Sedation and analgesia in the cardiac electrophysiology laboratory: a national survey of electrophysiologists investigating the who, how, and why?

OBJECTIVE: To investigate sedation and anesthesia trends and practice patterns for procedures in the cardiac electrophysiology laboratory (EPL). DESIGN: A survey distributed by e-mail. SETTING: US teaching hospitals with a training program in cardiac electrophysiology. PARTICIPANTS: Cardiologists involved in procedures in the electrophysiology laboratory of academic electrophysiology programs. INTERVENTIONS: A survey was e-mailed to the selected programs. The survey questions included the use of anesthesia professional (MD/CRNA) and nonanesthesia professional (RN) services, medications administered, commonly performed airway interventions, satisfaction with anesthesia services, and reasons that anesthesia professionals are not used when RNs administer sedation. MEASUREMENTS AND MAIN RESULTS: Of the 95 academic electrophysiology programs surveyed, there were 38 responses (40%). The majority (71%) of respondents used a combined model of care with both anesthesia professional care and nonanesthesia professional (RN) sedation, although there were EPLs that had exclusively anesthesia professional (n = 6) and exclusively nonanesthesia professional coverage (n = 5); 26.3% of respondents answered that care by an anesthesia professional was warranted most (>50%) of the time regardless of their current care model. The main reasons cited for having RN-administered sedation were the lack of availability of anesthesia professionals, difficulty with scheduling, and increased operating room suite turnover times. Programs using exclusively RN sedation (13%) reported all levels of anesthesia including general anesthesia (patient unarousable to repeated deep stimulation). CONCLUSIONS: This survey suggested that sedation for EPL procedures was sometimes allowed to progress to deep sedation and general anesthesia and that selection of anesthesia provider frequently was made based on availability, operating room efficiency, and economic reasons before patient safety issues. The implications of the survey must be explored further in a larger-scale sample population before more definitive statements can be made, but results suggested that sedation in the EPL is an area that would benefit from updated guidelines specific to the current practice as well as attention from the anesthesia community to address the deficiency in provision of anesthesia care.

Left atrial Lasso catheter thrombus aspiration.

Sheath- and catheter-associated thrombi have become increasingly identified with the use of intracardiac echocardiography during left-sided ablation procedures. Despite adequate anticoagulation, these thrombi are found in ∼10% of cases. Management of these thrombi includes withdrawal of the sheath and catheter when the thrombi are felt to be firmly attached. In our case, we show another management technique, aspiration.

Nontraditional implantable cardioverter defibrillator placement in adult patients with limited venous access: a case series.

BACKGROUND: Conventional transvenous approaches for implantable cardioverter defibrillator (ICD) lead placement are not possible in some patients with limited venous access or severe tricuspid valve dysfunction. METHODS: We retrospectively identified six patients who underwent ICD placement or revision requiring nontraditional alternative surgical lead placement at our institution between November 2006 and August 2008. The baseline and operative patient characteristic data were accumulated and reviewed. RESULTS: All the patients (mean age 71 +/- 3.4 years) underwent nontraditional surgical placement of epicardial ICD leads and traditional placement of ventricular epicardial bipolar pacing/sensing leads. Five patients had the distal lead tip fixed to the anterior epicardium of the right ventricular outflow tract, which was then looped under and around the ventricles, forming a "sling," and tunneled to a left subclavicular pocket. One patient had a single unipolar subcutaneous array lead fashioned into a "loop" and placed under the inferior aspect of the ventricles. The average procedure time was 311 +/- 115 minutes with a mean defibrillatory threshold (DFT) of < or = 22 + 3 J. Post-procedure hospitalization was 9.3 +/- 4.4 days and no device-related complications were encountered. Mean device follow-up of 451 + 330 days showed normal function and two appropriate successful ICD discharges. CONCLUSION: Nontraditional alternative surgical methods for the placement of ICD systems in adult patients with limited venous access or TV dysfunction can achieve results similar to those of conventionally placed endovascular leads with limited complications and comparable DFTs in short-term follow-up.

Utilization of Electrocardiographic P-wave Duration for AV Interval Optimization in Dual-Chamber Pacemakers.

