Cardioneuroablation for reflex asystolic syncope: Mid-term safety, efficacy, and patient's acceptance.

BACKGROUND: Cardioneuroablation (CNA) is a promising therapy for reflex asystolic syncope; however, convincing data on the mid-term safety and efficacy of this procedure are lacking. OBJECTIVE: The purpose of this study was to assess the mid-term safety, efficacy, and patient acceptance of CNA. METHODS: This prospective observational single-center study included 115 consecutive patients (mean age 39 ± 13 years; 58% female) treated between 2016 and 2022 who completed at least 1-year follow-up. RESULTS: No significant procedure-related acute complications occurred. During median follow-up of 28 months (range 12-75), 95 (83%) remained free from syncope. Of the 20 patients (17%) with syncope recurrence, syncope burden decreased from a mean 17 (median 6.5) to 3.75 (median 2.5) episodes (P = .015). In 9 of 10 patients, pacing system removal was possible. Repeated CNA was needed in 3 patients (3%), whereas pacemaker implantation was performed in 5 (4%). The most frequent mid-term complication of CNA was sinus rhythm acceleration (from 60 ± 14 bpm to 90 ± 16 bpm; P <.0001), which was symptomatic in 31 patients (27%); 8 patients (7%) required chronic beta-blocker and/or ivabradine. Sinus node modification was necessary in 1 patient. Other complaints included dyspnea, chronic chest pain, and decreased exercise capacity, which were mild and reported by 16 patients (14%). Patient acceptance of CNA was very high: 96% stated that it was worth undergoing the procedure. CONCLUSIONS: Mid-term efficacy of CNA exceeds 80%, and acute complications are absent. The most frequent mid-term chronic complication is inappropriate sinus tachycardia, which in 7% required chronic treatment. The procedure is well accepted by patients.

Daily ECG transmission versus serial 6-day Holter ECG for the assessment of efficacy of ablation for atrial fibrillation - the AGNES-ECG study.

PURPOSE: To compare daily ECG transmissions using trans-telephonic monitoring (TTM) with repeated 6-day Holter ECG in detecting atrial fibrillation (AF) episodes following ablation. METHODS: Each patient underwent two types of recordings: daily ECG TTM lasting 30 s and standard 6-day ambulatory ECG monitoring performed 3, 6, and 12 months after ablation. Number of patients with detected AF recurrences, time to first detected recurrence of AF, and AF burden were assessed. RESULTS: Fifty patients (9 females, mean age 57 ± 11 years) were included. The mean duration of the follow-up was 382 ± 38 days. A total of 17,573 (mean 351 ± 111 per patient) TTM recordings were performed and 99.95% of recordings were of quality sufficient to assess cardiac rhythm. Altogether, 14 (28%) patients had AF recurrence. Holter ECG detected AF recurrence in 7 (14%) patients whereas TTM - in 12 (24%) patients, p = 0.0416 (TTM only - 7 (14%), Holter ECG only - 2 (4%), and both methods - 5 (10%)). Time to the first AF recurrence tended to be shorter using TTM than Holter ECG (156 ± 91 vs 204 ± 121 days, p = 0.0819). There was no significant difference in AF burden assessed by TTM versus Holter ECG recordings 3.1 ± 0.14% vs 4.8 ± 0.2%, p = 0.21. CONCLUSIONS: Compared with Holter ECG, daily 30-s ECG recordings detected more patients with AF recurrences. Time to first detected AF episode tended to be shorter using TTM. Daily ECG recordings transmitted using smartphone may replace standard Holter ECG in detecting AF after ablation. TRIAL REGISTRATION: Clinical Trials Identifier: NCT03877913.

Antazoline-insights into drug-induced electrocardiographic and hemodynamic effects: Results of the ELEPHANT II substudy.

