Differences between cardiac memory T wave changes after idiopathic left ventricular tachycardia and ischemic T wave inversion induced by acute coronary syndrome.

BACKGROUND: Cardiac memory (CM) after idiopathic left ventricular tachycardia (ILVT) mimics ischemic T wave inversion (TWI) induced by acute coronary syndrome (ACS). We aimed to establish electrocardiography criteria for differentiating the CM from ischemic TWI. METHODS AND RESULTS: We evaluated 16 ILVT and 48 ACS patients. We identified TWI after ILVT in 9/16 patients (CM group), typically in leads II, III, aVF, aVR, and V4-6. The characteristics of CM were similar to TWI induced by ACS involving right coronary artery, but the CM group had more TWI in V4 and shorter QTc. The criteria of (1) positive T in aVL, (2) negative or isoelectric T in II, and (3) negative T in V4-6 or (4) QTc <430ms were 100% sensitive and 96% specific for the CM group. CONCLUSION: CM after ILVT can be differentiated in most cases from ischemic TWI by the distribution of TWI and the QTc.

A case of coronary artery compression syndrome resulting from peri-valvular regurgitation and long-standing atrial fibrillation.

A man in his 70s with a history of mitral valve replacement (MVR) and long-standing persistent atrial fibrillation (AF) presented with effort angina. Coronary angiography revealed severe stenosis of the left main coronary artery (LMCA). As it was an emergent case, PCI (percutaneous coronary intervention) was selected for treatment. Intravascular ultrasonography revealed no atherosclerotic lesions in the LMCA. The LMCA was effectively dilated by the drug-eluting stent. No elevation in intracardiac pressure was observed in cardiac catheterization after PCI. Computed tomography scan indicated potential compression of the LMCA by the surrounding structures. In cases of long-standing persistent AF and an enlarged atrium after MVR, the possibility of LMCA stenosis due to anatomical changes should be considered. Learning Objectives: ◾Peri-valvular regurgitation and long-standing persistent atrial fibrillation can potentially cause atrial enlargement.◾Coronary artery stenosis without atherosclerosis can occur due to compression from surrounding structures or shifting of the coronary artery.◾Stent therapy provides a temporary solution and coronary artery bypass grafting or switching should be considered if re-stenosis occurs.

Systematic observation-based diagnosis of atrioventricular nodal reentrant tachycardia with a bystander concealed nodoventricular pathway.

Background: This study aimed to establish a systematic method for diagnosing atrioventricular nodal reentrant tachycardia (AVNRT) with a bystander concealed nodoventricular pathway (cNVP). Methods: We analyzed 13 cases of AVNRT with a bystander cNVP, 11 connected to the slow pathway (cNVP-SP) and two to the fast pathway (cNVP-FP), along with two cases of cNVP-related orthodromic reciprocating tachycardia (ORT). Results: The diagnostic process was summarized in three steps. Step 1 was identification of the presence of an accessory pathway by resetting the tachycardia with delay (n = 9) and termination without atrial capture (n = 4) immediately after delivery of a His-refractory premature ventricular contraction (PVC). Step 2 was exclusion of ORT by atrio-His block during the tachycardia (n = 4), disappearance of the reset phenomenon after the early PVC (n = 7), or dissociation of His from the tachycardia during ventricular overdrive pacing (n = 1). Moreover, tachycardia reset/termination without the atrial capture (n = 2/2) 1 cycle after the His-refractory PVC was specifically diagnostic. Exceptionally, the disappearance of the reset phenomenon was also observed in the two cNVP-ORTs. Step 3 was verification of the AVN as the cNVP insertion site, evidenced by an atrial reset/block preceding the His reset/block in fast-slow AVNRT with a cNVP-SP and slow-fast AVNRT with a cNVP-FP or His reset preceding the atrial reset in slow-fast AVNRT with a cNVP-SP. Conclusion: AVNRT with a bystander cNVP can be diagnosed in the three steps with few exceptions. Notably, tachycardia reset/termination without atrial capture one cycle after delivery of a His-refractory PVC is specifically diagnostic.

Effect of the Great East Japan Earthquake on cardiovascular diseases--report from the 10 hospitals in the disaster area.

