Predictors of adequate intraprocedural premature ventricular complex (pvc) frequency during idiopathic pvc ablation

Funding Acknowledgements

Type of funding sources: None.

Background

The aim of the present study was to determine the predictors of adequate intraprocedural premature ventricular complex (PVC) frequency for successful mapping and ablation of idiopathic PVCs.

Methods

A total of 101 consecutive patients (45 men; age: 47.9 ± 14.2 years) who had undergone idiopathic PVC ablation between 01 November 2018 and 24 June 2020 constituted our study population. Clinical and demographic data, procedural details and 24 h rhythm recordings that had been recorded before the procedure were retrospectively evaluated. Total PVC burden and diurnal variability assessed by the ratio of night time (22:00–06:00) over day time (06:00–22:00) PVC burden was calculated. Patients were classified into three groups based on the relationship between hourly PVC number and HR. If there was a significant positive correlation between hourly PVC number and corresponding hourly HR, patients were classified into the fast HR-PVC group. If there was a significant negative correlation between hourly PVC number and corresponding hourly HR, patients were classified into the slow HR-PVC group. Patients were classified into the independent HR-PVC group if there was no significant correlation between hourly PVC number and corresponding hourly HR. Clinical characteristics and Holter parameters were compared between groups with and without adequate intraprocedural frequency of PVCs that permitted activation mapping.

Results

In all, 74 patients had frequent intraprocedural PVC that permitted activation mapping (Group 1) and 27 patients (26.7%) had infrequent intraprocedural PVCs which necessitated isoproterenol infusion or cancellation of ablation procedure (Group 2). PVC burden was significantly higher in the group with frequent intraprocedural PVCs (26.1 ± 9.4% vs 21.2 ± 10.3%; p: 0.026). There were no significant differences between groups regarding the relationship between hourly PVC number and heart rate (Fast HR-PVC 42 (56.8%) vs 18 (66.6%); slow HR-PVC  4(5.4%) vs 3 (11.1%); independent HR PVC 28 (37.8%) vs 6 (22.2%) in the respective order for group 1 and group 2; p: 0.26) or the ratio of night/day PVC burden (median 0.99 (IQR 0.4) vs median 0.83 (IQR 0.54) in the respective for group 1 and group 2 ; p: 0.53). Binary logistic regression analysis revealed the 24 h Holter PVC burden as the sole parameter that is significant predictor of frequent intraprocedural PVCs permitting activation mapping. A Holter PVC burden ≥ 19.43% had 72% sensitivity and 60% specificity for the prediction of sufficient intraprocedural PVCs that permitted activation mapping and ablation (area under the curve: 0.65; p: 0.02)

Conclusion

The 24 h PVC burden was the only predictor of adequate intraprocedural PVC frequency permitting activation mapping during idiopathic PVC ablation.

P1371Catheter-induced premature ventricular complexes (pvc) may aid in the determination of optimal timing for clinical pvc ablation

Background

There is significant interpatient variability regarding the timing of the earliest local activation relative to surface QRS during premature ventricular complex (PVC) ablation. The aim of the present study is to evaluate whether catheter-induced premature ventricular complexes (PVCs) produced at the presumptive ablation site may aid in the identification of the optimal timing of the earliest local activation for the successful ablation of clinical PVCs.

Methods

Sixty-three consecutive patients (35 males, age: 53.5 ± 14.4 years) without any exclusion criteria who had undergone PVC ablation between 01/07/2018 and 01/07/2019 constituted our study population.  Catheter-induced PVCs were generated at the site with presumptive PVC origin according to the ECG criteria during the procedure of PVC ablation. Five PVCs were induced by mechanical stimulation in separate points, and the time interval between the beginning of EGM at catheter tracing and the beginning of the QRS complex of each catheter-induced PVC was noted. The mode of five time intervals (Cath EGM-ECG) was used in the analysis. The time interval between the beginning of local EGM of clinical PVCs at the earliest site and the beginning of the QRS complex of clinical PVCs (PVC earliest EGM-ECG) was also noted. The value of Cath EGM-ECG as a reference for procedural success of ablation was evaluated by examining the relationship between Cath EGM-ECG and PVC earliest EGM-ECG.

Results

Fifty-two patients had successful ablation, and 43 of them (82.7%) had PVC earliest EGM-ECG values greater than or equal to Cath EGM-ECG. Eleven patients had procedural failure, and all of them had PVC earliest EGM-ECG values lower than Cath EGM-ECG (Table 1). A PVC earliest EGM-ECG value -1.5 ms greater than Cath EGM-ECG predicted successful ablation with a sensitivity of 90.4% and a specificity of 100.0% in the general patient population (Figure 1).