BACKGROUND: Empiric programming of the atrio-ventricular (AV) delay is commonly performed during pacemaker implantation. Transmitral flow assessment by Doppler echocardiography can be used to find the optimal AV delay by Ritter's method, but this cannot easily be performed during pacemaker implantation. We sought to determine a non-invasive surrogate for this assessment. Since electrocardiographic P-wave duration estimates atrial activation time, we hypothesized this measurement may provide a more appropriate basis for programming AV intervals. METHODS: A total of 19 patients were examined at the time of dual chamber pacemaker implantation, 13 (68%) being male with a mean age of 77. Each patient had the optimal AV interval determined by Ritter's method. The P-wave duration was measured independently on electrocardiograms using MUSE® Cardiology Information System (version 7.1.1). The relationship between P-wave duration and the optimal AV interval was analyzed. RESULTS: The P-wave duration and optimal AV delay were related by a correlation coefficient of 0.815 and a correction factor of 1.26. The mean BMI was 27. The presence of hypertension, atrial fibrillation, and valvular heart disease was 13 (68%), 3 (16%), and 2 (11%) respectively. Mean echocardiographic parameters included an ejection fraction of 58%, left atrial index of 32 ml/m(2), and diastolic dysfunction grade 1 (out of 4). CONCLUSIONS: In patients with dual chamber pacemakers in AV sequentially paced mode and normal EF, electrocardiographic P-wave duration correlates to the optimal AV delay by Ritter's method by a factor of 1.26.

Airway interventions in the cardiac electrophysiology laboratory: a retrospective review.

OBJECTIVE: To quantify the incidence of airway interventions during cardiac electrophysiology laboratory procedures. DESIGN: A retrospective chart review. SETTING: A tertiary care teaching hospital. PARTICIPANTS: Two-hundred eight adult patients undergoing cardiac electrophysiology laboratory procedures during a 2-year period, March 2006 to March 2008. The patients underwent the following procedures: supraventricular tachycardia ablation, atrial tachycardia ablation, atrial flutter ablation, premature ventricular contraction ablation, and ventricular tachycardia ablation. Patients who were intubated (in the intensive care unit or emergency department) before the ablation began, patients with ventricular assist devices or intra-aortic balloon pumps, and patients receiving inotropic support before the procedure were excluded. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: The data were summarized by using the mean and standard deviation. Of the 208 patients, 186 were planned monitored anesthesia care, and 22 were planned general anesthetics. Of the monitored anesthesia care cases, 20 were converted to general anesthesia, and 54 received some type of airway intervention including oral-pharyngeal airway or nasal airway insertion. Therefore, 40% (74/186) of the non-general anesthesia cases required an airway intervention. CONCLUSIONS: These results suggest that a significant proportion of the authors' patients undergoing cardiac electrophysiology laboratory procedures required deep sedation if not general anesthesia, although a non-general anesthetic was planned. The issue of depth of sedation has implications for patient safety, privileging, and regulatory compliance. Based on the present results, the authors believe sedation for these procedures is best given by anesthesia providers; furthermore, caregivers should be aware that these procedures are likely to require deep sedation if not general anesthesia.

New algorithm using only lead aVR for differential diagnosis of wide QRS complex tachycardia.

BACKGROUND: We recently reported an ECG algorithm for differential diagnosis of regular wide QRS complex tachycardias that was superior to the Brugada algorithm. OBJECTIVE: The purpose of this study was to further simplify the algorithm by omitting the complicated morphologic criteria and restricting the analysis to lead aVR. METHODS: In this study, 483 wide QRS complex tachycardias [351 ventricular tachycardias (VTs), 112 supraventricular tachycardias (SVTs), 20 preexcited tachycardias] from 313 patients with proven diagnoses were prospectively analyzed by two of the authors blinded to the diagnosis. Lead aVR was analyzed for (1) presence of an initial R wave, (2) width of an initial r or q wave >40 ms, (3) notching on the initial downstroke of a predominantly negative QRS complex, and (4) ventricular activation-velocity ratio (v(i)/v(t)), the vertical excursion (in millivolts) recorded during the initial (v(i)) and terminal (v(t)) 40 ms of the QRS complex. When any of criteria 1 to 3 was present, VT was diagnosed; when absent, the next criterion was analyzed. In step 4, v(i)/v(t) >1 suggested SVT, and v(i)/v(t) < or =1 suggested VT. RESULTS: The accuracy of the new aVR algorithm and our previous algorithm was superior to that of the Brugada algorithm (P = .002 and P = .007, respectively). The aVR algorithm and our previous algorithm had greater sensitivity (P <.001 and P = .001, respectively) and negative predictive value for diagnosing VT and greater specificity (P <.001 and P = .001, respectively) and positive predictive value for diagnosing SVT compared with the Brugada criteria. CONCLUSION: The simplified aVR algorithm classified wide QRS complex tachycardias with the same accuracy as standard criteria and our previous algorithm and was superior to the Brugada algorithm.