BACKGROUND: We reported an increased occurrence of cardiovascular diseases (CVDs) after the Great East Japan Earthquake by examining ambulance records, but it had to be confirmed by cardiologists. METHODS AND RESULTS: We enrolled patients admitted to the cardiology department of the 10 hospitals in the disaster area from 4 weeks prior to 15 weeks after March 11 in the years 2008-2011 (n=14,078). The weekly occurrence of several CVDs, including heart failure (HF), pulmonary thromboembolism (PTE) and infectious endocarditis (IE), was sharply and significantly increased after the Earthquake. CONCLUSIONS: The Disaster caused significantly increases in the occurrence of HF, PTE and IE.

A case of retractable helix lead auto-retraction: A possible cause of deep septal lead dislodgement.

This paper explains the phenomenon where the helix lead automatically retracts because of residual torque during deep septal pacing.

Reentrant ventricular outflow tract tachycardia arising from focal scar detected by delayed enhancement magnetic resonance imaging.

A 58-year-old man was referred to our emergency room with hemodynamically unstable sustained ventricular tachycardia (VT). The morphology of the VT exhibited a left bundle branch block and inferior axis deviation. He had no past history of cardiovascular disease. Echocardiography, cardiac catheterization, cardiac biopsy, gallium scintigram, myocardial scintigram, T1,T2-weighted magnetic resonance imaging (MRI), and gadolinium-enhanced cine MRI did not detect any structural heart disease or abnormal cardiac function. However, delayed-enhancement MRI (DE-MRI) detected a focal intramural scar within the septal ventricular outflow tract. An electrophysiological study revealed a sustained VT with several morphologies and the entrainment phenomenon. Radiofrequency catheter ablation to the site corresponding to the focal scar detected by DE-MRI successfully eliminated the VT.

Extra- and intracellular recordings from the avjunction: discerning the mechanisms for irregular ventricular responses during supraventricular arrhythmias.

INTRODUCTION: There has been a long-standing controversy regarding the mechanism(s) to explain the irregular ventricular response during atrial tachycardia (AT) or atrial fibrillation (AF) and where the site of block, if any, resides in the atrioventricular (AV) junction. METHODS: We studied 12 Langendorff preparations perfused with modified Tyrode's solution containing 5-10 mM diacetyl monoxime which suppressed contractility but allowed the use of intracellular action potential (AP) recordings. Octapolar catheters (2-mm rings, 2-mm spacing) were secured along the tricuspid annulus from the apex to the base of the triangle of Koch and along the anterior limbus of the fossa ovalis to record extracellular, slow pathway, fast pathway, His bundle (Hb) and AV nodal (AVN) extracellular potentials as well as intracellular action potentials. RESULTS: AT or AF induced by rapid atrial pacing showed a variety of irregular responses due to: (1) Wenckebach conduction showing decrement within the AVN and progressive diminution of extracellular AVN potentials (n = 5); (2) repetitive concealed conduction proximal to the AVN (n = 3); (3) ectopic beats arising within the AVN (n = 2); (4) ectopic beats arising at the Hb (n = 2). CONCLUSIONS: In this experimental preparation, extracellular and intracellular recordings provided presumptive evidence for the mechanisms causing the irregularities of the ventricular response such as repetitive concealed conduction, enhanced automaticity or electrotonically triggered activity. Also more definitive determinations of the site of block in the AV junction were also obtained.

Impact of Catheter Ablation on Brain Microstructure and Blood Flow Alterations for Cognitive Improvements in Patients with Atrial Fibrillation: A Pilot Longitudinal Study.

Atrial fibrillation (AF) predisposes patients to develop cognitive decline and dementia. Clinical and epidemiological data propose that catheter ablation may provide further benefit to improve neurocognitive function in patients with AF, but the underlying mechanism is poorly available. Here, we conducted a pilot prospective study to investigate whether AF ablation can alter regional cerebral blood flow (rCBF) and brain microstructures, using multimodal magnetic resonance imaging (MRI) technique. Eight patients (63 ± 7 years) with persistent AF underwent arterial-spin labeling (ASL) perfusion, 3D T1-structural images and cognitive test batteries before and 6 months after intervention. ASL and structural MR images were spatially normalized, and the rCBF and cortical thickness of different brain areas were compared between pre- and 6-month post-treatment. Cognitive-psychological function was improved, and rCBF was significantly increased in the left posterior cingulate cortex (PCC) (p = 0.013), whereas decreased cortical thickness was found in the left posterior insular cortex (p = 0.023). Given that the PCC is a strategic site in the limbic system, while the insular cortex is known to play an important part in the central autonomic nervous system, our findings extend the hypothesis that autonomic system alterations are an important mechanism explaining the positive effect of AF ablation on cognitive function.

Prevalence and characteristics of idiopathic right ventricular outflow tract arrhythmias associated with J-waves.

