A Direction-independent, High-density Mapping Catheter Provides Electrophysiological Advantage in Complex Atrial Tachycardia Ablation Following Pulmonary Vein Isolation.

Catheter ablation of recurrent atrial arrhythmias following pulmonary vein isolation can be challenging given the complex nature of previously ablated tissue, and managing these already complex cases may be rendered more difficult by the impact of wavefront directionality on mapping catheter orientation, which can make the accurate identification of arrhythmogenic substrate more difficult to achieve. In this report, a 72-year-old man with a history of symptomatic paroxysmal atrial fibrillation and prior pulmonary vein isolation (PVI) underwent repeat ablation. Importantly, this case study demonstrates how a direction-independent high-density mapping catheter (Advisor™ HD Grid; Abbott, Chicago, IL, USA) can identify fractionated low-voltage zones that may be missed when using a standard linear ablation catheter.

Placental mesenchymal dysplasia.

Placental mesenchymal dysplasia is a benign condition that can be confused with a molar pregnancy by ultrasound scanning and gross examination. Conservative management should be considered with a normal-appearing singleton fetus and a cystic-appearing placenta. We present a case of placental mesenchymal dysplasia with a favorable outcome.

Detection of a retention wire fracture in an asymptomatic patient 18 years after implantation.

An asymptomatic patient with a Teletronics Accufix atrial lead (Teletronics, Englewood, CO, USA) presented for an annual fluoroscopic examination. The examination revealed a retention wire fracture, which occurred 18 years after the initial implantation. Annual fluoroscopic examination of these leads should still be performed.

Appropriate evaluation and treatment of heart failure patients after implantable cardioverter-defibrillator discharge: time to go beyond the initial shock.

Multiple clinical trials support the use of implantable cardioverter-defibrillators (ICDs) for prevention of sudden cardiac death in patients with heart failure (HF). Unfortunately, several complicating issues have arisen from the universal use of ICDs in HF patients. An estimated 20% to 35% of HF patients who receive an ICD for primary prevention will experience an appropriate shock within 1 to 3 years of implant, and one-third of patients will experience an inappropriate shock. An ICD shock is associated with a 2- to 5-fold increase in mortality, with the most common cause being progressive HF. The median time from initial ICD shock to death ranges from 168 to 294 days depending on HF etiology and the appropriateness of the ICD therapy. Despite this prognosis, current guidelines do not provide a clear stepwise approach to managing these high-risk patients. An ICD shock increases HF event risk and should trigger a thorough evaluation to determine the etiology of the shock and guide subsequent therapeutic interventions. Several combinations of pharmacologic and device-based interventions such as adding amiodarone to baseline beta-blocker therapy, adjusting ICD sensitivity, and employing antitachycardia pacing may reduce future appropriate and inappropriate shocks. Aggressive HF surveillance and management is required after an ICD shock, as the risk of sudden cardiac death is transformed to an increased HF event risk.

Benefit of cardiac resynchronization in elderly patients: results from the Multicenter InSync Randomized Clinical Evaluation (MIRACLE) and Multicenter InSync ICD Randomized Clinical Evaluation (MIRACLE-ICD) trials.

PURPOSE: Heart failure (HF) affects five million patients each year with both prevalence and incidence increasing with age. At least 20% of hospital admissions in patients > age 65 are due to HF. Cardiac resynchronization therapy (CRT) has been shown to improve HF symptoms and decrease mortality. However, little data are available which specifically address the effects of CRT in the elderly (>65). METHODS: We performed an analysis of the NYHA III/IV 839 patients randomized in the MIRACLE (n = 470) and MIRACLE-ICD (n = 369) trials. Both included patients with moderate to severe HF, ejection fraction (EF) or=130 msec. Patients were grouped by age <65, 65-75, and >75 years. For each group, patients with CRT activated (ON) were compared with patients with CRT inactivated (OFF) for end points at 6 months, including New York Heart Association (NYHA) functional class and EF. RESULTS: Of the 839 patients, 368 were <65, 297 were 65-75, and 174 were >75 years old. Compared with controls, patients from all three age groups, whose CRT was activated, had statistically significant improvements in NYHA class (-0.84 for age <65, -0.78 for age 65-75, and -0.78 for age >75). All age groups with CRT ON also had statistically significant improvements in left ventricular EF (5.23%, 2.98%, and 4.03% respectively). There were no between group differences by age in LVEF improvement. CONCLUSIONS: In elderly patients enrolled in the MIRACLE and MIRACLE-ICD trials, CRT resulted in significant improvements in NYHA class and LVEF, regardless of age. These data suggest that the full age range of patients with appropriate indications for implantation can benefit from CRT.

