lower with extrastimulation than with entrainment (1% vs. 9%, P = 0.01). For ATs with a CL < 210 ms, extrastimulation yielded a good diagnostic performance without any AT alterations. CONCLUSION: AT resetting by a scanned extrastimulus is diagnostic and avoids AT alterations.

Prognostic importance of the Controlling Nutritional Status (CONUT) score in patients undergoing cardiac resynchronisation therapy.

AIMS: Malnutrition is common and associated with worse clinical outcomes in patients with heart failure (HF). The Controlling Nutritional Status (CONUT) score is an integrated index for evaluating diverse aspects of the complex mechanism of malnutrition. However, the relationship between the severity of malnutrition assessed by the CONUT score and clinical outcomes of HF patients receiving cardiac resynchronisation therapy (CRT) has not been fully clarified. METHODS: Clinical records of 263 patients who underwent pacemaker or defibrillator implantation for CRT between March 2003 and October 2020 were retrospectively evaluated. The CONUT score was calculated from laboratory data obtained before CRT device implantation. Patients were divided into three groups: normal nutrition (CONUT scores 0-1, n=58), mild malnutrition (CONUT scores 2-4, n=132) and moderate or severe malnutrition (CONUT scores 5-12, n=73). The primary endpoint was all-cause mortality. RESULTS: The moderate or severe malnutrition group had a lower body mass index, more advanced New York Heart Association functional class, higher Clinical Frailty Scale score, lower levels of haemoglobin and higher levels of N-terminal probrain natriuretic peptide (all p<0.05). In the moderate or severe malnutrition group, the CRT response rate was significantly lower than for the other two groups (p=0.001). During a median follow-up period of 31 (10-67) months, 103 (39.1%) patients died. Kaplan-Meier analysis revealed that the moderate or severe malnutrition group had a significantly higher mortality rate (log-rank p<0.001). A higher CONUT score and CONUT score ≥5 remained significantly associated with all-cause mortality after adjusting for previously reported clinically relevant factors and the conventional risk score (VALID-CRT risk score) (all p<0.05). CONCLUSIONS: A higher CONUT score before CRT device implantation was strongly associated with HF severity, frailty, lower CRT response rate and subsequent long-term all-cause mortality.

Toe white line separation associated with the notch (crena marginalis) on the distal phalanges in Thoroughbred yearling horses.

The shape of the white line of the hoof is closely related to the shape of the notch on the dorsal distal bearing border of the distal phalanx (P3). In this study, a radiographic survey of the P3 of both forelimbs of 163 Thoroughbred yearling horses was conducted. The correlation of the depth and width of the notch were analyzed with the toe white line separation grades (0 to 3). As a result, the toe white line separation grade increased, the depth and the width of the notch also increased significantly. Radiographic examination of the P3 of the forelimbs might be useful for deciding whether to implement hoof care to prevent onset of toe white line separation.

Current Status and Issues Concerning Magnetic Resonance Imaging in Patients with a Magnetic Resonance Conditional Cardiac Implantable Electrical Device: A Single-center Study.

Objective Following the introduction of magnetic resonance (MR)-conditional cardiac implantable electrical devices (CIEDs), patients with CIEDs have undergone MRI scanning more frequently. As the required settings of MRI equipment for scanning patients with a CIED vary by device, a number of precautions should be taken to allow safe examinations, including the confirmation of conditions and selection of MRI modes appropriate for pacing status in individual patients. In this study, we examined the current status and issues concerning the performance of MRI examinations in patients with an MRI-conditional CIED. Method and Results We reviewed a total of 262 MRI scans. The most common site of MRI scanning was the head, followed by the spine, abdomen, and heart in order. Regarding the MRI mode, DOO was most often used, followed by OFF, AOO, and finally VOO mode, to maintain atrioventricular synchrony. Although no obvious adverse events were observed related to MRI scanning, there were several cases encountered that might have been predisposed to a significant incident or in which the patient's intrinsic pulse rates or subjective symptoms changed before and during scanning. Conclusion As MRI is a very useful diagnostic tool for cerebrovascular diseases and orthopedic disorders, the demand for MRI scanning is high when treating these areas. Although MRI scanning in patients with MR-conditional devices was performed without any adverse events, there were incidents that could have potentially led to major harm. This highlights the importance of confirming the appropriate MRI mode is being used before scanning and monitoring patients during scanning.