AIM: The arrhythmogenic relationship between the presence of J-waves during sinus rhythm and idiopathic ventricular tachycardia (VT) or pre-mature ventricular contractions (PVCs) originating from the right ventricular outflow tract (RVOT) has not been reported. The aim of this study was to investigate the prevalence and characteristics of idiopathic RVOT-VT/PVCs associated with J-waves. METHODS AND RESULTS: The study enrolled 138 consecutive idiopathic RVOT-VT/PVC patients undergoing radiofrequency catheter ablation (RFCA) and 276 age- and gender-matched control subjects. The prevalence of J-waves was assessed in each cohort, and the clinical and electrophysiological data were compared between the RVOT-VT/PVC patients with J-waves (J-RVOT-VT/PVC group) and those without (non-J-RVOT-VT/PVC group). J-waves were more common among patients with idiopathic RVOT-VT/PVCs than among the matched control subjects (40 vs. 16% P < 0.001). The J-RVOT-VT/PVC group had a higher incidence of sustained VT (25 vs. 5%, P < 0.01), shorter VT cycle length (302 ± 57 vs. 351 ± 58 ms, P < 0.001), and more episodes of syncope (25 vs. 2%, P < 0.001) than did the non-J-RVOT-VT/PVC group. However, no patients demonstrated any ventricular fibrillation (VF) or cardiac sudden death in either group. CONCLUSIONS: There was a high prevalence of J-waves in the idiopathic RVOT-VT/PVC patients referred for RFCA. Although patients with idiopathic RVOT arrhythmias associated with J-waves might have a more enhanced arrhythmogenicity than those without J-waves, the significance of those J-waves was limited in terms of the prognosis and VF.

Real-World Safety Profile of Atrial Fibrillation Ablation Using a Second-Generation Cryoballoon in Japan: Insight From a Large Multicenter Observational Study.

OBJECTIVES: This study sought to investigate the incidence and characteristics of the real-world safety profile of second-generation cryoballoon ablation (2nd-CBA) in Japan. BACKGROUND: Pulmonary vein isolation using second-generation cryoballoons is an accepted atrial fibrillation ablation strategy. METHODS: This multicenter observational study included 4,173 patients with atrial fibrillation (3,807 paroxysmal) who underwent a 2nd-CBA in 18 participating centers. The baseline data and details of all procedure-related complications within 3 months post-procedure in consecutive patients from the first case at each center were retrospectively collected. RESULTS: Adjunctive ablation after the pulmonary vein isolation was performed in 2,745 (65.8%) patients. Complications associated with the entire procedure were observed in 206 (4.9%) total patients, and in the multivariate analysis, the age (odds ratio: 1.015; 95% confidence interval: 1.001 to 1.030; p = 0.035) and study period were predictors. Air embolisms manifesting as ST-segment elevation and cardiac tamponade requiring drainage occurred in 63 (1.5%) and 15 (0.36%) patients, respectively. Six (0.14%) patients had strokes/transient ischemic attacks, among whom 5 underwent ablation under an interrupted anticoagulation regimen. No atrioesophageal fistulae occurred; however, 10 (0.24%) patients had symptomatic gastric hypomotility. Esophageal temperature monitoring did not reduce the incidence, and the incidence was significantly higher in patients with adjunctive posterior wall isolations or mitral isthmus ablation than those without (p = 0.004). Phrenic nerve injury occurred during the 2nd-CBA in 58 (1.4%) patients; however, all were asymptomatic and recovered within 13 months. One patient died of aspiration pneumonia. CONCLUSIONS: This study had a high safety profile of 2nd-CBA despite including the early experience and high rate of adjunctive ablation. Care should be taken for air embolisms during 2nd-CBA.

Clinical and electrophysiological difference between idiopathic right ventricular outflow tract arrhythmias and pulmonary artery arrhythmias.