Effects of concomitant amiodarone and haloperidol on Q-Tc interval prolongation.

PURPOSE: The effects of concomitant amiodarone and haloperidol on Q-Tc interval prolongation were studied. METHODS: All adult patients admitted to a 618-bed tertiary referral teaching hospital between January 1, 2005, and December 31, 2006, who received amiodarone and haloperidol concomitantly were included in this retrospective descriptive analysis. Data collected to assess patients' risk of developing Q-T interval prolongation included age, sex, past medical history, and number of days of concomitant exposure. Data relevant for the assessment of cardiac effects were collected for the time period between 24 hours before and after the administration of haloperidol and included laboratory test values, use of other Q-T interval-prolonging drugs, heart rate, Q-Tc intervals, and clinical documentation of arrhythmia. To determine change in the Q-Tc interval, Q-T and R-R values were recorded using cardiac rhythm strips or electrocardiogram. Nurses' and physicians' records were reviewed to determine if an arrhythmia occurred. Descriptive statistics were used to analyze baseline patient information and Q-Tc interval data. RESULTS: A total of 49 patients met inclusion criteria, yielding 381 distinct amiodarone-haloperidol exposures. During 138 (36.2%) of 381 haloperidol-amiodarone exposures, patients received at least one additional Q-T interval-prolonging drug. When amiodarone-haloperidol exposures were grouped by the number of concomitant Q-T prolonging drugs, no apparent association was detected between longer Q-Tc intervals and an increased number of concomitant Q-T interval-prolonging drugs. CONCLUSION: A small, potentially significant Q-Tc interval prolongation, but not ventricular arrhythmia, was observed in adult patients who received a concomitant administration of amiodarone and haloperidol at a tertiary referral teaching hospital.

Incidence, predictors, and outcomes of cardiac pacing after cardiac transplantation: an 11-year retrospective analysis.

More than 20% of cardiac transplant patients go on to require permanent pacing. We sought to determine the incidence of cardiac pacing in our cardiac transplant population and identify characteristics that may predict which patients will require permanent pacing. We reviewed medical records of cardiac transplant recipients and compared baseline characteristics of patients who received pacemakers with those of patients who did not receive pacemakers. Of 292 patients included in this analysis, 71 (24%) required permanent posttransplant pacing. Use of amiodarone before transplant was associated with a nonsignificant trend toward needing a pacemaker after transplant (P=0.08). Patients undergoing biatrial anastomosis were more likely to require permanent pacing than patients undergoing bicaval anastomosis (P<0.001). Approximately one fourth of cardiac transplant patients require permanent pacing. Surgical technique is a major predictor of who will require permanent pacing after cardiac transplantation.

Tako-tsubo cardiomyopathy complicating left atrial radiofrequency ablation.

Two female patients undergoing left atrial radiofrequency catheter ablation developed Tako-tsubo cardiomyopathy. This reversible form of left ventricular dysfunction is known to occur under conditions associated with marked sympathetic nervous activation. Radiofrequency catheter ablation in the left atrium can damage autonomic ganglionated plexi, leading to vagal withdrawal, thus resulting in enhanced sympathetic tone. Tako-tsubo cardiomyopathy has not been previously described following radiofrequency catheter ablation.

Atrial fibrillation as a cause of left ventricular dysfunction after cardiac transplantation.

We report 3 cases of late-onset atrial fibrillation several years after cardiac transplantation, each involving left ventricular systolic dysfunction in the absence of cardiac rejection or cardiac allograft vasculopathy. Although the etiology of late-onset atrial fibrillation in cardiac transplant recipients is not clear, its presence in the absence of cardiac rejection or coronary allograft vasculopathy can result in left ventricular systolic dysfunction, and therefore should be considered in the differential diagnosis of cardiac allograft failure. The onset of atrial fibrillation years after a heart transplant is not necessarily an indication of rejection. Aggressive rate control and restoration of normal sinus rhythm may improve allograft function in such cases.

