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Background: Atrial fibrillation (AF)-associated embolic stroke is preventable, and AF detection may help to prevent stroke in subjects with paroxysmal AF. We aimed to evaluate the AF detection performance of smartwatch photoplethysmography (PPG) and the feasibility of ambulatory monitoring for AF detection in the daily life., Design and Methods: Consecutive subjects who underwent ambulatory Holter electrocardiogram (ECG) monitoring for AF detection or AF burden evaluation were enrolled. The participants underwent 24 hours of simultaneous Holter ECG monitoring and continuous PPG recording using a Garmin smartwatch. The PPG signals were processed for noise rejection, beat detection, beat labeling, and rhythm labeling for each 5-minute segment. The accuracy of the PPG AF detection was calculated using the corresponding simultaneous Holter ECG as the AF diagnostic standard., Results: Among the 200 available participants, 112 participants (56%) developed AF (the AF group). The sensitivity, specificity, and positive predicted value of AF detection in participants were 97.3%, 88.6%, and 91.6%, respectively. The area under the receiver operating characteristic curve was 0.90. When the performance was analyzed in these 5-minute segments, the sensitivity, specificity, and positive predicted values of AF detection were 97.1%, 86.8%, and 89.7%, respectively., Conclusions: This study demonstrated the feasibility of ambulatory monitoring for AF detection using a commercial smartwatch in daily life. A smartwatch may be an alternative screening tool to standard ambulatory Holter monitoring., (Copyright © 2022 The Author(s). Published by Elsevier Inc. All rights reserved.)

Rationale: The P2Y 12 receptor inhibitor clopidogrel is widely used in patients with acute coronary syndrome, percutaneous coronary intervention, or ischemic stroke. Platelet inhibition by clopidogrel shows wide interpatient variability, and high on-treatment platelet reactivity is a risk factor for atherothrombotic events, particularly in high-risk populations. CYP2C19 polymorphism plays an important role in this variability, but heritability estimates suggest that additional genetic variants remain unidentified. The aim of the International Clopidogrel Pharmacogenomics Consortium (ICPC) is to identify genetic determinants of clopidogrel pharmacodynamics and clinical response., Study Design: Based on the data published on www.clinicaltrials.gov, clopidogrel intervention studies containing genetic and platelet function data were identified for participation. Lead investigators were invited to share DNA samples, platelet function test results, patient characteristics, and cardiovascular outcomes to perform candidate gene and genome-wide studies., Results: In total, 17 study sites from 13 countries participate in the ICPC, contributing individual patient data from 8,829 patients. Available adenosine diphosphate-stimulated platelet function tests included vasodilator-stimulated phosphoprotein assay, light transmittance aggregometry, and the VerifyNow P2Y 12 assay. A proof-of-principle analysis based on genotype data provided by each group showed a strong and consistent association between CYP2C19*2 and platelet reactivity (P value=5.1 × 10 -40 )., Conclusion: The ICPC aims to identify new loci influencing clopidogrel efficacy by using state-of-the-art genetic approaches in a large cohort of clopidogrel-treated patients to better understand the genetic basis of on-treatment response variability., (Copyright © 2017 Elsevier Inc. All rights reserved.)

This study examined the incidence and significance of catheter-induced atrioventricular nodal block (AVNB) during a radiofrequency ablation procedure that uses stiff large-tip steerable ablation catheters. AVNB was noted in 10 (1.6%) of 613 consecutive patients undergoing radiofrequency ablation therapy for atrioventricular nodal (AVN) reentrant tachycardia (592 patients) or atrioventricular reentry tachycardia incorporating a midseptal accessory pathway (21 patients). Of these 10 patients, 9 underwent AVN modification for AVN reentrant tachycardia and 1 for ablation of a midseptal accessory pathway. One patient had two episodes of AVNB during two sessions undertaken because of recurrence of tachycardia. No patient had a preexisting conduction defect before the study. In all 10 patients, AVNB was transient, and it lasted for a mean of 9.1 +/- 19 minutes. It occurred during positioning of the ablation catheter in the junctional area before (8 patients) or after (2 patients) the start of radiofrequency current applications. Complete AVNB was noted on six occasions, second-degree AVNB on four occasions, and first-degree AVNB on one occasion. All blocks were associated with narrow QRS ventricular beats and with a site of block proximal to the His bundle. The mean ventricular heart rate during AVNB was 60 +/- 23 beats/min. Two patients had transient asystole, with one having loss of consciousness. No patient required special treatment for heart block. One-to-one conduction resumed after repositioning of the catheters, and the subsequent ablation procedure was successfully completed in 8 of the 10 patients. During a follow-up of 20 +/- 12 months, none of the patients had severe dizziness or syncope, and none required implantation of a permanent pacemaker. In conclusion, transient AVNB due to mechanical injury occurs during positioning of a stiff large-tip steerable ablation catheter in the junctional area. Delivery of radiofrequency current to the site that provokes catheter-induced AVNB should be avoided.

