Poster 2 CRT-ICD for advanced symptoms and widened QRS, which indicates a need for more devices in CHF pts. However, the specific need is unknown for a primary rural population with previously low device penetrance. The Chabert heart failure program in Louisiana delivers care and medications through a unique health care system focused on the indigent rural population. This study evaluates the potential for expanding ICD and CRT therapy into this population by proposed criteria. Methods: Data from 451 CHF pts were entered at the time of CHF program enrollment 2002-4. Proposed criteria used for CRT were: LVEF ⱕ 35%, NYHA III-IV, and QRS ⱖ 120 msec or modified to ⱖ 150. For ICD, EF ⱕ 30 % for all etiologies was applied and then re-applied with LVEF ⱕ 35%. Patients were excluded for major co-morbidities of cancer, CVA, HIV, severe lung disease and dementia. Results: Mean age was 57 years, 65% male, 37% black, mean LVEF 33%, NYHA: I- 28% II-36%, III-32%, IV -5%, median income $11,800, payer status: 70% free care, 23% Medicaid, 7% Medicare. At enrollment into Heart Failure management, only 30 pts had ICD and 5 more had CRT (7.8% total devices). Using EF ⱕ 30% for primary ICD identified 185 (41%) pts, increasing to 266 (59%) for EF ⱕ 35%. For CRT, 39 (8.6%) pts were eligible with QRS ⱖ 120 msec, increasing to 100 (22%) with Class I-II pts. QRS ⱖ 150 identified only 19 (4%) pts . Expected enrollment rates with these data predict an additional 82 new pts/yr for ICD (95% CI, 63 to 101) and 13 for CRT-ICD (95% CI, 5 to 21) from this site. Implications: Where current device penetration is currently only 7.8%, approximately half of patients in an indigent rural population would be eligible by expanded criteria for devices, mostly ICD. It is not known how these criteria would affect insured urban populations, nor how the benefits in trial populations would translate to the indigent setting. P2-114 RADIATION EXPOSURE TO PHYSICIAN OPERATORS DURING BIVENTRICULAR DEVICE IMPLANTS Rajjit Abrol, MD, Brian D. Le, MD, Carol L. Nguyen, RN, BSN, John Cogan, MD, William H. Nesbitt, MD, R. Haris Naseem, MD, Robert C. Kowal, MD, PhD, Mohamed H. Hamdan, MD, Jon A. Anderson, PhD and Jose A. Joglar, MD. University of Texas Southwestern Medical Center, Dallas, TX. Prior studies on radiation exposure in the electrophysiology lab have focused on ablation procedures and patient safety. There is very little data on operator safety. Biventricular (BiV) pacing has developed into an important therapy for patients with CHF, but the procedure itself adds significant radiation exposure time to operators mainly due to the time it takes to place the coronary sinus lead. The magnitude of this radiation load has never been investigated. The purpose of this study is to determine the amount of radiation exposure to operators incurred during BiV implants in an academic center. Methods and Results: Radiation exposure was measured using an investigational collar badge worn by both the fellow and attending physician. Five implants were successful, one procedure resulted in failure to place the coronary sinus lead. All procedures were performed with usual safety measures including leaded jackets, aprons and thyroid neck shields for operators. In five of the six cases, an under table lead shield and a protective drape (RADPADTM) were used. The average fluoroscopy time was 37.7 minutes (times varying from 15.8 to 82.8 minutes). The average radiation exposure to the operator was 81 mREM (deep) and 79.7 mREM (shallow) on the collar badges for the fellows and 24 mREM (deep) and 29.7 mREM (shallow) on the badges for the attendings. Badges worn under the leaded apron worn consistently blocked all radiation yielding levels below the level of detection. Conclusion: BiV device implant procedures add significant fluoroscopy time to procedures due to the time it takes to place the coronary sinus lead. Using an accepted yearly radiation exposure limit for radiation workers of 5000 mREM, the amount of radiation from BiV device implants may limit the absolute numbers of procedures that can be safely performed by physicians in training. It should be noted, however, that standard lead protection limits this exposure effectively, although shallow exposure re-