INTRODUCTION: The precise incidence and characteristics of ventricular arrhythmias originating from the pulmonary artery have not been fully described. The purpose of this prospective study was to clarify these points. METHODS: Thirty-three consecutive patients with an idiopathic left bundle branch block and inferior-axis deviation type ventricular arrhythmia were included. All patients underwent detailed electroanatomical mapping (CARTO, Biosense-Webster, Diamond Bar, CA, USA) during sinus rhythm prior to the catheter ablation. The precise location of the catheter tip at the successful ablation site was confirmed by both electroanatomical mapping and contrast radiography. The clinical and electrophysiological data were compared between the right ventricular outflow tract (RVOT) arrhythmia patients (RVOT group) and PA arrhythmia patients (PA group). RESULTS: Eight patients (8/33 patients: 24.2%) had their ventricular arrhythmias successfully ablated within the PA. The local bipolar electrogram at the successful ablation sites in the PA group exhibited a significantly greater duration (P < 0.05) and lower amplitude (P < 0.05) than did those in the RVOT group (n = 19). In the PA group, all patients exhibited a multicomponent electrograms composed of a spiky potential and a dull potential, which might have consisted of near-field PA activation and a far-field ventricular activation, respectively, at the successful ablation site. Direct ablation to the spiky electrogram was able to eliminate the arrhythmias in all the PA group patients. CONCLUSIONS: PA arrhythmias may be more common than previously recognized. Careful mapping and interpretation of low amplitude and multicomponent electrograms are important for recognizing ventricular arrhythmias originating from the PA.

Distribution of successful ablation sites of idiopathic right ventricular outflow tract tachycardia.

BACKGROUND: There are few studies evaluating the distribution of successful ablation sites of idiopathic right ventricular outflow tract (RVOT) arrhythmias using a three-dimensional electroanatomical mapping system. This study aims to clarify the favorite site of idiopathic RVOT arrhythmias through electroanatomical voltage mapping using the CARTO system (Biosense Webster, Diamond Bar, CA, USA). METHODS: A consecutive series of 72 patients (mean age 43.6 +/- 16.2 years, 32 males) who underwent radiofrequency catheter ablation (RFCA) for a total of 82 morphologies of idiopathic RVOT arrhythmias were studied. Detailed three-dimensional electroanatomical voltage maps of the RVOT were obtained using the CARTO system prior to the RFCA during sinus rhythm. The voltage on bipolar electrogram was defined as follows: amplitude < 0.5 mV as "low-voltage zone," amplitude between 0.5 and 1.5 mV as "transitional-voltage zone," and amplitude >1.5 mV as "high-voltage zone." Successful ablation sites were electroanatomically classified into each voltage zone. RESULTS: Successful ablation was acquired in 63 patients and 71 RVOT arrhythmias (63/72 patients: 87.5%, 71/82 RVOT arrhythmias: 86.5%). In the successful group, three arrhythmias (4.2%) were classified in the low-voltage zone, 63 arrhythmias (88.7%) in the transitional-voltage zone, and five arrhythmias (7.0%) in the high-voltage zone. CONCLUSIONS: This study indicates that the vast majority of successful ablation sites for idiopathic RVOT arrhythmias are located in the transitional-voltage zone. Mapping of the transitional-voltage zone may be an important landmark of RFCA for RVOT arrhythmia.

Idiopathic ventricular arrhythmias arising from the posterior septum of tricuspid and mitral annuli: comparison of electrocardiographic characteristics and outcomes of catheter ablation.

PURPOSE: Ventricular arrhythmia (VA) arising from the tricuspid annulus in the posterior septum (PS) (TAPS-VA) has similar electrocardiographic characteristics as VA arising from the mitral annulus in the PS (MAPS-VA) because the two locations are adjacent. We examined the electrocardiographic characteristics that differentiate MAPS-VA from TAPS-VA and the efficacy of catheter ablation. METHODS: We studied 13 patients whose VAs were successfully ablated in the TAPS (n = 7) and MAPS (n = 6). RESULTS: QRS morphologies of both groups were characterized by left and right bundle block morphologies in lead V1, superior axis deviation, and precordial transition at ≤ lead V3 in nine patients. Compared with TAPS-VA, MAPS-VA had (1) R < S wave in lead II, (2) precordial transition in lead V2, (3) s-wave in lead V6, and (4) slurred initial part of the QRS complex in the precordial leads, e.g., [4a] pseudo delta wave ≥ 34 ms, [4b] intrinsicoid deflection time ≥ 85 ms, and [4c] maximum deflection index ≥ 0.55. Patients who met ≥ 2 of (1)-(3) and any of [4a]-[4c] could be classified as having MAPS-VA, with a sensitivity and specificity of 100%. VA recurred in one patient in the TAPS group during the median follow-up of 7 (interquartile range 6 to 15.5) months. CONCLUSIONS: VA arising from the PS has superior axis deviation, and left and right bundle block morphologies with relatively early precordial transition. MAPS-VA can be differentiated from TAPS-VA based on electrocardiographic characteristics. This study provides useful information for treatment involving catheter ablation for VA arising from the PS.