Search

To compare daily ECG transmissions using trans-telephonic monitoring (TTM) with repeated 6-day Holter ECG in detecting atrial fibrillation (AF) episodes following ablation.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.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.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.Clinical Trials Identifier: NCT03877913.

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/cm 5 ), 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.

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.To identify predictors of successful AVNRT ablation.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.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%, p0.001) and typical jump (vs. no jump or multiple jumps) at baseline (74% vs. 89%, p0.06) 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 or2 electrode approaches between patients with or without AVNRT recurrences.Typical jump and complete SP elimination are associated with a better outcome. A 2-electrode approach is as effective as2 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.

KULAKOWSKI, P., et al.: QT Interval Dispersion in Ventricular Beats: A Noninvasive Marker of Susceptibility to Sustained Ventricular Arrhythmias. Increased QT dispersion (QTd) calculated from sinus beats has been shown to identify patients prone to sustained VT. However, predictive accuracy of this parameter is limited. Electrophysiological properties of the myocardium may be altered by a premature ventricular beats, which is a well-established trigger for sustained VT. Therefore, the author hypothesised that QTd in spontaneous or paced ventricular beats may improve identification of patients with inducible sustained VT. In 28 consecutive patients (men, mean age 61 ± 13 years) who underwent programmed ventricular stimulation, the values of QTd calculated in sinus and ventricular beats were compared between inducible and noninducible patients. The mean QTd values obtained using three different methods differed significantly, QTd in paced ventricular beats being the highest, QTd in spontaneous ventricular beats was intermediate, and QTd in sinus beats was the lowest (83.9 ± 30 vs 63.0 ± 29 ms vs 53.9 ± 27 ms, P < 0.0001 and P < 0.004, respectively). In 13 (46%) patients sustained VT was induced. QTd values were significantly higher in inducible than noninducible patients (QTd sinus beats: 67.5 ± 31 vs 42.1 ± 11 ms, P = 0.02; QTd spontaneous ventricular beats: 79.3 ± 35 vs 46.7 ± 13 ms, P = 0.008, and QTd-paced ventricular beats: 104.8 ± 32 vs 65.9 ± 9 ms, P = 0.0009). The receiver operator characteristic curves showed that at a sensitivity level of 100%, the highest specificity for identification of inducible patients had QTd measured in paced ventricular beats (87%) followed by QTd in spontaneous ventricular beats (45%), and QTd in sinus beats (40%). In conclusion, (1) QTd in ventricular beats is greater than in sinus beats, and (2) QTd calculated from paced ventricular beats identifies patients with inducible sustained VT better than QTd measured during sinus rhythm.

Aims Intravenous amiodarone has recently emerged as an important drug for the acute treatment of ventricular tachyarrhythmias. However, electrophysiological actions and the efficacy of the drug in the suppression of ventricular tachycardia inducibility have not yet been fully established. The present study was designed to address these issues. Methods and Results The study group consisted of 18 patients (all males, mean age 75±14 years), who underwent electrophysiological study due to a history of sustained ventricular tachyarrhythmia or syncope with non-sustained ventricular tachycardia detected on ambulatory ECG monitoring. The effects of 5 mg . kg−1or 10 mg . kg−1of intravenous amiodarone on (1) ventricular refractoriness (QTc interval, right ventricular effective refractory period and monophasic action potential duration), (2) intraventricular conduction (paced-QRS and signal-averaged QRS duration), and (3) ventricular tachycardia inducibility, were examined. The drug had no significant effect on ventricular refractoriness. However, a relatively small but significant slowing of intraventricular conduction was seen (paced-QRS duration: 182±27 ms vs 191±28 ms, P< 0·0007; 183±32 ms vs 195±33 ms, P< 0·0007; and 177±21 ms vs 192±24 ms, P< 0·003, at the cycle lengths of 600, 500 and 400 ms, respectively). This effect was more evident during extrasystolic beats than during stable pacing (for example, at the cycle length of 600 ms, the magnitude of amiodarone-induced lengthening of QRS duration was 23·9±17·6 ms vs 9·7±7·2 ms, P< 0·009, respectively). Intravenous amiodarone did not prevent induction of sustained ventricular tachycardia in any of five patients inducible at baseline. Of six patients with non-sustained ventricular tachycardia, five had sustained ventricular tachycardia or fibrillation induced after amiodarone infusion. Conclusion Intravenous amiodarone does not prolong ventricular refractoriness, slows intraventricular conduction and may facilitate inducibility of sustained ventricular arrhythmias.

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

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.To compare haemodynamic parameters obtained in supine and erect positions in CRT patients undergoing optimisation procedures.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).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, p0.025).Tilting causes significant and often abnormal changes in haemodynamic parameters in CRT patients. The clinical significance of these findings needs further evaluation.