Among 652 patients with Wolff-Parkinson-White syndrome who underwent radiofrequency ablation in this laboratory, 139 (21%) were found to have a total of 146 posteroseptal accessory pathways. Ablation was conducted by the regular transvenous or transaortic approach; ablation from cardiac venous structures was used only if regular approaches were unsuccessful. Of the 146 posteroseptal accessory pathways, 94 were successfully ablated from the left posteroseptal region and 45 from the right posteroseptal region. In 3, successful ablation of the accessory pathway required delivery of the current to the proximal coronary sinus, and in 1 it required delivery of the current to both the atrial and ventricular aspects of the tricuspid valve at the right posteroseptum. Thus, the accessory pathway was successfully ablated in 143 (98%) of 146 instances or in 136 (98%) patients. In 3 patients, ablation was unsuccessful despite delivery of current to the left posteroseptum, the right posteroseptum, the proximal coronary sinus, and the middle cardiac vein. Seventy-seven (57%) patients with an initial success, including 9 patients with resumed preexcitation or recurrence of paipitations, underwent a follow-up electro-physiologic study 90 +/- 72 days after ablation. Of these 9 patients, the initial successful ablation site was the right posteroseptum in 7 and the left posteroseptum in 2. The accessory pathways were ablated successfully by subsequent trials in 8 patients, whereas in 1 the accessory pathway was severely damaged. Thus radiofrequency ablation of posteroseptal accessory pathways can be achieved by the regular transvenous or transaortic approach; delivery of current to the coronary sinus or middle cardiac vein is unnecessary in most patients.

The purpose of this study was to examine the advantages of multiplane transesophageal echocardiography in the diagnosis of congenital coronary artery fistula, specifically in depicting the origin, the course, and the drainage site. Seven consecutive patients ranging in age from 20 to 72 years with a suspected coronary artery fistula underwent conventional transthoracic and multiplane transesophageal echocardiographic studies between March 1993 and July 1994. When a coronary artery fistula was noted, the origin, the course, and the drainage site were carefully searched for. All patients then underwent a cardiac catheterization with the performance of coronary angiography. A large right coronary artery fistula was detected in three patients; one of them had a drainage to the posterior left ventricle, one to the lateral right ventricle, and the other to the medial aspect of the right ventricle just below the insertion of the septal leaflet of the tricuspid valve. A small coronary artery fistula arising from the left coronary artery was noted in four patients, two from the left anterior descending artery and the other two from the left circumflex artery. Three of these four patients had a drainage to the main pulmonary artery and one to the left ventricle. The drainage site was clearly depicted in all seven patients, whereas the origin and the course were precisely defined in five patients by using multiplane transesophageal echocardiographic examination. The multiplane transesophageal echocardiography provides a panoramic view of the coronary artery and the fistulous vessel with a precise definition of the origin, the course, and the drainage site of the fistula. Therefore it is the noninvasive diagnostic mode of choice.