BACKGROUND: Antazoline is an old antihistaminic and new antiarrhythmic agent with unknown mechanisms of action which recently has been shown to effectively terminate atrial fibrillation. The aim of study was to examine the effects of antazoline on hemodynamic and ECG parameters. METHODS: Antazoline was given intravenously in three 100 mg boluses to 10 healthy volunteers (four males, mean age 40 + 11 years). Hemodynamic and ECG parameters were measured using impedance cardiography [systolic (sBP), diastolic (dBP), mean (mBP) blood pressure, stroke volume (SV), cardiac output (CO), total peripheral resistance (TPR) and heart rate (HR), P wave, PR interval, QRS complex, QT and corrected QT (QTcF) interval]. Plasma concentration of antazoline was also measured. RESULTS: Antazoline caused significant prolongation of P wave, QRS as well as QT and QTcF (101 ± 10 vs 110 ± 16 ms, p < .05, and 101 ± 12 vs 107 ± 12 ms, p < .05, 399 ± 27 vs 444 ± 23 ms, p < .05, and 403 ± 21 vs 448 ± 27 ms, p < .05, respectively). Also, a significant decrease in SV was noted (94.9 ± 21.8 vs 82.4 ± 19.6 ml, p < .05). A significant correlation between changes in plasma drug concentration and changes in CO, HR, and dBP was found. CONCLUSIONS: Antazoline impairs slightly hemodynamics, significantly reducing SV. Significant prolongation of P wave and QRS duration corresponds to drug-induced prolongation of conduction, whereas QT prolongation represents drug-induced prolongation of repolarization.

Haemodynamic effects of etomidate, propofol and electrical shock in patients undergoing implantable cardioverter-defibrillator testing.

BACKGROUND: Anaesthetic drugs and internal electrical shock may alter the haemodynamic status of patients undergoing implantable cardioverter-defibrillator (ICD) testing. Comparative data on the mechanisms of etomidate and propofol-induced changes in haemodynamic parameters are inconsistent. Also the effects of ICD shock on haemodynamics have not been extensively studied. AIM: To compare the haemodynamic effects of etomidate and propofol as well as electrical shock during ICD testing in a prospective, randomised trial. METHODS: The study group consisted of 63 consecutive patients (mean age 66 ± 10 years, 51 males) who underwent ICD testing. Haemodynamic parameters were measured using impedance cardiography (Task Force Monitor Systems, CNSystems, Austria) before and after injection of etomidate (n = 30) or propofol (n = 33) as well as immediately after internal defibrillation of ventricular fibrillation (VF). Parameters measured included heart rate, systolic (sBP), diastolic (dBP) and mean (mBP) blood pressure, stroke volume (SV), cardiac output (CO) and total peripheral resistance (TPR). RESULTS: Propofol significantly decreased the values of all measured parameters (sBP: 123.4 ± 17.1 vs. 106.3 ± 18 mm Hg, p < 0.0001; dBP: 83.7 ± 12.2 vs. 74.1 ± 13.8 mm Hg, p < 0.0001; mBP: 93.9 ± 13.1 vs. 81.1 ± 16.1 mm Hg, p < 0.0001; SV: 61.1 ± 19.3 vs. 56.4 ± 15.7 mL, p < 0.003; CO: 4.51 ± 1.07 vs. 4.17 ± 0.73 L/min, p < 0.003; and TPR: 1,735.8 ± 532.6 vs. 1,573.9 ± 390.5 dyn×s/cm5), whereas the only significant change following etomidate infusion was a decrease in SV (60.6 ± 11 vs. 56.8 ± 10 mL, p < 0.022). The propofol-induced changes were similar in patients with reduced (< 40%) vs. preserved (≥ 40%) left ventricular ejection fraction (LVEF) and in patients in heart failure NYHA class 0-II vs. class III-IV. Induction of VF and internal electrical shock did not cause major haemodynamic changes apart from significant, albeit very modest, drops in dBP and mBP (77 ± 2 vs. 72.9 ± 18 mm Hg, p < 0.002, and 85.2 ± 17 vs. 81.8 ± 20 mm Hg, p < 0.017, respectively). There were no complications during ICD testing. CONCLUSIONS: Propofol significantly decreased BP probably by both reducing CO and causing vasodilatation, whereas etomidate only slightly decreased dBP and mBP without affecting other parameters. Propofol-induced changes were independent of LVEF or NYHA class. Induction of VF and internal defibrillation did not cause clinically significant changes apart from very modest drops in dBP and mBP values.

