|Year : 2018 | Volume
| Issue : 1 | Page : 20-25
Acute Complications in Cardiac Electrophysiology Procedures: A Prospective Study in a High-volume Tertiary Heart Center
Ali Vasheghani-Farahani1, Akbar Shafiee2, Mohammadali Akbarzadeh3, Negar Bahrololoumi-Bafruee4, Abolfath Alizadeh-Diz4, Zahra Emkanjoo4, Amirfarjam Fazelifar4, Hooman Bakhshandeh4, Majid Haghjoo4
1 Tehran Heart Center, Tehran University of Medical Sciences, Tehran, Iran, India
2 Tehran Heart Center, Tehran University of Medical Sciences; Department of Community Medicine, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
3 Cardiovascular Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
4 Cardiac Electrophysiology Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran, India
|Date of Web Publication||26-Feb-2018|
Dr. Majid Haghjoo
Cardiac Electrophysiology Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Niayesh Blvd, Vali-e-asr Street, Tehran 1996911151
Source of Support: None, Conflict of Interest: None
Background: Several complications can occur during electrophysiology (EP) study and radiofrequency catheter ablation (RFCA). In this study, we aimed to determine the frequency and types of complications following EP study and RF ablation in a tertiary cardiovascular center. Methods: Between September 2012 and December 2012, patients undergoing RF ablation and EP studies were prospectively enrolled. Demographic and clinical data of the patients, as well as the underlying arrhythmia and indication for EP study, were recorded. Complications occurring during the procedure and admission period were documented. Results: A total of 382 procedures were performed in 357 patients with the mean age of 47 ± 18 years within the study period. The most common arrhythmia was atrioventricular nodal reentrant tachycardia (26.4%). Major complication happened in 10 (2.6%) procedures while minor complications occurred in 36 (9.4%) procedures. Tamponade was the most common major complication (n = 3 [0.7%]), and pericardial effusion was the most common minor complication (n = 19 [4.9%]). Patients with complication were significantly younger and had a lower ejection fraction (P = 0.003 and P = 0.02, respectively). Conclusion: The complications observed in this study are comparable to previous reports, and EP study and RFCA can be considered as safe procedures.
Keywords: Cardiac arrhythmias, cardiac electrophysiology, complication, radiofrequency catheter ablation
|How to cite this article:|
Vasheghani-Farahani A, Shafiee A, Akbarzadeh M, Bahrololoumi-Bafruee N, Alizadeh-Diz A, Emkanjoo Z, Fazelifar A, Bakhshandeh H, Haghjoo M. Acute Complications in Cardiac Electrophysiology Procedures: A Prospective Study in a High-volume Tertiary Heart Center. Res Cardiovasc Med 2018;7:20-5
|How to cite this URL:|
Vasheghani-Farahani A, Shafiee A, Akbarzadeh M, Bahrololoumi-Bafruee N, Alizadeh-Diz A, Emkanjoo Z, Fazelifar A, Bakhshandeh H, Haghjoo M. Acute Complications in Cardiac Electrophysiology Procedures: A Prospective Study in a High-volume Tertiary Heart Center. Res Cardiovasc Med [serial online] 2018 [cited 2019 May 20];7:20-5. Available from: http://www.rcvmonline.com/text.asp?2018/7/1/20/226165
| Introduction|| |
Electrophysiology (EP) study and radiofrequency catheter ablation (RFCA) are now widely used for the treatment and management of most arrhythmias. Although these techniques have remarkably high success rate, they can quietly increase patient's quality of life., In case the patients do not respond to RFCA alone, it can be effectively combined with pharmacologic treatment to maintain sinus rhythm in patients with arrhythmia. However, like any other intervention, various complications may occur during these procedures.
The most common complications following EP study and RFCA include arterial injury, thrombophlebitis, pulmonary embolism, cardiac perforation, catheter-induced permanent atrioventricular (AV) block, infection, pneumothorax, pericardial effusion, and death.,, If the procedures are performed by experienced personnel in an appropriately staffed and well-equipped catheterization laboratory, such complications are acceptable to some degrees in comparison to the malignant nature of the arrhythmias. Therefore, identification of these complications and their predictors can help achieving a suitable therapeutic approach for their management. Certainly, till now little is known about the frequency of these complications in Iran. The aim of this study was to determine the frequency and types of complications following EP study and RFCA in a tertiary cardiovascular center.
| Methods|| |
Between September 2012 and December 2012, all consecutive patients undergoing EP study and RFCA in our center, a tertiary referral center in Iran, were prospectively enrolled in this study. All participants signed informed consent before enrolment, and those who did not give consent to participate were excluded from this study. The study protocol was approved by the institutional Committee of Medical ethics and the Research Board of Tehran University of Medical Sciences. This study conforms to the principles outlined in the Declaration of Helsinki.
