Endovascular Management of Abdominal Aortic Aneurysms: the Year in Review.

OPINION STATEMENT: Endovascular aneurysm repair (EVAR) has become the predominant method of treatment for abdominal aortic aneurysms (AAA). The use of conscious sedation with local anesthesia and percutaneous femoral access has further decreased the morbidity of the procedure. Current devices can more effectively manage increasingly "hostile" aneurysm necks, while chimney grafts or dedicated fenestrated stent-grafts can be used for juxta-renal disease with favorable results. However, endovascular repair does present a new set of challenges, and endoleaks remain an area of concern. While there is general consensus that type I and type III endoleaks require treatment, type II endoleaks are the topic of ongoing research and debate. Development of devices and techniques to prevent and treat endoleak continues to progress. Advances in contrast-enhanced ultrasound are reducing reliance on computed tomography for post-operative monitoring. This is an important step in this population at high risk for the development of kidney failure. Despite these many innovations, further research is needed to optimize the care of patients with AAA.

Regional patterns of dyssynchrony: lateral wall delay is desirable but not essential for left ventricular remodeling in biventricular pacing.

BACKGROUND: Tissue synchronization imaging (TSI), a parametric imaging technique based on tissue velocity imaging, often demonstrates patterns other than lateral delay in patients evaluated for cardiac resynchronization therapy (CRT). The prevalence of these patterns and their response to CRT has not been well described. We hypothesized that regional patterns of dyssynchrony might correlate with the extent of reverse remodeling. METHODS: A consecutive series of 32 patients underwent echocardiographic study prior to CRT implant and 3 months postimplant. TSI was used to color-code the time-to-peak positive systolic velocity at six basal and six mid-LV segments. Each patient was assigned to one of four groups based on the predominant location of greatest delay (≥ 2 segments): (1) posterolateral delay, (2) septal delay, (3) no dyssynchrony, or (4) other. RESULTS: Patients were classified as follows: posterolateral delay in 44% of patients (n = 14), septal delay in 28% (n = 9), no dyssynchrony in 16% (n = 5), and other pattern in 13% (n = 4). At 3-month follow-up, the group with the lateral delay pattern was associated with the greatest decrease in left ventricular end-systolic volume (LVESV) and the largest improvement in left ventricular ejection fraction (LVEF) (-45 mL and +9.3%, respectively, P < 0.05). The LVESV in the other three groups changed as follows: -24 mL (septal), -28 mL (no dyssynchrony), and -15 mL (other). Similar trends were observed for LVEF and left ventricular end-diastolic volume. CONCLUSIONS: Despite the presence of wide QRS and a left bundle branch block, the most delayed segment is not always the posterolateral wall. Posterolateral delay is associated with the best response to CRT, while other patterns respond at a lower magnitude.

Clinical utility of intraprocedural transesophageal echocardiography during transvenous lead extraction.

BACKGROUND: Transvenous lead extraction carries a risk of significant complications. Although intraoperative transesophageal echocardiography (TEE) is widely used to monitor cardiac performance and structures, its utility during transvenous lead extraction has not been well described. OBJECTIVE: This study evaluates the utility of TEE during transvenous lead extraction. METHODS: The records of 108 consecutive patients who underwent transvenous lead extraction with TEE guidance were reviewed. RESULTS: Transvenous extraction of 202 leads was attempted; complete extraction was achieved for 174 leads (86%) and partial extraction for 13 leads with clinically acceptable outcomes in 187 leads (93%). Mean age of the patients was 63 +/- 21 (14-99) years and 37% were female. The average number of leads per patient was 1.9 (1-6). Mean implant duration was 71 +/- 57 (1-360) months. Indications for extraction were pocket infection (53 patients), bacteremia (33), atrial J-lead fracture or recall (13), lead malfunction (8), and venous thrombosis (1). TEE identified critical findings that prompted emergency surgical intervention or converted transvenous lead extraction to surgical explantation in 6 patients (two cases with cardiac laceration, 3 cases of cardiac tamponade, and one case with a large vegetation and a patent foramen ovale). TEE eliminated the need for the premature termination of the procedure in 11 patients by excluding significant structural cardiac damage. Overall, TEE provided clinically useful information during transvenous lead extraction in 17 cases (16%). CONCLUSIONS: TEE during transvenous lead extraction provides valuable real-time information that improves efficacy and safety.

Effects of cardioactive medications on retrograde conduction: continuing relevance for current devices.

INTRODUCTION: Retroconduction (ventriculo-atrial conduction) remains a problem for patients with implanted cardiac rhythm devices. Pacemaker algorithms can detect and terminate endless loop tachycardia (ELT), but actual prevention of ELT may require anti-arrhythmic drugs (AADs). Similarly, AADs can affect ICD rhythm discrimination algorithms that depend on atrio-ventricular ratios. There is concern whether these drugs remain effective during stress situations. METHODS: Electrophysiologic studies that included retroconduction testing using slow ramp pacing were done in 1332 patients. The presence or absence of retroconduction at baseline and with drug was recorded, as was the rate at block. As a stress surrogate, isoproterenol was used to test retroconduction and reversal of drug-induced block. RESULTS: Procainamide, mexiletine, phenytoin, disopyramide, quinidine, beta-blockers, encainide, and amiodarone caused complete retrograde block or decreased the rate at which block occurred (mean 76% of patients, p < 0.008), whereas digoxin, lidocaine, diltiazem, and verapamil did not. Isoproterenol (in the absence of AADs) increased the rate at block in 82% of 404 patients with retroconduction at baseline (p < 0.005). Of 319 patients without retroconduction at baseline, 134 (42%) developed retroconduction after isoproterenol. Isoproterenol reversed retrograde block in 39% of patients with block on an AAD. Amiodarone, digoxin, and the combination of digoxin plus a beta-blocker were most effective at resisting this reversal of ventriculo-atrial block (80%, 68%, and 75% respectively). CONCLUSION: Most of the AADs reviewed increase the cycle length at block or abolish retroconduction, while isoproterenol has the opposite effect. Anti-arrhythmic medications, particularly amiodarone, digoxin, and the combination of digoxin plus a beta-blocker may be considered for a patient with multiple ELT episodes or certain ICD detection problems.