Risk assessment in patients with symptomatic and asymptomatic pre-excitation.

AIMS: Controversy remains as to whether the exercise stress test (EST) is sufficient for risk evaluation in patients with pre-excitation. This study aims to clarify the usefulness of EST in risk stratification in both asymptomatic and symptomatic patients presenting with pre-excitation. METHODS AND RESULTS: This prospective study includes consecutive asymptomatic and symptomatic patients with pre-excitation referred for risk assessment. All participants performed an incremental EST (bicycle) prior to an electrophysiology study (EPS). Primary data from the EST included loss of pre-excitation during exercise, and primary data from the EPS included the measurement of accessory pathway effective refractory period (APERP), shortest pre-excited RR interval (SPERRI), and inducible arrhythmia with the use of a beta-adrenergic receptor agonist if deemed necessary. One hundred and sixty-four patients (59 asymptomatic, 105 symptomatic) completed an EST and EPS. Forty-five patients (27%) demonstrated low-risk findings on EST, of which 19 were asymptomatic and 26 were symptomatic. Six patients with low-risk EST findings had SPERRI/APERP ≤ 250 ms at EPS, and two of them were asymptomatic. The sensitivity, specificity, positive predictive value, negative predictive value (NPV), and accuracy of low-risk EST for excluding patients with SPERRI/APERP ≤ 250 ms were 40, 91, 87, 51, and 60%, respectively. The number of patients with inducible arrhythmia at EPS was similar in the asymptomatic (36, 69%) and symptomatic (73, 61%) groups. CONCLUSION: Sudden loss of pre-excitation during EST has a low NPV in excluding high-risk APs. The EPS with the use of isoproterenol should be considered to accurately assess the risk of patients with pre-excitation regardless of symptoms (ClinicalTrials.gov Identifier: NCT03301935).

Association between catheter ablation of atrial fibrillation and mortality or stroke.

OBJECTIVE: Catheter ablation of atrial fibrillation effectively reduces symptomatic burden. However, its long-term effect on mortality and stroke is unclear. We investigated if patients with atrial fibrillation who undergo catheter ablation have lower risk for all-cause mortality or stroke than patients who are managed medically. METHODS: We retrospectively included 5628 consecutive patients who underwent first-time catheter ablation for atrial fibrillation between 2008 and 2018 at three major Swedish electrophysiology units. Control individuals with an atrial fibrillation diagnosis but without previous stroke were selected from the Swedish National Patient Register, resulting in a control group of 48 676 patients. Propensity score matching was performed to produce two cohorts of equal size (n=3955) with similar baseline characteristics. The primary endpoint was a composite of all-cause mortality or stroke. RESULTS: Patients who underwent catheter ablation were healthier (mean CHA2DS2-VASc score 1.4±1.4 vs 1.6±1.5, p<0.001), had a higher median income (288 vs 212 1000 Swedish krona [KSEK]/year, p<0.001) and had more frequently received university education (45.1% vs 28.9%, p<0.001). Mean follow-up was 4.5±2.8 years. After propensity score matching, catheter ablation was associated with lower risk for the combined primary endpoint (HR 0.58, 95% CI 0.48 to 0.69). The result was mainly driven by a decrease in all-cause mortality (HR 0.51, 95% CI 0.41 to 0.63), with stroke reduction showing a trend in favour of catheter ablation (HR 0.75, 95% CI 0.53 to 1.07). CONCLUSIONS: Catheter ablation of atrial fibrillation was associated with a reduction in the primary endpoint of all-cause mortality or stroke. This result was driven by a marked reduction in all-cause mortality.

Electrical cardioversion for early recurrences post pulmonary vein isolation.

BACKGROUND: To study the association between timing and success of electrical cardioversion (ECV) for the treatment of early recurrences (ERs) of atrial fibrillation post pulmonary vein isolation (PVI) on long-term rhythm outcome. METHODS: Data of 133 patients ablated for paroxysmal or persistent atrial fibrillation receiving ECV for ERs, i.e., atrial tachyarrhythmia recurrences within 90 days post ablation were analyzed. During 1-year follow-up, patients were screened for late recurrences (LRs), i.e., recurrences after the blanking period. RESULTS: In 114 patients (85.7%), ECV was successful compared to 19 patients (14.3%) with failed ECV. A higher body mass index (odds ratio (OR) 1.19 (95% CI 1.02-1.39), p = 0.029), a lower left ventricular ejection fraction (OR 1.07 (95% CI 0.99-1.15), p = 0.079), and performance of ECV > 7 days from ER onset (OR 2.99 (95% CI 1.01-8.87), p = 0.048) remained independently associated with ECV failure. During 1-year follow-up, the rate of LR was significantly higher among patients with failed ECV as compared to patients with successful ECV (hazard ratio (HR) 3.00 (95% CI, 1.79-5.03), p < 0.001). Patients with ECV performed > 7 days from ER onset had a significantly higher risk of developing LR as compared to patients with ECV performed within ≤ 7 days from ER onset (HR 1.73 (95% CI 1.15-2.62), p = 0.009). Performance of ECV > 7 days from ER onset (HR 1.76 (95% CI 1.16-2.67), p = 0.008) and failed ECV (HR 3.32 (95% CI 1.96-5.64), p < 0.001) remained independently associated with LR. CONCLUSIONS: A failed ECV and performance of ECV > 7 days from ER onset were independently associated with LR.