At the time of procedure, a standard questionnaire containing the patient's demographic data, underlying diseases and comorbidities, clinical manifestations, prophylactic antibiotic, and anticoagulant therapy was completed by a trained general practitioner. Complications occurring during the procedure were documented during and following EP procedures.
After transferring the patient to the cardiology ward, another questionnaire containing results of chest X-ray, postoperative echocardiography, postimplant device analysis, postprocedure antibiotic, and anticoagulant therapy was completed by a general physician. All the complications occurring before the patient's discharge were documented.
Electrophysiology study and radiofrequency catheter ablation
All procedures were done according to current guidelines., The procedures were performed in an EP laboratory that is equipped with all standard monitoring and resuscitative facilities. Six EP fellows performed almost all of the procedures. Five staff EPs controlled them and assisted the fellows in case of any special issue. A nurse and an anesthesiology technician were always present in the catheterization room during the procedures.
Venous or arterial access was achieved by the puncture of the right and left femoral vein and arteries. In few cases that the cannulation of coronary sinus was not possible by the advancement of the catheter through the femoral vein, subclavian access was used. Antibiotic prophylaxis was not administered for these procedures.
Heparin was not routinely administered and was just used in cases that the catheter was inserted into the left atrium or the left ventricle, or in patients who had intracardiac shunt. If it deemed necessary, heparin was given in dose of 100 unit/kg and was repeated to maintain an activated clot time of about 300–350 s.
Major complications were defined as those that were likely to result in permanent sequel, needed intervention to prevent permanent injury, or death. Based on this definition, major complications included cardiopulmonary arrest, death, cerebrovascular accident, tamponade, vascular damage, deep venous thrombosis, and AV block. Minor complications were hematoma, bleeding, mild-to-moderate pericardial effusion, and arteriovenous fistula. Complications were recorded during and after the procedure until the patient's discharge.
Continuous data are presented as mean ± standard deviation, and categorical data were shown as frequency (percentage). Continuous variables were compared by Student's t-test, whereas Chi-square analysis was used for categorical data and Fisher's exact test for cell count <5. The P < 0.05 was defined statistically significant. The software SPSS version 18.0 (SPSS Inc., Chicago, IL, USA) was used for statistical analysis.
| Results|| |
A total of 382 procedures were performed in 357 patients with a mean age of 47 ± 18 (range 15–98) years within the study period. There were 171 (47.8%) male patients with the mean age of 49 ± 20 years and 186 (52.2%) patients were female with the mean age of 47 ± 17 years. Clinical data of the study participants are presented in [Table 1].
The most common arrhythmia (26.4%) was AV nodal reentrant tachycardia (AVNRT). Diagnostic EP study was the second most common procedure, ahead of premature ventricular complex (PVC)/idiopathic ventricular tachycardia (VT) ablation. [Table 2] describes the frequency and percentage of arrhythmia ablations and EP study procedures.
|Table 2: Frequency/percentage of minor and major complications following electrophysiologic study|
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During the study period, 40 (10.7%) procedures were complicated. Four procedures had more than one complication, and in total, there were 10 major and 38 minor complications. The most common complication was mild-to-moderate pericardial effusion which occurred in 19 (5.1%) cases, and the second common complication was puncture site hematoma occurring in 14 (3.8%) cases. Most complications occurred in scar-related VT ablation followed by atrial fibrillation (AF) ablation. The rate of complication in supraventricular arrhythmia was 1.4%. There were 6 cases of arrhythmia recurrence: Three cases of PVC ablation, two cases of accessory pathways (AP), and one case of AF ablation. Comparison of the study variables between the patients with and without complication is summarized in [Table 3].
|Table 3: Comparing the study variables between the patients with and without complication|
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Hematoma, vascular damage, arteriovenous fistula, and cerebrovascular accidents led to an increase in hospitalization period (P< 0.05).