S171 mains unaffected. The long term health effects from this exposure remain unknown. Additional protective measures should be investigated further, as radiation exposure during BiV implants is significant. P2-115 WIDE COMPLEX TACHYCARDIA: A DIAGNOSTIC DILEMMA Seth Hurwitz, MD, Jeffrey S. Berger, MD, Sam Hanon, MD, David L. Brown, MD and Paul Schweitzer, MD. Beth Israel Medical Center, New York, NY. Background: Accurate interpretation of wide complex tachycardia (WCT) is essential. The current study evaluated the ability of residents, fellows and attendings to diagnose a variety of WCTs. Methods: Participants (n⫽182) from four academic hospitals included residents, cardiology and critical care fellows, and cardiology attendings. Participants reported their self-rated proficiency at ECG interpretation and perceived adequacy of training in electrocardiography. Eight WCT ECGs (4 ventricular tachycardia (VT), 2 supraventricular tachycardia (SVT) and 2 artifact) were selected for analysis. Participants were asked to record the rhythm diagnosis and rate their certainty. Two investigators independently scored each tracing. Results: The mean number of correct diagnoses was 2.9, 5.1 and 6.2 out of 8 for residents, fellows and attendings, respectively (P⬍0.01). Postgraduate year significantly correlated with self-rated proficiency (r⫽0.61, P⬍0.01), total score (r⫽0.43, P⬍0.01), and diagnostic certainty (r⫽0.52, P⬍0.01). Accurate identification of VT, SVT and artifact increased with level of training (p⬍0.01 for all). More than 75% of all house officers felt that their ECG training was not sufficient. Conclusion: Competency in diagnosing WCTs improved with clinical experience. Nevertheless, the overall ability to identify a potentially lifethreatening arrhythmia was poor. Future research should focus on methods to optimize identification of WCT at all levels of training. Mean number of correct diagnoses according to level of training
P2-116 VALIDATION OF CARDIAC RESYNCHRONIZATION THERAPY TRAINING PROGRAMS *Randy A. Lieberman, MD and Cardiac Rhythm Education Services Of Medtronic, Inc. Harper University Hosptial, Detroit, MI. Background: Post-graduate medical education programs have become the gold standard for physicians to keep pace with evolving medical therapies. To date, there is no validated method for physicians to acquire technical skills. Available methods include: expert lectures, animal labs, observing live or video taped procedures, patient implant simulators, proctoring, and hands-on experience at training centers. Previously at Cardiostim 2004, we presented results surveying thirty-one physicians evaluating the new Medtronic implant simulator (Gen II). Reporting a mean satisfaction rating of 9.0 on a scale of 1 (Low) - 10 (High) for the overall BiV implant training experience. Suggesting the new Medtronic implant simulator (Gen II) is a valid tool, representing the steps and “feel” of the actual Cardiac Resynchronization Therapy (CRT) implant procedure. Medtronic CRT Educational Programs beginning September 2001, assisted physicians in gaining implant skills via all the above methods including established Centers of Excellence in CRT. We retrospectively compared these variables in physician training satisfaction and impact on CRT implants. Methods: Randomly surveyed 160 physicians who attended one or more Medtronic CRT Educational Programs from the following disciplines: Electrophysiology, Cardiology, and CT Surgeons. The physicians were asked a series of questions rating their training experience prior to March 1, 2004.
S172 Results: On a scale of 0 (Low) - 10 (High), the following results are mean ratings measuring the effectiveness of training conducted: Working with Proctor Physician during procedure (hands-on) ⫽ 8.6, Observing Proctor Physician during procedure (observational) ⫽ 8.45, Lecture/Expert ⫽ 7.32, Animal Lab ⫽6.85, Simulated Patient (Gen I) ⫽ 6.2, Heart Model ⫽ 5.65, Video Tape ⫽ 5.64. Survey results also indicated that 71% of physicians who attended one or more training programs increased their rate in performing CRT implants. Conclusion: While physician satisfaction is greatest with live hands-on training; simulated hands-on training has the potential to reduce implant complications of live learning and is emerging as a potential surrogate to in-vivo training. P2-117 A CASE OF UNDETECTED VENTRICULAR TACHYCARDIA DUE TO THE RATE SMOOTHING ALGORITHM Rhea C. Pimentel, MD and Loren D. Berenbom, MD. MidAmerican Cardiology, Kansas City, KS. HH is a 58 year old male with a history of ischemic cardiomyopathy and ventricular tachycardia (VT) status post biventricular implantable cardioverter defibrillator (ICD) who was admitted to the hospital with recurrent dizziness and syncope. Interrogation of his Guidant Renewal 3 ICD revealed episodes of monomorphic VT. During telemetry monitoring, frequent premature ventricular contractions (PVC) were recorded. To prevent the long-short sequences that may initiate VT, a Rate Smoothing algorithm was enabled at 3% of the preceding cycle length. Upper tracking rate was 135 beats per minute (bpm). A VT zone was set at 145 bpm to deliver antitachycardia pacing (ATP) prior to shock. Four days later, the patient experienced multiple episodes of VT not treated by his ICD, requiring rescue external defibrillation. ICD interrogation showed:
The device recognized the second beat of VT as a PVC and initiated rate smoothing. Every other beat of VT fell within the ventricular refractory period (VRP). Thus, the device “saw” a ventricular paced beat followed by a PVC. Intermittently, the VT rate accelerated and was detected by the ICD which then attempted ATP. Repeatedly, the device believed it was successful and reverts to its rate smoothing algorithm despite continued VT. This is an unusual example of arrhythmia non-detection due to a programmable feature meant to prevent VT initiation. While rate smoothing has been proven in a prospective multicenter study to reduce sustained ventricular tachyarrhythmias, a clear understanding of the limitations of this feature is essential to prevent “device failure”. P2-118 A NOVEL INHERITED SYNDROME OF SHORT QT INTERVAL, MALIGNANT VENTRICULAR ARRHYTMIAS AND FAMILIAL CLUSTERING OF OTOSCLEROSIS Olli M. Anttonen, MD, Juha Silvola, MD, Liisa Kokkonen, MD, Ramo´n Brugada, MD, Juhani Junttila, MD, Kui Hong, MD, PhD and Heikki V. Huikuri, MD. Paijat-Hame Central Hospital, Lahti, Finland, Masonic Medical Research Laboratory, Utica, NY and Oulu University Hospital, Oulu, Finland. Background: Short QT syndrome is an inherited arrhytmogenic disorder characterized by a QT interval ⬍ 300ms and tall, peaked T waves. It has
Heart Rhythm, Vol 2, No 5, May Supplement 2005 been associated with mutations in HERG and KCNQ1 genes giving rise to a gain of function in Ikr and Iks, respectively. Cases: We report a family where a 19 yr old man had an aborted sudden death due to ventricular fibrillation(VF).His 12-lead ECG revealed a short QT interval (280ms,QTc 313ms) and peaked T-waves. His 55 yrs old father had also a short QT interval (310ms,QTc 307ms) and runs of polymorphic ventricular tachycardia (VT) during exercise test. Grandfarher of the proband, now 79 yrs old, has QT interval of 280ms but he has no documented VT or VF ; only isolated ventricular premature beats.All three individuals with a short QT interval also had an abnormal behavior of the QT interval during the exercise test without rate-dependent changes in repolarization. Detailed ECG analysis of the whole family did not reveal any more subjects with a short QT interval, but all three brothers of the father of the proband have combined conductive and sensorineural hearing loss and a hearing aid in use. Otological investigations,audiogram and earlier ear operations confirmed the diagnosis of otosclerosis with sensorineural hearing loss component, which has a known genetic background but without an exact localization of gene defect. Preliminary DNA analyses of the subjects with a short QT interval have not revealed a specific mutation either in the HERG or KCNQ1 gene. Conclusions: Short QT interval and familial clustering of otosclerosis suggests to a distinct inherited syndrome with a vulnerability to fatal or near-fatal ventricular arrhytmias. Specific gene mutation affecting most probably the ion channel function(s) remains unknown at the moment but clinical linkage to otosclerosis may suggest a common genetic background.
P2-119 CARDIAC CT IMAGING USED IN CONJUNCTION WITH A NONFLUOROSCOPIC NAVIGATION SYSTEM (NAVX) FOR ATRIAL FIBRILLATION ABLATION Bryan T. Piedad, MD, John R. Bullinga, MD, Jesse S. Sethi, MD, Douglas S. Holmes, MD, Neil E. Bernstein, MD and *Larry A. Chinitz, MD. New York University Medical Center, New York, NY. Case: A 55 year old man with paroxysmal AF was referred to our center for catheter ablation of AF. Cardiac CT imaging with a 64-slice scanner was performed 1 week before the procedure. The raw imaging data was processed using proprietary software (Endocardial Solutions, MN) in order to precisely define the anatomic relationship of the left atrium, pulmonary veins, and esophagus. On the day of the procedure, the processed CT image was imported into the NavX navigation system and was used in conjunction with a NavX-generated geometric map [Figure] to guide circumferential ablation around the right and left pulmonary veins. Ablation was performed using an 8-mm tip ablation catheter, and microbubble monitor-