A new score model to predict the inducibility of supraventricular tachycardia in patients with palpitation without documented electrocardiography.

OBJECTIVE: Although electrophysiological study (EPS) is one of the most useful diagnostic approaches to detect the cardiac origin of palpitations, there is no clear indication for EPS in patients with palpitation in the absence of documented supraventricular tachycardia (SVT). In this study, we aimed to create a new SVT score model to detect the requirement of EPS in patients with palpitation without documented tachycardia. METHODS: A total of 154 patients with palpitation were included in this study. To create the SVT score, we considered four main criteria with their subunits. They were severity, frequency, duration, and termination of the symptoms. EPS was performed on all the patients after their scoring assessment. RESULTS: Median SVT score of induced tachycardia and non-induced patients was determined as 10 and 6 points, respectively; and it was found to be statistically significant; p<0.001. The cut-off value for inducibility was found to be 7.5 points through receiver operating characteristic curve analysis, (94.9% sensitivity, 92.1% specificity), and the area under the curve was determined to be 97.2 (94.8-99.5, p<0.001). CONCLUSION: According to our new SVT score model, ≥8 points strongly correlates with the inducibility of SVT during EPS.

Focal atrial tachycardia-the localization differences between men and women: A study of 487 consecutive patients.

OBJECTIVE: The preferential sites for focal atrial tachycardia (FAT) are mainly in the right atrium in both sexes. However, a limited number of studies have indicated that sex differences in the localization of FAT. This study investigated possible sex differences in the distribution of FAT in a large cohort of patients referred for ablation. METHODS: From 2004 to 2019, 487 patients (298 women) were referred to our institution for ablation of FAT. A standard electrophysiological study was conducted, and isoproterenol or atropine was given when needed. Conventional catheter mapping, electroanatomic contact mapping, and noncontact mapping were used to assess the origin of ectopic atrial tachycardia. RESULTS: Overall, 451 foci were successfully ablated in 436 patients (90%). Although the foci located along the crista terminalis were more common in women than in men (42% vs. 29%; p=0.023), the opposite were found in the foci located along the tricuspid annulus (5% vs. 11%; p=0.032) and the right atrial appendage (RAA) (1% vs. 3%; p=0.032). Other locations were similarly distributed in men and women. In addition, the presence of persistent FAT was more frequent in men than in women (22% vs. 5%; p<0.001). Finally, the difference in the induction pattern of FAT was also remarkable between sexes. CONCLUSION: The distribution of FAT in women and men is different. In addition, persistent FAT seems more often in men than in women. The different distribution, persistency, and induction pattern of FAT should be considered in the successful management of this type of tachycardia.

Relationship between myocardial performance index and severity of coronary artery disease in patients with non-ST-segment elevation acute coronary syndrome.

OBJECTIVES: We aimed to investigate the relationship between myocardial performance index (MPI) and severity of coronary artery disease, as assessed by the Gensini score (GS), in patients with non-ST-segment elevation myocardial infarction (NSTEMI). METHODS: Ninety patients with an initial diagnosis of NSTEMI were enrolled in our study. They were divided into tertiles according to the GS: low GS < 19; mid GS > 19 and ≤ 96; and high GS > 96. RESULTS: The low-, mid- and high-GS groups included 24, 38 and 28 patients, respectively. Clinical features such as gender distribution; body mass index (BMI); prevalence of diabetes mellitus, hypertension and hyperlipidaemia; and smoking status were similar in the three groups. MPI and isovolumic relaxation time were significantly higher in the high-GS group than in the low- and mid-GS groups (p < 0.001 and p = 0.005, respectively). Furthermore, the high-GS group had a significantly lower ejection fraction and ejection time (p = 0.01 and p < 0.001, respectively). MPI was positively correlated with the GS (r = 0.47, p < 0.001), and multivariate regression analysis showed that MPI was an independent predictor of the GS (ß = 0.358, p < 0.001). CONCLUSIONS: Patients with NSTEMI who fall within the high-risk group may be identified by means of a simple MPI measurement.

Right ventricular outflow tract tachycardia after an initial dose of amantadine.

Amantadine hydrochloride is an antiviral agent that is also effective in the treatment of Parkinson's disease. In the literature, cardiac arrhythmia is reported in toxic doses of amantadine, but in this paper we report a patient with right ventricular outflow tract (RVOT) tachycardia after an initial dose of amantadine. A 47-year-old female patient was admitted to the emergency department with the complaint of palpitation and dizziness after taking 200 mg amantadine. A 12-lead standard ECG showed wide QRS complex tachycardia with a heart rate of 167/min. The wide QRS complex tachycardia had an inferior axis and left bundle branch block morphology, compatible with RVOT ventricular tachycardia (RVOT-VT). Tachycardia terminated spontaneously and sinus ECG was completely normal. No arrhythmia was inducible at the electrophysiological study. To the best of our knowledge, this is the first case in the literature to describe RVOT-VT after amantadine intake. Amantadine may cause RVOT-VT as well as other cardiac arrhythmias.