Mortality and death
One patient died during this study. The patient was a 67-year-old male a case of ischemic cardiomyopathy, for whom intracardiac defibrillator (ICD) was implanted 4 years before, and he was candidate for VT ablation due to frequent episodes of ICD discharge. His left ventricular function was severely impaired (ejection fraction = 10%) and his arrhythmia did not stop by antiarrhythmic drugs. The procedure was done under the guidance of Ensite NAVX 6.0 software (Endocardial Solutions, St. Jude Medical Inc., St. Paul, MN, USA). Because of episodes of unstable VT or ventricular fibrillation, the patient received six episodes of cardioversion during the study. The procedure ended with partial success, but after the termination of the procedure, he developed apnea and asystole in the recovery unit. Cardiopulmonary resuscitation was done successfully in the recovery unit, but he expired the next day due to cardiogenic shock in the cardiac care unit.
Vascular damage, hematoma, bleeding
Only one major vascular damage occurred within the study period. A 32-year-old female was referred to this center due to unsuccessful AP ablation. Because of inability to cannulate coronary sinus after the advancement of the catheter from the femoral vein, its cannulation was planned to be performed from subclavian vein, but subclavian artery puncture and sheet insertion were performed by mistake. Following the diagnosis, the perforated lesion was sealed by prolonged balloon dilation.
There were 14 cases of puncture site hematoma and one case of puncture site bleeding and two cases of arteriovenous fistula that all were managed conservatively without any problem. There was no significant association between using aspirin, clopidogrel or other anticoagulants, and vascular complications, but older age was associated with hematoma (P = 0.01).
During our study, we had 2 cases of cerebrovascular accident, both of them were during the ablation of scar-related VT through femoral access. Both of them received heparin during the ablation to maintain advanced cardiac therapeutics (ACT) between 300 and 350. One of them was a 66-year-old male who developed dysarthria post ablation and his brain computed tomography (CT) scan revealed a low-attenuated area involving the left posterior parietal lobe and mainly posterior central gyrus due to ischemic lesion. The other one was a 78-year-old male who developed right hemiparesia and large lacunar infarct was seen in his brain CT scan. Both cases improved gradually during hospitalization time and thereafter.
Tamponade and pericardial effusion
We had three cases of tamponade. One occurred during the ablation of AF, the other during the ablation of left atrial tachycardia and the last one was a 65-year-old male who underwent RF ablation for premature ventricular beats originated from right ventricular outflow track. The first two cases received heparin during the procedure for maintaining ACT between 300 and 350. All of these cases successfully underwent pericardiocentesis and had no mortality.
There were also 18 cases of mild-to-moderate postablation pericardial effusion which were managed conservatively and did not require surgical intervention.
Deep vein thrombosis
In one case of AVNRT ablation (a 65-year old female, deep vein thrombosis was developed. This complication was managed with intravenous heparin with no other complication.
Transient complete atrioventricular block
In one patient during ablation of concealed right posteroseptal AP, transient complete AV block occurred, so temporary pacemaker was implanted. Fortunately, AV node conduction returned the next day, so pacemaker was removed, and the patient was discharged without permanent pacemaker implantation.
| Discussion|| |
Usefulness of EP studies and RFCA for the diagnosis and treatment of abnormal cardiac conduction system and arrhythmias has been well established. According to the previous studies, the risk of serious complications during these procedures is very low., Our study confirms that EP studies and ablation are safe, with rare procedure-related mortality (1 out of 382) and with a low incidence of major adverse events (2.4%) and mortality rate (0.2%). In this study, none of our patients required permanent pacemaker due to procedure-related complication. EP study without ablation did not have any major complication. If we exclude AF and scare-related VT ablation, the overall major adverse event rate of other arrhythmia ablation was 1.4% without any mortality.
According to the Spanish registry, increase in the number of ablations was obvious in this country from 2001 to 2010., Furthermore, distribution of substrates was markedly different. A considerable increase in the absolute number and the proportion of ablation procedures for AF and also atrial flutter (AFL) are seen, and AFL has become the second most frequently treated substrate instead of AP ablation. In the Sweden registry, AF ablation was the most commonly treated substrate followed by AVNRT and AFL ablation.