T-wave oversensing and inappropriate shocks: a case report.

A 27-year-old male with congenital long QT syndrome, SCN5A mutation experienced recurrent inappropriate exercise-related implantable cardioverter defibrillator (ICD) shocks. This device showed T-wave oversensing with double, which lead to these device discharges. Dynamic T-wave oversensing was reproducibly provoked at exercise treadmill testing and was confirmed as the mechanism leading to double counting. The insertion of a new pacing and sensing lead with increased R-wave amplitude did not solve the problem. Exchanging the existing ICD generator with one capable of automatic sensitivity control (Biotronik, Lexos DR, Biotronik, Berlin, Germany) completely eliminated T-wave oversensing and inappropriate shocks.

Exertional sudden cardiac death in a young athlete with anomalous origin of the left coronary artery from the opposite sinus.

An 18-year-old male athlete sustained exertional sudden cardiac death. Evaluation and intervention revealed the finding of an anomalous origin of the left coronary artery circulation from the opposite coronary sinus.

Reversible pacemaker dysfunction in a patient with transient cardiac apical ballooning syndrome: a case report.

Transient cardiac apical ballooning syndrome (TCABS) is diagnosed by transthoracic echocardiography demonstrating apical akinesis with left ventricular (LV) apical ballooning and preserved mid-to-basal LV systolic function, and left heart catheterization showing the absence of significant obstructive epicardial coronary artery disease. Presenting symptoms are suggestive of an acute coronary syndrome and electrocardiogram findings mimic acute myocardial injury. Right ventricular involvement has been reported. We describe a case of acute pacemaker dysfunction caused by the TCABS, which responded to conservative therapy.

Relation of electrocardiographic criteria for left atrial enlargement to two-dimensional echocardiographic left atrial volume measurements.

Left atrial (LA) enlargement by 2-dimensional (2-D) echocardiography predicts adverse cardiovascular outcomes. Electrocardiographic (ECG) criteria for LA enlargement are based on M-mode echocardiographic LA diameter, which is inferior to 2-D-derived LA volumes. This study compared established ECG criteria for LA enlargement with atrial volume obtained by 2-D echocardiography to determine if traditional ECG criteria accurately represent LA chamber enlargement, therefore offering a low-cost screening tool. A total of 261 randomly selected patients who underwent electrocardiography and 2-D echocardiography were enrolled. ECG parameters and electronically derived P-wave medians were analyzed with electronic calipers for maximal accuracy. LA volumes by 2-D echocardiography were measured with Simpson's method of discs, with enlargement defined as 32 ml/m(2). Sensitivity and specificity tables and receiver-operating characteristic curves were constructed for each criterion. Univariate and multivariate analyses were performed for predictors of 2-D echocardiographic LA enlargement. LA enlargement was present in 43% of patients. ECG P-wave duration was the most sensitive for the detection of LA enlargement (69%) but had low specificity (49%). Conversely, a biphasic P wave was the most specific (92%) but had low sensitivity (12%). The maximum area under the receiver-operating characteristic curve for any criterion was 0.64, too low to be of clinical utility. In conclusion, established ECG criteria for LA enlargement do not reliably reflect LA enlargement and lack sufficient predictive value to be useful clinically. These results suggest that P-wave abnormalities should be noted as nonspecific LA abnormalities, with the term "LA enlargement" no longer used.

Isolated left ventricular basal ballooning phenotype of transient cardiomyopathy in young women.

This report describes a variant of transient regional left ventricular dysfunction in which isolated basal left ventricular akinesia with normal mid-ventricular (papillary-level) wall motion and apical hypercontractility were noted in young women (mean age 31 years). This finding was demonstrated in 3 consecutive patients; the first patient was experiencing emotional life-altering events, and the second presented with an acute flare of multiple sclerosis. The third patient presented < 24 hours after methamphetamine use. Coronary angiography demonstrated normal epicardial coronary arteries in all patients. Wall motion abnormalities resolved within 2 to 6 weeks. In conclusion, the entity described in this report is reminiscent of apical ballooning ("Tako-Tsubo"), mid-ventricular ballooning, and apical sparing syndromes; however, isolated basal left ventricular involvement has not been previously described and is a newer variant in the spectrum of transient cardiomyopathies. The pathophysiology of this entity has not been elucidated. A unifying feature between the transient cardiomyopathic syndromes most likely is in the concentration, distribution, and activity of cardiac adrenergic receptors.