Electrophysiologic study and radiofrequency ablation therapy were performed in 23 patients with atypical (8 patients) or multiple (15) atrioventricular node reentry tachycardias. Dual pathways with anterograde fast and slow pathway conductions were demonstrated in 16 patients. Studies on retrograde conduction revealed the presence of three different pathways, including fast (15 patients), intermediate (17), and slow (16). The radiofrequency current was applied to the inferior aspect, one-third anterior two-thirds posterior between the His bundle and the ostium of the coronary sinus, of Koch's triangle along the tricuspid annulus in all patients. Application of the current resulted in selective ablation or modification of both retrograde intermediate and slow pathway conductions in 20 patients. In two patients retrograde fast pathway conduction was also modified. Complete atrioventricular block occurred in the remaining patient. Sixteen patients had no induction of tachycardia or echo, 4 had induction of a single echo, and 2 had induction of the slow-fast form tachycardia; one of those 2 patients underwent a second trial and was successful. A median application of 2 was delivered at a power of 25 +/- 5 W and a duration of 18 +/- 4 sec. The total fluoroscopic time was 25 +/- 21 minutes. The anterograde fast pathway conduction was unaffected; the shortest atrial paced cycle length that sustained 1:1 fast pathway conduction was 329 +/- 65 msec and 330 +/- 68 msec before and after ablation, respectively. A follow-up electrophysiologic study was performed in 16 patients 60 +/- 15 days after ablation. Eleven had no induction of tachycardia or echo, and five had induction of < 3 echoes. This study demonstrated that radiofrequency ablation with the inferior approach is effective and safe in atypical or multiple atrioventricular node reentry tachycardias. It resulted in ablation of the slow pathway and retrograde intermediate pathway conduction with preserved atrioventricular conduction.

A late electrophysiologic study was conducted in 182 of 289 patients with slow-fast atrioventricular node reentry tachycardia 81 +/- 36 days after radiofrequency ablation therapy by the inferior approach. Of these 182 patients, electrophysiologic study immediately after ablation revealed a selective modification of the slow pathway in 159, a modification of both the slow and fast pathways in 15, a modification of the fast pathway alone in 3, and failure of ablation in 5. One hundred two patients had no induction of echoes; 75 had induction of fewer than four echoes; and 5 had induction of sustained tachycardia with or without isoproterenol infusion. The late electrophysiologic study in these 182 patients revealed a persistent effect without changes in conduction properties in 161 (88%) patients. A change in conduction properties was noted in 21 patients, including 5 with resumption of slow- or fast-pathway conduction with induction of sustained tachycardia, 8 with improved fast- or slow-pathway conduction, and 8 with an additional depression of fast- or slow-pathway conduction. Of the 102 patients with no induction of echoes and the 75 patients with induction of fewer than four echoes during the immediate postablation electrophysiologic study, 5 (3 and 2, respectively) patients had induction of tachycardia. Of the 5 patients with induction of sustained tachycardia in the immediate postablation electrophysiologic study, 3 continued to have induction of sustained tachycardia; 1 had induction of echoes only; and 1 had no induction of echoes.(ABSTRACT TRUNCATED AT 250 WORDS)

Seven patients with multiple atrioventricular node reentry tachycardia were analyzed to unravel the mechanism of these tachycardias. Six of the seven patients showed anterograde dual atrioventricular node pathways and one showed anterograde conduction through the fast pathway. Three types of retrograde pathways were noted among these seven patients: (1) the fast pathway with the earliest atrial activation at the His bundle area; (2) the intermediate pathway with the earliest atrial activation at the ostium of the coronary sinus; and (3) the slow pathway with the earliest atrial activation at the ostium of the coronary sinus. All seven patients used the intermediate pathway for retrograde conduction. However, one patient showed evidence of retrograde slow pathway conduction with demonstrable retrograde dual pathways, and another showed evidence of retrograde fast pathway conduction with a shift of atrial activation sequence when conduction switched to the intermediate pathway. Four different types of reentry circuits using either the fast or the slow pathway as the anterograde limb and one of the three retrograde pathways as the retrograde limb were demonstrated in these seven patients, resulting in two types of tachycardias in four patients and three types of tachycardias in three patients. A change in tachycardia type could be induced with atrial or ventricular stimulation. A radiofrequency current delivered to the inferior aspect of Koch's triangle along the tricuspid anulus in five patients resulted in selective ablation or modification of the intermediate pathway or the slow pathway, with preservation of anterograde atrioventricular conduction and abolition of tachycardias. The findings suggest that a double loop figure-of-8 reentry circuit including a fast pathway, a slow pathway, and an intermediate pathway is responsible for multiple atrioventricular node reentry tachycardias.