Although our laboratory is the most active laboratory in Iran for AF ablation, this procedure is relatively young in our country, so we expect progressive increase in the portion of AF ablation as long as our experience improves. This seems to be similar to the findings of the Spanish registry.
Increasing the portion of AFL ablation compared to AP ablation in the last decade can be explained by increasing acceptance of AFL ablation as the first-line treatment for this arrhythmia after its inclusion in clinical practice guidelines. Furthermore, attenuation of the prevalence of AP in the general population during the past decades in developed countries can be the other reason., However, it seems that in Iran, still most of the cardiologists treat AFL pharmacologically and/or with cardioversion, so the portion of AFL ablation in our country is relatively less than European countries.
The Multicenter European Radiofrequency Survey (MERFS) reported a high rate of serious complications (5.1%) in 1993, but it seems that these results were due to the training period of the majority of participating centers at that time.
In one study, the success rate and peri- and post-procedural complications of RFCA in 544 patients with AVNRT was reported. Based on this study, these complications included 21 (3.9%) transient III-degree AV blocks, 4 (0.7%) prolonged II- or III-degree AV blocks, 3 (0.5%) deep vein thrombosis, and 1 (0.2%) arteriovenous fistula while no mortality was reported.
Mortality rates were 0.1%, 0.04%, 0.06%, and 0.04% and the percentages of patients with adverse events were 1.5%, 1.75%, 1.7%, and 1.8% in Spanish registry reports in 2001, 2007, 2010, and Swedish registry report in 2007, respectively.,,,
In our study, the rate of procedure-related mortality was 0.2% (1 of 382), and incidence of most major adverse events was 2.4%. None of our patients required permanent pacemaker due to procedure-related complication. EP study without ablation did not have any major complication.
In comparison to MERFS study, the safety of EP procedures was better in our center. Some factors are likely to contribute slightly higher complication rate in our study compared to Spanish and Swedish registries. First of all, the majority of the procedures in our laboratory were operated by fellows, and also most of the catheters were reused due to economic considerations. The second factor is that, the significant difference in the rate of complications in our study is due to higher scar-related VT ablation complications in our center. If we exclude AF and scare-related VT ablation, the overall major adverse event rate of other arrhythmia ablation was 1.4% without any mortality. On the other hand, validity of registry data depends on many factors. If a center with higher complication rate does not join the registry or if the local coding policy differs in different centers, the validity of analysis of registry data is threatened.
Scar-related VT procedures have a higher complication rate than the other procedure types in our study. There are two published prospective multicenter clinical trials that evaluated the safety of catheter ablation on nonidiopathic VT. In the first clinical trial including 146 patients, major complications occurred in 16 (10.8%) of cases, including death (2.7%), myocardial infarction, tamponade, complete AV block, cerebrovascular accident/transient ischemic attack, and valve injury. In the more recent trial, nonfatal major complication rate was 7.3%, and the mortality rate was 3% in 231 patients.
On the other hand, complications may result from the specific condition of a patient, such as vascular anomalies. One study showed that ablation in posteroseptal diverticula was correlated with more procedural complications due to proximity to the epicardial coronary arteries, although it was not associated with lower success rates. Therefore, extreme caution should be taken in patients who have anatomical variations in their vessels.
The first limitation of our study is the limited number of included cases. Nonetheless, this was compensated by the prospective design of our study, so every complication was observed and recorded during the study period. Second, this was a single-center study in a university referral center. Therefore, our findings may be different from the nature and frequency of complications observed in other hospitals.
| Conclusion|| |
According to our study, EP study and RFCA are safe procedures for the diagnosis and treatment of cardiac arrhythmia. However, lack of nationwide registries for monitoring and evaluating operator experience improvement is obvious. Therefore, we recommend implementing a national registry of all EPS procedures in Iran. That would hugely contribute to the quality assessment of the procedures in different centers. Finally, training of fellows and residents about cardiac EP study complications is important and must be part of the educational curriculum.
Declaration of patient consent
The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed.
This study was supported by Rajaie Cardiovascular Medical and Research Center.
Financial support and sponsorship
Conflicts of interest
There are no conflicts of interest.
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[Table 1], [Table 2], [Table 3]