Conclusion

The results of the present study indicate that catheter-induced PVCs generated at the site of the presumptive source of origin of clinical PVCs may guide the timing of the earliest site during clinical PVC ablation. Further studies are required to validate our results and test the predictive value of Cath EGM- ECG interval for long-term success of PVC ablation.

Table 1 PVC earliest EGM-ECG < Cath EGM- ECG PVC earliest EGM-ECG ≥ Cath EGM- ECG Ablation successful (n:52) 9 (17.3%) 43 (82.7%) Ablation not successful (n:11) 11 (100.0%) 0 (0%) Outcome of ablation in general patient population according to the relationship between PVC earliest EGM-ECG and Cath EGM- ECG

Abstract Figure 1

Carotid and cerebral CT angiography using low volume of iodinated contrast material and low tube voltage

PURPOSE

To evaluate image quality of carotid computed tomography angiography (CTA) using a low voltage (80kV) and low amount of iodinated contrast material.

MATERIALS-METHODS

A total of 101 patients referred for carotid CTA were randomly assigned to receive a specific protocol. In group A patients received intravenous administration of contrast material at a dose of 1mL/kg and CTA examinations were performed at 100kV. In group B, patients received intravenous administration of contrast material at a dose of 0.5mL/kg and CTA examinations were performed at 80kV. The same nonionic iodinated contrast material containing 370mg of iodine per mL was used in both groups. Attenuation values were measured from the center of specific arterial segments using regions of interest. Attenuation values above 300HU were accepted as significant. Institutional review board approval was obtained.

RESULTS

A total of 50 patients were included in group A (38 men, 12 women; mean age, 63.56 years±13.18 [SD]) and 51 patients in group B (33 men, 18 women; mean age, 59.60 years±16.63 [SD]). A total of 1615 arterial segments (1515 common carotid artery-middle cerebral artery and 101 aortic arches) were analyzed. Venous contamination was not observed in either group. The mean attenuation values of all arterial segments in both groups were greater than 300HU. Mean arterial attenuation value in group B (499.22HU±97.25 [SD]) was significantly greater than in group A (374.36HU±73.79 [SD]) (P<0.01). Hemodynamically significant stenosis (grade III stenosis or >70%) was detected in 2 segments in group A and in 3 segments in group B, while grade IV stenosis (occlusion) was detected in 2 segments in group B. Distal common carotid artery dissection was detected in 1 patient and aortic dissection was detected in 1 patient in group B. Total dose-length product (DLP) value was significantly greater in group A (225.74mGy·cm±21.80 [SD]) than in group B (116.60mGy·cm±21.22 [SD]) (P<0.01). The mean tube current was similar in group A (2013.11mAs±195.92 [SD]) and in group B (2096.64 mAs±309.03 [SD]) (P<0.05).

CONCLUSION

Carotid and cerebral CTA examinations using 128-section CT can be successfully obtained using an imaging protocol that combines low voltage and 50% reduction in the volume of iodinated contrast material. This provides good image quality with low radiation dose.

The association between mean platelet volume and coronary collateral circulation

BACKGROUND

Platelets are important in the pathogenesis of atherosclerotic complications. Higher mean platelet volume (MPV) levels are related to greater in vitro aggregation, and have been identified as an independent risk factor for myocardial infarction, and for death or recurrent vascular events.

AIM

To determine the relationship between MPV and the coronary collateral circulation.

METHODS

The sample consisted of 96 patients with coronary artery disease, and patients were separated into two groups according to their poorly developed or well-developed collateral circulation. Coronary collateral vessels were analyzed according to the Cohen and Rentrop grading system of 0-3.

RESULTS

All analyses were conducted using SPSS 11.5 (SPSS for Windows 11.5, Chicago, IL, USA). Continuous variables were expressed as mean ± SD, and categorical variables were expressed as percentages. Comparison of categorical and continuous variables between the group with well-developed coronary collateral vessels and the group with poorly developed vessels was performed using the chi-squared test and independent samples t-test, respectively. Platelet count and MPV values were similar between the two groups.

CONCLUSIONS

Our study found that MPV levels are not related to coronary collateral circulation.  

Implantable cardioverter defibrillator pocket infection caused by Klebsiella pneumonia

Like any other foreign bodies, implanted cardiac devices can become infected. Staphylococcus aureus and coagulase-negative Staphilococci are the most common causes of infections of pacemaker and defibrillator systems. In this case an implantable cardioverter defibrillator pocket infection caused by an extremely rare microorganism, Klebsiella pneumonia, is presented.