Ablation of atrioventricular nodal reentrant tachycardia: predictors of long-term success.

BACKGROUND: Atrioventricular nodal reentrant tachycardia (AVNRT) is the commonest regular supraventricular tachyarrhythmia. Ablation in the area of slow pathway (SP) has been successfully implemented in everyday clinical electrophysiological practice for more than 20 years. Although the procedure is generally regarded as effective and safe, data on long-term effects and predictors of success or failure are incomplete. AIM: To identify predictors of successful AVNRT ablation. METHODS: The study group consisted of 359 patients (105 males, mean age 51.1 ± 16.7 years) who underwent AVNRT radiofrequency ablation using typical combined electrophysiological and anatomical approach. RESULTS: Acute success was achieved in 342 (95%) patients, including 187 (52%) with SP ablation and 155 (43%) with SP modification. Patients with SP modification were younger, had shorter AVNRT cycle length, less often had typical echo, and had more frequent isoproterenol usage after ablation. Long-term follow-up data was available for 308 patients (86% of the total study group). During the mean follow-up of 52.9 ± 27.3 months (median 48, range 12-130 months), 22 patients experienced AVNRT recurrences (long-term efficacy 93%). These patients had less often complete SP abolition than SP modification (27% vs. 56%, p < 0.001) and typical jump (vs. no jump or multiple jumps) at baseline (74% vs. 89%, p < 0.06) than patients without recurrences. Multivariate Cox regression analysis showed that typical jump was associated with a favourable outcome (HR 5.8, 95% CI 0.44-3.1, p = 0.0089). There were no significant differences in the use of 2 or > 2 electrode approaches between patients with or without AVNRT recurrences. CONCLUSIONS: Typical jump and complete SP elimination are associated with a better outcome. A 2-electrode approach is as effective as > 2 electrode approach. The electrophysiological profile of patients in whom complete SP elimination was achieved may differ from that of patients in whom only SP modification was possible.

Tilt-induced changes in haemodynamic parameters in patients with cardiac resynchronisation therapy - a pilot study.

BACKGROUND: Cardiac resynchronisation therapy (CRT) has become a standard care in selected patients with advanced chronic heart failure (CHF). In order to achieve an adequate clinical response, CRT parameters have to be optimised following implantation. This procedure is usually performed on a patient in a supine position; however, measurement of haemodynamic parameters in an upright position may be clinically important. AIM: To compare haemodynamic parameters obtained in supine and erect positions in CRT patients undergoing optimisation procedures. METHODS: The study group consisted of 10 consecutive patients (mean age 69.6+/-9 years, all males) who were scheduled for control outpatient CRT follow-up visits. Apart from routine device check-up, haemodynamic parameters [impedance cardiography (ICG) Task Force Monitor Systems, CNSystems, Austria] were measured. The ICG parameters were recorded during 20-min periods while supine and while tilted to 80 degrees. The last 30 cardiac cycles from each period were taken for further analysis. Parameters measured included heart rate (HR), systolic and diastolic blood pressure, stroke volume, cardiac output (CO) and total peripheral resistance (TPR). RESULTS: Out of 60 measurements performed (6 parameters in 10 patients) all but nine differed significantly when comparing supine and erect positions. There was no uniform pattern regarding these changes. For example, HR increased after tilting in five patients, did not change in four, and slowed down in one patient. The changes in CO were significant in all but two patients, reaching a 50% increase in one patient. An abnormal response of TPR (significant decrease) was observed in 5 patients. There was no apparent association between tilt-induced changes in haemodynamic parameters and clinical response to CRT, whereas a significant negative correlation between tilt-induced changes in CO and left ventricular ejection fraction was found (r=-0.7, p <0.025). CONCLUSIONS: Tilting causes significant and often abnormal changes in haemodynamic parameters in CRT patients. The clinical significance of these findings needs further evaluation.