Reducing Ionizing Radiation Associated with Atrial Fibrillation Ablation: An Ultrasound-Guided Approach.

Radiation exposure with cardiac interventional procedures is an emerging concern. Patients receiving radiofrequency ablation for atrial fibrillation (AF) still routinely undergo pre-ablation computed tomography (CT) scans for definition of left atrial and pulmonary vein anatomy, as well as creation of a surrogate geometry. In an effort to decrease ionizing radiation associated with AF ablation, an ultrasound-guided surrogate geometry approach is proposed as an alternative to routine CT imaging. Ten patients underwent AF ablation using intracardiac ultrasound for the creation of a surrogate left atrial geometry (CartoSound, Biosense Webster, CA); and ten control-cases who had conventional CT-guided imaging (CartoMerge, Biosense Webster, CA) were matched for age, gender, and type of catheter ablation. Sources of radiation included 1) intraprocedural fluoroscopy (CartoSound: 151 ± 43 mGray*cm^2, CartoMerge: 174 ± 130 mGray*cm^2; p=0.6) and 2) CT ionizing radiation (CartoSound: 0 mSv, CartoMerge 9.4 ± 2.3 mSv/CT scan.) When comparing clinical success rates after a trial of previously ineffective anti-arrhythmic drugs, ultrasound-guided AF ablation was non-inferior to a CT-guided approach. This potentially obviates the need for CT-guided imaging, therefore reducing doses of ionizing radiation by nearly 10 mSv per AF catheter ablation.

Radiotherapy-induced pacemaker and implantable cardioverter defibrillator malfunction.

It is well known that ionizing radiation can interfere with circuits in permanent pacemakers and implantable cardioverter defibrillators. Contemporary implantable cardiac devices use complementary metal-oxide silicon in combination with other very sensitive transistors. These sensitive components are especially susceptible to electromagnetic and ionizing radiation, which can potentially cause permanent damage. Electromagnetic interference is, in general, a transient phenomenon. Radiologic imaging tests have been implicated in rare cases of implantable device dysfunction and these events have been mostly transient. The American Association of Physicists in Medicine last published recommendations regarding irradiation of pacemakers in 1994. This publication is outdated and may not be pertinent for the current technology used both in the field of artificial cardiac pacing and defibrillation and in the field of radiation oncology. Updated guidelines are definitely needed.

Nontraditional surgical approaches for implantation of pacemaker and cardioverter defibrillator systems in patients with limited venous access.

BACKGROUND: Indications for placement of implantable cardioverter-defibrillators (ICD) and pacemakers have expanded, and traditional transvenous implantation may not be feasible in patients with aberrant anatomy or venous obstruction. In these settings, successful lead placement has required innovative surgical approaches. A case series of successful placement of these systems in challenging patients is presented. METHODS: A 2-year retrospective study of patients undergoing placement of minimally invasive epicardial pacing leads or ICD coils was performed. RESULTS: Eleven patients underwent minimally invasive surgical placement of leads or coils. None were converted to open sternotomy. One required extension to minianterior thoracotomy. Causes of intravenous placement failure included aberrant anatomy with failure to access coronary sinus in 9 and venous occlusion in 2. Four patients had previous operations through a median sternotomy. Procedures included left video-assisted thoracoscopic (VATS) placement of a left ventricular epicardial lead in 8, left VATS conversion to minianterior thoracotomy left ventricular epicardial lead placement in 1, left VATS placement of ICD coil in 1, subxiphoid placement of a right ventricular epicardial lead in 1, subxiphoid ICD coil in 2, and subcutaneous ICD coil placement in 3. Mean hospitalization was 4.6 days. Postoperative hypotension and pulmonary edema occurred in 27% of patients. No patients died. CONCLUSIONS: Conventional transvenous lead implantation may be difficult or impossible in some patients with aberrant or occluded venous access. Novel surgical approaches with the use of minimally invasive procedures can establish optimally functional pacing and ICD systems without sternotomy and low associated morbidity.

Value of multislice computed tomography angiography of the thorax in preparation for catheter ablation for the treatment of atrial fibrillation: the impact of unexpected cardiac and extracardiac findings on patient care.