Management of heart failure after cardiac resynchronization therapy: integrating advanced heart failure treatment with optimal device function.

Cardiac resynchronization therapy (CRT) is an established adjunctive treatment for patients with systolic heart failure (HF) and ventricular dyssynchrony. The majority of recipients respond to CRT with improvements in quality of life, New York Heart Association functional class, 6-min walk test, and ventricular function. Management of HF after CRT may include up-titration of neurohormonal blockade and an exercise prescription through cardiac rehabilitation to further improve and sustain clinical outcomes. Diagnostic data provided by the CRT device may help to facilitate and optimize treatment. Initial nonresponder rates remain problematic. We suggest a simple step-by-step management and troubleshooting strategy that integrates device function with advanced HF therapy in patients who do not initially respond to CRT. This algorithm represents a new, comprehensive, collaborative approach between the HF and electrophysiology specialists to further improve and sustain outcomes in the field of CRT.

Ventricular reverse remodeling and 6-month outcomes in patients receiving cardiac resynchronization therapy: analysis of the MIRACLE study.

OBJECTIVE: The objective of this analysis was to determine if there were differences in ventricular reverse remodeling and 6-month outcome with cardiac resynchronization therapy (CRT) among specific subgroups enrolled in the Multicenter InSync Randomized Clinical Evaluation (MIRACLE) Study. BACKGROUND: Analysis of major subgroups receiving CRT is important in determining who may be most likely to benefit, since all patients who receive CRT do not demonstrate improvement. METHODS: Differences in response to CRT between subgroups based on baseline echocardiographic parameters, New York Heart Association (NYHA) class, age, gender, beta blocker use, and etiology of heart failure (HF) were analyzed for the clinical end points of the study as well as 6-month HF re-hospitalization or death. RESULTS: The benefit of CRT over control was similar in all subgroups with respect to all clinical endpoints. However, non-ischemic HF patients had greater improvements with CRT compared to ischemic HF patients in left ventricular end diastolic volume (P < 0.001) and ejection fraction (EF) (6.7% increase vs. 3.2% [P < 0.001]). Greater improvements in EF were also seen in those patients with less severe baseline mitral regurgitation (MR) (P < 0.001). Women but not men receiving CRT were more likely to be event-free from first HF hospitalization or death compared to the control group (Hazard Ratio = 0.157). CONCLUSIONS: The benefits of CRT with respect to EF and reverse remodeling were greater in patients with non-ischemic HF and less severe MR. Women may also derive more benefit than men with respect to the occurrence of HF hospitalization or death.

Use of cardiac resynchronization therapy to optimize beta-blocker therapy in patients with heart failure and prolonged QRS duration.

A retrospective analysis was performed on 52 patients with heart failure to determine the change in beta-blocker therapy after cardiac resynchronization therapy (CRT). After 6 months of CRT, the number of patients receiving beta-blocker therapy increased from 36 to 44, with improved clinical outcomes and larger beta-blocker doses, indicating that these 2 therapies may work together to improve outcomes by allowing the use of larger doses of beta blockers while correcting ventricular dyssynchrony.

Rapid method development for chiral separation in drug discovery using sample pooling and supercritical fluid chromatography-mass spectrometry.

A novel strategy for rapid chiral method development has been implemented using sample pooling and supercritical fluid chromatography-mass spectrometry (SFC-MS) on four chiral stationary phases, namely Chiralpak AD and AS, and Chiralcel OJ and OD, and eight different modifier concentrations (5 to 40% methanol-0.2% isopropylamine). The screening is performed under an outlet pressure of 110 bar at 35 degrees C, and at a flow-rate of 2.5 ml/min for the initial 20 min and then ramped up to 4 ml/min and held for 4.5 min to elute all solutes from the column. The entire process is fully automated from injection to data processing, and operates unattended for 15 h overnight to obtain optimal chiral separation for multiple compounds. A unique feature of using SFC-MS to monitor chiral synthesis is the negligible interferences from achiral impurities. In addition, with SFC-MS, enantiomeric excess can be determined with much lower detection limits than UV and much shorter analysis times compared to normal-phase/reversed-phase liquid chromatography.