OBJECTIVE: In patients referred for catheter ablation for the treatment of atrial fibrillation, multislice computed tomography angiography of the thorax is routinely performed to assess pulmonary vein anatomy. We sought to investigate the incidence of unexpected cardiac and extracardiac findings in this select patient population and to establish how these findings influence subsequent patient care. METHODS: Ninety-five patients (mean age 62+/-10 years, 35% female) referred to our institution for ablation therapy for atrial fibrillation between July 2003 and October 2007 underwent multislice computed tomography angiography of the thorax. Radiologists interpreted all images. Need for additional testing, consultation and eventual diagnosis were assessed by electronic record review. RESULTS: A total of 83 (5 cardiac, 78 extracardiac) unexpected findings were observed in 50/95 (53%) of patients. The findings prompted 23 additional tests (5 cardiac, 18 noncardiac) in 15/95 (16%) of patients and 8 subsequent referrals in 7/95 (7%) patients. In 6 patients the findings significantly altered future patient care and resulted in postponement of ablation therapy in 4 patients. In 2 patients, extracardiac findings (pulmonary emboli and adenocarcinoma of the lung) were of potentially life-saving consequence. CONCLUSIONS: In patients undergoing multislice computed tomography angiography of the thorax in anticipation of planned catheter ablation therapy for the treatment of atrial fibrillation, unexpected findings are common and of potentially significant value. In comparison, there is a higher prevalence of unexpected extracardiac, rather than cardiac findings. Further investigation of these findings may lead to postponement of ablation therapy, but may also be of potentially lifesaving consequence.

Typical atrial flutter as a risk factor for the development of atrial fibrillation in patients without otherwise demonstrable atrial tachyarrhythmias.

OBJECTIVE: To investigate the incidence of atrial fibrillation after successful radiofrequency ablation for typical atrial flutter (AFL) and to compare its incidence with that of a reference population from the Framingham Heart Study to determine whether atrial flutter is an independent predictor for development of atrial fibrillation. PATIENTS AND METHODS: Medical records of 234 patients who underwent radiofrequency ablation for AFL between January 1, 2002, and June 30, 2006, were reviewed. Patients were excluded if they had a history of atrial fibrillation or sustained atrial arrhythmia other than AFL or if they had atrial tachyarrhythmias other than AFL that could be induced during electrophysiology study (133 total patients excluded). The remaining 101 patients who underwent successful radiofrequency ablation for AFL were monitored for new-onset atrial fibrillation. RESULTS: During the mean+/-SD follow-up period of 574+/-315 days, atrial fibrillation developed in 13 (12.9%) of 101 patients. Atrial fibrillation developed in 12 of these patients within 6 months of ablation. The cumulative event-free rates (95% confidence intervals) were 97% (94%-100%) at 1 month, 91% (87%-97%) at 3 months, and 86% (81%-94%) at 6 months. Compared with the general population, patients aged 50 to 79 years who had ablation had a significantly higher incidence of atrial fibrillation (50-59 years, P=.01; 60-69 years, P=.001; 70-79 years, P=.007). CONCLUSION: Our finding of atrial fibrillation in 12.9% of patients whose atrial flutter was successfully eradicated suggests that patients with atrial flutter are at increased risk of developing atrial fibrillation, especially within the first 6 months after ablation.

Application of a new algorithm in the differential diagnosis of wide QRS complex tachycardia.

AIMS: The Brugada criteria proposed to distinguish between regular, monomorphic wide QRS complex tachycardias (WCT) caused by supraventricular (SVT) and ventricular tachycardia (VT) have been reported to have a better sensitivity and specificity than the traditional criteria. By incorporating two new criteria, a new, simplified algorithm was devised and compared with the Brugada criteria. METHODS AND RESULTS: A total of 453 WCTs (331 VTs, 105 SVTs, 17 pre-excited tachycardias) from 287 consecutive patients with a proven electrophysiological (EP) diagnosis were prospectively analysed by two of the authors blinded to the EP diagnosis. The following criteria were analysed: (i) presence of AV dissociation; (ii) presence of an initial R wave in lead aVR; (iii) whether the morphology of the WCT correspond to bundle branch or fascicular block; (iv) estimation of initial (v(i)) and terminal (v(t)) ventricular activation velocity ratio (v(i)/v(t)) by measuring the voltage change on the ECG tracing during the initial 40 ms (v(i)) and the terminal 40 ms (v(t)) of the same bi- or multiphasic QRS complex. A v(i)/v(t) >1 was suggestive of SVT and a v(i)/v(t)